Fact sheets on air emission abatement techniques - Infomil

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Fact sheets on air emission abatement techniques

File: B8176 Registration number: MD-MV20090007 Version: 3 VITO/InfoMil February 2009

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Table of contents

1 Introduction ................................................................................................ 5

2 Research lay-out and results ....................................................................... 6

3 Use of the fact sheets .................................................................................. 8 3.1 Selection and application of air emission abatement techniques ..................... 8 3.2 Lay-out fact sheets..................................................................................11 3.3 Sub-division of techniques........................................................................12

4 Fact sheets ................................................................................................ 14

4.1 Gravitation .............................................................................................14 Settling chamber / Gravitational separator ........................................................................... 15 Cyclone / Dust cyclone / Wet cyclone / Multi-cyclone / Vortex separation ................................. 18

4.2 Scrubbing ..............................................................................................22 Scrubbing (general) / Wet dust remover / Wet dust scrubber.................................................. 23 Spraying tower / Rotational scrubber / Dynamic scrubber ...................................................... 26 Venturi-scrubber / Venturi-scrubber / Whirl scrubber............................................................. 29

4.3 Filtration ................................................................................................32 Fabric filter (filtering dust separator) / Tube filter / Bag filter .................................................. 33 Ceramic filter (filtering dust-separator) / Ceramic filter / High temperature filter / Candle filter.... 37 Two-stage dust filter......................................................................................................... 40 Absolute filter / HEPA-filter / surface filter / cartridge filter / micro filter ................................... 43 Demister / Aerosol filter / Deep bed filter............................................................................. 46 Dry electrostatic precipitator / Electrostatic precipitator (ESP) / Dry E-Filter / Dry ESP / Dry electrostatic precipitator / Electro filter ........................................................................ 48 Wet electrostatic precipitator / Wet E-filter / Wet ESP / Wet Electrostatic precipitator / Electro-filter .................................................................................................................. 51

4.4 Condensation..........................................................................................54 Condenser / Heat exchanger / Odour control condensation (OCC) ........................................... 55 Cryocondensation / Cooled condensation ............................................................................. 58

4.5 Adsorption..............................................................................................61 Adsorption (general)......................................................................................................... 62 Adsorption of active coal / Active coal filtering / Coal filter...................................................... 65 Zeolite filter (adsorption) / Zeolite filter / Hefite filter ............................................................ 69 Polymer adsorption........................................................................................................... 72 Dry lime injection / dry lime-sorption / Fixed bed lime-sorption / Cascade adsorption................. 75 Semi-dry lime injection / Spray-dry adsorption / Semi-dry lime adsorption / Semi-wet lime sorption ................................................................................................... 78

4.6 Absorption..............................................................................................81 Gas scrubber (general) / Scrubber / Absorber / Air scrubber................................................... 82 Acid gas scrubber / Acid scrubber ....................................................................................... 85 Alkaline gas scrubber........................................................................................................ 88 Gas scrubber alkaline-oxidative .......................................................................................... 91

4.7 Biological cleaning...................................................................................94 Biofiltration / Bio-bed / Biological filter / Bio-bed filter / Compost filter..................................... 95 Biotrickling / Lavafilter / BTF / Biodenox .............................................................................. 99 Biological scrubber (general) / Bioscrubber / Bioscrubber ..................................................... 102 Moving bed trickling filter / MBTF...................................................................................... 105

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4.8 Thermal oxidation .................................................................................108 Thermal incinerator / Incinerator / Thermal oxidation .......................................................... 109 Catalytic incinerator / Catalytic oxidation (catox) / Thermocat............................................... 113 Flare ............................................................................................................................ 117

4.9 Cold oxidation.......................................................................................121 Ionization / Active oxygen injection / Ozone injection / Plasma cleaning ................................. 122 Photo oxidation / UV-oxidation ......................................................................................... 125

4.10 Chemical reduction................................................................................127 Selective non-catalytic reduction / SNCR ........................................................................... 128 Selective catalytic reduction / SCR.................................................................................... 130 Non-selective catalytic reduction / NSCR............................................................................ 133

4.11 Other techniques...................................................................................135 Membrane filtration / Solvent recuperation / Air separation with membranes .......................... 136 Vapor recovery unit / VRU ............................................................................................... 139

5 Additional research on specific techniques .............................................. 140 5.1 Techniques...........................................................................................140 5.2 Field-testing of emissions.......................................................................143

6 Cost effectiveness.................................................................................... 144

7 Recommendations for future research..................................................... 145

8 Index ....................................................................................................... 146

9 Annexes................................................................................................... 147 Annex 1 Field emission data.................................................................................148 Annex 2 Illustrative calculations of cost effectiveness..............................................149 Annex 3 List of suppliers who provided information.................................................150

10 Colophon .............................................................................................. 151

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1 Introduction

The fact sheets with basic information on air emission abatement techniques are meant to answer the most frequently asked questions on these techniques. They are an aid in determining the Best Available Techniques (BAT) in specific situations. They also are the Dutch and Flemish input in the revision of the BREF Wastewater and gas treatment for the chemical industry. The fact sheets give a brief description of the functioning, efficiency, financial aspects, etcetera of the air emission abatement techniques that have proven to work in the field. Because of the standardized lay-out the information is easy to find. Based on the fact sheets a first selection of the possible techniques for a specific application can be made. The primary target audience of the fact sheets are the competent authorities, advisors and companies that are not or barely familiar with the techniques. For detailed technical information one can contact the suppliers. The precursor of this document, publication, L26 ‘Fact sheets waste gas treatment techniques’ (2000), was issued in 1999. On behalf of InfoMil, DHV has researched the topicality of the fact sheets en renewed them where necessary. The revision of the BAT Reference document (BREF) Waste gas and water treatment for the chemical industry was a reason to check the fact sheets for topicality. The information in these renewed fact sheets was offered as information for the revision of this BREF. The range of application of the fact sheets however, is broader than just the chemical industry. In the Flanders region of Belgium, VITO provides similar information fact sheetvia ‘LUSS’ (starting 2004). LUSS is a system that may help with first explorations and final decisions on possible air pollution abatement techniques. This system is digitally available through http://www.emis.vito.be/luss/.

The renewal of the fact sheets took place in close cooperation with research institute VITO and with suppliers, companies and governments. The research consisted of: a) Literature study (including LUSS and BREFs); b) Survey among Dutch suppliers; c) Interviews with suppliers, companies and the competent authoritiy. This manual is restricted to air emission abatement techniques that are currently applied on an industrial scale. Techniques that are only applied on a research or laboratory scale are not described in these fact sheets. Distinction between the techniques is based on their working principle, such as: gravitational separation, filtering and adsorption; the most important implementations are described in the fact sheets. The before mentioned techniques represent the majority of air emission abatement techniques in existence, although not every single existing technique can be found in this manual. Reading directions In chapter 2 the research and the resulting conclusions are briefly explained. Chapter 3 explains the use of the fact sheets, including an overview of the described techniques and the most critical parameters per technique. Chapter 4 contains the 36 fact sheets in total. Chapter 5 displays the results of further research on some techniques. These techniques are relatively new or interesting for further research, for different reasons. For a number of techniques the topicality of the previously determined emission ranges was also judged. In chapter 6 some examples are given of cost effectiveness calculations. Chapter 7 gives an overview of the missing information (blank spots).

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2 Research lay-out and results

The predetermined lay-out of the renewal of the fact sheets is displayed in general outlines in figure 1. The research project was guided by a commission wherein the competent authority, the suppliers, the industry, the Ministry of VROM and InfoMil were represented.

Figure 1. Research project renewal fact sheets

Existing sheets

3.3. questionnaire suppliers

3.5. Interviews selected suppliers

3.1. Desk study, first analysis

3.4. Analysis 2

3.6. Report & updated sheets

1st updated sheets

BREF, EPA, LUSS, literature, cost assessment

Kick off meeting

Meeting with project

committee

Final meeting

Input from literature, competent authorities,

Emission reports, permits

The research plan assumed that for the renewal of the data, information would be gathered from literature and from the internet (point 3.1 from figure 1), as well as from the market (point 3.2 in figure 1). The key literature and internet sources used are: BREFs, LUSS and the US Environmental Protection Agency (EPA).

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In gaining information from the market, the suppliers played an essential part. By means of amonst others a surveythey were interviewed about recent market developments regarding their products. Over 80 suppliers were summoned and asked to answer a number of questions regarding costs, new techniques and changes in techniques in their range of products. The Organization of Suppliers of Environmental Equipment (VLM, about 30 members) approached its its membersabout. In spite of this, the response of the suppliers was low: about 15%. An important consequence of this low response is that the indexation of the costs is primarily based on data from literature and only very little upon data from suppliers. Simply applying an index number on the old economical numbers turned out to be impossible in a number of cases. In one case the costs had decreased (minimum caustic scrubber), while in another case the costs have remained the same or have risen sharply (active coal). The suppliers that did respond reported that the development of air emission abatement techniques is slow. The techniques evolve, but there are no reports of revolutionary developments. However, new variants of existing techniques and optimizations are reported. These developments can be described as the fine-tuning of existing techniques. A different development is the application of existing techniques within different sectors. Stricter environmental legislation (emission requirements) within a specific sector is often the cause . Chapter 5 further investigates the developments as reported by the suppliers and competent authorities. The research lay-out also aimed at verifying the efficiency and emission values through use of measurement reports. Measurement reports were collected from the competent authorities, suppliers of installations and from open information sources (internet). In practice it sometimes turned out to be difficult to get clear to what specific configurations of techniques the measurements apply. For this reason fewer measurements were collected than was planned. In Annex 1 the gathered emission values are further investigated.

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3 Use of the fact sheets

3.1 Selection and application of air emission abatement techniques

The factsheets containing basic information on air emission abatement techniques serve as an aid in selecting the Best Available Techniques (BAT) in specific situations. The described techniques can be applied after checking the applicability of process integrated measures for preventing or decreasing the environmental impact, for example by switching to different raw materials or recycling of emission streams. If this is not feasable, air emission abatement techniques are to be considered. In order to make a first selection of air emission abatement techniques, an overview-table (table 3.1) is included. With the aid of this table a first choice can be made based on the component to be removed, the flow or other critical process variables. For a first selection of techniques for removing (fine) dust, figure 2 can be used as well. For example, in figure 2 one can find that a cyclone and gravitation-separator are effective at a larger dust load (about 10 g/m³) and particle size (>µm 10), while a wet scrubber is more effective for a smaller dust load and particle size. Sometimes a combination of techniques is necessary to attain a low emission value.

(Source: D.R. Woods, Process design and engineering practice, Prentice Hall PTR, New Jersey,

ISBN 0-13-805755-9)

After the first indicative selection of techniques (table 3.1), the corresponding fact sheets may be used to compare the techniques’ most important features and to further consider their application in the situation concerned. Further elaboration may be needed for the preferred technique, requiring more information than that offered in the fact sheet. In that case one may decide to search for further expertise or information. One example of this is

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the calculation of a techniques’ cost effectiveness. The fact sheets do not always provide sufficient information for calculating the cost effectiveness in a specific situation according to the NeR1-method 4.13 (see also chapter 6). Table 3.1. The table below indicates which chemicals can be removed by use of a specific air emission abatement technique. If a technique’s primary goal is not the removal of a specific pollution, but this pollution is (partly) removed by the technique, this is indicated by a ‘+’.

Removed components Parameters Working

principle Name technique

Dry

dust

Wet

dus

VO

C

SO

2

NO

x

NH

3

Inorg

anic

gas

ses

Odour

Eff

icie

ncy

[%]

Indic

atio

nof

applie

dflow

[m3/h

]

Critica

lpar

amet

ers

Sinking chamber

� � 10 -90 100 – 100,000

Fluid percentage Gravitational separation

Cyclone � � 5 - 99 1 – 100,000 Fluid percentage

Dust scrubber

� � � � � � � 99 720 – 170,000

Pollution

Spray tower � � � � � 70 - 99 1,000 – 50,000

Temperature, pollution

Dust scrubber

Venturi scrubber

� � � � � � 50 -99 720 – 100,000

Fabric filter

� 99.95 300 – 1,800,000

Temperature, fluid percentage

Ceramic filter

� 80 – 99.99

300 – 1,800,000

Stickiness

Two-stage dust filter

� < 75,000 Ingoing gas flow and speed

Absolute filter

� 99.99-99.999

100 - 360 Fluid percentage

Demister � � � <99 <150,000 Temperature Dry electrostatic precipitator

� � 97 - >99.9

1,800 – 2,000,000

Energy consumption, maintenance

Filters

Wet electrostatic precipitator

� � 97 - 99 1,800 – 9,000,000

Energy consumption, maintenance

Condenser � � � � 60 -90 100 – 100,000

Saturation of ingoing gas

Condensation

Cryoconden-sation

� >99 <5,000 Fluid percentage of ingoing gas

Adsorption (general)

� � � 80 – 95 100 – 100,000

Fluid percentage, VOC conc.

Adsorption (active coal)

� � � 80 – 98 100 – 1,000,000

Fluid percentage, VOC conc.

Adsorption zeolites � � � � 80 - 99

< 100,000 Fluid percentage, dust in ingoing gas

Adsorption polymeric

� � 95 – 98 - Dust in ingoing gas

Dry lime injection

� � 10 - 95 10,000 – 300,000

Temperature, pressure

Adsorption

Semi dry lime injection

� � 85 – >90

< 1,000,000

Gas scrubber

� � � � � � 30 – 99 50 - 500,000

Temperature Absorption

Acid gas scrubber

� � � � � � 80 - 99 50 – 500,000

Temperature

1 NeR is short for ‘Nederlandse emissierichtlijn lucht’ (Netherlands emission guidelines for air).

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Removed components Parameters Working principle

Name technique

Dry

dust

Wet

dus

VO

C

SO

2

NO

x

NH

3

Inorg

anic

gas

ses

Odour

Eff

icie

ncy

[%]

Indic

atio

nof

applie

dflow

[m3/h

]

Critica

lpar

amet

ers

Alkaline gas scrubber

� � � � � � 90 - 99 50 – 500,000

Temperature

Gas scrubber alkaline oxidative

� 80 – 90

50 – 500,000

Temperature

Bio filtration � � 70 – 95 100 - 100,000

Temperature

Bio trickling � � � � 70 – 99 1,000 - 500,000

Temperature

Biological scrubber

� � � � 70 – 95 - Temperature

Biological cleaning

Moving bed trickling filter

� � � 80 - > 98

5,000 - 40,000

Temperature

Thermal incinerator � � � 98 –

99,9

90 – 86,000 Ingoing concentration VOC

Catalytic incinerator � � � 80 – 99

90 – 90,000 ingoing concentration VOC

Thermal oxidation

Flare � > 99 < 1,800,000 Caloric value of ingoing gas

Ionization � � � 80 – 99.9

20 – 200,000

Fluid percentage of ingoing gas

Cold oxidation

Photo oxidation

� � � � 80 -98 2,000 – 60,000

Temperature, fluid percentage

Selective non-catalytic reduction

� � 40 -70 < 200,000 High T required

Selective catalytic reduction

� � 80 - 97 < 1,000,000 High T required

Chemical reduction

Non-selective catalytic reduction

� � � 90 – 98

< 35,000

Remaining techniques

Membrane filtration

� � 99.9 < 3,000

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3.2 Lay-out fact sheets

Title / synonyms First a common name for the technique concerned is given as a title, followed by synonyms that are used in practice . Brief description Here the main description of the technique is given. The abatement principle is clarified using a schemetic diagram. Often VITO provides a more extensive description: http://www.emis.vito.be/Luss/. Applicability Under this heading the industrial sectors are listed wherein these techniques are often applied. The list is not always exhaustive and the application of the technique in other sectors than indicated is possible. Also the efficiency, remaining emission and the quality of these data are listed here. The quality of the information is divided into three categories: - Validation number 1 means no validation: the numbers are not substantiated by

measurement reports. - Validation number 2 means limited validation: when measurements weren’t directly

presentable or available, for example when measurements are mentioned in an environmental permit or measurements taken by a non-certified agency.

- Validation number 3 means validation: the numbers are substantiated by at least one measurement report.

The efficiency and emission data used here are those gained from suppliers and/or competent authorities. The values were often gained under different circumstances and in specific situations and thus must be regarded as indicative. The preconditions and process conditions are of great importance and are often presented as a wide range. The wide ranges are a result of the often wide variety in possible applicability of a technique. Measured values are based upon half-hour average values as prescribed in the NeR. Elaborate description Some techniques have a strong resemblance to the described technique and may be seen as a variant of this technique. In those cases they are referred to in the fact sheet as a variant and are not described in a separate fact sheet. The variants can be found easily through the index in the back of this document. Qualitative criteria for design and maintenance are also described under this heading. The quantitative information on maintenance, when available, is listed under the financial aspects. The elaborate description also further examines the monitoring. A brief consideration is given of the points of interest. Monitoring is a very important and complex aspect of air emission abatement techniques and the corresponding emissions of residues. A further observation of this subject falls outside of the range of the fact sheets and for this we refer to the specific literature and legislation on this subject like the NeR and BEES (Netherlands decree on emission limits for combustion plants). Environmental pros and cons The pros and cons listed here apply to the application of the technique in an “average situation”. In specific situations these pros and cons won’t all apply. The cross media effects may imply an important pro or con for the environment and are mentioned here for this reason. Also the use of additional materials, which is connected to the assessment, is mentioned here because it may affect the choice of a technique in a severe(ly) (negative) manner.

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Financial aspects The ranges mentioned give an indication of the costs. The exact costs of course depend on the specific conditions, situation (existent or not) and configuration of the technique. The costs apply to operational costs and investment costs. These costs can be subdivided further, for example into fixed costs, like maintenance and operation, and variable costs like gas, water, electricity and residue processing (see method 4.13 from the NeR). Operational costs in the fact sheets basically imply all these costs, unless otherwise indicated. As many nuances as possible were taken into consideration. Where possible the personal costs, or utility costs (including electricity) are explicitly mentioned. The aforementioned investment costs apply to the bare purchase price. Additional and single investments may far exceed this purchase price, especially in existent situations. Chapter 6 offers examples for calculating the cost effectiveness of several techniques. Information source Here the most important reference documents used to test the existing information (L26) are listed. Besides the documents listed under this heading especially the suppliers (Annex 3) and the competent authorities (paragraph 5.2) were an important source of information for this research.

3.3 Sub-division of techniques

In chapter 4 the techniques are divided as follows: Gravitation (paragraph 4.1) Techniques that are based on the principle of separation by gravitation or gravity include the settling chamber and the cyclone.

Dust scrubbers (paragraph 4.2) The dust scrubbers are techniques where the separation of dust and air takes place by means of using the medium water. The techniques described here include the scrubbing (general), the venturi scrubber and the spraying tower.

Filtration (paragraph 4.3) Filters work based on a filter medium that filters the dust from the incoming polluted gas. The dust remains on the filter. The filter medium may consist of a fixed filter that the gas stream and particles must pass, like a fabric filter, or an electrical field with collectors, like the electro filter. Six different applications of this technique are described in the fact sheets: fabric filter, ceramic filter, two-stage dust filter, absolute filter, demister, dry electrostatic precipitator and wet electrostatic precipitator. Condensation (paragraph 4.4.) The techniques that belong to this group are based on the principal of separation by cooling through means of a cooling medium and a lowering of the vapor pressure of a component that is to be removed. Applications mentioned here are the condenser and cryocondensation.

Adsorption (paragraph 4.5) Adsorption is a reaction binding the polluted components to a solid or liquid, adsorbing it and removing it from the incoming gas stream. Six different applications of this technique are described in the fact sheets: adsorption (general), active coal, zeolite filter, polymer adsorption, dry and semi-dry lime injection. Absorption (paragraph 4.6) With absorption, as opposed to adsorption, no chemical reaction takes place. In the wet absorption section however, an exchange does take place between the absorption medium and the component to be removed. The techniques described here are four different applications of gas scrubbers: gas scrubber, acid gas scrubber, alkaline gas scrubber and gas scrubber with alkaline oxidative.

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Biological cleaning (paragraph 4.7) In case of biological cleaning, the incoming gas stream is led through a column or filter bed consisting of micro organisms on a carrier material. The micro organisms break down the pollution. Four techniques based on this principle are described in the fact sheets: bio filtration, bio trickling, biological scrubbing and Moving Bed Trickling Filter (MBTF)

Thermal oxidation (paragraph 4.8) Thermal oxidation implies the combustion of incoming gas streams at high temperatures. Described are: the thermal incinerator, catalytic incinerator and flare. Cold oxidation (paragraph 4.9) As opposed to thermal oxidation, in case of cold oxidation no rise in temperature occurs. Charged particles cause a breakdown and partial oxidation of any present pollution. The techniques described here are: ionization and photo oxidation. Chemical reduction (paragraph 4.10) Chemical reduction stands for the removal of a polluted component by injecting a reducing reagent, like ammonia, into the incoming gas. Three techniques are described in the factsheets: SNCR, SCR and NSCR.

Remaining techniques (paragraph 4.11) Two techniques are presented here: membrane filtration and vapor recovery, which can either be seen as a combination of techniques or cannot be easily fitted into one of the other categories.

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4 Fact sheets

4.1 Gravitation

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Settling chamber / Gravitational separator

Brief description Description The gas stream is led into a room where dust, aerosols and/or drops are separated from the gas under influence of gravity and momentum. Because of the sharp drop in gas speed in the settling chambers the larger particles will sink under the influence of gravity. The separating effect becomes more effective because of the change in the gas’ flowing direction and the collision of particles and partitions, plates or metallic gasses. Settling chambers are primarily used as pre-separators.

Schematic diagram

Applicability Great range of applicability in the following sectors: - wood and furniture industry - construction sector - brickyards - glass industry - storage and handling - ferro and non-ferro: removal of dust for the protection of techniques in sequence. Settling chambers are also very suitable for the removal of hot or glowing particles before the gas stream is led to an additional technique.

Settlingchamber

Gas flow in Clean gas

Dust particles

Dust discharge

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Components Removed components

Removal efficiency1, % Remaining emission, mg/m0

3

Validation number

Dust 10 – 90 High; > 100 is possible

1

1 Depending on the specific configuration and the working conditions. Values are based upon half-hour averages. The settling chamber’s efficiency is strongly dependant on particle size; large particles are neatly removed, smaller particles less so.

Preconditions Gas flow, m0

3/h 100 – 100,000 Temperature, ºC No limitation, at least up to 540 Pressure, bar No limitation Pressure drop, mbar Little Fluid percentage Above dew point Dust, g/m0

3 No limitation

Elaborate description Variations - Gravity counter stream separator: The flow direction of the incoming gas in the

separator is vertical. Under influence of gravity the particles settle in the opposite direction of the flow direction.

- Gravity diagonal stream separator: Here the flow direction of the incoming gas in the separator is diagonal. Under influence of gravity the particles settle perpendicular to the flow direction.

- Impact filter: Because of the implementation of multiple obstacles, such as plates, the gas stream is redirected. The particles cannot follow the stream direction due to their slowness and thus are removed.

Installation: design and maintenance Settling chambers may be constructed out of various materials, including steel and synthetic material, depending on the composition of the incoming gas stream. In the application of settling chambers a good uniform speed distribution is essential. Preferential streams have a negative effect on the functioning of the settling chamber. By using internal obstructions one can work at higher speeds, resulting in a smaller settling chamber. Downside to this is the increase in pressure drop on the system. Leakage of cold air into the settling chamber must be avoided to prevent condensation of the gas stream. Condensation may lead to corrosion, dust accumulation and obstruction of the dust outlet. Monitoring The most frequently occurring cause of malfunction is obstruction of the chamber by dust. This can be prevented through constant monitoring and periodical inspection of the chamber. Environmental pros and cons Specific pros - Reasonably suitable for the removal of large and midsized particles (> 15 µm) - Simple construction - No moving parts - Low investment costs - Simple management - Low maintenance - Low pressure drop - Low energy consumption - Can be constructed to specifically apply in extreme conditions, for example high and

low temperatures Specific cons - Low removal efficiency - Unsuitable for the removal of smaller particles, mostly suitable as a pre-cleanser of

rough particles

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- Unsuitable for sticky particles - Large machine. Additives Settling chambers do not use additives. In some specific Applicabilitys (like the drip separator), a settling chamber has cleaning system to keep the partitions and plates clean. The amount of water needed for this depends on the applicability. It can range between 100 – 200 liters/m².

Cross Media Effects The separated dust has to be carried off, and it may be conveyed as regular or chemical/hazardous waste depending on the incoming gas stream’s composition. Sometimes the dust can be recycled into the process.

Financial aspects Investments, EUR/1,000 m0

3/h Small if the system is integrated into other systems (Large inlet or convoy partition). Exact value is hard to determine.

Operational expenses, EUR/1,000 m03/h Low

Personnel Very little Help and additives None Energy consumption, kWh/1,000 m0

3/h Low, just for the ventilator Electricity costs, EUR/1,000 m0

3/h Low, just for the ventilator Cost-determining parameters Pressure drop, (if relevant) costs of conveying dust Benefits None, (if relevant) recovery of raw materials

Information source 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Factsheet (http://www.epa.gov/ttn/catc/dir1/fsetling.pdf)

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Cyclone / Dust cyclone / Wet cyclone / Multi-cyclone / Vortex separation Brief Description Description The contaminated gas stream is passed into the cylinder shaped chamber. The dust is swung to the wall by the centrifugal force, after which the dust is carried of through the bottom. The purified gas leaves the cyclone in the middle at the top. The gas entering is forced to move down past the inside of the cyclone in a circular motion, and at the bottom of the cyclone the incoming stream reverses and leaves the cyclone at the top.

Schematic diagram

Applicability Because of its relatively small efficiency and relatively high residue emission a cyclone is used as pre-separator to take away the largest dust load, followed by, for example, a scrubber or fabric filter. The pre-treatment usually applies to particles > 5 µm.

Broad range of application in the following sectors: - wood and furniture industries - construction industry - glass industry - transport industry (storage and handling) - food industry - waste incineration - chemical industries - melting processes in metallurgy - sintering processes - coffee roasting

Dust removal

Cyclone

Gas flow inClean gas

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3

Validation number

Dust (< 1 µm) Dust (6-10 µm) Dust (> 10 µm) Dust (> 50 µm)

550 90 99

--100 -

1121

¹Depending on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages.


3/h 1 – 100,000 Pressure, bar Not critical Pressure drop, mbar 5 – 20 Temperature, oC Dependant on the construction; may be very

high

Dust, g/m03 Up to dozens

Extensive description Variations - High throughput cyclones have a diameter of more than 1.5m and are suitable for the

removal of particles 20 µm and up. - High efficiency cyclones have a diameter that varies between 0.4 and 1.5m and are

applicable for the removal of particles 10 µm and up. - Multi-cyclones are constructed in parallel out of cyclones with a diameter ranging

between 0,005 and 0,3m. Here the gas feed occurs tangential or axial, after which the gas is brought into rotation by blades. A multi-cyclone is sensitive to good distribution of the gas amongst the smaller cyclones. If the distribution is wrong, a reversal or clogging of the gas may occur. Multi-cyclones can reach a high removal efficiency of over 99%, depending on particle size.

- Electric cyclones work by applying an electric field between the centre and the wall of the cyclone. This way the driving force pushing the particles towards the wall is increased causing higher removal efficiency.

- Secondary flow enhanced cyclone: In a cylindrical casing the gas enters at the bottom with a rotational movement. By tangential supply of secondary air at the top the centrifugal forces working the particles are increased, causing a higher efficiency. The secondary air can be clean or cleansed air.

- Condensation cyclone: these cyclones are cooled to below the dew point so substances like fats and water condensate and can be removed.

- Wet cyclone: to increase the removal efficiency for dust (< 20 µm) water is atomized. The water binds to the fine dust and is drained off like slurry.

- Micronsep wringing separator: The system consists of a spiral-shaped interior that is fitted into a cyclone-like casing. The system has an efficiency of more than 99.5% for particles larger than 1 µm, distinguishing itself from classical cyclones.

- Rotating particles separator (RPS): The core of the particle filter consists of the filter element. The filter consists of a large amount of channels that, as a whole, rotate around a collective rotation axis. Solid or liquid particles are forced against the walls by the so-called centrifugal force and remain there. The cleansed gas or liquid leaves the filter element and the filter can be periodically cleaned if necessary. Even at high gas speeds (a few meters per second), particles smaller than one µm can be caught by increasing the filter’s length (usually up to a meter). The length and height of the channels can thus be so dimensioned that the pressure drop amongst the channels is restricted to a few mbar. The RDS has been applied in very different situations, wherein a good efficiency at a low investment price was noted (efficiency is nearly on the same level as the EPS but the costs are significantly lower). There is currently no set supplier, only a licensee.

Installation: design and maintenance The efficiency of cyclones is dependant on the assessment of efficient with a low capacity or less efficient with a high capacity. Cyclones are most efficient at high air entering speeds, small cyclone diameter and large cylinder length, in contradiction to the so-called “high

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throughput” cyclone, where the high capacity and thus large size take their toll on the efficiency. The air entering speed of a cyclone is between 10 and 20 m/s, the average speed is about 16 m/s. Fluctuations in this speed (lower speed) causes the removal efficiency to sharply drop. The efficiency of a cyclone is determined by the particle size and the design of the cyclone. The efficiency is increased by: - Particle size and density - Cyclone length - Amount of circulations of the incoming gas stream in the cyclone - Dust load - Slipperiness of the inside of the cyclone

The efficiency is decreased by an increase in: - The cyclone chamber’s diameter - Diameter of the outgoing gas stream - Surface of the incoming gas stream’s entry point - Gas density

The maintenance requirements of a cyclone are simple: they have to be easily accessible for periodical inspection for corrosion or erosion. The pressure drop has to be checked regularly and the dust-catching mechanism has to be inspected for obstructions. Monitoring In order to monitor the cyclone’s efficiency the dust concentration in the cleansed gas stream can be determined by isokinetic sampling (without obstructing the gas stream) or a measurement method based on, for example, UV, visible light transparency, beta radiation or particle detection. Environmental pros and cons Specific pros - Simple construction - Recovery of raw materials possible - No moving parts - Low maintenance - Low investment costs and operational expenses - Consistent pressure drop Specific cons - Low efficiency for smaller particles < 10 µm- High pressure drop (5 - 20 mbar) depending on the variant - Bad results with shared loads - Emission of waste water in case of the wet cyclone - Not applicable for particles causing excessive corrosion or obstruction - Potential noise pollution Additives - Energy consumption - Consumption among other things dependant on the temperature of incoming gas (in

the wet cyclone’s case) Cross Media Effects Removed dust must be disposed off as waste product or recycled. The dust slurry of a wet cyclone has to be treatedin a water treatment plant.

MD-MV20090007 -21-


3/h 1,200 Operational expenses None Personnel, hours per week Up to 2 Help and additives Water (wet cyclone) Energy consumption, kWh/1,000 m0

3/h 0.25 – 1.5 Cost-determining parameters Gas flow, pressure drop Benefits Potential regaining of raw materials

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Factsheet (http://www.epa.gov/ttn/catc/dir1/fcyclon.pdf) 6. Interview Airtechnic Solutions, Romico Holding (rotating particles separator), 2008 7. Kok, H. Particle size distribution of emitted fine dust at industrial sources, TNO October 2006.

MD-MV20090007 -22-

4.2 Scrubbing

MD-MV20090007 -23-

Scrubbing (general) / Wet dust remover / Wet dust scrubber Brief description Description Wet scrubbing is a variation on wet gas scrubbing. The two most common techniques are the venturi scrubber and rotational scrubber. Wet scrubbing entails separating the dust by intensively mixing the incoming gas with mater, mostly combined with a removal of the coarse particles through us of centrifugal force. In order to achieve this, the gas is put in tangentially (at an angle from the side). The removed solid dust is collected in the bottom of the dust scrubber. Aside from the dust, inorganic chemicals like SO2, NH3 and VOC and heavy metals that may be attached to the dust are removed. The major goal for which the scrubber is applied is the removal of the dust. Schematic diagram

Applicability Many applications including the chemical industry and asphalt production. For the specific applications, such as the venturi and rotational scrubber, we refer to the specific fact sheets of those variants.

Water & dustdischarge

Wet dust scrubber

Clean gas

Gas flow in

Scrubbingwater

MD-MV20090007 -24-

Components

Removed components


3

Validation number

(fine) dust

99

< 10

2

¹Dependant on the specific configuration and operational conditions. Values are based upon half-hour averages. Other components such as heavy metals and inorganic chemicals can be removed simultaneously (also see absorption). Preconditions Gas flow, m0

3/h 720 – 170,000 Temperature, °C 4 - 370 Dust, g/m0

3 0.2 - 115 Pressure, bar atmospheric Pressure drop, mbar 20 – 50

Extensive description Variations There are many variations on the wet dust scrubber like the venturi scrubber, the rotational scrubber, the whirl scrubber, the spraying chamber, the wet cyclone and the packed bed and dish columns. Some of these scrubbers are also used as gas scrubbers. Installation: design and maintenance The liquid-gas-ratio of a dust scrubber is the ratio between gas flow and the srcubber liquid flow. For the proper dimensioning and judgment of a dust scrubber’s performance it is important to know how much liquid per m0

3 is necessary to achieve the preferred level of emission. The performance is strongly dependent on the degree of pollution of the dust scrubber. Regular inspection, maintenance and cleaning are necessary for a good performance. Monitoring To judge the dust scrubber’s performance, one can apply isokinetic sampling, UV or beta radiation. Parameters that have to be checked regularly include the pressure drop on the scrubber, the gas-liquid-ratio, the optimal amount of spraying water, and the pH. The dust scrubber needs to be accessible in order to check these factors regularly. Environmental pros and cons Specific pros - Low risk in applying dust scrubber for gas streams containing explosive or flammable

chemicals. - May also be used as cooler for hot gasses - Neutralizes corrosive gasses - Simultaneous removal of dust and inorganic components Specific cons - Produces waste water - Wet by-product - Chance of freezing - Incoming gas has to be treated further in order to prevent the forming of plumes Additives Water and possibly additional chemicals to increase the precipitation of the component that is to be removed. Cross Media Effects Waste water that has to be treated or discharged. Residues that have to be drained off after dehydration.

MD-MV20090007 -25-

Financial aspects Investment costs, EUR/1,000 m0

3/h Operational costs, EUR/1,000 m0

3/h Personnel, hours per month Help and additives Energy consumption, kWh/1,000 m0

3 /h Cost-determining parameters Benefits

5,000 5,000 – 50,000 About 4 Drainage of waste matter and treatment of waste water < 0,5 Scale and eventual special treatment of gas stream None

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. http://www.frtr.gov/matrix2/section4/4-60.html5. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008

MD-MV20090007 -26-

Spraying tower / Rotational scrubber / Dynamic scrubber Brief description Description The spraying tower is a specific type of dust scrubber. The washing liquid is sprayed or scattered by a fast-spinning nebulizer disc or rotating sprays, creating a large contact surface for the drops and the gas. There are variations of the spraying tower that do not have a spinning turbine. The gas is put in tangentially (at an angle from the side) into the dust removal chamber. The centrifugal forces and the rotating nebulas drag the dust particles to the chamber wall, making high removal efficiency possible. The separated dust has to be dehydrated and disposed of.

Schematic diagram

Applicability The scrubber is primarily applied for separating very small dust particles (< PM10). Other easily soluble water components such as HF, HCI and SO2 can also be efficiently removed. Broad range of application including the following sectors: - chemical industry for the removal of dust and aerosols - metal industry for various kinds of gasses - waste-incineration - potato processing industry for the removal of amylum - glass industry

Scrubbingwater

Water & dustdischarge

Clean gas

Gas flow in

Spraying tower

Droplet separator

Rotating wheel

MD-MV20090007 -27-

- foundries - sintering processes - drying process - fertilizer production - pharmaceutical industry - plastics industry. Components Removed components


3

Validation number

PM10 70-992 <10

2

¹Dependent on the specific configuration and operational conditions. Values are based on half-hourly averages. ²Including particles up to 1-2 µm. Preconditions Gas flow, m0

3/h 750 – 50,000 Temperature, ºC < 200 Dust, g/m0

3 some Pressure, bar low Pressure drop, mbar low

Extensive description Variations For a more extensive description of this technique’s variants we refer to the guide on air cleaning techniques drawn up by VITO (http://www.emis.vito.be). Installation: design and maintenance Relatively small occupation of space. The presence of moving parts in the scrubbing section can lead to high maintenance costs. Monitoring To measure the scrubber’s efficiency it is necessary to do isokinetic sampling on both the incoming and outgoing dust concentration. For details we refer to the Dutch air emission guideline, NeR paragraph 3.7 and Annex 4.7.

Environmental pros and cons Specific pros - Scrubbing water can be re-circulated without risk of clogging - The scrubber has low pressure drop - Can be used for sticky, explosive and flammable chemicals - Very high efficiency, even with small particles - Insensitive to fluctuating gas flow - Self-cleaning Specific cons - Relatively high energy consumption - Relatively high investment costs Additives Water and possibly additional chemicals to increase the precipitation of the component that is to be removed. Cross Media Effects Waste water that has to be treated or discharged. Residues that have to be disposed of after dehydration.

MD-MV20090007 -28-


3/h1

Personnel, hours per week Operational costs, EUR/1,000 m0

3/h Residue, EUR/ton Energy consumption, kWh/1,000 m0

3/h Benefits

5.000 - 25.000 About 1 1,000 – 30.000 Ranging from 100 – 250 depending on the type of waste Costs for treatment of waste water 0,4 - 2,7 depending on design None

¹ For capacities > 10,000 m03/h an up scaling to the power of 0.3 applies (additional costs

> price0.3 for extra capacity beyond 10,000 m03/h).

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008 6. http://www.frtr.gov/matrix2/section4/4-60.html7. Supplier information DMT Environmental Technology

MD-MV20090007 -29-

Venturi-scrubber / Venturi-scrubber / Whirl scrubber Brief description Description A venturi-scrubber consists of a converged neck (the narrowest part of the venturi tube), a diverging expansion chamber and beyond that a drip precipitator. The dust/gas mixture streams into the venturi tube and reaches high speeds in the neck. Then the mixture reaches the expansion chamber where the speed diminishes. The liquid is added to the gas just before or inside the neck. Then an intensive mixing of the gas and liquid takes place in the venturi tube. Because of the gas and liquid’s high speed the water scatters into small drops resulting in an intense contact between the gas and liquid phases. Achieving this fine droplet distribution takes a relatively large amount of energy. Venturi-scrubbers can be applied for the removal of small particles (< 1 µm) from a gas stream, although the efficiency generally decreases with particle size. They can however also be applied for larger particles, although in such as a case the energy consumption rate is much higher than those of competing techniques. Some dusts cannot be removed, even at a very high pressure drop. Schematic diagram

Applicability The scrubber is primarily applied for the removal of fine dust (PM10). Broad range of application including the following sectors: - Chemical industry - Basic metal industry - Asphalt production - Wood and paper industry - Waste incineration

Venturi scrubber

water water

Gas in

Clean gas

Dust and wastewater

MD-MV20090007 -30-


Removal efficiency1, %

Remaining emission, mg/m0

3

Validation number

PM10 PM0,3 à PM0,5 HCl, HF

70-992

<50 3

50 - 90

<10 -<10

212

1Dependent on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages. 2 Dependent on particle size. 3 The efficiency is particularly low with components that are not easily humidified. Preconditions Gas flow, m0

3/h 720 – 100.000

Temperature, ºC1 4 – 370

Dust in, g/m03 1 - 115

Pressure, bar atmospheric Pressure drop, mbar 25 – 200

1The venturi-scrubber is also used as a cooler to quench hot gasses (up to 1,000 °C) Extensive description Variants Some venturis have the advantage of having a neck that has a changeable diameter, allowing for the separator to be modified in order to maintain a high efficiency at varying capacities. One variant is the Vane-Cage scrubber, consisting of internal static blades creating a mist. Installation: design and maintenance The venturi-scrubber itself has a small volume. The total size of the installation is primarily determined by the demister that may be several times the scrubber’s size. A liquid-gas (L/G) ratio of 1 to 5m³ per 1,000 m0³/h can be stuck to as a guideline. The venturi is often constructed of erosion and corrosion-proof material in order to significantly lengthen its lifespan. Te drip catcher has to be checked for pollution regularly. In general the venturi-scrubber requires very little maintenance. Monitoring In order to increase the scrubber’s efficiency it is necessary to measure the incoming and outgoing mass. This can be done either chemically or with infrared light depending on the components. In case of dust the measurement should be in the form of isokinetic sampling. For details we refer to the Dutch emission guideline, NeR paragraph 3.7 and Annex 4.7. Environmental pros and cons Specific pros - Relatively low maintenance - High removal efficiency rates - Simple and compact construction - No mechanical parts - Gaseous components are absorbed - Insensitive to fluctuating gas capacities Specific cons - High pressure drops and corresponding energy consumption - Realistic chance of erosion and corrosion - Potential noise pollution - Only applicable for dust (PM) and gas components easily soluble in water. Additives - Water Cross Media Effects Waste water that has to be treated or disposed of. Residues that have to be disposed of after dehydration.

MD-MV20090007 -31-

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. EPA-CICA fact sheet: http://www.epa.gov/ttn/catc/dir1/fventuri.pdf5. http://www.frtr.gov/matrix2/section4/4-60.html6. Dutch Association of Cost Engineers, edition 25, November 2006. 7. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008 8. Supplier information: Pure Air Solutions

Investments, EUR/1,000 m03/h

Personnel, hours per week Operational costs, EUR/1,000 m0

3/h Additives and residues Energy consumption, kWh/1,000 m0

3 /h Benefits

5,000 – 7,000, depending on design About 1 2,000 – 50,000 Strongly dependent on the application 0.5 – 7 None

MD-MV20090007 -32-

4.3 Filtration

MD-MV20090007 -33-

Fabric filter (filtering dust separator) / Tube filter / Bag filter Brief description Description The polluted air is lead through the fabric filter and the dust particles are separated. The dust is periodically removed from the filter and collected in a funnel (hopper) placed below the filtering installation. The fabric filter can be attached in many ways such as in tubes, envelopes, etc. The incoming air usually does not stream directly into the filters but is lead through one or multiple dividing plates. The goal here is to achieve a good distribution of the pressure on the cloth. This way the air also uses a lot of its kinetic energy, allowing for a pre-removal through gravity. A tapping mechanism is used to frequently remove the accumulating dust from the filter. The dust that falls off the cloth is caught in the bottom of the filter and can in some cases be re-cycled into the process. Schematic diagram

Applicability Fabric filters are primarily used for the removal of dust and particles up to <PM2,5. Heavy metals present on the dust are also removed. In combination with injection systems the technique can also be applied for the removal of specific gaseous pollutions like dioxins. Broad range of application including the following sectors: - Chemical industry - Metallurgic industry - Feed industry - Food and stimulant industry - Waste processing industry

Clean gas

Gas flow in

Dust discharge

Compressed airor mechanics fordust discharge

Fabric filter

MD-MV20090007 -34-

Various types of cloth can be used for different purposes. Some examples of this are given below. Examples of fabric filter material

Chemical resistance Material Acid milieu Basic milieu

Working temperature, ºC

Polyester Good Reasonable 130 M-Aramide Good Good 200 PTFE Very good Very 260 Polyamide Good Good 260




3

Validation number

Dust (> 2,5 µm)

Dioxin / furans

99,95 <5 Depending on type of cloth used 0,1 ng/m0

3 ITEQ

3

11Dependent on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages. Preconditions Gas flow m0

3/h 300 – 1,800,000 Temperature, ºC Above dew point, < 280, depending on the

type of cloth Pressure, bar Atmospheric Pressure drop, mbar Up to 15 Fluid level Above dew point Dust g/m0

3 0.1 – 230

Extensive description Variants - (Improved) compact filters, also known as cassette filters or envelope filters. Compact

filters are built in various sizes and with various capacities. Standard units are often used, which can be combined into filtering installations with higher capacities. The difference with the fabric filter is the compact construction and the way the filter elements are installed in the filter chamber. They are installed in a way making them easily replaceable. Synonyms include Sintamatic, Sinter-plate filter, Spirot Tubes.

- Catalytic cloths. For some specific applications catalysts can be implemented into the cloths, making the so-called catalytic cloths. Vanadium or titanium is used as a catalyst. The most important application is the removal of dioxins and furans, but other pollutions such as VOC, PAHs, PCBs and other chlorinated compounds can also be removed.

- A reactive fabric filter. This filtering material has the quality of decomposeing dioxins and furans instead of adsorbing them. The material can withstand a temperature of 260°C works optimally at a temperature of 220°C.

Installation: design and maintenance The most important design parameters are: - Incoming gas flow - Working temperature and maximum temperature - Incoming gas composition - Fabric filter load (filter ratio). The fabric filter load is dependent on the type and nature

of the cloth material, the dust load and the type and size of the particles. Examples are glass fiber: 60-120 m/h; and PFTE (Teflon): 80-100 m/h

- In the food industry the ease of cleaning and the design of the exterior is important for hygienic reasons.

Monitoring The performance of the filter can be checked by measuring the particle mass in the outgoing gas. This can be done using isokinetic sampling, a UV/transparency meter,

MD-MV20090007 -35-

etcetera. Temperature and pressure have to be checked regularly. The pressure drop on the filter determines when the cleaning cycle has to be initiated. Regular inspection of the filters is necessary for checking the filters and casing for deterioration, so easy access to the filter is necessary. A well-inspected fabric filter needs to have a leak-detection system with an alarm to prevent uncontrolled emissions. Environmental pros and cons Specific pros - High removal efficiency - Changing loads have no influence on pressure drop and efficiency - Removed dust can eventually be re-used as raw material Specific cons - Not suited for wet or sticky chemicals because of the risk of filter clogging. Eventual

heating of gas stream prevents condensation of fluid on the filter. - Risk of explosion - Potential electrostatic charge - Takes up a lot of space

Additives - Different types of cloth are available (varying in quality and depending on the type of

pollution). - The most common filter materials are cotton, wool, nylon, polypropylene, Orlon,

Dacron, Dynel, glass fiber, Nomex, polyethylene and Teflon. - Pre-coating of the fabric filter may be necessary in case of sticky or static chemicals for

the protection of the cloth. - Compressed air: 3 - 7 bar is needed to clean the filter elements and for compressed air

and ultrasonic cleaning. - Energy consumption: 0.2 – 2 kWh/1,000 m0

3.- Filter cloths: 11 - 17 m2 /1,000 m0

3/h.

Cross Media Effects Solid waste including the removed dust and the cloths used. The quantity is dependent on the application. Systems with a heightened risk (explosion, fire) are to be fitted with safety regulations such as an expansion hatch or sprinklers. Financial aspects Investment costs, EUR/1,000 m0

3/h Filter material, EUR/1,000 m0

3/h 1,000 – 4,500, depending on the design 660 – 920

Operational expenses, EUR per year/1,000 m0

3/h About 200 – 1,500

Personnel, hours per week 2 Energy consumption, kWh/1,000 m0

3/h 0.2 – 2 Cost-determining parameters Pressure drop, and eventual costs for

conveying dust Benefits Saving in costs of raw materials when recycling

is possible, for instance in the glass industry

MD-MV20090007 -36-

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA APTI Virtual Classroom: http://yosemite.epa.gov/oaqps/EOGtrain.nsf/DisplayView/SI_412A_0-5?OpenDocument6. Mikropul Filter Media Fiber Selector. 7. Various emission rapports on asphalt plants from the competent authorities, 2003-2008. 8. Kok, H. Particle size distribution of emitted fine dust in industrial sources. TNO October 2006.

MD-MV20090007 -37-

Ceramic filter (filtering dust-separator) / Ceramic filter / High temperature filter / Candle filter Brief description Description In a ceramic filter the contaminated gas is lead through filtering material, comparable to the fabric filter. The filter ensures that the particles remain in the filtering material and the incoming gas is cleaned. The difference with a fabric filter is that the filtering material is ceramic. There are also designs where the acid components such as HCI, NOx and SOx and dioxins are removed. In such a case the filtering material is fitted with catalysts and the injection of reagents may be necessary.

Applicability Mostly applied for dust removal at high temperatures, especially with: - combustion installations and gasification systems with coal as fuel - waste processing industry - plastics processing industry - chemical industry - glass industry

Dust discharge

Clean gas

Gas flow in

Ceramic filter

Compressedair

MD-MV20090007 -38-




3Validation number

Dust HCl SO2

NOx

dioxin

99 – 99.99 95 80 95 99

< 2unknown unknown

< 200 unknown

21111

1 Dependent on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages. Preconditions Gas flow, m0

3/h 300 – 1,800,000 Temperature, °C < 1,200 Pressure, mbar ~ 50 higher of lower then atmospheric Pressure drop, mbar 25 Fluid level Has to be above the dew point of condensable

materials in the gas to avoid clogging Dust, g/m0

3 < 20 Sticky particles have to be avoided

Extensive description Variants - (Improved) compact filter - Three-stage filter The filtering material of the ceramic filter can be applied in many different forms. It is possible to convert the ceramic material into cloth, fiber felt, fiber elements, sinter element or filter candles. The table below gives an overview of the different applications: Filter medium Filter cloth1 Fiber felt Fiber element Sinter element Design Bag with

supporting basket

Bag with supporting materials

Pipe, self-carrying

Pipe, candle, self-carrying

Surface weights (g/m2)

1,000 – 2,000 2,500 – 3,500 2,000 – 4,500 12,500 – 22,800

Mechanical qualities

Flexible, not very grating-proof

Flexible, not very grating-proof

Half stiff, a little grating-proof

Stiff, grating-proof

Air transparency

High Average Average Small

1 Cloth with ceramic material

Installation: design and maintenance The ceramic filters require a relatively large amount of maintenance and regular inspection, in order to prevent clogging and bad performance of the filtering elements. For these reasons it may decided that the process temperatures should be lowered and fabric filters installed, for they are easier to maintain. Monitoring The performance of the filter can be checked by measuring the particle mass in the outgoing gas. This can be achieved by, for example, isokinetic sampling, tribo-electric flow gauge, UV/Transparency meter, etc. The temperature and pressure drop have to be registered in order to determine the condition of the filtering material and to ensure that it is cleaned in time. For details we refer to the NeR paragraph 3.7 and Annex 4.7.

MD-MV20090007 -39-

Environmental pros and cons Specific pros - High dust removal efficiency - Modular construction - Can handle high and varying capacities - Can withstand acid and basic chemicals - Removed dust may potentially be re-used - Simple mechanic Specific cons - Vulnerable (ceramic material) - Relatively high pressure drop - A lot of maintenance and relatively large weight - Less suitable for wet and/or sticky chemicals - Explosion risk in case of flammable chemicals - Relatively high operational costs compared with other filtering materials

Additives Filtering material Compressed air for the cleaning of the filtering elements Cross Media Effects The lifespan of the filtering material is dependent on the design and application. The removed dust can be disposed of as waste or recycled back into the process. Financial aspects Investment costs, EUR/1,000 m0

3/h 30,000 – 55,000 Operational costs, EUR/1,000 m0

3/h About 1,000 Help and additives, EUR/ton - 0 (in case of recycling. See: benefits)

- Inert waste: about 75 (solid, non-hazardous waste) - Hazardous wastel: about 250

Energy consumption, kWh/1,000 m03/h 0.2 – 2

Cost-determining parameters Gas flow , filtering material, surface pressure Benefits Cost-saving because of potential recycling of material

Information sources 1. Description of air emission abatement techniques, l26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC, BREF Waste Gas and Waste Water Treatment, 2003. 4. Reference document on BAT in the large volume inorganic chemicals, ammonia, acids and fertilizers industry, draft 2004. 5. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008. 6. Suppliers: Airtechnic Solutions, Lutec, Nedfilter 7. Gamma Holding, Madison Filter; Cerafil, presentation January 2007.

MD-MV20090007 -40-

Two-stage dust filter Brief description Description The two-stage dust filter has metallic gauze as filtering material. In the first stage a filtering layer is accumulated after which the filtering takes place in the second stage. Depending on the pressure drop on the filters the second stage is cleaned and the air stream is switched between the two stages. The first filter now serves as the second and vice versa. The dust falls to the bottom of the installation where it may be removed. Schematic diagram

Afgas

Gereinigd gas

Afgescheiden stof Afgescheiden

stof

Klep om gasstroomrichting om te draaien

Klep om gasstroomrichting om te draaien

metaalgaasfilter

Applicability The two-stage dust filter has the same applications as the improved compact filter and is primarily suited for the removal of dust. It has a range of application in the following sectors: - Waste processing industry - Chemical industry - Wood industry - Refineries

Clean gas

Gas flow in

Dust dischargeDust discharge

Metal gasketfilter

Valve for turninggas flow

Valve for turninggas flow

MD-MV20090007 -41-


Removal efficiency Remaining emission [mg/m0

3]Validation number

Dust (PM) - 1 - 20 3


3/h Up to 75,000 per module Temperature, ºC Up to about 500 Pressure, bar Atmospheric Pressure drop, mbar About 25 Fluid percentage No known limitation Ingoing mass No limitation

Extensive description Variants One variation on the standard issue two-stage dust filter is a system with more than two metallic gauze filters where a filtering layer is accumulated before the filter is placed into the incoming untreated gas stream. This prevents the removal efficiency from decreasing just after the cleaning of the filters. Installation: design and maintenance The most important design parameters are the incoming gas flow and speed when travelling through the filtering material and the filters. Because this filtering material can handle a bigger load than a fabric filter, less filtering surface is required which may result in gain in space. However, because of the fact this is a two-stage system this advantage is nullified. It is claimed that the additional space in the two-stage system is entirely compensated by the higher filter load. Monitoring The performance of the filter can be checked by measuring the particle mass in the outgoing gas. This can be done using isokinetic sampling, UV/Transparency meter, etc. Temperature and pressure have to be checked regularly. The pressure drop on the filter determines when the cleaning cycle should start. Regular inspection of the filter is necessary in order to prevent deterioration of the filters and the casing, so good access to the filter is essential. A dust filter should have a leak detection system with an alarm in order to be sure of a good performance. Environmental pros and cons Specific pros - High dust removal efficiency - Regaining of solid materials is possible - Modular structure - Filtering material barely needs replacement, all-steel design - Filter load higher than with a cloth or compact filter - Also applicable for fluid, sticky, fibrous or static dust - Can withstand high temperatures (limited fire risk) - Possibility of regaining heat at high temperatures Specific cons - Higher costs than a fabric or compact filter when used at ambient temperatures, this

does not apply at higher temperatures - Frequent changing between the two compartments (with a normal two-stage filter) - Valves necessary in a dusty environment; greater change of malfunctions - Explosion risk Additives - Metallic gauze as filtering material - Compressed air for the cleaning of the filters - Energy consumption

MD-MV20090007 -42-

Cross Media Effects The removed dust can be polluted, depending on the application. For example, dioxins and/or heavy metals can be present in the dust in case of combustion processes. The dust may then be classified as toxic waste. Financial aspects

InformInformation sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 3. Dutch Association of Cost Engineers, edition 25, November 2006. 4. BP Australia, Installs & commissions Pall GSS 3rd stage blow back filter system to reduce RCC flue gas emissions, 2004. 5. Bioflamm, http://www.bioflamm.de 2008

Investments, EUR/1,000 m03/h 40,000

Operational costs, kWh/1,000 m03 /h about 1.5

Personnel, hours/week About 2 Help and additives, EUR/ton Conveyance as toxic waste: 150 - 250 Cost-determining parameters Gas flow, pressure drop, conveyance toxic waste Benefits Savings or profits from regained materials (in

case of eventual recycling)

MD-MV20090007 -43-

Absolute filter / HEPA-filter / surface filter / cartridge filter / micro filter Brief description Description The incoming gas stream is lead into a chamber and guided through a High Efficiency Particle Air filter (HEPA filter). A HEPA’s filtering material consists of very thin glass fibers mounted in paper or a paper filter. In order to attain the largest possible filtering surface, the glass fiber paper is folded like a harmoniabout This is necessary because the thick mass of glass fiber paper doesn’t let much air trough. In order to move a high enough volume of air a large surface is required. The dust remains on the filter, but does not penetrate it. So the process consists of surface filtration. The layer of dust that forms a layer onto the filter can initially improve the dust removal efficiency. If the pressure drop on the filter grows too large after some use, it has to be replaced. The HEPA-filter can be placed directly into a piping, or in a separate casing. HEPA-filters do require a pre-cleaning stage to remove the coarse dust. Because of this, HEPA-filters are often the last filtering stage for the removal of dust. HEPA-filters are rarely re-used, because the cleaning of it may cause damage or leakage of the filter. Schematic diagram

Applicability Absolute filters are applicable for the removal of dust between PM0.12 and PM0.3 and for toxic or dangerous particles, like most heavy metals. Because of it’s high efficiency another installation is placed before the absolute filter for the removal of coarse particles, like an electrostatic precipitator or fabric filter. Absolute filters are often used for the filtration of inside air in locations where a good air quality is necessary like in operating rooms in hospitals or in production spaces of the pharmaceutical, the photographic and the electronics sectors. Other sectors where the absolute filter is applied include: - Biochemical industry - Food industry - Chemical industry Components Removed components

Removal efficiency, % Remaining emission, mg/m0

3

Validation number

PM > 99.999 > 0.0001 1 PM0.01 > 99.99 unknown 1 PM0.1 > 99.999 unknown 1

1 Depending on the specific configuration and working conditions

Gas flow in

Clean gas

Pre filter

MD-MV20090007 -44-


3/h 100 – 360 per module Temperature, ºC < 200 for most common HEPA

< 530 for glass or ceramic HEPA Pressure Atmospheric Pressure drop, mbar Size unknown, although pressure drop is

present Fluid level, % < 95; always above the incoming gas’ dew

point Ingoing dust concentration, mg/m0

3 1 - 30

Extensive description Variants One can distinguish between two variants: - HEPA (High Efficiency Particle Air) filter: 99.97% minimal removal efficiency for fine

dust > 0.3 micrometer - ULPA (Ultra Low Penetration Air) filter: 99.9995% minimal removal efficiency for fine

dust > 0.12 micrometer Installation: design and maintenance Absolute filters are the last filtering phase for the removal of dust, prior to the absolute filter an ESP or fabric filter is applied in order to remove the coarse particles. Determining parameters for the design of the mechanical aspect and the casing are temperature and pressure. With the most common designs, the filtering units are either right-angled or cylindrical in shape. The filter is folded in order to enlarge the surface. Monitoring The outgoing gas stream can be monitored with the help of an isokinetic sampler or a meter based on UV, light-transparency, beta-radiation or particle detection. Environmental pros and cons Specific pros - Filters submicron particles of fine dust - Very high efficiency, low remaining emission (see applicability) - Filtered incoming gas stream is very clean and can be re-circulated into the process - Modular design - Not sensitive to small variations in the gas stream - Relatively easy operational management - Not sensitive to corrosion Specific cons - Not suitable for the removal of wet dust or Applicability in humid conditions - Not suitable for large dust loads (unless after pre-filtering) - Not suitable for gas streams containing bases - Explosion risk - Frequent replacement of filtering element is necessary Additives Filtering material (paper and/or glass fibers) has to be replaced frequently. Energy consumption < 0,1 kW/1,000 m0

3/h. Cross Media Effects The used filter is carried off as waste material, with one filtering module generally absorbing 1 kilogram of dust. Multiple modules can be in effect simultaneously. Financial aspects Investment costs, EUR/1,000 m0

3/h 2,400 – 3,200 Operational costs, kWh/1,000 m0

3/h < 0.1 Personnel, hours per week About 2 Help and additives, EUR per year/1,000 m0

3/h 100 - 190

Cost-determining parameters Gas flow, filtering material Benefits None

MD-MV20090007 -45-

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, Edition 25, November 2006. 5. http://www.epa.gov/ttn/catc/dir1/ff-hepa.pdf

MD-MV20090007 -46-

Demister / Aerosol filter / Deep bed filter Brief description Description Most demisters are woven elements of metal or synthetic material. The filters work on the principal of mechanical removal and depend on the speed at which the particles or drops pass the filter. The efficiency of demisters can rise up to 99% for dust and aerosols. Filtering elements with a small mesh for the removal of dust (1 - 3 µm) are more efficient for the smallest drops, but the chance of clogging increases. For the removal of sticky matter and fatty or viscous fluids, interchangeable filters can be applied. In case of fatty fumes the filter may become clogged if coagulation takes place as a result of a drop in temperature. Schematic diagram

Applicability Demisters often form an integrated part of other techniques, for example a gas scrubber. Broad range of application for the removal of pollution in the form of drops and aerosols after steam kettles and gas scrubbers in the: - Chemical industry - Textile industry - Food industry - Plastics processing Components Removed components



3Validation number

Dust, drops and aerosols

< 99%

Scrubbing liquid with removed dust and polluted filtering material

1

1 Depending on the specific configuration and operational conditions. Values are based on half-hour averages. Preconditions Gas flow, m0

3/h Up to 150,000 Temperature, °C < 170 Pressure - Pressure drop, mbar Normally up to 25 (up to 90 at high loads) Aerosol level, g/m0

3 Some Dust, mg/m0

3 < 1

Gas flow in

Clean gas

Demister

Filter element

MD-MV20090007 -47-

Extensive description Variants Besides those demisters based on woven elements of metal or synthetic materials there are also variants based on specially designed gaskets or bended plates. Installation: design and maintenance Material of choice: steel. Dimensioning basis: gas flow and filter load. When the demister separates drops and aerosols, these may be self-cleaning because of the running fluid. In this is not the case, the filter should be rinsed. Monitoring The pressure drop after each filtering stage should be measured separately in order to determine the performance of the filter. Environmental pros and cons Specific pros - Self-cleaning in case of removal of fluids - Suitable for filtration of fluid aerosols. Specific cons - Polluted scrubbing fluid when cleaning the filter - Chance of high pressure drop when separating solid dust particles - Chance of obstruction because of solid matter and fatty fumes. Additives - Filtering medium - If applicable scrubbing fluid for cleaning. Cross Media Effects Scrubbing fluid containing removed dust and polluted filter material should be considered waste, depending on the chemical. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC BREF, Waste Water and Waste Gas Treatment, 2003.

Investment costs, EUR/ 1,000 m0

3/h < 2,300

Operational costs, EUR/year 2,500 + (450 * flow/1,000) Personnel about 2 hours per week Help and additives, EUR per year/1,000 m0

3/h 250 to 600 (filtering material)

Energy consumption, kWh/1,000 m0

3/h Energy consumption rate depends on the filtering system

Cost-determining parameters Gas flow, pressure drop, filtering element Benefits None

MD-MV20090007 -48-

Dry electrostatic precipitator / Electrostatic precipitator (ESP) / Dry E-Filter / Dry ESP / Dry electrostatic precipitator / Electro filter Brief description Description A dry electrostatic precipitator is a device that charges (ionizes) particles by means of electrical fields and removes them from the gas stream by having them pulled towards collecting electrodes. The removed particles fall because of gravity or (in the case of solids) because of the periodical tapping or shaking of the collecting electrons and end up in a dumping bunker. There are two types of dry electrostatic precipitators: - The plate filter wherein the gas is carried horizontally past the plates. - The pipe filter wherein the gas is carried through the tubes vertically. Schematic diagram

Applicability The primary areas of application are large complex waste gas cleaning systems in power plants and waste incineration facilities. Components

Removed components

Removal efficiency1,%


3Validation number

Dust, aerosols PM1

PM2

PM5

> 97 > 98 > 99.9

5 – 20 3

1 Depending on the specific configurations and operational conditions. Values are based on half-hour averages.

Gas flow in

Clean gas

Discharge ofdust

High voltage

Dry Electrostatic precipitator

Isolator

Discharge electrode

Collector electrode

MD-MV20090007 -49-


3/h 360,000 – 2,000,000 (plate filter) 1,800 – 180,000 (pipe filter)

Temperature, °C ≤ 700 Pressure Atmospheric Pressure drop, mbar 0.5 – 3 Dust, mg/m0

3 2 - 110 (plate filter) 1 – 10 (pipe filter)

Extended description Variants The two-stage electro-filter consists of two compartments, with the ionization of the particles taking place in the first compartment and the removal and collection of the particles in the second compartment. Installation: design and maintenance - Material of choice: steel - Dimensioning basis: gas flow, gas speed in filter (0.6 - 1 m/s) - Capacity (m3/1,000 m0

3/h): 1.4 – 2.8 Construction aspects An electro-filter consists of one or more chambers among which the incoming gas is evenly divided. This done by means of a gas-dividing screen. The system is built based on a series of independently operating fields, placed in serial order. The first field removes the majority of the dust, while the last fields are there in order to keep the remaining emissions low. Independently coordinated fields are preferred because of the operational safety. Each field should be fitted with it’s own dust funnel. Cleaning of the electrodes Because of the electrodes being tapped the removed dust can be collected in the dust funnel. However, when too many plates are being cleaned at the same time the remaining emission will temporarily be higher. It is thus beneficial to limit the amount of electrodes being tapped simultaneously. The plates should be tapped frequently in order to prevent the layer of fly ash to become too thick and thus decreasing the efficiency. However, when the plates are tapped too often, the fly ash layer doesn’t become thick enough, and breaks of into pieces and is sucked away with the gas stream. The configuration of the plates is important in this regard, with low gas-speed zones and the height/width ratio of the plates being essential for a good efficiency. Maintenance Electro-filters are relatively sensitive to proper maintenance and adjustments in the settings. Especially the removal of dust and the tapping mechanism may be a cause for extra maintenance. Monitoring The performance of the filter can checked by measuring the particle mass in the effluent gas. This can be done by means of isokinetic sampling or a UV transparency meter. For details we refer to NeR paragraph 3.7 and Annex 4.7. The system itself is to be regularly checked for corrosion of the electrodes and the isolation material. Environmental pros and cons Specific pros - Very high efficiency (including small particles) - Dust can be removed dry, making re-use possible. - Suitable for very large gas streams. - Suitable for use at high temperatures. - The efficiency of electro-filters can be increased by adding additional fields or zones. - Low pressure drop.

MD-MV20090007 -50-

Specific cons - Less suited for processes with varying gas streams, temperatures or dust

concentration. This however, can be compensated for by automatic adjustments. Varying operational conditions are no problem, if the installation is designed for the worst case situation.

- Sensitive to maintenance and the right settings. - Risk of explosion in combination with flammable chemicals such as soot. - Cleaning capacity is dependent on the conductibility of the chemicals that are to be

removed. - Takes up a lot of space. Additives None Cross Media Effects The removed dust can be re-used as, for example, filling matter in the asphalt and cement industry (depending on the dust’s nature), or it has to be disposed of as waste.

Financial aspects

1) Costs may turn out higher when the system has to be constructed out of stainless steel or titanium as a result of the nature of the dust that is to be separated. Information sources 1. Fact sheets on air emission abatement techniques, www.infomil.nl, Infomil 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC, BREF, Large Combustion Plants, 2006 4. IPPC, BREF Waste Water and Waste Gas Treatment, 2003 5. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008 6. Dutch power station, emission measurement, 2008 7. Kok, H. Particle size distribution of emitted fine dust in industrial sources, TNO October, 2006

Investment costs, EUR/1,000 m03 /h 10,000 – 30,000 (for systems 30,000 –

200,000 m03/h)1

Operational costs, EUR/1,000 m03/h 0.05 – 0.1 (for systems > 50.000 m0

3/h) Personnel, hours/day about 0.25 (maintenance of electrodes) Help and additives, EUR/ton Processing costs of the removed dust are

dependent on the nature of the remaining dust. In case of recycling: 0 Inert non-hazardous waste: about 75 Chemical waste: 150 – 250

Energy consumption, kW/1,000 m03/h 0.2 - 1

Cost-determining parameters Gas flow, dust concentration, efficiency Benefits Use of removed dust

MD-MV20090007 -51-

Wet electrostatic precipitator / Wet E-filter / Wet ESP / Wet Electrostatic precipitator / Electro-filter Brief description Description A wet electrostatic precipitator consists of one or more chambers among which the untreated gas is evenly divided. This is done by means of a gas-dividing screen. The filter consists of a number of independently operating, serially placed electrodes. The wet electrostatic precipitator works in the same way as the dry version, however the collecting electrodes are not tapped, but the removed dust is removed by a flushing liquid. The incoming air should be moistened beforehand. There are two types of wet electrostatic precipitators: - The plate filter wherein the gas is carried horizontally past the plates. - The pipe filter wherein the gas is carried through the tubes vertically. Schematic diagram

Applicability The primary areas of applications are small-scale waste gas cleaning systems in the metal industry and the chemical industry where dry electrostatic precipitators do not suffice when handling wet and sticky matter, flammable and explosive mixes and material with a high resistance. It is also applied for the removal of mercury in waste incineration plants. Components Removed components



3

Validation number

Dust, aerosols 97 – 99 - 1 1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages.

Gas flow in

Clean gas

Wet Electrostatic filter

High voltage

Water in

Dust discharge

Isolator

Discharge electrode

Collector electrode

MD-MV20090007 -52-

Preconditions Flow, m0

3/h 180,000 – 900,000 (plate filter) 1,800 – 180,000 (pipe filter)

Temperature, °C 80 - 90 Pressure Atmospheric Pressure drop, mbar Some Dust, g/m0

3 2 - 110 (plate filter) 1 – 10 (pipe filter)

Extensive description Variants The two-stage electro-filter consists of two compartments with the ionization taking place in the first and the particles being collected in the second. Installation: design and maintenance - Material of choice: steel. - Capacity: 1.4 - 2.8 m3 per 1,000 m0

3/h. - Sensitive to proper maintenance. Monitoring The performance of the filter can be checked by measuring the particle mass in the effluent gas. This can be done by means of isokinetic sampling, a UV/Transparency meter, etcetera. For details we refer to the NeR, paragraph 3.7 and Annex 4.7. The system should be checked regularly on corrosion of the electrodes and the isolation material. Environmental pros and cons Specific pros - Very small particles can be removed - Both wet and dry dust is removed - System can be constructed in modules - Partial removal of acid fumes. - At a voltage of > 50 kV, the removal is independent of the residence time, making

compact construction possible. - It is possible to remove sticky particles, fumes and explosive chemicals. Specific cons - Waste water is released - The electro-filter is very heavy - High investment costs. Additives Scrubbing liquid (usually water) is used as an additive. This can be (partly) recycled, minimizing the consumption rate. Cross Media Effects The removed dust and waste water can be re-used or has to be disposed of as waste.

MD-MV20090007 -53-

Financial aspects

Information sources 1. Fact sheets on air emission abatement techniques, www.infomil.nl, InfoMil 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC, BREF, Large Combustion Plants, July 2006. 4. IPPC, BREF Waste Water and Waste Gas Treatment, 2003. 5. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008.

Investment costs, EUR per 1,000 m0

3/h 60,000 – 300,000 (systems of 30,000 – 200,000 m0

3/h) Operational costs 0.05 – 0.1 (systems larger than 50,000 m0

3/h) Personnel, hours/day about 0.25 (maintenance electrodes) Help and additives, EUR/ton Processing costs of the removed dust is dependent

on the nature of the dust. Recycling waste: 0. Inert waste: about 75 Chemical waste: 150 – 250

Energy consumption, kW/1,000/m0

3/h 0.2 – 1 (including fan)

Cost determining parameters Flow, dust concentration, efficiency Benefits Eventual recycling of removed dust

MD-MV20090007 -54-

4.4 Condensation

MD-MV20090007 -55-

Condenser / Heat exchanger / Odour control condensation (OCC) Brief description Description When applying a condenser (odour) components (including acids, alcohols and ammonia) are removed from a gas stream that is saturate with water or warm and damp, by condensing to far below the water’s dew point. The condensate that forms on the heat exchanger, serves as an absorption liquid (only) for (odour) components that are easily dissolvable in water. The relatively large contact surface that is required for the exchange of heat is also used as a contact surface for the exchange of dust. After passing trough the condenser the gas stream is 100% saturated with water, and the remaining condensate drips are to be collected with a demister. The odour components are absorbed in the condensate. Schematic diagram

Applicability Condensation is primarily applied for the cleaning of humid gasses with odour components or high solvent concentrations (> 50 g/m0

3). For solvents, cryocondensation is often applied (see fact sheet on cryocondensation). Condensation is also used as a preliminary treatment so that abatement technique is less loaded, reducing the total processing costs. Broad range of application in the following sectors: - Food industry - Feed industry - Composting facilities - Sludge processing facilities Components Removed components



3

Validation number

Ammonia 80 – 90 - 1 Odour 60 – 90 - 1 Dust 80 – 90 - 1

1 Depending on the specific configuration and operational conditions.

Gas flow in

Clean gas

Cooler

Condensate

Separator

Coolant

MD-MV20090007 -56-


3/hour 100 – 100,000 Temperature, ºC 50 – 125 Pressure Atmospheric Pressure drop, mbar Some Fluid level Humid or saturated incoming gas stream The water dew

point should be at a temperature of 42 ºC or above. Dust, mg/m0

3

NH3, mg/m03

Odour, ouE/m03

< 50, not sticky 200 – 1,000 >50,000. Can only be applied for (odour)components easily dissolvable in water.

Extensive description Variants Two types of heat exchangers are applied: - Conventional Shell-and-tube heat exchanger. - Spiral heat exchanger, consisting of two concentric passages. The coolant streams

through one passage en leaves the heat exchanger through the center. The incoming gas enters through the center and exits the heat exchanger at the periphery (counterflow principal).

There is also a difference between direct and indirect systems: - With direct systems, the coolant comes in direct contact with the incoming gas stream.

This causes a very good heat exchange. Practical designs include, for example, the spraying chamber. The disadvantage is that the coolant then has to be processed to remove the dissolved chemicals.

- With indirect condensers the coolant does not come in direct contact with the incoming gas. Thus, the cooling medium does not get polluted. The disadvantage is that this way, it is impossible to remove sticky chemicals.

Installation: design and maintenance Condensation may occur at different temperatures, depending on the composition of the incoming gas stream. This has an effect on the construction of the condenser and the accompanying cooling unit (for cooling the coolant that runs through the condenser). The cooling unit may consist of, for example, a compression cooling unit (low condensation temperatures) or a cooling tower (higher condensation temperatures up to 25ºC). The cooling of the gas streams to below 25-30ºC often only guarantees a minimal improvement in efficiency, considering that the amount of condensation will only increase very little in such a case. In order to increase the humidity level in the air, especially for relatively hot and dry gas streams, it is useful to humidify the air in advance. Monitoring The removal efficiency of the installation is determined by measuring the concentration of the component that is to be removed (like odour) before and after passing through the condenser. For odour components the efficiency can be determined by means of olfactory measurement. Ammonia can be chemically determined, when wet. A measurement of the dust concentration should take place under isokinetic conditions. Environmental pros and cons Specific pros - Compact and robust technology - Possibility of recovering (some) heat - Suitable for separating the majority of the pollution, making more economical or

technical use of the subsequent processing techniques possible. - Possibility of regaining solvents, if the composition of the dissolved VOCs allows for

this. Specific cons - In some designs cooling water is necessary - The removal efficiency is dependent on the incoming gas composition and flow - Often further treatment is necessary.

MD-MV20090007 -57-

Additives - Coolant, for the coolant other supporting additives are necessary - Corrosion-inhibitors - Biocides to prevent the growth of bio-organisms - Energy for cooling installation. Cross Media Effects In case of direct condensation the components from the incoming gas stream are absorbed by the coolant. The amount of waste water corresponds directly to the amount of condensation water, that in turn corresponds directly to the fluid level and the selected cooling temperature. For example: when cooling 100% saturated air from 50 to 25ºC, about 80 liters of condensation fluid gets released per 1,000 m0

3.

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. Supplier information: DMT Environmental technologies.

Investment costs, EUR per 1,000 m03/h 7,500 – 15,000

Operational costs Unknown Personnel, hrs/week 2 Help and additives Coolant, depending on the system Energy consumption, kWh/1,000 m0

3/h Energy consumption depending on the type and application of the cooling system

Cost determining parameters Coolant temperature and flow, airflow and temperature.

Benefits Eventual re-covery of remaining heat

MD-MV20090007 -58-

Cryocondensation / Cooled condensation Brief description Description Cryocondensation is based primarily on the condensation of volatiles by cooling. The remaining emission is determined by the selected temperature; the remaining emission decreases at a lower temperature. With a precise control on temperature, the components can be removed at the required rate. The cooling may take place through the use of liquid nitrogen or by using a compression cooling system. Schematic diagram

Applicability Cryogenic condensers are applied with: - process gasses from reactors - gasses from storage tanks (especially during filling) - small gas streams with high VOC-concentrations - pharmaceutical industry - chemical industry - (hazardous) waste-treatment industry - transport of chemicals Components Removed components



3

Validation number

Acetone - < 150 3 Dichloromethane - < 20 3 MEK - < 150 3 Methanol - < 150 3 Toluene - < 100 3 VOC > 99 < 150 3

1 Depending on the specific configuration and operational conditions. Values are based on half-hour averages.

Gas flow in

Clean gas

Liquidnitrogen Heat exchange

Cryocondensation

Separator

Atmosphere orreuse

Secondary cooling system

MD-MV20090007 -59-


3/h Maximum < 5,000; standard about < 250 Temperature, ºC < 80 Pressure 20 mbar – 6 bar Pressure, mbar A few dozen Fluid level Dry gas stream; the forming of ice with the condensation

may not occur, eventually by de-humidifying Ingoing concentration, g/m0

3

Acetone MEK Methanol Toluene VOC

Up to 1,000

Extensive description Variants Direct use of nitrogen: there is the possibility to bring liquid nitrogen directly into the gas stream. The solvents will then freeze in the air and produce solvent snow. This snow is then removed by filtering. The solvents are later regained by defrosting them. Installation: design and maintenance In order to increase the removal of the solvents a few points of attention must be considered: - A sufficiently long residence time and a turbulent stream in order to cool all the gas; - The condenser temperature has to be low enough and there has to be enough cooling

capacity available; - The amount of air in the organic fraction should be kept to a minimum. This air causes

a higher energy consumption rate and a higher percentage of solvents that cannot be removed (lower efficiency). In order to limit the volume of air, a form of adsorption can be applied where the more concentrated de-sorption stream is processed in the condenser. This causes a severe drop in cooling power and a heightened removal efficiency in the condenser;

- The temperature of the condenser is best kept below the freezing point of the solvent so the damp pressure of the solvent is kept to a minimum;

- Periodically, the solvents have to be removed from the condenser surface; - The effectiveness can be increased by compressing the incoming gas. Nearly any emission value can be achieved, as long as the cooling is strong enough. In practice, it has rarely been lower than -95°C, with an average temperature between -50°C and -80°C. The final dimensioning is based on a careful assessment between the efficiency, the remaining emission and the amount of recoverded VOC on the one hand and the investments and operational costs, including the nitrogen consumption, on the other hand. Most systems are applied on relatively small gas flows (up to 50 m0

3/hour) and for the treatment of batch emissions, for which the system is on stand-by during most of its operational time. Non-stop systems larger than 250 m0

3/h are less common, the largest units in construction have a range of around 500 m0

3/h; for applications larger than 1000 m0

3/h condensation temperatures are limited to -30°C. Systems are usually designed to reach an efficiency of at least 99%. If necessary an adsorption technique (active coal, zeolith) is used afterwards in order to meet the emission limit values. Monitoring The condenser has to be defrosted regularly in case ice forming takes place. This can be done by periodically defrosting or by defrosting depending on the amount of ice on the condenser. The system can be fully automated. The pressure drop has to be checked in order to prevent leaks.

MD-MV20090007 -60-

Environmental pros and cons Specific pros - Compact technology - Recovering of organic solvents if the solvents can be recovered purely; - The required final concentration can be steered by carefully selecting condenser

temperature; - High efficiency in case of high VOC concentrations. Specific cons - Consumption of liquid nitrogen which has to be produced or obtained; - In case of humid gas streams, precautions have to be made in order to minimize ice

forming on the condenser, for example by de-humidifying. Additives - Liquid nitrogen. The consumption of liquid nitrogen can be divided into stand-by

consumption (for keeping the system at the right temperature) and the consumption for the cooling of the (warm) incoming gas stream down to the required temperature plus the energy that is needed to condense the components (equal to damping heat). Consumption rate averages at 10 - 15 kg/kW cooling.

- Compressed air. A minimal use of compressed air for the pneumatic control of the system. This compressed air should be moisture-free.

- Energy consumption. If the cooling takes place by a compression cooling system, the energy consumption rate is around 70 kWh per 1,000 m0

3, The energy consumption is dependent on the cooling system and the damping temperature.

Cross Media Effects - Remaining emissions are primarily determined by the chosen temperature. Also, inert

nitrogen releases, which could be used in a limited number of processes. In order to minimize the unwanted emission of condensed drops, the use of a de-misting unit is inevitable;

- Condensate. The condensate can be reused, processed or disposed of as liquid waste. Financial aspects

Information sources 1.Description of air emission abatement techniques, L26 Infomil/Tauw, March, 2000. 2.Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3.IPPC Reference document on Best Available Techniques in Common Waste Water and

Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4.Dutch Association of Cost Engineers, edition 25, November 2006. 5.US EPA CACT Air Pollution Control Technology Fact Sheet 6.http://www.epa.gov/ttn/catc/dir1/refrigeratedcondensers.pdf7.Linde Gas Benelux, 2008.

Investment costs, EUR/1,000 m03/h 400,000 apart from nitrogen storage and additional techniques

Operational costs - Personnel, days per week 1 Help and additives, kg/kW cooling Nitrogen consumption 10 – 15 Energy consumption, kWh/1,000 m0

3 Nitrogen cooling; negligible Compressor cooling system: 7

Cost-determining parameters Gas flow, cooling capacity, desired cleaning level Benefits Recovering of product (in some cases)

MD-MV20090007 -61-

4.5 Adsorption

MD-MV20090007 -62-

Adsorption (general) Brief description Description Adsorption is a heterogenic reaction where the polluted components are attached to a solid or liquid (adsorbent) that has a tendency to attach itself to a certain chemical, and thus removed from the incoming gas stream, Adsorption is a exothermic process. If the adsorbent is completely saturated, it can be decomposed or regenerated (de-sorption). During the regeneration the removed components return in high concentrations and can then be recovered or disposed of. There are different kinds of adsorbents, with active coal being the one most applied. Different designs are available, with a distinction between systems with integrated continuous regeneration of the adsorbent and systems where the regeneration takes place separate from the adsorption process. The de-sorption can be realized by lowering the pressure, increasing the temperature or a combination of those. For the de-sorption, usually steam, hot air or hot inert gas are used. The gasses that are released in the de-sorption process require further treatment. In case of steam or vacuum regeneration, the solvent can easily be regained from the de-sorption gasses using a condenser. This leaves only a very small stream of non-condensable components that can be sent back to the adsorption circle. It is important to remember that the operational capacity of the adsorbent is smaller in a regenerative installation than it is when using fresh adsorbents. This is because not all active places are returned in the de-sorption cycle. When using active coal, the operational capacity is approximately 50% of the capacity when using fresh active coal. With zeolite, the capacity is about 90% of that when using fresh zeolite and with polymer the capacity varies between 50% and 90%. This should be considered when designing the installation. Specific designs are further explained in the followingfact sheets. The diagram below represents an overview of the different adsorbents, systems and regeneration processes.

Schematic diagram

Active coal

Zeolites

Polymers

Continuousmoving bedadsorption

Fluid bedadsorption

Fixed bedadsorption

These techniques allhave continuousadsorbent regeneration

Regeneration fixed bed

Thermal regeneration

Vacuum regeneration

MD-MV20090007 -63-

Applicability Broad range of application in the following sectors: - degreasing - paint sprayers - solvents extraction - surface treatment of metals, plastics and paper - pharmaceutical sector - foundries - chemical sector - waste incineration plants. Adsorption is less suitable for high concentrations of VOCS because this severely increases the regeneration costs. Components Removed components



3

Validation number

VOC 80 – 95 -

Toluene 90 -

Odour 80 – 95 -

Mercury - < 0.01 – 0.05

H2S 80 – 95 -

Dioxins - <0.1 mg TEQ2/m03

See: specific adsorption techniques

1 Depending on the specific configuration and operational conditions. Values are based on half-hour averages. 2 TEQ = Toxicity equivalent Preconditions Flow, m0

3/h 100 – 100,000 Temperature, ºC Active coal: 15 – 80

Zeolites < 250 Pressure, bar Active coal: 0.1 – 2

Zeolites: atmospheric Fluid level, % Active coal: < 70, as low as possible VOC Maximum of 25% of LEL1 value Dioxins, mg TEQ*/m0

3 10 -100 1 LEL = lower explosion limit. Extensive description Variants The most important designs are: - Fixed bed adsorption. Fixed bed adsorption is applied often, usually with multiple beds

so that one bed can be regenerated while the other remaining beds process the incoming gas. The regeneration is not integrated and is achieved by heating the adsorbent, by creating a vacuum or through pressure-swing adsorption.

- Floating bed adsorption. The incoming gas stream (with a speed between 0.8 and 1.2 m/s) keeps the adsorbent floating. The adsorbent has to be able to withstand wear and tear to prevent it from decaying to dust. The regeneration is continuous because the adsorbent is regenerated by a heat exchanger under the adsorber. The adsorbent is then pneumatically re-routed into the system.

- Continuously moving bed adsorption. The adsorbent is continually entering through the top of the adsorber and thus passes the incoming gas counter-stream. In the bottom of the adsorber the saturated adsorbent is conveyed and regenerated in a moving bed regenerator.

- Pressure swing adsorption (PSA). PSA removes gasses or fumes from a gas stream and continuously regenerates the adsorbent. The process consists of four stages. 1) Pressure is built up from the gas flowing into the adsorber. 2) Adsorption of pure components takes place at a high pressure. 3) Pressure is lowered. 4) Components are released at high pressure or in a vacuum.

MD-MV20090007 -64-

Regeneration - Thermal regeneration: with thermal regeneration the installation consists of 2 or more

adsorbing beds. While one bed is regenerated the other remains active for adsorption. The third bed (if present) is dried and cooled after regeneration and remains on standby. The regeneration can be achieved through steam, hot air, hot nitrogen, built-in heating elements and micro-waves. This happens at temperatures between 80 and 200 °C. After de-sorption, cooling air is blown through the bed so it cools and dries. This is done until the preferred temperature and moisture are achieved. Thermal regeneration is most suitable for VOC.

- In a rotor concentrator the adsorbent is placed in a spinning wheel. The wheel’s largest surface is used to remove the pollution from the incoming gasses. A small part of the rotor is used for de-sorption. In a concentrator the incoming gasses the gasses are concentrated 10 - 15 times, making it possible for the following incinerator to be 10 times smaller in scale and thus consuming only a fraction of the additional fuel required originally. Especially with large incoming gas flows with low solvent concentrations, a rotor concentrator is present to lower the costs of cleaning the incoming gas. It is important that the concentrated gas stream stays below 25% of the lower explosion limit (LEL) as a safety measure.

Installation: design and maintenance See the specific fact sheets. Monitoring Determining the pressure drop is important for determining the clogging of the filter by dust or by pulverization of the granules. The pressure should be evenly divided and constant over the whole bed. Measuring the temperature is necessary in order to prevent fires. By continuously measuring one can determine when a bed is saturated and has to start regeneration. This causes the beds and the de-sorption to be fully optimized leading to a higher energy efficiency. Environmental pros and cons Specific pros - high efficiency for the removal and regaining of VOC - simple and robust technology - high saturation value of the adsorbent - easy installation and maintenance. Specific cons - dust particles in the incoming gas stream may cause complications - mixtures may cause a premature bursting of the adsorption bed - not suitable for humid incoming gas streams - fire risk. Additives See the specific fact sheets for active coal and polymers. Cross Media Effects When no regeneration takes place, the adsorbent should be treated as waste and incinerated (unless it contains mercury). In case of regeneration using steam, waste water is released with relatively high concentrations of waste materials. Financial aspects See the specific fact sheets. Information sources 1. Description of air emission abatement techniques, L26, Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Fact Sheet http://www.epa.gov/ttn/catc/dir1/fadsorb.pdf

MD-MV20090007 -65-

Adsorption of active coal / Active coal filtering / Coal filter Brief description Description Active coal is a micro porous inert carbon matrix with a very large intern surface (700 to 1,500 m²/g) making it ideal for adsorption. The gas stream is lead through the active coal, where the components that are to be removed are combined until the active coal is saturated. After reaching the saturation level of the active coal, the coal is replaced or regenerated. When replaced, the loaded active coal is often taken back by the manufacturer that treats it as hazourdous waste or regenerates it. When the company regenerates the coal themselves it is known as regenerative adsorption. Detailed information concerning adsorption can be found in the fact sheet ‘Adsorption (general)’. Schematic diagram

Applicability Active coal has a very broad range of application including the following sectors: - foundries - printing works (VOC) - waste incinceration (dioxins, heavy metals like mercury and other remaining emissions) - steel industry, cement industry, coal-fired power plants - landfills and solvent recuperation (including synthesis gasses, hydrogen, natural gas,

carbon dioxide) - food industry and stimulant industry - pharmaceutical industry - (petro)chemical industry.

Active coal adsorption

Clean gas

Gas flow in

Heatexchanger

Combustionchamber

Air

Desorption

Active coal

Burner

MD-MV20090007 -66-




3Validatiekengetal

VOC 80 – 95 5 – 100 3 Odour 80 – 95 - 3 Mercury > 983 < 0.05 3 H2S 80 – 95 - 3 Dioxines > 98 <0.1 ng TEQ2/m0

3 3Toluene 90 - 3

1 Depending on the specific configuration, operational conditions and reagents. Values are based on half-hour averages. 2 TEQ = Toxicity equivalent 3 With a fixed bed filter removal efficiencies up to 99,5% are possible. When cleaning waste gas, powder coal is often used making efficiencies up to 98% possible. The effectiveness is dependent on the type of pollution, the type of active coal used and the incoming gas temperature and humidity. With a proper functioning installation, one can expect an efficiency of 95 - 99% with incoming concentrations of 500 - 2,000 ppm. When functioning properly, concentrations of 400 - 2,000 ppm can be decreased to below 50 ppm. Preconditions Flow, m0

3/h 100 – 1,000,000 Temperature, ºC 15 – 80, ideally about 20 Pressure, bar 1 – 20 Pressure drop, mbar About 10 Fluid level, % < 70; minimal precondition is no condensation. At humidity levels

above 70%, the efficiency will decrease because of the water taking up the active spaces in the carbon.

Dust, mg/m03 Dust levels low enough to prevent the forming of obstructions in

the bed. Basically, the air has to be dust-free. A maximum value 3³ is essential.

Ingoing concentration:

VOC, mg/m03 10 - 50,000

Odour, ouE/m3 5,000 - 100,000 Mercury, mg/m0

3 1 - 10 Dioxins, ng TEQ/m0

3 10 - 100 H2S, ppm Maximum of 1,000

Extensive description Variants There are many different designs of the active coal bed: - filled cartridges - loose sheet-ironed coal in a packed bed - injection of powdered coal combined with a fabric filter - prepacked filtering cartridges that have to be periodically replaced in the filtering

installation (for systems with that are not fully loaded) - Impregnated active coal. For specific applications and to increase the removal efficiency

the active coal is chemically treated or impregnated. Impregnated active coal adsorbs and holds the specific components long enough for the chemical to react with the pollution (chemi-sorption). Impregnated active coal is specifically designed for the removal of chemical components that are hard to adsorb with regular active coal. Potential applications include: • Active coal impregnated with oxydators, like KMnO4, for the removal of odour. • Active coal impregnated with sulfur compounds in order to better remove heavy

metals such as Hg (mercury) by forming of sulfides. • Impregnation with potassium iodide in order to increase the adsorbing capacity for

H2S, with H2S being oxidized into SO2 which can be removed by rinsing the active coal.

• Impregnation with an acid such as sulfur and phosphorus in order to remove basic components such as NH3.

MD-MV20090007 -67-

• Impregnation with base (for example NaOH), to remove acid components such as H2S.

- Sorbalite (active coal + lime): this mixture is used for the cleaning of the gas streams of incinerators. This way one products can tackle both problems of SOx and dioxins.

- Active coal is also used as an additional technique to prevent emissions of dioxins and furans. This is applied in the waste incinerators where it is referred to as a police-filter.

Installation: design and maintenance In practice, adsorption often takes place in a bed of active coal. In the bed, an adsorption zone begins to form that moves away from the air intake and towards the exit as the bed gets more saturated. The air enters the saturation zone with a 100% ingoing concentration and leaves the zone with the lowest possible fume pressure, balanced with the active coal. All adsorption processes are exothermal so adsorbing heat releases to the bed. Also, the active coal or the metals on or in the active coal can cause a catalytic oxidation of the VOC in the bed. This might cause strong local heating and even self-ignition of the bed that (partially) decomposes the bed. Self-ignition can be prevented by humidifying the air and preventing any ingoing concentrations > 50 mg/m0

3. In this case one must also beware that the efficiency of the active coal does not drastically decrease. In general the saturation level is expressed in grams of adsorbed dust per kilogram of active coal. There is a direct relation between the concentration of polluted chemicals and the capacity of the active coal. In general an adsorption capacity of 20 - 25 g solvent (carbon) per 100 g active coal can be adsorbed when the adsorption is effectively functioning. If the component is not easily adsorbed, the temperature rises and the air humidity increases, the capacity will decrease. This general capacity rate does not apply for impregnated active coal where the process includes chemi-sorption (see variants). The life-span of a filter can be calculated by some suppliers when inquired. Monitoring The efficiency can be determined by measuring the VOC concentrations before and after the filter (using a flame-ionization detector), odour emission can be determined using olfactory measurement. Determining the pressure drop is essential in preventing clogging of the filter by dust. The pressure should be evenly divided across the bed. Temperature measurement is necessary to prevent fire. Environmental pros and cons Specific pros - simple and robust technology - high saturation level of the adsorbent - suitable for discontinuous processes - easy maintenance - easy positioning Specific cons - dust can cause obstructions - not suitable for very high VOC concentrations < 50 mg/m0

3

- mixtures of components may cause a fast bleeding of the bed - not suitable for wet gasses (not as critical with impregnated active coal) - risk of self-igniting the bed (ketons, turpentines) - risk of polymerization of unsaturated VOC on the active coal (exothermal and causes

clogging) Additives Active coal, when saturated, should be replaced or regenerated. The active coal consumption depends on: - gas flow - component concentrations; with higher concentrations, more coal is used. However the

specific load increases, in other words one needs less active coal to remove a specific quantity of the component.

- type of component - gas temperature: a higher temperature means a greater consumption - gas fluid level: a higher fluid level means a greater consumption - higher pressure decreases the volume and thus the consumption

MD-MV20090007 -68-

Cross Media Effects The used active coal has to be regenerated of disposed of (incinerated). In most cases the used active coal can be returned to the supplier. In most cases this is also the most economical solution. If regeneration takes place locally the life span of the coal is increased and the amount of waste limited. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Fact Sheet http://www.epa.gov/ttn/catc/dir1/fadsorb.pdf6. Supplier information: Norit BV, 2008

Investment costs, EUR/1,000 m03/h 10,000 – 50,000

Operational costs Low, except for the purchase of active coal Personnel A few days a year, depending on the specific

design Help and additives, EUR/ton 800 to 1,700 non-impregnated active coal incl.

collection of saturated coal. 2,250 – 3,300 non-impregnated active coal incl. collection and processing of saturated coal. 4,000 – 6,000 impregnated active coal incl. collection of saturated coal.

Energy consumption, kWh/1,000 m03/h Low

Electricity costs, EUR/1,000 m03/h None

Cost determining parameters Concentration and flow of gas stream, lifespan of the filter (purchase of active coal)

Benefits Potential recovery in regeneration stage

MD-MV20090007 -69-

Zeolite filter (adsorption) / Zeolite filter / Hefite filter Brief description Description Zeolite is an aluminium silicate, which appears in nature but can also be produced synthetically..Zeolites are a good adsorbent for polar chemicals. When the aluminium is retracted from the zeolite it becomes hydrophobic, making it possible to adsorb a-polar chemicals. Zeolites can be applied in packed beds or in an injection/fabric filter system, just like active coal. The zeolite has a constant adsorption capacity and can be regenerated after use. Schematic diagram

Applicability Zeolite is primarily applied for the concentrating of effluent gasses in spraying cabins, varnish production etc. The concentrated gas can be treated more effectively than through, for example, incineration or condensation. Components Removed components

Removal efficiency1,% Remaining emission, mg/m0

3

Validation number

VOC Solvents NH3

Odour

99 --80 – 95

----

1--1

1 Depending on the specific configuration and operational conditions. The performance depends on: the type of zeolite, the type of VOC, the gasses’ temperature and humidity levels.

Gas flow in

Clean gas

Zeoliteadsorption

Combustionchamber

Air

Desorptionsystem

Heat exchange

MD-MV20090007 -70-


3/h < 100,000 Temperature, °C < 250 Pressure Atmospheric Pressure drop, mbar - Fluid level - Dust - Ingoing concentration < 25% LEL (lower explosion limit of gas)

Extensive description Variants - Zeolite combined with active coal or polymers: active coal or polymers might be used

to remove high concentrations of pollution, after which zeolites might be used as last cleaning phase. This can be achieved by using multiple bed, or by mixing the adsorbents in one bed.

- Amalgator: the amalgator is dedicated to removing Hg and dioxins. The principle is based on adsorption in a special adsorption material based on vanadium oxide. The removal efficiency is 99.8% for Hg and 99% for dioxins. In order to prevent dust clogging, a dust filter has to be used as pretreatment when the gas stream contains a lot of dust. The amalgator is applied in crematoria and wood furnaces, among others. A part of the amalgator is a regeneration system. The system makes continuous regeneration possible as well as the recovery of mercury as a fluid. When regenerating, about 10% of the catalyst is lost (with active coal this is about 20%). Currently (2008) there are about 35 amalgators in service. The costs are about five times higher than with active coal, however the lifespan is also five times as long.

Installation: design and maintenance - Material of choice: steel (casing), fabric material - Basis for dimensioning: flow, components that are to be removed, pilot test is preferred - Maintenance: easy, however the zeolite is sensitive to clogging Monitoring The efficiency of the system can be determined by monitoring the concentrations before and after passing the zeolite. Volatile Organic Compounds (VOC) can be measured as total carbon by a flame-ionization detector. A qualitative emission analysis can be made by analyzing with GC/MS. Environmental pros and cons Specific pros - efficient VOC removal - very suitable for low concentrations of VOC - simple and robust technology - suitable for discontinuous processes - easy positioning and maintenance Specific cons - dust may cause clogging - mixture of components may cause fast bleeding of the bed/filter - risk of fires in the bed (ketons, turpentines, etc.) Additives The zeolite only has to be replaced once in a while when applied in a regenerating system. Generally the lifespan guarantee is about five years. Because of the high costs zeolites are not commonly applied for a single use. Depending on the system used steam, inert gas, coolant or heat is required. Cross Media Effects Sporadically, used up zeolite has to be disposed of. In case of steam regeneration, poluted waste water is produced (4-6 m0

3/ton regenerated zeolite).

MD-MV20090007 -71-

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. Zeolite a versatile air pollutant adsorber, EPA, 456/F-98-00, July 1998. 4. Amalgator, Vermeulen Product Engineering, Deventer 2008.

Investment costs Greatly varying, depending on application and design Operational costs, EUR/ton VOC 1,000 - 3,000 Personnel - Help and additives, EUR/kg Hydrophobic zeolite: 20 - 100 Energy consumption, kWh/1,000 m0

3/h -

Cost-determining parameters Flow, filtering material, fabric load, odour load Benefits none

MD-MV20090007 -72-

Polymer adsorption Brief description Description When adsorbing with polymers, the adsorbent used is a polymer in the form of small plastic balls. The polymer is about twenty times as expensive as the active coal. For this reason, polymers are only used in regenerating applications. When producing polymers, pores of different sizes appear. The polymer’s smallest pores however, are still bigger than the active coal’s micro pores. Polymers have a low selectiveness towards VOC adsorption. Every type of polymer does have a specific type of VOC which it adsorbs better. Polymers also have a high adsorption capacity. The polymer is used in a fixed bed to remove the VOC. The saturation and evolution of the adsorption zone is the same as for active coal (see Fact Sheet Adsorption active coal). Polymers have a linear adsorption-isotherm. This means their adsorption capacity increases corresponding to the (partial) pressure of the VOC in the gasses. The higher the pressure of the incoming gasses, the higher the concentration in the incoming gasses, the more VOC can be adsorbed per kg of polymer. Detailed information on adsorption can be found Fact Sheet Adsorption (general). Schematic diagram

Applicability Is applied in the wood-processing industry, for example. Components

Removed components


Remaining emission,ppm

Validation number

VOC Formaldehyde

95 – 98 unknown

10 – 200 < 1

11

1 Depending on the specific configuration and operational conditions. Values are based on half-hour averages.

Combustionchamber

Gas flow in

Clean gas

Polymer adsorption

Air

Desorptionsystem

Heat exchange

MD-MV20090007 -73-

Preconditions Flow - Temperature Low temperature Pressure - Fluid level Less critical than with active coal Dust Low concentration to prevent obstruction Ingoing concentration: VOC, ppm

500 – 2,000

When regenerating the temperature has to be above the boiling point of the VOC but also below the melting point of the polymer. The concentration of VOC can be maximally 25% of the lower explosion limit (LEL). Extensive description Variants Polymers can be used in combination with active coal and zeolite. This can be done in series with the polymers in the first stage separating the high concentrations and the zeolites in the second stage separating the lower concentrations, or it can be done it a mixed bed. Installation: design and maintenance No information available. Monitoring The efficiency of the system can be determined by monitoring the concentrations before and after the filter. Volatile organic compounds (VOC) can be measured as total carbon by a flame-ionization detector. A qualitative emission analysis can be made by analyzing samples using GC/MS. Environmental pros and cons Specific pros - Simple and robust technology - Easy de-sorption of the VOC - High adsorption capacity - No tendency towards catalytic reactions that cause self-ignition - Long lifespan - Not sensitive to fluid/humidity - Suitable for discontinuous processes - Easy maintenance - Easy positioning Specific cons - Dust may cause clogging - Mixtures of components may cause fast bleeding of the bed - High initial costs Additives Periodical replacement of the polymer is only sporadically needed when applied in a regenerating system. Cross Media Effects Replaced polymer has to be disposed of as (hazardous) waste.

MD-MV20090007 -74-

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. US EPA CACT Air Pollution Control Technology Fact Sheet http://www.epa.gov/ttn/catc/dir1/fadsorb.pdf

Investment costs Operational costs Personnel

Little information available

Help and additives, EUR/kg 20 - 100 (replaced polymer) Energy consumption, kWh/1,000 m0

3/h Minimal Cost-determining parameters - Benefits -

MD-MV20090007 -75-

Dry lime injection / dry lime-sorption / Fixed bed lime-sorption / Cascade adsorption Brief description Description Dry lime injection is applied in combination with a filtering technique, for example an electrostatic precipitator or a fabric filter. Lime is injected into the incoming gas or the filter in powder form. At high temperatures the gaseous components attach themselves to the lime. The removal of the components takes place in the reactor and in the following dust-separator. The removed (partially) polluted dust is disposed of. The load can be increased by reusing a part of the loaded dust (recirculation). When using a fabric filter for the removal of the reaction product, the contact between the lime and the gaseous pollution is better than when using an electrostatic precipitator. For the mechanics of dust-separators, we refer to the specific fact sheets. Due to the small contact surface, the necessary excess of chemicals is much bigger than when using a semi-dry cleaning method. Dust emissions can be removed simultaneously with the dry reaction products and the excessive chemicals. The used chemicals are partially re-circulated with the removed pollution. Even so, the chemical use and the quantity of removed dust are considerably higher than when using semi-dry cleaning. Schematic diagram

Dry Calcium oxide injection

Calcium oxidesupply

Clean gas

Gas flow in

Dust filter

Discharge ofrest materials

MD-MV20090007 -76-

Applicability Broad range of application in the following sectors: - Glass industry - Waste incineration - Ceramic industry - Chemical industry. Components

Removed components

Removal efficiency1, %(at a certain temperature)


3

Validation number

Electrostatic precipitator Fabric filter (400ºC) (200 - 280ºC) (130 - 240ºC)

SO2 50 10 10 – 70 (SOx) - 2HCl 70 35 80 < 10 1 HF 95 95 95 < 1 1

1 Depending on the specific configuration, operational conditions and reagents. Values are based on half-hour averages.


3/h 10,000 – 300,000 Temperature See table above Pressure Pressure drop, mbar Fluid level

See fabric filter

Ingoing concentration: SOx

HCl HF

wide range wide range wide range

Extensive description Variants - Cascade adsorption / bed adsorption: In this process the adsorbent is not injected into

the gas stream but the gas stream is lead through a fixed adsorption bed. The reaction of the adsorbent (mostly lime) with the pollutants takes place in a space where the adsorbents drops because of gravity and where the waste gasses are lead through in a counter stream or cross stream fashion. In order to ensure that the reaction time is sufficient and the contact surface large enough, obstacles have been placed in these spaces that decrease the dropping speed of the adsorbents and ensure an efficient circulation and division of the waste gasses in the installation. The reacted calcium carbonate is collected in the bottom of the installation.

- Sorbalite: In this process a mixture of lime and active coal is injected. This technique offers the advantage of not only removing the acid components, but having the active coal adsorbing a large portion of the PCDF’s and PCDD’s. This technique however may result in large quantities of polluted dust.

Installation: design and maintenance The reagents is injected as a powder, with a small average particle diameter being beneficial for a better removal. Smaller particles however, are harder to remove, requiring a high investment in the dust removal technique. Because of the transport of the solid matter the particle size will decrease because of the internal collisions and friction. This should be considered when applying recirculating systems. When injecting into the incoming gasses, speeds high enough prevent collapse of the injected reagents in the incoming gas channel should be ensured. The degree of cleaning can be increased injecting the reagent as suspension, vaporising the liquid completely (also see: semi-dry lime injection).

MD-MV20090007 -77-

Monitoring The performance is monitored by measuring the remaining concentrations and the dust removal efficiency. Temperature and pressure drop over the filter should be measured regularly (see the fact sheet on fabric filters). Environmental pros and cons Specific pros - No additional parts need to be installed, because a dust removal installation is mostly

already installed. - High efficiency rates can be achieved with a good reactor design. - No waste water Specific cons - Excessive quantity of lime is required; remaining emissions also contain excessive lime - Large quantity of remaining emission to be conveyed - The dosing of lime may cause problems concerning obstructions - Commonly a low efficiency rate Additives The required quantity of lime is three times the theoretically required amount. Different types of reagents are available: slaked, non-slaked and with an extra large specific surface. It is also possible to have other chemicals added (like active coal), making it possible to remove other components from the gas streams. (Also see: adsorption systems) Cross Media Effects Remaining emission: plaster, calcium mixture Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Fact Sheet http://www.epa.gov/ttn/catc/dir1/ffdg.pdf

Investment costs Very dependent on the installed dust removal system

Operational costs - Personnel, hours per week About 2 Help and additives, EUR/ton 100 – 160 (reagents) Energy consumption, kWh/1,000 m0

3/h Dependent dust removal system Electricity costs, EUR/1,000 m0

3/h Dependent dust removal system Cost-determining parameters flow, pressure drop, SO2-vracht Benefits none

MD-MV20090007 -78-

Semi-dry lime injection / Spray-dry adsorption / Semi-dry lime adsorption / Semi-wet lime sorption Brief description Description Semi-dry lime injection is applied in combination with a filtering technique. With semi-dry lime injection the adsorbent (Ca(OH)2, CaCO3 (lime)) is sprayed as a suspension (lime milk) into a reaction chamber which causes the liquid to vaporize during the reaction of the calcium and the acid components such as HCl, HF en SO2. This way a dry end product is created with the pollution in a solid form, which can be removed using, for example, a fabric filter. Schematic diagram

Applicability Broad range of application for the removal of acid in components in incineration processes in: - Waste incinerators - Production of anodes - Power plants

Gas flow in

Clean gas

Make up ofcalcium oxideliquid

Supply Calcium oxide

Semi dry Calcium oxide adsorption

Discharge ofrest materials

filter

Pump

MD-MV20090007 -79-



Remaining emission,mg/m0

3Validation number

SOx 85 – 90 < 40 1

HCl > 90 < 10 3

HF > 85 < 1 3 1 Depending on the specific configuration, operational conditions and reagents. Values are based on half-hour averages. Preconditions Flow, m0

3/h tot 1,000,000 Temperature, ºC < 200

> 280 Pressure - Pressure, mbar About 25 Ingoing concentration: SOx

HCl HF

Wide range of application

Extensive description Variants - Dry lime injection; see corresponding fact sheet - Wet lime injection; SO2 is removed from the incoming gas by direct contact with a

watery suspension containing powdered lime. This gas is then additionally cleaned by a demister.

Installation: design and maintenance Regular inspection of the system is required in order to prevent clogging of the piping and the moving parts and to ensure the performance of a following fabric filter. Monitoring The efficiency of the semi-dry lime injection system can be determined by measuring the concentration of acid components after cleaning. Temperature, pressure drop and fluid/gas ratio are measured when passing a following filter. For details we refer to the NeR paragraph 3.7 and Annex 4.7. Environmental pros and cons Specific pros - Better perfomance than dry lime injection - Relatively easy installation - Cheaper than wet gas scrubbing - No waste water Specific cons - If a fabric filter is placed serially after, fluid may eventually cause problems - Solid waste with excessive lime Additives - Adsorbents (lime). As an adsorbent, slaked calcium or limestone can be used

depending on the application - Water Cross Media Effects Solid waste when the removed product cannot be recovered. Depending on the type of process, pollution may occur in the waste material that is to be disposed of. This could be compounds that were not decomposed like dioxins and heavy metals. When sodium carbonate of hydrogen carbonate are used as adsorbent, an effect on NOx-emissions is expected. The efficiency is dependent on the ratio of SO2/NOx. The optimal performance is at an operational temperature of 120 to 160 ºC.

MD-MV20090007 -80-

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC BREF Waste Water and Waste Gas Treatment 4. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008.

Investment costs, EUR/1,000 m0

3/h 11,000

Operational costs, EUR/jaar 20,000 + (400 x flow/1,000) + adsorbent costs Personnel, days per week 1 Help and additives, EUR/ton Lime: (CaCO3: about 60)

Water: 0.03 – 0.04 L/m03

Energy consumption, kWh/1,000 m0

3/h 1 (depending on the dust removal system)

Cost-determining parameters Dust removal systems Benefits -

MD-MV20090007 -81-

4.6 Absorption

MD-MV20090007 -82-

Gas scrubber (general) / Scrubber / Absorber / Air scrubber Brief description Description A gas scrubber is an air cleaning installation, creating an intensive contact between the incoming gas stream and a liquid, often water (or watery solution), with the aim to transfer certain gaseous components from the gas to the fluid. Gas scrubbers can be applied as an emission abatement technique for many different gaseous emissions. Gas scrubbing is a form of absorption. Basically, the gas scrubber consists of three parts; an absorption section for component exchange on a moistened packing, a demister and a recirculation tank. The cleaning rate of gas scrubbers is dependent on the residence time of the gas in the absorption section, the type of packing used, the gas-liquid ratio (L/G), the refreshing rate, the temperature of the water and the adding of chemicals (see acid and alkalic scrubbers). Gravity and centrifugal force play a more important role in the removal of particles with dust scrubbers than with gas scrubbers (see corresponding fact sheet). The addition of chemicals is more typical of gas scrubbers. Schematic diagram

Applicability The technique is most commonly used for removal of compounds that are easily dissolvable in water such as alcohol and acetone. There are also systems using organic scrubbing fluids. Recovering of raw materials is sometimes possible using this technique. The technique can sometimes also be used for the treatment of odour. Wide range of application including the following sectors: - Chemical industry - Surface treatment - Storage and handling of chemicals - Pharmaceutical industry - Waste incinerators - Intensive lifestock farming - Primary aluminium industry

Scrubber liquid

ChemicalsGas flow in

Clean gas

Gas scrubber

Supply of scrubberliquid

Removal ofdroplets

Discharge ofscrubber liquid

Pump

MD-MV20090007 -83-

Components Removed components Removal

efficiency1, %Remaining emission, mg/m0

3

Validation number

Alcohols Acids like HCl, HF Chromatic acid Odour Ammonia, Amines Inorganic materials VOC SO2

30 - 99 99 99

60 - 85 > 99 95-99 50-99 95-98

>100 <10 <10

----

< 10

333----1



3/h 50 – 500,000 Temperature, ºC 5 – 65 Pressure Atmospheric Fluid level No restrictions Dust, mg/m0

3 <10; for a good performance low dust concentrations are required. Scrubbers that are designed for removing dust can work with higher dust concentrations.

Ingoing concentration, mg/ m03:

Alcohols Acids like HCl, HF

200 – 5,000 50 – 50,000

Extensive description Variants Upstream, cross stream and counter stream scrubbers. Scrubbers with packing material or dishes, and scrubbers without built-in packing material, such as venturi scrubbers, jet scrubbers and spraying towers. Installation: design and maintenance - An optimal designed scrubbing system with low emissions requires a high reliability, a

full automation and a good level of maintenance. - Content: 1 - 2 (m0

3/1,000 m03/h)

- The most important design parameters are gas flow, operational temperature, maximum temperature and gas composition.

Monitoring In order to measure the efficiency of the scrubber, it is necessary to measure the ingoing and outgoing gas concentration. This can be determined with infrared or phys chemically depending on the component. For details we refer to the NeR paragraph 3.7 and Annex 4.7. Routine measurements should concern the pressure drop, make-up water flow, recycling stream, the reagent stream and in some cases the pH values, temperature and conductibility of the outgoing water stream. Environmental pros and cons Specific pros - Wide range of application - Very high removal efficiency is possible - Compact installation and easy maintenance - Relatively simple technology - May serve as a cooler for hot gas streams (quencher). Specific cons - Waste water has to be treated - Water and reagent consumption - When dust is simultaneously being removed, extra drainage is necessary; more

important, other designs are often applied for the removal of dust - Sensitive to corrosion and frost

MD-MV20090007 -84-

- A plume may be visible (but cooling reduces the rising of the plume which negatively effects the spreading of odour)

- Depending on the positioning a supporting construction may be necessary. - Packing material is sensitive to dust clogging (> 10 mg/ m0

3) and fat. - For odour problems, piloting tests are required in order to see if the goal is achievable - Recirculation of scrubbing fluid may cause an increase in odour emission. Additives - Water. Vaporization losses are primarily determined by the difference in air humidity of

the ingoing and outgoing air stream and the settings of the drainage (refresh rate) of the scrubbing water. Vaporization losses are primarily determined by the temperature and humidity of the ingoing gas stream. The outgoing gas stream is mostly completely saturated with water vapor.

- Reacting agents: acids, bases, oxidants, bleach, peroxide, among others. This is dependent on the component in the untreated gas stream.

Cross Media Effects Waste water: in most cases the drainage water has to be cleansed. In some cases it can be evaporated and processed for the recovering of products. Acid scrubbing water is partially drained in order to control the pH. The scrubbing water is complemented with water. The drained scrubbing water has to be treated before it is discharged.

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Gas Treatment / Management systems in the Chemical Sector, February 2003. 4. IPPC Reference document on Best Available Techniques 5. http://www.epa.gov/ttn/catc/dir1/fventuri.pdf6. http://www.frtr.gov/matrix2/section4/4-60.html7. Dutch Association of Cost Engineers, edition 25, November 2006 8. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008. 9. Supplier information DMT Environmental Technology, KWB and Askove.

Investment costs, EUR/1,000 m03/h

Operational costs, hours per week Personnel, EUR/year Help and additives Energy consumption, kWh/1,000 m0

3

Cost-determining parameters Benefits

2,500 – 25,000, depending on the design About 4 About 5,000 - 8,000 Strongly dependent on the application 0.2 – 0.5 Flow and eventual remaining emission treatment (waste water) Potential recovering of raw materials

MD-MV20090007 -85-

Acid gas scrubber / Acid scrubber Brief description Description For the general mechanics of the gas scrubber we refer to the fact sheet “Scrubbers (general)”. An acid scrubber works at low pH values, resulting in better removal of alkaline components. As a result of this reaction, salts are formed. A part of the scrubbing water is drained, based on the density and/or conductivity. The drained water may contain up to 15% salts and is discharged after cleaning or evaporated for reuse. The dosing of the acid is done by means of a pH regulation. In most cases the pH is kept between pH 3 and 6. Sulphuric acid (H2SO4) is often the acid of choice for economical reasons. For specific applications, for example the removal of NH3, nitric acid (HNO3) is used. This way, ammonium nitrate is formed which can be used as fertiliser. Because of their alkaline nature, amines and esters can also be removed in an acid scrubber. Schematic diagram

Applicability The acid scrubber is most commonly applied in the following sectors: - Manure processing (ammonia) - Composting (ammonia) - Waste processing facilities (ammonia, amines) - Fertilizer production (ammonia) - Pharmaceutical industry (esters) - Chemical industry (esters) - Foundries (amines) - Production of fish feed (amines) It is most commonly applied for alkaline components in the polluted gas.

Scrubberliquid

Acid

Supply of scrubberliquid

Gas flow in

Acid scrubber

Cleaned gas

Demister

discharge ofscrubber liquid

MD-MV20090007 -86-



3

Validation number

NH3 and amines Esters Ethylene oxide

99 80 99

< 1--

331



3/h 50 – 500,000 Temperature, ºC 5 – 80 Pressure Atmospheric Pressure drop, mbar 4 - 8 Fluid level No restrictions Ingoing concentration, mg/m0

3

Dust Ammonia Amines Esters

< 10 200 – 1,000 10 – 1,000 > 100

Extensive description Variants Upstream, cross stream and counter stream scrubbers. Also see scrubbing in general. Installation: design and maintenance - When designing the acid scrubber, synthetic material is used as the primary

construction material. - Content: 0.5 - 1 (m0

3/1,000 m03/h)

- The most important design parameters are flow, maximum temperature and the composition of the gas that has to be cleaned

Monitoring In order to check the efficiency of the scrubber it is necessary to measure the ingoing and outgoing gas concentration. The concentration can be measured with UV, IR or phys chemically, depending on the component. For details we refer to the NeR paragraph 3.7 and Annex 4.7. Routine measurements should apply to the pressure drop, make-up water stream, recycling stream, reagent stream, pH values, temperature and conductivity of the outgoing water stream. Environmental pros and cons Specific pros - Very high removal efficiencies - Compact installation - Can be constructed in modules. Specific cons - Waste water has to be processed - Consumption of reagents. Additives Make-up water and reagents such as sulphuric acid, hydrochloric acid or nitric acid. Cross Media Effects In the most cases the drain water has to be cleaned. In some cases it can be evaporated and processed to recover products. Acid scrubbing water is partially drained in order to regulate the pH value. The scrubbing water is supplemented with water. The drained scrubbing water has to be treated before it is discharged.

MD-MV20090007 -87-

Financial aspects

Information sources 1. Description of air emission abatement techniques, L26, Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003 4. http://www.epa.gov/ttn/catc/dir1/fventuri.pdf5. http://www.frtr.gov/matrix2/section4/4-60.html6. Dutch Association of Cost Engineers, edition 25, November 2006 7. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008 8. Supplier information DMT Environmental Technology


Operational costs Personnel, days per week Help and additives, EUR/ton Energy consumption, kWh/1,000 m0

3/h Cost-determining parameters Benefits

7,500 – 25,000, depending on the scale and design About 0.5 Acids, about 150 0.2 – 1 Flow, reagents and eventual remaining emission processing (waste water) Is possible depending on the application.

MD-MV20090007 -88-

Alkaline gas scrubber Brief description Description For the general mechanics of the gas scrubber, we refer the fact sheet “scrubbers (general)”. An alkaline scrubber removes the acid components better by neutralizing them with an alkaline as scrubbing fluid. In this process salts are formed that can potentially be recovered. The drainage water is treated and discharged in the sewage. The dosing of the base is done by means of pH regulation or a direct measurement in the outgoing gas stream, for example an H2S measurement. The pH value of the alkaline scrubber is often kept between 8.5 and 9.5. The pH value should not be too high because of absorption of CO2 in the water. A pH value of 10 and up will cause the dissolved CO2 to be present in the water as carbonate, causing the alkaline consumption rate to increase dramatically. The calcium carbonate will also deposite on the gaskets, increasing the pressure drop. To avoid this , softened water can be used in an alkaline gas scrubber. Schematic diagram

Applicability The alkaline scrubber is mostly applied with acid components in the incoming gas, in the following sectors: - Chemical industry - Galvanic industry - Storage and handling of chemicals - Waste incinerators - Sludge processing installations, sewage water pumping stations, WWT plants

Gas flow in

Clean gas

Droplet separator

Supply ofscrubber liquid

Alkaline

Scrubber liquid

Alkaline scrubber


MD-MV20090007 -89-



3

Validation number

HCl HF SO2

H2SPhenols

99 99 99 90-95 90

<10 <1 <10 < 10 ppm -

33111

1 Depending on the specific configuration, operational conditions and reagents. Values are based on half-hour averages. Preconditions Flow, m0

3/h 50 – 500,000 Temperature, ºC 5 – 80 Pressure Atmospheric Fluid level No restrictions Ingoing concentration, mg/ m0

3

Dust HCl HF Phenols SO2

H2S

< 10; this number is higher for dust scrubbers (see specific fact sheet) 50 – 20,000 50 – 1,000 < 5,000 100 – 10,000 1,000 – 10,000 ppm

Extensive description Variants Upstream, cross stream and counter stream scrubbers. Also see scrubbing (general). Installation: design and maintenance - In designing the alkaline scrubber, synthetic material is the primary construction

material. - Contents: 1 - 2 (m0

3/1,000 m03/h).

- The most important design parameters are the incoming gas flow, maximum temperature of the untreated gas and the composition of the incoming gas stream.

Monitoring To measure the scrubber’s efficiency it is necessary to measure both the incoming and outgoing gas stream. The concentration can be determined using UV, IR or phys chemical measurement depending on the component. For details we refer to the NeR paragraph 3.7 and Annex 4.7. Routine measurements should apply to the pressure drop, make-up water stream, recycling stream, reagent stream, pH values, temperature and the density and conductivity of the outgoing water stream. Environmental pros and cons Specific pros - Very high removal efficiency - Potential simultaneous removal of dust - Compact installation - Relatively simple technology - Can be built in modules Specific cons - Sewage water has to be treated - Recovery of plaster when removing SO2 is negligible - Use of water and chemicals - When dust is removed simultaneously, extra drainage may be necessary - Plume rising may be visible (is reheating necessary?) - Packing material potentially sensitive to clogging caused by dust (> 10 mg/ m0

3) and fat.

MD-MV20090007 -90-

Additives - Water. The consumption of water is dependent on the ingoing and outgoing

concentrations of gaseous components. Evaporation losses are primarily determined by the temperature and the air humidity of the ingoing gas stream. The outgoing gas stream is in most cases completely saturated with water vapor.

- Reacting agents. Alkaline chemicals like caustic soda. Cross Media Effects Waste water. Scrubbing water is partly drained, to regulate the pH or to prevent the deposition of salts. The drained water in most cases requires treatment before being discharged. In some cases the water can be re-used, for example into plaster in the case of SO2 removal. The scrubbing water is supplemented by water. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. http://www.epa.gov/ttn/catc/dir1/fventuri.pdf5. http://www.frtr.gov/matrix2/section4/4-60.html6. Dutch Association of Cost Engineers, edition 25, November 2006 7. Netherlands emission guidelines for air, NeR paragraph 3.7 and Annex 4.7, 2008 8. Supplier information: Pure Air Solutions, DMT Environmental Technologies, KWB and Askove.


Operational costs Personnel, days per week Help and additives, EUR/ton Energy consumption, kWh/1,000 m0


2,500 – 35,000, Depending on scale and design -About 0,5 Especially base, use of caustic soda (20%), about 200 0.02 – 0.1 Flow, reagents and eventual remaining emission treatment (waste water) Commonly none

MD-MV20090007 -91-

Gas scrubber alkaline-oxidative Brief description Description For the general mechanics of the gas scrubber we refer to the fact sheet “Scrubbing (general)”. Alkaline-oxidative gas scrubbing is mostly applied for odour control. In this process the organic odour components in the alkaline environment are oxidized at pH 7 - 10. Sodium hypochlorite (NaOCL), potassium permanganate (KMnO4) or hydrogen peroxide (H2O2) are used as strong oxidants. In case of potassium permanganate, MnO2 is created which has to be removed from the scrubbing liquid periodically. In case of hypochlorite, chlorides are formed and in case of hydrogen peroxides no byproducts are formed. However, hydrogen is not as strong an oxidant as hypochlorite and permanganate. Especially for odour removal it recommended to test on a smaller scale first to determine the specific removal efficiency, because it can be complex concerning the composition of the odour components. If amines are present in the incoming gasses it is recommended to use acid scrubbing beforehand in order to prevent the forming of chloramines. Schematic diagram

Applicability The alkaline-oxidative scrubber is applied in the following sectors: - food industry - compound feed factories - slaughter houses - flavouring agents production - textile industry

Gas flow in

Clean gas

Droplet separator

Supply anddischarge ofscrubber liquid

Chemicals: alkaline and oxidation

Scrubberliquid

Alkaline-oxidative gas scrubber

MD-MV20090007 -92-

When using NaOCl at low pH, toxic chlorine fumes may be released. That is why, when applying NaOCl, an alkaline scrubber should be placed in series to remove the chlorine fumes. Components

Removed components


Remaining emission

Validation number

Odour 80 – 90 Very specific to the situation

3



3/h 50 – 500,000 Temperature, ºC 5 – 80 Pressure Atmospheric Pressure drop, mbar A dozen Fluid level No restrictions Ingoing concentration, mg/ m0

3

Dust < 10

Extensive description Variants Upstream, cross stream and counter stream scrubbers. Also see scrubbing (general). In case of H2S-scrubbing a two-tower system can be applied: first alkaline scrubbing and then oxidative scrubbing. This leads to higher investment costs, but lower operational costs, because the amount of (expensive) hypochlorite is reduced drastically this way. Installation: design and maintenance - In designing the alkaline scrubber, synthetic material is the construction material

primarily used. - Contents: 1 - 5 (m0

3/1,000 m03/h).

- The removal efficiency is dependent on the oxidizing ability of the components and the residence time in the scrubber. An increase in the residence time requires a larger installation and higher investment costs. Pilot tests are essential in achieving a good design.

Monitoring Odour measurements require a specific approach. For details we refer to the NeR paragraph 3.6 and Annex 4.7. Routine measurements should apply to the pressure drop, supplementary water stream, recycling stream, the reagent stream, pH values, temperature and conductibility of the outgoing water stream. Also see additives (dosing of reagents). Environmental pros and cons Specific pros - Relatively high removal efficiency for aromatic substances Specific cons - Use of strong oxidants requires some safety precautions and special design of the

installation Additives - Water - Base: caustic soda - Oxidants: sodium hypochlorite, potassium permanganate, hydrogen peroxide, and

others. The dosing of the reagents should be automised in order to achieve a constant performance and to minimize the use of reagents. The oxidant is dosed in a slight excess.

MD-MV20090007 -93-

Cross Media Effects Waste water and emissions. In a scrubber with NaOCl, toxic chlorine fumes might be formed at low pH values. When applying a scrubber with NaOCl, it is preferred to have an alkaline scrubber in series to remove to chlorine fumes. Financial aspects

Information Sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003 4. http://www.epa.gov/ttn/catc/dir1/fventuri.pdf5. http://www.frtr.gov/matrix2/section4/4-60.html6. Dutch Association of Cost Engineers, edition 25, November 2006 7. Netherlands emission guidelines for air, NeR paragraph 3.6 and Annex 4.7, 2008 8. Supplier information: Pure Air Solutions, DMT Environmental Technology


Operational costs Personnel, days per week Help and additives Energy consumption, kWh/1,000 m0


10,000 – 35,000, strongly dependent on the design -About 0.5 - 1 Depending on the chemicals applied 0.2 – 1 Flow, reagents and odour components None

MD-MV20090007 -94-

4.7 Biological cleaning

MD-MV20090007 -95-

Biofiltration / Bio-bed / Biological filter / Bio-bed filter / Compost filter Brief description Description A bio-filter consists of a bed packed with biological material, sometimes even two or three beds. The gas stream is lead through the filter bed where the pollution is removed from the waste gas by adsorption to and absorption by the filtering material. The components are then decomposed by micro-organisms. The filter or the incoming gas is (intermittently) moisturized with water to prevent the filter from dehydrating. The bed consists of a carrier containing biological material such as: compost, tree bark, coconut fibers or peat. To decrease the amount of acidification, calcium or dolomite is sometimes added to the packing material. Schematic diagram

Gas flow in

Clean gas

Droplet separator


water

Scrubberliquid

Water discharge

Bio filtration

Scrubber

MD-MV20090007 -96-

Applicability Broad range of application in the following sectors: - WWT plants - Composting facilities (sludge, organic waste, manure) - Aromatic substances and artificial flavoring industry - (Petro)chemical industry - Food industry - Meat and fish processing industry - Intensive lifestock farming Components Removed components



3Validation number

VOC 75 - 95 > 5 2 Odour 70 - 95 < 1,000 ouE/m³ 1 Toluene 80 - 95 > 5 2 Styrene 80 – 90 > 10 2

1 Depending on the specific configuration and operational conditions. Values are based on half-hour averages. For some odour sources (mercaptans, H2S) efficiencies above 75% are possible, for other odour sources the efficiency rate is somewhat lower. Comparative research for odour efficiencies between scrubbers and biofilters show that biofilters reach higher efficiencies.


3/h 100 – 100,000 Temperature, ºC 15 – 38; thermopile 50 - 60 Pressure Atmospheric Pressure drop, mbar 5 – 20 Fluid level, % > 95 Dust Dust-free to prevent clogging Ingoing concentration, mg/ m0

3

VOC 200 – 2,000 Toluene 20 - 100 Styrene 50 - 500 Ammonia 5 – 20 Hydrogen disulfide 5 – 20 Chlorous compounds 5 - 20

At too high concentrations of nitrogenous, sulfurous or chlorous compounds, the forming of respectively nitric acid, sulfuric acid and hydrochloric acid may acidify the filtering material rendering it useless, and thus drastically increasing the replacement frequency of the filtering material. The concrete of the carrier may also be damaged at high concentrations. When applying biofiltration it is important the filtering material has a pH value between 7 and 8 to decompose organic components. At a pH value of 6.5 the decomposition speed decreases. The residence time of the gas in the filter should be at least 30 - 45 seconds in order to properly remove the odour and solvents.

Extensive description Variants Thermophile: a thermophile bed works at higher temperatures (about 50 - 60ºC) than standard (meso-thermic) beds (about 15 - 38 ºC). They are most commonly applied with larger gas streams. Thermophile beds are more sensitive to changes in temperature and if the temperature is above 60 ºC the biological activity in the bed will quickly deteriorate. Good regulation is thus necessary. Sometimes multiple layers are used to obtain different

MD-MV20090007 -97-

bacteria cultures. The biofilter can be open or closed. When open, the biofilter is liable to weather influences. A closed biofilter is more secure from external weather influences and can be controlled and regulated more efficiently. A new development is the applicability of moulds. These can better withstand dehydration, acidification, temporal halting of the filter and high temperatures. Biofilters with moulds have thus far not been applied in any full-scale installations. According to the supplier, synthetic packing is not used commonly anymore. A supplier in Denmark (BBK) supplies biofilters with inorganic packing material that achieve high efficiencies in practice. Benefits include the long lifespan (about 8 years) and the low pressure drop. The filter however, is relatively expensive compared to the classical biofilter. Installation: design and maintenance The typical surface pressure of a biofilter is around 50 – 500 m0

3/m²/h, but it can drop to 5 or rise to 500 m0

3/m²/h. When applying the packing one must take care to evenly spread the filtering material and make sure there are no tight or loose areas. These can cause short-circuit streams causing the air to be treated badly and the effective filtering surface to decrease in size. When the filter dehydrates because of short-circuit streams, the efficiency will decrease even more. Cooling is necessary for applications with hot air flows (>38°C). This can be realized by a mixture of outside air, a (single-pass) water scrubber or a heat exchanger/condenser. The filtering material should be replaced periodically (every 0.5 – 5 years). This is dependent to the type of packing material and the composition of the gasses. Monitoring Although biofilters are static in principle and require little mechanical maintenance, practice shows that regular inspection and monitoring of the efficiency are necessary. The efficiency can be excellent during the first few years, but decrease drastically over a short period of time because of a lack of nutrients, problems with the fluid balance and/or the deteriorating of the filter material. Environmental pros and cons Specific pros - Low investment costs and operational costs - Biological decomposition of the pollution - Simple mechanic - Low amounts of waste water (percolate water) and waste material. Specific cons - Fluctuations of the gas stream conditions have a large impact on the performance - Filtering material has to be replaced periodically - Relatively voluminous - Control of fluid balance is necessary - Dust clogging risk - Poisoning and acidification must be avoided - The bed has to continually be aerated to prevent anaerobe conditions - Limited control (including the pH) - Energy consumption (in cases where cooling of the incoming gas is necessary)

MD-MV20090007 -98-

Additives Filtering material: the composition of the filtering material varies greatly: root wood, tree bark, peat, compost, cocos material and/or mixtures of these. The lifespan is primarily determined by acidification (N, S and Cl), depletion and/or poisoning and pressure drop. Sometimes additional nutrients need to be added if the filtering material degrades too slowly to supply the nutrients needed. Grafting material: depending on the type of component it may be necessary to perform a grafting with specific micro-organisms bred and selected for this application. The grafting is usually once. Water: The air stream should be saturated with softened water and a quantity of percolate water will also be released from the filtering material. Energy: The biofilter itself uses a low amount of energy (< 1 kW/1,000 m0

3/h). The pressure drop the fan has to overcome mainly determines the energy consumption. This pressure drop is around 2.5 mbar for a cocos filter and 15 mbar for a compost filter. Cross Media Effects Percolate water from the biofilter is polluted with decomposition products (nitrate, sulfate, etc.) and organic materials should be discharged into the sewage or, after some treatment, into the surface water. Periodically the filter bed material should be replaced and disposed of (composted, dumped or incinerated). Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Fact Sheet. http://www.epa.gov/ttn/catc/dir1/fbiorect.pdf6. Supplier information: Pure Air Solutions, DMT Environmental Technology. 7. Biofilters and Biotowers for Treating Odours, C. Easter, C. Quigley, P. Burrowes and J. Witherspoon, IWA Conference Barcelona 2008. 8. Efficiency evaluation of gas treatment equipments in terms of oder removal using dynamic olfactometry M. E. Quadros, P. Beli Filho and H. M. Lisboa, IWA Conference Barcelona 2008. 9. Suppliers information: BKK Denmark, information on biofilters with inorganic packing material.


Operational costs - Personnel 1 man-hour per week per filter + 2 man-days per

year Help and additives 5 liters of water per 1,000 m0

3, strongly dependent on the saturation level of the incoming gas < 200 EUR/m3 filtering material

Energy consumption, kWh/1,000 m03/h Low

Cost-determining parameters Flow, concentration, type component en desired efficiency, type of filtering material

Benefits None

MD-MV20090007 -99-

Biotrickling / Lavafilter / BTF / Biodenox Brief description Description A biotrickling filter is a combination of a biofilter and a bio-scrubber. It consists of a packed absorption column that is humidified and supplied with nutrients by discontinuous or continuous circular or singular supply. The idea is that the biomass stays on the packing and is not carried off by the water. After absorption in the thin water film the pollution is decomposed by a layer of micro-organisms growing on the packing (“biofilm’); potential decomposition products are conveyed by the same water phase. Thanks to the mobile water phase the drainage of acidifying decomposition products is easier than with biofilters with a stationary water phase: the degree of acidity of the circulation stream can be (slightly) corrected by dosing caustic solution or supplementary water. The filtering material consists of synthetic foam and packing constructed out of lava or plastic. The surface has to be structured in a way allowing for the biomass to properly attach. Schematic diagram

Biotricklingfilter

Ventilator

Afgas

Pomp

Spuiwaswater

Gereinigd gas

Dragermateriaal+

biomassaPomp

Opslagwaswater

Nutriënten

Applicability Broad range of application in the following sectors;: - WWT plants (H2S) - Intensive lifstock farming (NH3)- Textile industry (CS2 en H2S) - Tobacco industry (odour) - Printer shops, wood processing industry, furniture industry, metal processing industry

(NMVOC) - (Petro)chemical industry - Sludge processing installations, waste processing installations, sewage water pumping

stations

Gas flow in

Clean gas

Nutrients Scrubberwater

Water discharge

Bed materialsand biomass

MD-MV20090007 -100-



3

Validation number

Ammonia 80 – 95 - 2 Odour 70 – 90 - 1 H2S 80 – 99 <1 2 Mercaptans 70 – 90 - 1 VOC 70 – 99 - 1 Carbon disulfide 98 – 99 at ingoing concentration of 100 mg/m0

3

Alcohols such as ethanol, propane

90 - 95 at ingoing concentration of 50 – 5,000 mg/m03

Ethyl acetate 70 – 90 at ingoing concentration of 50 – 5,000 mg/m03

Toluene, xylene 70 - 90 at ingoing concentration of 50 – 5,000 mg/m03

Styrene 80 at ingoing concentration of 100 mg/m03

Monovinyl chloride 99 at ingoing concentration of 100 mg/m03

1 Depending on the specific configuration and operational conditions. Values are based on half-hour averages. Preconditions Flow, m0

3/h 1,000 – 500,000 Temperature, °C 15 – 40 Pressure Atmospheric Pressure drop, mbar 1 – 10 Fluid level No restricting preconditions Dust No restricting preconditions Ingoing concentration: VOC, mg/m0

3 400 – 4,000 NH3, mg/m0

3 100 – 400 Odour, ouE/m3 > 10,000 H2S, mg/m0

3 5 – 1,000 Mercaptan, mg/m0

3 100

Extensive description Variants Biotrickling filters be grafted with active sludge or grafting cultures (see fact sheet Bio-scrubber) Installation: design and maintenance The handling of the biological film layer (biofilm) of the packing is essential: a too high growth can lead to (local) clogging that finally results in preferential streams, causing the size of the exchange surface and thus the performance of the biotrickling filter to decrease. The growth and thickness of the biofilm can be controlled by adjusting the thickness with mechanics (like varying the humidification) or by adjusting the growth of the micro-organisms by varying the degree of acidity and/or the salt content. In biotrickling filters that process high H2S concentrations there is a chance of elementary sulfur forming because of incomplete biological oxidation. This can be recognized by the yellow granular textures and can eventually lead to clogging and preferential currents. Biotrickling filters that process high concentrations of inorganic compounds (NH3 or H2S) usually have micro-organisms that use CO2 from the air as a source of carbon. Given the relatively high concentrations of CO2 in the air, extra precautions should be taken to avoid strong growth of the biofilm. Monitoring The composition of the water should be determined by continuous measurement of pH values, temperature and conductibility. Environmental pros and cons Specific pros - Bio-degradation of the absorbed components - Suited for (medium) concentrations of acid components containing sulfur, chlorine and

nitrogen - pH-control and corrections possible within certain limitations

MD-MV20090007 -101-

- Low pressure drop - Average investment and operational costs - Compact construction and placing - Low energy consumption, and thus limited CO2 emissions - Little use of additives - Better performance and liability than a biofilter. Specific cons - Fluctuations in the composition and concentrations of ingoing air streams have an

influence on the performance. - Toxic and high concentrations of acid components should be avoided. - Less suited for (very) hard to dissolve components - The biomass can obstruct the packing - More complex to construct than a biofilter - Production of waste water stream, depending on the removed components Additives - Nutrients to feed the bacteria - Filtering material: synthetic foam, packing constructed from lava or plastic - Grafting material: depending on the type of component it may prove necessary to

perform grafting with a micro-organism specifically bred and selected for this application. The grafting is usually once .

- Water: supplementary water to compensate for the evaporation and drainage losses - Energy the biotrickling filter itself does not use a lot of energy (< 1 kW/1,000 m0

3/h). It is primarily the pressure drop the fan has to overcome that determines the energy consumption. This pressure drop is about 10 mbar, depending on the gas load of the system and the amount of biological growth.

Cross Media Effects The packing should periodically be replaced / refreshed. The composition of the sludge on the disposed packing is dependent on the concentration and the composition of the incoming gas. The drained water should be discharged. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Dutch Association of Cost Engineers, edition 25, November 2006. 5. US EPA CACT Air Pollution Control Technology Fact Sheet. http://www.epa.gov/ttn/catc/dir1/fbiorect.pdf6. Supplier information: Pure Air Solution, DMT Environmental Technologies.


Operational costs Minimal Personnel, hours/week about 4 (strongly dependent on the situation) Help and additives Minimal Energy consumption, kWh/1,000 m0

3/h < 1, excluding the ventilator Electricity costs, EUR/1,000 m0

3/h Minimal Cost-determining parameters Flow Benefits None

MD-MV20090007 -102-

Biological scrubber (general) / Bioscrubber / Bioscrubber Brief description Description A bioscrubber consists of a gas scrubber and a biological reactor. The components that are to be removed are absorbed from the gas stream inside the gas scrubber. Inside the biological reactor, the absorbed pollutants in the scrubbing water are biologically decomposed. The cleaned scrubbing fluid is re-circulated into the scrubber. Biologically decomposable hydrocarbons are turned into water and CO2. The hydrocarbons that cannot be decomposed remain in the scrubbing water. Components such as H2S and NH3 are turned into sulfates and nitrates respectively. In order to keep the level of salts and non-decomposable VOC low enough the scrubbing must be drained regularly. This can be done on a basis of conductivity or by fixed drainage. The degree of drainage is dependent on the composition of the untreated gas. An hydraulic residence time of the scrubbing water between 20 and 40 days (maximum) gives the greatest results. Schematic diagram

Applicability Wide range of application in the following sectors: - Cigarette industry - WWT plants - Removal of odours arising from enzyme production - Removal of odours arising from aroma production - Rubber industry - Removal of odour and sulfur components from gasses arising from methionine - Removal of odour arising from polymer production - Removal of odour, VOC and nitrogen components in the processing of paint waste - Landfills for hazardous waste - Intensive lifestock farming - Coffee-roasting houses - Slaughterhouses

Gas flow in

Clean gasScrubbingwater

Active sludgebasin

scrubber

Biological scrubber

Settlingbasin

WaterdischargeAir

Pollutedwater

scrubbingwater

MD-MV20090007 -103-



Remaining emission

Validation number

Odour2, ouE/m3

Ammonia, mg/m03

VOC, mg/m03

70 - 80 80 - 95 80 - 90

100 – 150 --

111

1 Depending on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages. 2 Phenols, mercaptans, H2S, acetic acid and acetates contribute to the odour.


3/h - Temperature, °C 15 – 40; optimal temperature 30 – 35°C; Pressure Atmospheric Pressure drop, mbar 2– 5 Fluid level No restricting conditions Dust - Ingoing concentration: VOC, mg/m0

3 100 – 1,000 Silt concentration, g/l 6 – 8 Odour, ouE/m3 > 10,000 Conductibility, µS/cm < 5,000

The following also applies: - The pollutants have to be soluble in water; - The pollutants have to be aerobe biologically decomposable; - The emission has to be constant in time; peak loads can be caught in a lesser extent. Extensive description Variants Can eventually be combined with an existing biological WWT. Installation: design and maintenance The gas scrubber has to be designed in such a way that the gasses’ residence time in the scrubber is around 1 second. Depending on the solubility of the components this may be slighter more or less. The scrubber requires a special open packing and special sprayer nozzles to prevent clogging by the biological sludge. A hydraulic residence time of the scrubbing water between 20 and 40 days gives the best results. Monitoring In order to determine the scrubber’s efficiency it is necessary to measure the ingoing and outgoing odour and/or gas concentrations. For details we refer to NeR paragraph 3.6, 3.7 and Annex 4.7. Routine measurements should apply to the pressure drop, the recycling stream, the pH, the temperature and the conductivity of the outgoing water stream. Environmental pros and cons Specific pros - Biodegradation or natural decomposition of components - High concentrations of sulfur, nitrogen and chlorine components can be removed by the possibility of controlling the pH values - Peak emissions can be controlled better than with a biofilter or biotrickling filter Specific cons - Primarily suited for easily soluble components - Components have be biologically decomposable - Production of sludge that has to be conveyed - The drainage water needs further treatment - Sensitive to changes in flow and process conditions - Biomass may attach to the packing causing clogging or even clinching into the packing Additives - Supplementary water to compromise the evaporation and drainage losses

MD-MV20090007 -104-

- Chemicals like acid or base to guarantee the pH for optimal biological activity - Nutrients for the sludge. Cross Media Effects A bioscrubber creates two waste flows: - drained water loaded with salts and non-biologically-decomposable CZV - drained sludge from the bioreactor, that has to be removed in an environmentally safe manner. One must be careful with the temporal storage of the scrubbing water. Because of anaerobic conditions, odour components may be formed here. These require further treatment. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003 4. Dutch Association of Cost Engineers, edition 25, November 2006 5. Netherlands emission guidelines for air, NeR paragraph 3.6, 3.7 and Annex 4.7, 2008


Personnel, hours/week Help and additives Energy consumption, kWh/1,000 m0

3/h Electricity costs Cost-determining parameters Benefits

6,000 – 20,000 About 4 Relatively low 0.2 – 0.5 -Flow, type and concentration of components None

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Moving bed trickling filter / MBTF Brief description Description The Moving Bed Trickling Filter (MBTF) is a system for the combined, or possibly separate, cleaning of air and water streams. The MBTF primarily consists of a synthetic tank. The tank is filled with 50 to 150 m3 of specially shaped synthetic balls. On and in these grooved balls micro-organisms grow that decompose the incoming pollutants. The untreated water is pumped to the top of the reactor by an adjustable circulation pump and spread over the bed by a rotating spraying arm. The treated water is caught in the buffer/settling chamber, where any potentially present sludge particles can settle. The untreated air is blown into the reactor along with the water by an external ventilator. At the bottom, special sections of the sieve plate ensure a good separation of the air and water, after which the treated air is emitted to the atmosphere. As with any biological cleaning, a part of the incoming pollutants is transformed into biomass. Thus the amount of biomass in the reactor will increase. Without precautions this will lead to clogging in conventional trickling filters. In the MBTF clogging is prevented by pumping some of the bio-balls to the top of the reactor where they will be dumped onto a sieve plate by a cyclone. A large part of the biomass on the balls will be removed by the cyclone and the drop onto the plate. The cleaned balls fall on top of the bed and can participate in the cleaning process again. The separated sludge is periodically disposed. Schematic diagram

Applicability Full scale units in the following sectors: - (Petro)chemical industry - Waste processing - Meat and fish processing industry

Gas flow in

Clean gas

Recycle water

Sludge

Recyclecarriermaterial

Clean water

Waste water

Sludgeseparator

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3Validation number

VOC Odour H2S (sulfur hydrogen) Mercaptans Styrene

80 – > 95% > 90% > 98% > 95% > 90%

-> 2,500 ouE/ m0

3

---

31111

1 Depending on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages.

Preconditions Air flow, m0

3/h Waste water flow, m0

3/h 5,000 – 40,000 < 200

Temperature, ºC 10 – 45 Pressure Atmospheric Fluid level No precondition Dust No precondition Ingoing concentration: VOC, mg/m0

3

Odour, ouE/m3

H2S, mg/ m03 1)

Styrene, mg/ m03

100 – 10,000 > 10,000 10 – 500 < 200 at 500 m0

3/(m2.h) < 500 at 200 m0

3/(m2.h) 1) Higher concentrations expected to be applicable, but not applied yet. Extensive description Variants The MBTF is a variant of the biotrickling filter (see specific fact sheet) Installation: design and maintenance The MBTF is primarily dimensioned for the waste input (air and water) and the air flow. Typical design values include: - COD-load: 10 – 20 kg/(m0

3.d) - Gas load: 200 – 2,000 m0

3/(m2.h) For the treatment of gas streams containing components that are not easily soluble in water, the design should include a severely higher recirculation capacity. In practice the MBTF is filled with about 80% of the designed volume. After starting the system could be loaded additionally. Eventual additions to the carrying construction are always possible. Maintenance is restricted to pumps etc. Monitoring See other biofilter techniques Environmental pros and cons Specific pros - Combined or separate treatment of waste water and waste gas is possible - Can handle very big loads - Free of clogging - Suited for gas streams with very fast and large variations in concentration - Barely sensitive to acidification when processing nitrogen, sulfur or chlorine compounds Specific cons - Investment costs strongly dependent on prices of raw material - Less suited for small gas streams (< 5.000 m0

3/h). No limitation when processed simultaneously with waste water - Construction height up to 20m

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Additives - Nutrients: only necessary if they are not present in the waste water. Without the treatment of waste water additional water is needed for the removal of remaining components (chloride, sulfate) and compensation of evaporation losses. In such a case surface water can be applied. - Carrying material: re-used or ‘virgin’ PE/PP - Grafting material: not necessary - Energy: the energy consumption is primarily determined by the ventilator. Pressure drop of MBTF is up to about 40 mbar. The MBTF’s energy consumption is restricted to the circulation pump and the carrier recirculation (intermitting). Cross Media Effects The MBTF is pre-eminently focused on Cross Media Effects (simultaneous treatment of water and air). The sludge produced has to be disposed. The drained water is already cleaned. Financial aspects

Information source 1. The Moving Bed Trickling Filter, National Water symposium 2005. 2. Symposium at Lucile International, 2006. 3. Supplier information: DHV Water, A. Silverentant, 2008.


Operational costs Small Personnel, hours/week 1 – 2 Help and remaining emissions Minimal Energy consumption, kWh/1000 m0

3/h Strongly variable: <1 – 5 Electricity costs, EUR/1,000 m0

3/h - Cost-determining parameters Waste load, air flow Benefits Simultaneous cleaning of air and water saves a lot

of money. The pay-back time is typically around 2 – 3 years.

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4.8 Thermal oxidation

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Thermal incinerator / Incinerator / Thermal oxidation Brief description Description Incoming gasses are heated to a high temperature by means of incineration. With thermal incineration this temperature varies between 750 and 1,200 °C. When the incoming gas is kept at this temperature long enough the pollutants (VOC, odour) will oxidize into compounds such as CO2, H2O, NOx, SOx.

Schematic diagram

Applicability This technique is broadly applied for the removal of odour or volatile organic compounds in practically all sectors. Because of the potentially high fuel consumption rate, thermal oxidation is primarily suited for applications with an average or high concentration of VOC in the incoming gas. Components

Removed components



3

Validation number

Odour VOC, PM10, CO, halogenated organic compounds2

98 – 99.9 98 – 99.9

-< 1 – 20

13

1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages. 2 When incinerating halogenated compounds very toxic dioxins and it’s compounds can be formed.

Gas flow in

Clean gasCombustor

Combustion chamber

Fan

Thermal incinerator

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Preconditions Normal Recuperative Regenerative Flow, m0

3/h 900 – 86,000 90 – 86,000 900 – 86,000 Temperature, °C 750 – 1,200 (depending on the type of pollutant) Pressure Atmospheric Pressure drop, mbar 10 - 50 Fluid level - Dust, mg/ m0

3 < 3Ingoing concentration VOC < 25% van de gas’ lower explosion limit (LEL)1

Residence time 0.5 – 2 seconds (depending on the temperature) 1 The VOC concentration of the incoming gas should be kept below 25% of the lower explosion limit (LEL). Extensive description Variants The most important variants are the: - Recuperative incinerator

The recuperative incinerator is identical to the thermal incinerator; however, a heat exchanger is present. With the help of the heat exchanger the untreated air is pre-heated with the combustion gasses causing up to 80% of the heat released to be available for use.

- Regenerative incinerator

A regenerative incinerator uses two or more ceramic beds that store the heat of the cleaned gas and preheat the untreated gas. The thermal efficiency can reach up to 97%. In the combustion room the gas is heated some more, resulting in thermal oxidation. The hot gas leaving the incinerator chamber heats the second ceramic bed. The cooled gas can be emitted afterwards. When the second bed is sufficiently heated, the gas flow is reversed so the second bed heats the gasses to be cleaned and the first bed to take care of the cooling of the cleaned gasses. A peak emission may occur during the reversal. Regenerative and recuperative incineration is more cost-effective than a ‘regular’ thermal incinerator because of the decreased fuel costs.

Gas flow in

Clean gas

Combustion

Heat exchange


Combustion

Ceramic bed

MD-MV20090007 -111-

Installation: design and maintenance Incinerators should be inspected regularly, and if necessary, cleaned to keep a good performance and efficiency. When excess depositions occurs, preventive actions have to be taken by cleaning the incoming gas before it enters the incinerator. From experience with recuperative incinerators shows that the warm side of the heat exchanger’s welds may fail, causing the maintenance costs to increase. There are companies that changed to regenerative incinerators for this reason. Monitoring The efficiency of the system can be determined by monitoring the concentrations before and after the thermal incinerator. Volatile organic compounds (VOC) can be measured as a total carbon by a flame-ionization detector. A qualitative emission analysis can be made by analyzing the gas samples with GC/MS. Environmental pros and cons Specific pros - Proven technology, much applied - High efficiency achievable up to >99.9% - Good performance with high concentrations of VOC - Makes use of the energy inside the incoming gasses. Specific cons - High variable costs for fuel at low VOC concentrations - Not suited for strongly variable flow - Forming of corrosive acid gasses when incinerating halogen and sulfur containing

components - Not cost effective with low concentrations and high flow, fuel necessary for starting up. Additives Additional fuel such as natural gas. Cross Media Effects When applying additional fuels extra CO2 is released in the uncleaned situation. Besides CO2 small amounts of CO en NOX can be formed. The forming of large qualities of CO en NOX can be avoided with the right process monitoring and incinerator settings. Financial aspects

1 Additional fuel is needed to keep the incineration going. The energy consumption is dependent on the VOC-level of the incoming gasses. When oxidizing the organic components in the gas streams, heat is released. When the concentration of VOC is high enough, the heat released is sufficient to keep the process at the right temperature.

Normal Recuperative Regenerative Investment costs, EUR/1,000 m0

3/h 10,000 – 40,000 10,000 – 50,000

20,000 – 40,000

Operational costs, EUR per year/ 1,000 m0

3/h < 1,000 3,000 – 14,000 1,000

Personnel, days per year 2 5 2 Help and additives, EUR per year/1,000 m0

3/h 24,000 tot 45,000 Eventually needed for additional fuel 1

- -

Energy consumption, kWh/1000 m0

3/h 3 – 8 - 1.5 – 2.25

Electricity costs, EUR/1,000 m03/h Dependent on EUR/kWh

Cost-determining parameters Flow, energy level of gasses, required removal efficiency, type of catalyst, measurement and controlling apparatus

Benefits None

MD-MV20090007 -112-

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC BREF, Waste Water and Waste Gas Treatment, 2003 4. US EPA, Air Pollution Control Technology Fact Sheet Thermal Incinerator, EPA-452/F-03/022

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Catalytic incinerator / Catalytic oxidation (catox) / Thermocat Brief description Description A catalytic incinerator works the same way an thermal incinerator does, however in this case the incoming gas is lead through a catalyst making reduced reaction temperatures for incineration possible. Gas temperatures before the catalyst are around 300 – 500 °C, temperatures after the catalyst around 500 - 700 °C. There are low temperature catalysts that work at temperatures of 200 – 250 °C. Schematic diagram

Applicability Catalytic oxidation is primarily applied for the removal of VOC in a broad range of stationary applications such as: - Fuel of bulk load stations - Synthetic organic chemical industry - Rubber and polymer industry - Polythene, polystyrene and polyester resin production - Paper industry. With catalytic oxidation it is important the emission stays relatively constant and it is preferable that no or little possible pollutants of the catalyst are present in the gas. Components Removed components



3

Validation number

VOC 95 – 99 < 1 – 20 3 PM10 < 99 - 1 Odour 80 – 95 - 3

1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages.

Gas flow in

Clean gas

Catalytic incinerator

Burner

Catalyst

Combustion chamber

MD-MV20090007 -114-

Preconditions Normal Recuperative Regenerative Flow, m0

3/h 1,200 – 90,000 90 – 90,000 1,200 – 90,000 Temperature, °C

300 – 500 before catalyst 500 – 700 after catalyst

Pressure Atmospheric Pressure drop, mbar

10 - 50

Dust, mg/m03 < 3

Ingoing concentration VOC

< 25% LEL-value (lower explosion limit) because of explosion risk

Extensive description Variants - Fixed bed installation - Fluidized bed installation. In a fluidized bed the air is sent upwards through the catalyst

bed. Because of the high gas speeds, the catalyst granules in the reactor begin to move and the bed starts behaving like a fluid (better reaction because of enlarged contact surface).

- Catalytic recuperative incineration

The recuperative incinerator is identical to the catalytic incinerator; however, a heat exchanger is present. With the help of the heat exchanger, the untreated air is pre-heated with the combustion gasses resulting in a thermal efficiency up to 80%.

Catalytic regenerative incinerator

This system is a combination of a catalytic incinerator and a regenerative thermal incinerator. The thermal efficiency can reach up to 98%. A catalytic regenerative incinerator uses two or more ceramic beds storing the heat of the cleaned gas to later tranfser it onto the gasses to be cleaned. When passing the first ceramic bed the gas will have close to the incineration temperature. In the combustion room the gas will be heated further, causing thermal oxidation to occur. The hot gas leaving the incineration chamber preheats the second ceramic bed. The cooled gas can then be emitted. When the second

Gas flow in

Clean gas

Catalytic recuperative incinerator

Burner

Catalyst

Combustion chamber


Catalytic regenerative incinerator

Burner

Ceramicbed withcatalyst

MD-MV20090007 -115-

bed is sufficiently heated the gas flow is reversed so the second bed heats the gasses to be cleaned and the first bed to take care of the cooling of the cleaned gasses . Peak emissions may occur during such a reversal. - Oxicator. This technique is based on catalytic oxidation of VOC where the catalyst is heated with microwaves. By using microwaves the system uses very little energy. Typical energy consumption is about 20 W/m3. Because of the relatively high costs of the specially designed catalyst, this technique is primarily applicable for smaller gas volumes (< 1000 m0

3/h), for example emissions from soil cleaning. Benefits of the system include the energy efficiency and the high cleaning efficiency (> 99% with remaining emissions <1 mg/m0

3). The system can be fitted with one or two microwaves, depending on the ingoing concentration. At high enough levels of VOC the oxidation reaction is selfsupporting and no external energy is needed.

Installation: design and maintenance Incinerators should be inspected regularly, and if necessary, cleaned to keep a good performance and efficiency. When excess depositions occur, preventive actions have to be taken by (partly) cleaning the incoming gas before it enters the incinerator Monitoring The catalyst temperature, pressure drop on the catalyst, incineration temperature and CO and O2 levels of the effluent gas should be checked in order to work at optimal incineration conditions. The cleaning efficiency of the system can be determined by measuring the remaining emission by means of flame ionization detectors. A qualitative measurement can be made by taking samples and analyzing them with GC/MS. Environmental pros and cons Specific pros - More compact than thermal incinerators - Higher efficiency for the removal of VOC than thermal oxidation; lower temperature

possible (less energy consumption, less isolation requires, lower risk of fire) - Lower NOx emissions (about 20 – 30% of thermal incineration) - Promotes complete incineration - Constantly high and reliable performance possible Specific cons - Higher investment costs than a thermal incinerator - System is sensitive to changes in energy content of the waste gas - Risk of dioxins formation when chlorine compounds are present - Catalyst may be sensitive to poisoning Additives The catalyst will have to be replaced periodically. The expected lifespan is 2 two years or more. Cross Media Effects Emissions may contain traces of CO. Because of the lower operational temperature compared to thermal incinerators, the level of NOx forming is also lower in catalytic incinerators.


Micro waves

Catalyst Cooling coil

MD-MV20090007 -116-

Because the catalyst cannot be regenerated, it has to be disposed of as hazardous waste. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000 2. Guide on air cleaning techniques, VITO 2004/IMS/4/066 3. IPPC BREF, Waste Water and Waste Gas Treatment, 2003 4. US EPA, Air Pollution Control Technology, Fact Sheet Catalytic Incinerator, EPA-452/F-03-018 5. Supplier information: Vemeulen Product Engineering (Oxicator)

Normal (catalytic) Recuperative Regenerative Investment costs, EUR/1,000 m0

3/h 10,000 – 80,000 10,000 – 50,000 25,000 – 89,000

Operational costs, EUR per year/1,000 m0

3/h

2,500 – 20,000 - 3,500 – 12,000

Personnel, hours/week

About 3 - 2

Help and additives, EUR/kg

Catalyst: 35 – 250 depending on the type

Energy consumption, kWh/1000 m0

3/h 1 – 2 Lower than the normal catalytic incinerator.

Cost-determining parameters

Flow, temperature, catalyst, instrumentation, type of heat exchanger, location

Benefits None

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Flare Brief description Description In a flare the incoming gas is lead to a remote, high location through a pipe and incinerated in the open air by an open flame, or lead to a closed ground flare. In order to reach a good incineration a well designed incinerator exit, pilot light and steam or air injection are necessary for a good turbulence and blending, and potentially additional fuel as well. Most flares work through a diffusion flame. With a diffusion flame, the outer edge of the fuel/incoming gas is supplemented with air so that the fuel is surrounded by a flammable gas mixture. When diffusing this mixture a stable flame is acquired. The heat exchange occurs through warmth diffusion between the outer layer and the fuel. When incinerating VOC, soot particles are formed. The glowing of these soot particles gives the flame its yellow color and clarity. In case of large diffusion flames a combustion segment may be closed off from the outside air by gas whirls and turbulence. This causes the forming of soot, causing local instability making the flame flicker. Schematic diagram

Applicability Flares are suitable for the processing of gasses with high fluctuations in the VOC level (including methane), flow, caloric warmth and level of inert chemicals. Flaring is primarily used as a safety device when destroying large quantities of organic chemicals in case of calamity. If a continuous emission has to be treated for environmental reasons, the applicability of the incinerator should be considered first. Broad range of application in the following sectors: - (Petro)chemical industry - Oil and gas industry - Blast-furnaces and cokes ovens - Flaring of landfill gas from landfills - Flaring of excessive biogas in fermentation

installations and anaerobe WWT plants.

Gas flow in

Flue gas

Flare

Natural gas supply

Steam and air

Security flame

MD-MV20090007 -118-


Removal- efficiëncy1, %


3Validation number

VOC (including CH4) > 99 - 1

1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages. Preconditions Flow, m0

3/h < 1,800,000 Minimal incineration value incoming gas, MJ/m0

38 - 11

Pressure Atmospheric Pressure drop, bar 1 Temperature, ºC 500 – 1,100

Extensive description Variants - Flares with steam injection. To provide sufficient air and a good blend of air and fuel,

steam is injected in the incineration zone of this type of flare. This is the most common type of flare in the chemical and petrochemical industry. In order to prevent noise nuisance from the steam lance, it is recommended to keep the steam pressure lower than 7 bar.

- Flares with air injection. Air is injected into flares with air injection in the incineration zone to keep enough air and turbulence for a smoke-free incineration. The benefit of air injection is that no steam has to be present at the flare’s location. This type of flare is not widely used for the larger flares.

- Flares with pressure blending. Flares with pressure blending use the pressure of the incoming gasses to achieve a good blend at the burner. Flares with pressure blending are usually at ground level and thus have to be located in a remote area with sufficient space.

- Flares without additional blending. These flares have a burner without additives to support the blending with air. Their use is limited to gasses with a low incineration value and gasses with a low carbon/hydrogen ration that burn easily without the forming of soot. The gas streams require less air for complete incineration and give lower incineration temperatures.

Installation: design and maintenance There are two types of flares: elevated flares and ground flares. Ground flares are primarily applied for the continuous incineration of the base load. The elevated flares are applied for the processing of incidental and accidental large volumes. Industries often have an integrated system with a ground flare optimized for the efficient incineration of the base load and a elvated flare for the unforeseen large volumes. Elevated flare. The use of a elevated flare (10 – 180 m) can prevent potentially dangerous situations like an open flame close to a processing unit or tank park. By placing the flare up high, other nuisances like noise, heat, smoke and odour can be reduced. The smoke and the odour are created by incomplete incineration. A elvated flare is always an open flare. Ground flare. The disadvantage of open ground flares is that dangerous situations may occur when people are near the incinerator during activation. Another disadvantage is that the odour and incineration gasses have less room to spread than with an elevated flare. Closed ground flares. The closed cylinder where incineration takes place, reduced the nuisance from sound, light and heat and offers protection from the wind. There is no visible flame and there is no elevated flare towering over all the surrounding buildings. A new type of ground flare uses pre-blended gas mixture on a permeable medium of different layers of wire. The incoming gas is incinerated just above the permeable medium. The system makes it possible to recover heat.

MD-MV20090007 -119-

Monitoring The flare and the pilot light have to be measured to guarantee a good performance of the flare. Measuring can be done by means of thermocouples, UV monitoring, ionization-probes, low pressure alarm and flow measurements of the gas. Environmental pros and cons Specific pros - Economical way of processing accidental and incidental large quantities of VOC or

methane containing gasses. - Normally, no additional fuel is necessary for good incineration (caloric values of the

untreated gas is sufficiently high) - Suitable for strongly fluctuating or periodical emissions Specific cons - May cause nuissance of noise, smoke, heat and light. - Production of SOx, NOx, CO and soot2.- Not suitable for the treatment of halogenated compounds. - The heat produced by the incineration is lost. Additives Depending on the design: - Steam - Air supply (through ventilator) - Fuel gas for the pilot flame (and incinerator) - Gas to keep the system in overpressure (nitrogen, fuel). Cross Media Effects Flares are essentially a safety device. However, they also contribute to the decreasing of emissions of VOC. When flaring however, nuissance caused by light, noise and odour may occur. The light nuissance is only with high flares. The odour nuissance is a result of incomplete incineration. Also, the following emissions may be formed: - soot particles - non-incinerated VOC - NOx, SOx, CO. Noise pollution is primarily caused by the injection of steam to prevent smoke forming, incineration processes and ventilation. Financial aspects

1 The costs, expressed in EUR per 1,000 m03/h, can vary strongly because it is dependent on the

amount of hours the flare is on. Because a flare is primarily a safety precaution, the amount of hours it is on will be low (10 to 100) hours per year.

2 The forming of soot and thermally composed NOx can be decreased by using steam


Operational costs, EUR/1,000 m03/h

about 100,000 – 650,0001

on-shore design without landing Personnel Can also strongly vary; the skill of the

maintenance personnel is the essential factor here Help and additives Eventual steam, additional fuel, nitrogen Energy consumption, kWh/1,000 m0

3/h Depending on steam en extra fuel Electricity costs, EUR/1,000 m0

3/h Low, depending on, for example, use of compressed air

Cost-determining parameters Eventual additional fuel Benefits None

MD-MV20090007 -120-

Information sources 1. Description of air emission abatement techniques, l26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 4. Reference document on BAT in the large volume organic chemical industry, February 2003. 5. Reference document on BAT for the mineral oil and gas refineries, February 2003. 6. US EPA CACT Air Pollution Control Technology Fact Sheet http://www.epa.gov/ttn/catc/dir1/fflare.pdf

MD-MV20090007 -121-

4.9 Cold oxidation

MD-MV20090007 -122-

Ionization / Active oxygen injection / Ozone injection / Plasma cleaning Brief description Description The air or the incoming gas flow is lead through a reaction chamber, and in there it is submitted to a very strong electrical field (20 – 30 kV) generated by electrodes causing ions, free electrons, radicals and other high reacting particles to form. However, no notable rise in temperature takes place. The high reacting components cause a decomposition and (partial) oxidation of the pollutants present. The most active particles is this process are the N, O and OH radicals. They are formed out of nitrogen (N2), oxygen (O2) and water (H2O). If the gas flow is sent directly into the plasma reactor, it acts as an electrostatic precipitator with a dust removal efficiency of > 90%. In order to keep the reactor clean a (self)cleaning system should be installed. The cleaning may occur through vibration, compressed air or water. In dust-free air streams this cleaning system is not necessary. With direct treatment the removal of organic chemicals is possible. In case of injection of an ionized air stream one primarily gets a modification of the odour molecules and to a lesser extent a removal of the organic load. Schematic diagram

Applicability Broad range of application in the following sectors: - Feed industry - Slaughter houses - Sludge processing - WWT plants Components Removed components



3Validation number

Odour2

VOC3

NOx4

80 – 98 80 – 99.9 80 - 95

1,000 – 20,000 ouE/m3

--

331

1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages. 2 The acquired odour reductions are strongly dependent on the application and the lay out of the installation (directly into the gas stream or side stream, see variants). 3 VOC removal in the wood industry 4 Variant “LoTox”


Ionization

High voltage

Gas ionization

MD-MV20090007 -123-


3/h 20 – 200,000 Temperature, oC 20 – 80 higher temperatures up to 120 with plasma oxidation Pressure Atmospheric Pressure drop, mbar Some Fluid level Not too high because of risks of condensation and short-

circuiting. A heightened humidity increases the performance in a side stream set-up.

Dust If applied directly into the gas stream this has to include relatively low amounts of dust. The ionizer will then act as an electrostatic precipitator.

Energy Ionization is primarily suited for gas streams with a low energy level (low concentrations of VOC) because of the low energy consumption compared to incinerators.

Extensive description Variants - Ionization combined with a catalyst. After the ionization phase itself, the air stream can

be lead over a catalyst. This works at ambient temperature and ensures a removal of the present ozone and causes further oxidation of the components that are to be removed. In some designs such a catalyst is a standard, in other is available as an option. These are often active coal catalysts.

- Side stream injection (active oxygen injection): at too high temperatures, too high dust concentrations or corrosive gasses it can be necessary to ionize a side-stream of air and injecting it into the main stream. Because the added gas stream has a volume of 10 – 20% of the main gas stream, the outgoing flow is about 10 – 20 % percent larger than the ingoing flow, deluting it somewhat. The performance of the side stream is often less efficient than direct ionization. Feasibility studies are appointed for measuring the efficiency.

- Non-thermal micro-plasma chemistry stands out because of its low energy consumption rate (0.005 to 0.040 kWh/1000 m0

3/h). This is achieved through means of a Dielectric Barrier Discharge (DBD), creating a dielectric field (1.5 – 2.0 kV) through which no electricity runs and thus no notable energy consumption takes place. The investment costs are 5,000 to 25,000 EUR/1 000 m0

3/h of the untreated air (excluding the costs of the catalyst of 300 EUR, life span 8,000 to 15,000 hours).

- The design and configuration of the electrodes and the nature of the used materials differs for every technology and is often protected by patents.

Installation: design and maintenance Basic compact installation Monitoring Odour measurements require a specific handling. For details we refer to the NeR paragraph 3.6 and Annex 4.7. Environmental pros and cons Specific pros - Very compact - May be turned on and off at will (almost no start up time) - Relatively simple management - Not sensitive to variations in the gas stream - The ionization process takes place at low temperature - Low energy consumption rate compared to incinerators (for gas streams with low

energy levels) - When operating in bypass not sensitive to dust Specific cons - Electricity consumption - Test installation is preferred for the proper judgment of situation-specific effects and

possible removal efficiency - Only suitable for VOC removal when the system is applied directly to the gas stream - Risk of electromagnetic radiation. This risk is limited when the casing is made of metals.

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Additives Energy; about 0.3 – 3kW/1 000 m0

3. For applications in odour removal the lower of the range range applies. The consumption is dependent on the concentration and type of components to be removed and the air humidity. Catalyst; lifespan around 8,000 working hours, can be regenerated. Cross Media Effects - Ozone; in the electrical field ozone is created as a by-product. If it is not completely

reacted it leads to ozone emissions. Ozone has a distinctive smell and can be harmful in high concentrations. Under normal atmospheric conditions the ozone is quickly transformed into oxygen. When placing a catalyst in series after the ionizer, the ozone is completely removed. In industrial applications the ozone emission stays below the 1 ppm.

- Waste water: waste water is emitted as a small quantity of drainage water. - When dust is present in the gas stream it is emitted as solid waste. Financial aspects

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Supplier website www.aexoninjector.com3. Netherlands emission guidelines for air, NeR paragraph 3.6 and Annex 4.7, 2008. 4. IPPC Reference document on Best Available Techniques in Common Waste Water and Waste Gas Treatment / Management Systems in the Chemical Sector, February 2003. 5. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 6. Dutch Association of Cost Engineers, edition 25, November 2006. 7. US EPA CACT Air Pollution Control Technology Factsheet http://www.epa.gov/ttn/catc/dir1/fnonthrm.pdf8. Suppliers: Aerox, Circlair.


Total Injector (part of total) Catalyst (part of total)

Strongly dependent on the application. Up to 5,000 2,600 Up to 660 (8,000 hours lifespan)

Operational Costs, EUR/year 3 - 5% of the installation costs Personnel, man-days per year 1 – 2 Help and additives Restricted Energy consumption, kWh/1 000 m0

3 0.3 - 3 Cost-determining parameters Flow Benefits None

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Photo oxidation / UV-oxidation Brief description Description The untreated gas stream is lead through a reaction chamber and radiated with UV-waves (100 – 280 nm). This radiation causes the decomposition of the undesired compounds. This decomposition takes place in two ways: 1. Direct photolysis; compounds like VOC, NH3, H2S and amines are directly broken down in the radiation. 2. Oxidation through reactive oxygen radicals; the presence of high reactive oxygen radicals oxidize components that are not broken down by photolysis and reaction products from the photolysis. Schematic diagram

Applicability Photo oxidation is primarily suited for discontinuous processes with low pollutant concentrations in; - coating installations - WWT plants - waste processing installations - fermentation processes - food industry Components

Removed components


Remaining emissions, mg/m0

3

Validation number

VOC 95 25 – 50 1 H2S, NH3, amines, mercaptans

< 98 - 1

Odour 80 – 98 - 1 1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages.


3/h 2,000 – 58,000 (in theory not very critical) Temperature, oC < 60 Pressure Atmospheric Pressure drop, mbar - Fluid level, % < 85 (max. dew point, no mist) Ingoing concentration: VOC, mg/m0

3 < 500 H2S, NH3, amines, mercaptans, ppm < 50 Dust Preferably dust removal

Gas flow inClean gas

UV- lights Catalyst

Photo oxidation

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Extensive description Variants Some suppliers place a catalyst (active coal) or a second set of lamps with a different wavelength after the first photo oxidation phase to reach the highest possible removal rate. This extra phase also serves to break down the remaining ozone into oxygen. Installation: design and maintenance Expected lifespan of UV-lamps is about 8,000 hours and it should be replaced after this period. Monitoring Odour measurements require a specific approach. For details we refer to the NeR paragraph 3.6 and Annex 4.7. Environmental pros and cons Specific pros - compact and modular system - close to no start up time - operation at low temperature - low energy consumption rate - noise free Specific cons - not suitable for high concentrations of pollutants Additives Only when a catalyst is included. Cross Media Effects The outgoing gas could contain remaining ozone. Under normal conditions however ozone is quickly decomposed to oxygen. Besides UV lamps, no waste is created.

Financial aspects

Information sources 1. Netherlands emission guidelines for air, NeR paragraph 3.6 and Annex 4.7, 2008. 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. Dutch Association of Cost Engineers, edition 25, November 2006

Investment costs, EUR/1000 m03/h 5,000 – 7,000

Operational costs, EUR/kg VOC removed 3 – 25 Personnel - Help and additives, EUR/1000 m0

3/h UV-lamps: 0.06 – 0.2 (life span about 8,000 hours) Possibly catalyst (active coal): 0.06 – 0.12

Energy consumption rate, kW/1000 m03/h 0.3 – 1.5 lamp power

Cost-determining parameters Lamps, catalyst Benefits None

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4.10 Chemical reduction

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Selective non-catalytic reduction / SNCR Brief description Description With selective non-catalytic reduction, NOx is removed by injection a reducing reagent into the incoming gas. Often ammonia is used as the reagent. The optimal temperature for this injection is there where the gas has a temperature between the 930 – 980 °C. Temperature, reagent/reactant ratio and residence time are the most important parameters for the efficiency. Schematic diagram

Applicability SNCR is applied for the reduction of NOx emissions during release in processes in: - Chemical industry - Power plants/large combustion plants (biomass, coal, oil, gas) - Waste incineration - Cement industry - Metal industry - Greenhouse horticulture



Remaining emission,

mg/m03

Validation number

Nox 40 – 80 60 - 70 3 1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages.


3/h < 200,000 Temperature, °C 800 – 1,100 Pressure Atmospheric Ingoing concentration NOX, g/m0

3 Wide range NH3/NOX-ratio < 1.2

Air

Flue gas

Furnace

Ammoniacor Urea

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Extensive description Variants The SCR can be seen as a variant of the SNCR. See the fact sheet on SCR. Installation: design and maintenance The adjustment (retrofitting) of a SNCR installation is relatively easy because only injection units and a storage tank for the reagents have to be installed. Monitoring The performance of the SCR systems can be determined in two different ways: first, by measuring the NOx levels before and after treatment and second, by measuring the ammonia and (excess) oxygen levels of the treated gas. For details we refer to the NeR, paragraph 3.7 and Annex 4.7. Environmental pros and cons Specific pros - Under optimal conditions, a high reduction of NOx is possible - Gas with a high dust concentration can also be treated - Relatively easy installation (also when retrofitting) - Low investment costs compared to other NOx removing techniques - Low energy consumption rate - Requires little space Specific cons - High temperatures required, and the optimal reaction temperature is in a precise range - Not suited for sources with a low NOx level - The fly ash contains ammonia - Beyond operational reach, ammonia is emitted or the NOx emissions are increased - Nitrous oxide (N2O) might be formed as a by-product Additives - Reacting agents: a 25% solution of ammonia or urea - Steam: for the evaporation of the ammonia/urea before it is injected Cross Media Effects - Possible aerosol forming of ammonium chloride and ammonium sulfate. - Potential NH3 emissions as a result of non-optimal process. - Nitrous oxide (N2O) might be formed as a by-product. Financial aspects Investment costs, EUR/1000 m0

3/h 2,500 – 10,000 Operational costs - Personnel, EUR/year 20,000 Help and additives, EUR/ton 150 - 200

up to 570 kg NH3-solution per ton of removed NOx

Energy consumption, kWh/1000 m03/h Only energy consumption is for the dosing of ammonia or

urea Cost-determining parameters Consumption of ammonia or ureum, uncontrolled NOx-

concentrations, preffered reduction, thermal efficiency, retrofitting

Benefits None, besides benefits from NOx emission trade

Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000. 2. Guide on air cleaning techniques, VITO 2004/IMS/r/066. 3. IPPC BREF Waste Water and Waste Gas Treatment, 2003 4. US EPA, Air Pollution Control Technology Factsheet SNCR, EPA-452/F-03-031 5. Cementa AB, Sweden, Paper, date unknown

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Selective catalytic reduction / SCR Brief description Description Selective catalytic reduction (SCR) aims at reducing the emission of NOx. The incoming gas is enriched with an addition of NH3 or urea and led over a catalyst converting the NOx into N2 and H2O. Temperatures are between 200 oC and 500 oC, depending on the type of catalyst. Schematic diagram

Applicability SCR is applied to abate NOx emissions from processes like: - waste incineration - chemical industry - power plants/large combustion plants - metal industry - greenhouse farming Components Removed components



3Validation number

NOx 90 – 94 40 - 50 possible aerosol forming of ammonium chloride and ammonium sulfate2.

3

1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages. 2 When SO2 is present, the ammonia is formed into ammonium sulfate. The ammonium sulfate might clog the catalyst and is emitted as a aerosol that is hard to remove.

Air

Cleanedgas

Furnace

Ammoniaor urea

Dustfilter

Catalyticbed

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3/h < 1,000,000 Temperature, °C 200 - 500 (depending on the catalyst), fluctuations

of about 90 °C are acceptable. Pressure Atmospheric Pressure drop, mbar < 10 Fluid level - Dust, g/m0

3 Some Ingoing concentration NOX, g/m0

3 < 3 (including diesel motors)

NH3/NOX- mol ratio < 1.1

Extensive description Variants - SCR installations placed directly behind the boiler; a so-called “high-dust” sequence.

This is possible if the outgoing gas has very little to no dust that could cause the catalyst to be poisened. This configuration is also applied at coal fired power plants with dust concentrations up to 10 g/m0

3.- Serially placed SCR installations behind dust filters with scrubbers; a so-called “low-

dust” sequence. With this technique it is necessary to clean the incoming gas before it enters the catalyst chamber. It is necessary to reheat the waste gas to the reaction temperature.

- In the DESONOX process, the dust-free gas is mixed with ammonia and led across a catalyst at 450 ºC to remove the NOx after which it led over a catalyst to convert the SO2 into SO3, which reacts with sulfuric acid.

Installation: design and maintenance The catalyst has a lifespan ranging between the 5 and 10 years under normal operational conditions. This can be expanded with clean incoming gas. The catalyst cannot be regenerated but is often recycled by the manufacturer. The adjustment (“Retrofitting”) of an existing installation to install the SCR may require large modifications and therefore lead to extra high costs (in comparison with a new construction). Monitoring The performance of the SCR systems can be determined by measuring the NOx levels before and after the treatment and by measuring the ammonia and oxygen levels of the treated gas. The temperature and pressure drop should be routinely checked. For details we refer to the NeR, paragraph 3.7 and Annex 4.7. Environmental pros and cons Specific pros - Higher NOx reduction efficiency than SNCR and low-NOx burners - Low and relatively broad temperature range application possible - Also applicable for sources with low NOx-concentrations - Less ammonia slip than SNCR, because of lower dust levels - Relatively easy installation, no modifications to the incinerators are necessary Specific cons - At relatively high SO3 levels, the process has to be executed at a high temperature to prevent condensation - Costs of the catalyst (potential clogging, poisoning and possible erosion of the catalyst by fly ashes. - Relatively high investment costs compared to the SNCR and low-NOx burners - In a “high-dust” sequence the fly ashes are loaded with NH3

- In a “low-dust” sequence the reheating of the waste gasses is required - Requires a relatively large amount of space Additives - Reductants: a 25% solution of ammonia or urea - In some cases, steam: to evaporate the reductants before they are injected - Catalyst: among other, V2O5 (vanadium pentoxide) and/or TiO2 (titanium dioxide).

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Cross Media Effects - Potential NH3 emissions as a result of non-optimal process execution (NH3 silt) - Spent catalyst - Nitrous oxide (N2O) may be formed as a by-product - In “high-dust” sequences the fly ashes are loaded with NH3.

Financial aspects 1

83,000

EUR/11) 83 000 m0

3/h for a waste-combustion furnace with a capacity of 80,000 tons per year. Information sources 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066. 3. IPPC BREF Waste Water and Waste Gas Treatment, 2003 4. US EPA, Air Pollution Control Technology Factsheet SCR, EPA-452/F-03-032 5. Haldor Topsoe (Lyngby), news article 25-07-2008; increase in SCR DeNOX catalyst prices 6. Supplier information: Hanwell Codinox, RAI Amsterdam, October 2008

Investment costs, EUR/1,000 m03/h 10,000 – 83,0001 (very dependent on the application)

Retrofit may lead to 100% higher costs. Operational costs, EUR/ton NOX

removed 500 – 5,000

Personnel, EUR/year 20,000

370 - 450 Help and additives NH3-solution/ton of removed NOX, kg Catalyst, EUR/ton 11,000 Energy consumption, kWh/1000 m0

3/h For the heating of smoke gasses in a “low-dust” installation

Electricity costs, EUR/1000 m03/h Low

Cost-determining parameters Use of catalyst and reagents Benefits None

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Non-selective catalytic reduction / NSCR Brief description Description Non-selective catalytic reduction (NSCR) converts the chemicals CO, NOx and VOC into CO2, N2 and/or H2O through use of a catalyst. Because the non-combusted VOC is used as the reacting agent this technique requires no extra reagent injections (but ammonia and urea are also used sometimes). However, the gasses should not contain more than 0.5% oxygen. The used catalysts are often constructed out of platinum. Schematic diagram

Applicability NSCR is primarily applied in the car industry. It also applied in places where the incineration is stoichiometric such as stationary engines for energy generation or drive (not for diesel engines because of the amount of oxygen present). It may also be applied with the production of inert gasses and in the chemical sector, like nitric acid production. Because of the low efficiency, stoichiometric engines in stationary applications are not applied often yet. Components Removed components2


3Validation number

NOX 90 – 98 50 3 1 Depending on the specific configuration and operational conditions. Values are based upon half-hour averages.


3/h < 34,000 Temperature, 0C 375 – 825 Pressure, bar < 8 Pressure drop Fluid level Dust

No information

Ingoing concentration: Oxygen, % NOX, mg/m0

3

CO, mg/m03

VOC, ppm

0.2 – 0.7 4,000 – 8,000 3,000 – 6,000 1,000 – 2,000

Air & fuel

Clean gasOff gas

Catalyst

Ratio Air& fuel

MD-MV20090007 -134-

Extensive description Variants Some suppliers use natural gas as a reducer for the NOx. This way the acceptable oxygen concentration can be increased up to 2%. Installation: design and maintenance The catalyst has to be replaced periodically. A lifespan of 2-3 years is generally guaranteed. Monitoring The performance of the NSCR systems can be determined by measuring the NOx, VOC and CO levels before and after treatment. For details we refer to the NeR paragraph 3.7 and Annex 4.7. Environmental pros and cons Specific pros - No extra reducing agent required Specific cons - Engine must be controlled based on the oxygen level - Limited applicability Additives The catalyst has to be replaced periodically Cross Media Effects Application of NSCR may result in higher CO-levels because of the requirement of a rich mixture in the engine, so the CO is available for the catalyst to remove NOx. At high CO levels an oxidation catalyst could be placed in series behind the catalyst to convert the CO into CO2. Financial aspects

1

Based

on

8,000 hours per year including maintenance and debiting. 2 The catalyst has to be replaced periodically. The used catalyst is sometimes sold. Information sources 1. Guide on air cleaning techniques, VITO 2004/IMS/R/066 2. Johnson Mattey, Emission Control Technologies, NSCR Catalysts, 2008 3. Dutch Emission guideline air, NeR paragraph 3.7 and Annex 4.7, 2003 4. Supplier information: Hanwell Codinox, RAI Amsterdam, October 2008.

Investment costs, EUR 15,000 – 250,000, strongly dependent on the engine size (80 – 8,000 hp)

Operational costs, EUR 69,000 – 244,000, strongly dependent on the engine size (80 – 8.000 hp)1

Personnel, days/year None Help and additives Catalyst2

Energy consumption, kWh/1000 m03/h Excessive use of fuel because of the higher pressure

drop of the catalyst (0–5% depending on the design) The capacity of the motor decreases with 1 – 2%.

Electricity costs, EUR/1000 m03/h -

Cost-determining parameters Engine size, flow Benefits None

MD-MV20090007 -135-

4.11 Other techniques

MD-MV20090007 -136-

Membrane filtration / Solvent recuperation / Air separation with membranes Description Description Membrane filtration uses the difference in the selective permeability of chemicals (some chemicals pass the membrane more easily than others). The incoming gas is compressed and sent through a membrane. The membrane stops the air and lets the compounds that have to be removed pass through. The untreated air is at overpressure. The other side of the membrane is at underpressure. Because of the pressure difference, some components penetrate the membrane. As a result one gets a low and a high concentrated gas stream. It is often necessary to treat the remaining stream to guarantee a sufficiently low emission concentration. Schematic diagram

Applicability Broad range of application in the production or recuperation of (industrial) gasses in the: - Chemical industry - Petrochemical industry - Pharmaceutical industry - Refineries Components Removed components

Removal efficiency1, % Remaining emission,mg/m0

3Validation number

VOC < 99.9 150 - 300 1 1 Depending on the specific configuration, operational conditions and reagents. Values are based upon half-hour averages.

Gas flow in

Cleaned gas

Heat exchange

Separator

Membrane filtration

MD-MV20090007 -137-


3/h < 3,000 Temperature Environmental temperature, dependent on the membrane material Pressure, bar About 3.5; up to 100 with inorganic membranes Pressure, bar 1 - 10 Dust Very low concentration, dust pollutes the membrane Ingoing concentration: VOC

High concentrations can be treated

Extensive description Variants The configuration of the membrane is dependent on the supplier: this varies from flat membranes to hollow fiber membranes. There is also the choice between organic and inorganic membranes. The choices between these different systems are dependent on the gas qualities (temperature, pressure, permeability, etcetera). Installation: design and maintenance The installation is dimensioned based on the flow, concentration type of gasses, type of membrane (surface pressure) and required degree of regaining of component. Simple mechanical principle and little maintenance required. While designing of the LEL-values have to be taken into account to prevent the risk of explosion. Monitoring The efficiency of the membrane filter can be determined by measuring the concentrations of chemicals before and after the membrane. Volatile organic compounds (VOC) can be measured as total carbon by a flame-ionization detector. For safety reasons (explosion risk) the VOC-oxygen ration should be checked. Environmental pros and cons Specific pros - Reuse of raw materials possible - Easy to use (low maintenance, ease of operation) - No waste produced in the process. Specific cons - Membrane filtration is just a concentration technique and should be followed by a second cleaning stage - Risk of explosion. Additives The membrane will have to be replaced periodically, although it theoretically has an unlimited lifespan. The guarantee on the lifespan of membranes is often 5 years. Cross Media Effects The technique is often used to recover a component in a concentrated stream. The remaining emission often has to be treated. However, in some cases the solvent concentration can be reduced to below the norm with membrane separation. Financial aspects Investment costs, EUR 345,000 for a system of 200 m0

3/h Operational costs, EUR/1000 m0

3/h < 50 Personnel, days per year 4 Energy consumption, kWh/1000 m0

3/h 250 – 300 (including ventilator) Cost-determining parameters Flow, technical lifespan of membrane, required degree of

regain, required final concentration Benefits Eventual regained product

MD-MV20090007 -138-

Information source 1. Description of air emission abatement techniques, L26 Infomil/Tauw, March 2000 2. Guide on air cleaning techniques, VITO 2004/IMS/R/066 3. IPPC BREF, Waste Water and Waste Gas Treatment, February 2003

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Vapor recovery unit / VRU Brief description Description The term vapor recovery unit (VRU) is a collective term for techniques for the recovering VOC vapor. The separate techniques are already described in the different fact sheets. In this fact sheet an overview of the techniques is presented. VRUs are primarily applied for the recovering hydrocarbons of storage and handling of (highly) flammable products in the oil and gas industry. The most commonly applied techniques are; - Absorption; the VOC are dissolved into an absorption fluid like water or glycol (see fact

sheets absorption) - Adsorption; the VOC are adsorbed by solid materials like active coal or zeolites (see

fact sheets adsorption) - Gas separation with membranes; because of the pressure difference only the VOC

penetrate the membrane. The result is a component-free gas stream and one saturated with components (see fact sheets membrane filtration)

- Condensation; by cooling the gas stream the VOC can condensate and be separated as a fluid (see fact sheets condensation)

- Hybrid systems; VOC are removed by a combination of the techniques described above in order to reach a higher efficiency rate, for example condensation followed by absorption.

MD-MV20090007 -140-

5 Additional research on specific techniques

5.1 Techniques Introduction For a number of techniques further research has been done. For this the suppliers where specifically approached. This is done to get a better understanding of the technique, the delivery pack and the specific applications of the techniques and the sectors where the suppliers are active. The techniques chosen have drawn attention, because of the components that are to be removed, for example fine dust and acidifying components such as Nox, or because of developments in recent years. Much of the information that is relevant to the fact sheets is also incorporated into the fact sheets. The part of the information that cannot be incorporated into the fact sheets easily is incorporated per technique into the paragraphs below. Dust filters Fabric filter The fabric filter is a proven, renowned and widely spread technology within the industry for the removal of dust and dust-bound chemicals such as metals. However, there are current technologies that make a broader range of application possible. There is now also the standard possibility of coating fabric filters with PTFE (Teflon) and thus making use of the good qualities of Teflon (like a coating in frying pans). Beside that there is the possibility of coating fabrics to make them oil and water resistant. The right choice of fabric will always depend on the specific process from where the air has to be cleaned because this determines the qualities of the pollution. The choice of coating a fabric or choosing a different type of fiber depends on the specific process parameters. In the food industry coated fabrics are applied with intention of using the coating to make the fibers as smooth as possible. This serves to prevent sticky products (food remains) to remain in the filter, for hygienic purposes and to prevent the forming of moulds. Within the Dutch metal industry, there is an ongoing search for an improved application of the fabric filter. By applying a fabric filter after a sinter factory the emission of heavy minerals and dust from the installation can be reduced. These systems are already being applied in Austria and Germany. These techniques do not differ from the principles and techniques described in the fact sheets. Different types of fabric have been examined on a wide scale. 3

Ceramic-metal filters and multi-cyclones A number of suppliers have removed the ceramic filters from their supply because of the low demand. Currently people often use fiber filters because it is often more economical to reduce the process temperatures and to use the more conventional techniques. Sometimes the pollution, at variable loads, can be a problem for cleaning and performance of a ceramic filter. Some suppliers prefer to use multi-cyclones in unfavorable situations, because their performance is regarded as highly robust. On top of this very small fractions can be removes by a series of multiple cyclones.

3 Bakker, PNH Studierapport nieuwe reinigingstechnologie rookgassen Sinterfabriek, september 2008.

MD-MV20090007 -141-

Filtering installations equipped with sintered, metal filtering media Automatically cleanable dust removal filters equipped with sintered metal filtering media are applicable in processes where conventional, synthetic filtering materials can not be applied due to the high operational temperature (> 300 ºC). Which construction materials are suited is dependent on the composition of the process gas it is exposed to. The most common materials are RVS304, RVS316, Inconel, Hastellov and Fecrallov. The benefits of sintered metal filtering media include: - Applicable at temperatures up to 1000ºC - Suitable for processes where thermal and mechanical fluctuations occur - High degree of chemical resistance - Emission reduction of < 1 mg/m0

3 can be achieved - Easily cleaned with compressed air, nitrogen or process gas (depending on the composition) - Low pressure drop because of filtering material’s high porosity - High degree of reliability and very long lifespan Sintered metal filtering media are relatively costly compared to synthetic filtering materials; however because of the specific qualities sintered metal filtering elements are primarily applied for heavy industrial installations in refineries and petrochemical plants, where safety and reliability are essential. A specific application of sintered metal filtering media is the filtering of fine catalyst dust particles that are emitted through stacks at refineries. A catalyst is used in FCC units (Fluid Catalytic Cracking), a conversion unit that transforms oil into valuable products such as gasoline and light olefins. Many refineries are equipped with a waste gas treatment system based on cyclones. However, local emission limit values for catalyst dust in the refineries getting stricter and stricter. Refineries around the world are to adjust their so-called FCC stack to the local environmental ELV’s. For this application, many sintered metal filtering systems have been installed that have been operating successfully for a long time and are designed to have a lifespan of 4 to 5 years, excluding unplanned stops. Electro-filter An electro-filter can achieve low emissions of fine dust. However, the demand for electro-filters has decreased over the last years. Because the emission norms for fine dust continue to grow stricter and because the electro-filter, in some situations, for example during malfunctions, is an open drain. To prevent this, a filter will have to be installed behind the electro-filter. According to the suppliers it is more practical to only install a dedicated filtering system in such a case. Electro-filters are often specifically designed and installed and are still optimized years later for the specific operational conditions of that moment. Rotating particle separator (RPS) The RPS has been applied in many different situations, with claimed good efficiency rate at low investment costs. The efficiency rate is almost at the same level as that of the ESP but the costs are significantly lower. There is currently no supplier, only a licensee. The information on the RPS is incorporated into the fact sheets as a variant of the cyclone.

Active coal filter Applications and marketThe chemical sector is a broad topical market with many different kinds of emissions. At this moment questions are being raised from the styrene processing industry. Specific solutions to questions are being delivered with the existing active coal technologies (see fact sheet active coal). The market for air emissions is also very diverse and varies from applications in the large volume chemical industry to odour emissions at bakeries and desulfurizing gas fired engines at WWT plants and the agriculture. Designs / ExecutionsFor the smaller applications there are many sales of plate-shaped units (Norithene) and rental of 2m3 units. Another application form of active coal is the concentric cylinder, wherein the untreated gas enters through the core of the cylinder and flows through the

MD-MV20090007 -142-

coal bed in outer ring. The supplier takes care of the design and construction, like a supplier of dosing apparatus for active coal injection does. Sometimes the active coal is recycled. In the ‘air treatment’ market, especially the application of smaller units, 90% of the used active coal is not recycled. Active coal is also used in vapor recovery systems (see the fact sheet on remaining techniques), for example to recover volatile organic compounds when handling gasoline. This technique has been applied for more than ten years. In the USA, stricter laws direct the developments in the application of active coal towards a decrease of mercury emissions from power plants. Improvements of technique and developmentsThe developments are generally slow and cannot be considered revolutionary. Important developments primarily focus on the improvements in the areas of impregnation (chemical treatment to ensure the selectivity of adsorption to the coal), reaction kinetics (reaction speed of the coal) or custom made products. Efficiency rates and emissionsEfficiency rates vary depending on the demand and application between the 70 and >99%. An example is the removal of methyl ethyl keton (MEK) in the oil and gas industries (>99%). Higher efficiencies can also be acquired if necessary, like the mercury removal at LNG production (99.99%). CostsThe investment costs are more or less 6,000 EURO per mo

3. The operational costs are very specific to the situation (coal load, flow, ingoing concentration, component, retrofitting situation, etc.) but a range for the costs can be given. For recycled coal 1000 euro per ton can be taken into account, and 1500 euro per ton of non-recycled coal. Biological filter No large innovations were applied to the biological filters in recent years. The most important change is that the range of application has been expanded. Applications and marketOne can differentiate between mesophile and thermophile applications. Mesophile systems operate between 15 – 50°C and thermophile systems work between 50 – 60°C. Thermophile applications are more sensitive to temperature fluctuations. If the temperature peaks above 60°C, the biological activity will quickly diminish (pasteurization of the bed). With mesophile applications, changes in temperature are less of a problem. The performance will diminish for a short period, but the filter will recover. Synthetic packing are said to not be applied much in the market anymore. Points of improvement The technique can be improved further by decreasing starting up times and by a better fixation of the sulfur compounds in the beds. Biotrickling Sectors and availability Biotrickling is a beneficial alternative for incinerators if the VOC emissions are low and discontinuous. Incinerators are often more favorable if the concentration of VOC in the gasses is higher than 1 -2 g/m0

3. For a good performance of the installation, the design has to be custom made for the operational conditions, nutrient solvents and range of application. The range of application and the efficiency rate are strongly dependent on the specific component that is to be removed. Environmental pros and cons When applying with VOC, the water drainage is minimal. For H2S removal the water drainage is bigger to prevent acidification. A watery sulfuric acid is released as waste product.

MD-MV20090007 -143-

Efficiencies The efficiency rates of the biotrickling filters (or bio-towers) strongly vary depending on the type of hydrocarbon, odour (70%) or sulfuric compounds (ranging from 15% for dimethyl sulfide up to 90% for hydrogen sulphide). For references and additional information we refer to the corresponding fact sheet. SCR The improvement and development of these techniques is slow and cannot be considered revolutionary. However, improvements have occurred concerning the lifespan of the catalyst and the reduction of NH3 slip by making adjustments in the fields of the measuring and controlling technique and the application of specific type of catalyst (red catalyst, ammonia killer). The efficiency rates are somewhat optimized and vary from 90 - 94%. Typical emissions for NOx in heating installations are 40 mg/m0

3 .

25% ammonium solvent or a maximum of 40% urea solvent is used. For safety reasons, urea is preferred since the safety regulations can be rather costly. The range of application has broadened in the last ten years and has directed itself onto the developments in the area of applications of biogas. Oxicator This technique is based on the catalytic oxidation of VOC with the catalyst being heated by microwaves. By using microwaves the system is very energy efficient. Information on this is incorporated into the fact sheet on catalytic incinerators as a variant.

5.2 Field-testing of emissions The emission numbers that are mentioned in the fact sheets are primarily based on data from literature. These have been randomly checked by inquiring field data from some provinces and companies and comparing this to the information found in the fact sheets. An overview of this data, the techniques, emissions and types of companies, can be found in Annex 1. Approximately half of the tested emission values are within the range of the emission limits described per technique in the fact sheets. Another part of the emission values from the measuring reports are hard to compare with the emission values found in the fact sheets, for example because the situation (potentially combined with the polluted component) is too specific. The last part of the examined emissions is outside the range (up to 100%) of emissions found in the fact sheet. This can be the case when different units are used for the emissions in the permit. For this reason we advice to apply the emission values given in the fact sheet with caution. The reported emissions are meant to be indicative, are strongly dependent on the field situation and are meant as a target for what is feasible.

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6 Cost effectiveness In a large number of situations for which an environmental permit is applied, the cost effectiveness of the air emission abatement technique is considered. To give an indication of the levels of cost effectiveness, exemplary calculations have been made for five techniques. The (fictional) calculations have been made with realistic values from field data. Assumptions have been made where no data were available Table 6.1 presents a summary of the cost effectiveness calculations. The information in the table is meant as an indication of the cost effectiveness of different techniques in situations such as those that could occur in the field. Annex 2 includes a more extensive overview of the data and (basic) assumptions that were used in the cost effectiveness calculations of the five techniques. The calculations are based on the method described in the Netherlands Emission Guidelines for Air, NeR 4.13. Table 6.1 Examples of cost effectiveness of air emission abatement techniques 1

Technique component Flow, m3/h

Operational investment, 1,000 EUR

Capital costs 2,1,000 EUR

Efficiency, %

Avoided emissions, Ton

Cost effectiveness,

EUR/kg Gas scrubber

SO2 100,000 468 106 99 99 6

Active coal filter

Styrene 4,000 28.5 5 98 2 17

SCR NOx 60,000 37 191 90 32 7 E-filter Dust 20,000 70 286 99.9 200 2 Biological filter

VOC 80,000 88 85 90 18 9

1) The results are of course dependent on the chosen situation and the assumptions that were made. 2) These are the fixed investment costs multiplied by the annuity factor (NeR 4.13).

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7 Recommendations for future research

The study to actualize the fact sheets has not delivered all desired information. It is desirable to add the missing information on the techniques in the fact sheets as time goes by. An overview of the missing information is given in table 7.1 Table 7.1. Overview of the missing information Fact sheet Partial or missing information Rotational scrubber Pressure, pressure drop Two-phase dust filter Fluid level, removal efficiency Absolute filter Emissions of very small particles Mist filter Pressure Wet ESP filter Emissions Condenser Emissions Zeolite filter Emissions, different preconditions Polymer adsorption Flow, pressure, design and maintenance, emissions Biological scrubber Emission data Flare VOC-emission (efficiency is known) Ionization Design and maintenance NSCR Pressure drop, permeability of fluid and dust

It is obvious from the table that additional information is especially needed on emissions and preconditions of process conditions like acceptable pressure and dust level.

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8 Index

Absolute filter 43 Cyclone 18 Ozone injection 122Absorber 82 Deep bed filter 46 Photo oxidation 125Absorption 81 Demister 46 Plasma cleaning 122Acid gas scrubber 85 Dry E-Filter 48 Polymer adsorption 72Acid scrubber 85 Dry electrostatic precipitator 48 Rotational scrubber 26Active coal filtering 65 Dry electrostatic precipitator 48 SCR 130Active oxygen injection 122 Dry ESP 48 Scrubber 82Adsorption (general) 62 Dry lime injection 75 Scrubbing (general) 23Adsorption 61 Dry lime-sorption 75 Scrubbing 22Adsorption of active coal 65 Dust cyclone 18 Selective catalytic reduction 130Aerosol filter 46 Dynamic scrubber 26 Selective non-catalytic reduction 128Air scrubber 82 Electro filter 48 Semi-dry lime adsorption 78Air separation with membranes 136 Electro-filter 51 Semi-dry lime injection 78Alkaline gas scrubber 88 Electrostatic precipitator 48 Semi-wet lime sorption 78Bag filter 33 ESP 48 Settling chamber 15Bio-bed 95 Fabric filter 33 SNCR 128Bio-bed filter 95 Filtering dust separator 33 Solvent recuperation 136Biodenox 99 Filtering dust-separator 37 Spray-dry adsorption 78Biofiltration 95 Filtration 32 Spraying tower 26Biological cleaning 94 Fixed bed lime-sorption 75 Surface filter 43/Biological filter 95 Flare 117 Thermal incinerator 109Biological scrubber (general) 102 Gas scrubber (general) 82 Thermal oxidation 108Bioscrubber 102 Gas scrubber alkaline-oxidative 91 Thermal oxidation 109Bioscrubber 102 Gravitation 14 Thermocat 113Biotrickling 99 Gravitational separator 15 Tube filter 33BTF 99 Heat exchanger 55 Two-stage dust filter 40Candle filter 37 Hefite filter 69 UV-oxidation 125Cartridge filter 43 HEPA-filter 43 Vapor recovery unit 139Cascade adsorption 75 High temperature filter 37 Venturi-scrubber 29Catalytic incinerator 113 Incinerator 109 Venturi-scrubber 29Catalytic oxidation 113 Ionization 122 Vortex separation 18Catox 113 Lavafilter 99 VRU 139Ceramic filter 37 MBTF 105 Wet cyclone 18Ceramic filter 37 Membrane filtration 136 Wet dust remover 23Chemical reduction 127 Micro filter 43 Wet dust scrubber 23Coal filter 65 Moving bed trickling filter 105 Wet E-filter 51Cold oxidation 121 Multi-cyclone 18 Wet Electrostatic precipitator 51Compost filter 95 Non-selective catalytic reduction 133 Wet electrostatic precipitator 52Condensation 54 NSCR 133 Wet ESP 51Condenser 55 OCC 55 Whirl scrubber 29Cooled condensation 58 Odour control condensation 55 Zeolite filter (adsorption) 69Cryocondensation 58 Other techniques 135 Zeolite filter 69

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9 Annexes Annex 1. Field emission data

Annex 2. Cost effectiveness calculations

Annex 3. List of suppliers that provided information

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Annex 1 Field emission data

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Annex 2 Illustrative calculations of cost effectiveness

gas flow characteristic costs efficiency concentration out concentration in difference reduced1. alkalische scrubber energie loog fixed operationeel purchase added annuiteit nm3/hour EUR/1.000 Nm3/hour mg/nm3 kg KEvariant 1 8800 440000 19500 0 500000 150000 105950 100000 5000 99 10 1000 990 99000 5,800505SO2 reduction kWh/year*euro/kWh euro/year 0,03 euro/year 0,3 0,163 euro/kg

0,11 euro/kWh ton/year*euro/ton 3-5 % day/jr*euro/day 30 - 250%220 euro/ton 0,3 - 2,53000 ton year

variant 2 8800 440000 45000 0 500000 1000000 244500 100000 5000 99 10 1000 990 99000 7,457576SO2 reduction kWh/year*euro/kWh euro/year 0,03 euro/year 2 0,163 euro/kg

0,11 euro/kWh ton/year*euro/ton day/jr*euro/day retrofit situation220 euro/ton3000 ton year

variant 3 8800 380000 19500 0 500000 150000 105950 100000 5000 99 10 1000 990 99000 5,194444SO2 reduction kWh/year*euro/kWh euro/year 0,03 euro/year 0,3 0,163 euro/kg

0,11 euro/kWh ton/year*euro/ton day/jr*euro/day190 euro/ton3000 ton year

2. Active Coal filter gas flow characteristic costs efficiency concentration out concentration in difference reducedreduction of VOS energie actief kool fixed of > operationeel purchase added annuiteit nm3/hour EUR/1.000 Nm3/hour mg/nm3 kg KEstyreen 25 26525,33333 0 2000 24000 7200 5085,6 4000 6000 98 10 500 490 1960 17,16119

kWh/year*euro/kWh 1400 euro/ton 0 euro/year 0,3 0,163 euro/kg0,11 euro/kWh 8 hour/day 30% belading day/jr*euro/day

van kool 1800 kg26525,33333

3. SCR gas flow characteristic costs efficiency concentration out concentration in difference reducedreduction NOx energie ammoniak fixed operationeel purchase added annuiteit nm3/hour EUR/1.000 Nm3/hour mg/nm3 kg KE

50 1798,2 35100 0 900000 270000 190710 60000 15000 90 60 600 540 32400 7,026488kWh/year*euro/kWh 150 0,03 euro/year 0,3 0,163 euro/kg0,11 euro/kWh 150 euro/ton NH3 day/jr*euro/day

370370 kg NH3/ton NOx

4. E-filter gas flow characteristic costs efficiency concentration out concentration in difference reducedreduction of dust energie reststoffen fixed operationeel purchase added annuiteit nm3/hour EUR/1.000 Nm3/hour mg/nm3 kg KE

47850 19990 0 2000 2000000 600000 286000 100000 20000 99,95 1 2000 1999 199900 1,780090,5 100 0 euro/year 0,3 0,11 euro/kg

0,5 kWh/ 1000nm3/h 100 euro/ton day/jr*euro/day 25 year afschrijving0,11 euro/kWh8760 h/year

8700

5. Bio-filter gas flow characteristic costs efficiency concentration out concentration in difference reducedreduction VOS nuts filtermateriaal fixed operationeel purchase added annuiteit nm3/hour EUR/1.000 Nm3/hour mg/nm3 kg KE

75000 10000 0 3200 400000 120000 84760 80000 5000 90 25 250 225 18000 9,6088890 euro/year 0,3 0,163 euro/kg

day/jr*euro/day 25 year afschrijving

mg/nm3

mg/nm3

mg/nm3

fixed investments

mg/nm3

mg/nm3

fixed investments

fixed investments

fixed investments

fixed investments

variable investments





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Annex 3 List of suppliers who provided information

Operating principle Factsheets / supplier BIENFAIT AIRTECHNIC HMVT LindeGas

Pure AirSolutions

Norit DMT Wateco Uniqfill Askove Freshfilter KWB Circlair DHV Esher Dahlman Codinox Mesys BV

Settling chamber x x xCyclone x x x xSpraying tower x x x x x xVenturi scrubber x x x x xDust scrubber general x x x x x x xElectrostatic filter (dry)Electrostatic filter (wet)2-traps dust filter x x xFabric filter x x x x x xCeramic filter xAbsolute filter x x x xDemister x x x x x x xMembrane filtration x x xCondensor x x xCryocondensation xAdsorption General x x xAdsorption Active Coal x x x x x x x xAdsorption Zeolites x xDry injection CaOSemi-Dry injection CaO xGas scrubber general x x x x x x x xAcid scrubber x x x x x x xAlkaline scrubber x x x x x xAlkaline oxidative scrubber x x x x xBiofilter x x x x x xBiotricklingfilter x x x xBio-scrubberMBTR xThermal incinerator x xCatalytic oxidation x xTorch x x

Oxidation Ionisation x x xSNCRSCR xNSCR x

Separation by gravity

Dust scrubbing

Biological treatment

Thermal oxidation

Chemical reduction

Filters

Condensation

Adsorption

Absorptie

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10 Colophon Infomil/Manual on air emission abatement techniques Client: InfoMil Project: Fact sheets on air emission abatement techniques File: B8176 Report size: 152 pages Author(s): Erwin Schenk, Juriaan Mieog, Dennis Evers (DHV) Contribution: Internal regulation: C. Cronenberg Project leader: Erwin Schenk Project manager: Date: February 2009 Name/initials:

DHV B.V. Ruimte en Mobiliteit Laan 1914 nr. 35 3818 EX Amersfoort Postbus 1132 3800 BC Amersfoort T (033) 468 20 00 F (033) 468 28 01 E [email protected] www.dhv.nl

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Fact sheets on air emission abatement techniques - Infomil