NOx Reduction using Reburning with Natural Gas

Final Report from Fuii-Scale Trial at SYSAV's Waste Incineration Plant in Malmö

Jan Bergström Miljökonsulterna

Nordisk Gasteknisk Center Nordie Gas Technology Centre

NOx Reduction using Reburning with Natural Gas

Final Report from Fuii-Scale Trial at SYSAV's Waste Incineration Plant in Malmö

Jan Bergström Miljökonsulterna

September 1993

NGC, GRI Disclaimer

LEGAL NOTICE. This report was prepared by Miljökonsulterna i Studsvik AB, as an account of work sponsored by the Gas Research Institute (GR!). Neither NGC, GRI, members ofNGC, members ofGRI, nor any person acting on behalf of either:

a. Makes any warranty or representation, express or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process di selosed in this report maynot infringe privately owned rights; or

b. Assumes an y Hability with respect to the use of, or for darnages resulting from the use of, any information, apparatus, method or process disciased in this report.

SYSAY ______________________ __

FOR EWO R D

In December 1991, SYSAV decided together with eight cc-funders to carry out a full­seale test at Malmö waste to energy plant with the purpose of reducing the contents of nitrogen oxides (NOx) in the tlue gas.

The method osed in this full-seale test is called "Reburning" and it irnplies injecting natural gas/landf1ll gas in to the fumace in order to establish a reducing zone.

The reburning method has been tested in USA at laboratory scale as weil as in a full­seale test with waste incineration and the tests showed a reduction of NOx emissions of up 60% with a moderate gas supply.

The objective of this full-seale test was to achieve an NOx reduction of at !east 50% without increasing the emission of other harmful substances.

The total budget of the project was SEK 8.5 mil!.

The overall responsibility and control of the project restedwith a steering committee set up by the funders:

Kaj Jönsson Jörgen Thunell Kerstin Larsson Karin Persson Bo Drougge Bent Karll Christer Pettersson Kjerstin Elevall

chainnan secretary

SYSAV SGC NUTEK SEU Naturvårdsverket NGC (representing GR!) REFORSK RVF

The responsibility for the practical implementation of the project rested with a project management group:

Erik Nord Kaj Jönsson Juhani Sirviö Bent Karll Lars Nilsson

project manager deputy project manager

SYSAV SYSAV SYSAV NGC Sydgas

The installation of the rebuming system and the fu11·scale test were carried out in 1992 and have resulted in this report

Malmö June 1993

~SAV B

A -~M--. önsson

Chainnan

Af;M!~t(_ Project manager

2

SUMMAR Y

Sydvästra Skånes Avfallsaktiebolag (SYSA V) operates a waste-to-energy

plant in Malmö with two units, incinerating 220.000 tonslyear of municipal

and industrial waste. These fumaces are since 1991 equipped with urea

injection to reduce emissions of nitrogen oxides.

In the autumn of 1991 SYSAV decided together with a number of co-funding

organizations to perfonn full-seale testing of "rebuming" with natural gas, as

an alternative or complement to urea injcction. Rebuming means injection of

natural gas to producc a reducing zone in the fumace where already fonned

nitrogen oxidcs are convertcd to nitrogen. Combustion air, in sufficient

quantity to accomplish complete combustion, is added after the rcducing

zone.

The rebuming system was designed by the Energy and Environmental

Research Corporation {EER) in California, USA, in ro-operation with the

Nordie Gas Tcchnology Centre in Denmark. In the design were also includcd

modifications of the airjetsto the fumace and supplementing with flue gas

recirculation to the fumace.

The aim of the project was to demoostrate that the above mentioned measures

could reduce the concentration of nitrogen oxides in the flue gas from nonnal

350 mg/m3 to lessthan 175 mg!m3, i.e. with more than 50% (m3 rueans

standard dry gas corrected to 10% C02).

The results showed that it is possible to reduce the concentration of nitrogen

oxides in the flue gas to 160 mg!m3 with injection of natural gas rorrespon­

ding to 20% of the thermal input to the fumace and in combination with flue

gas recirculation. The operating conditions of the fumace were howcver less

stable than before and the frequency of earbon monoxide peaks increased.

160 mg!m3 of nitrogen oxides rorrespond to an emission of 75 mg!MJ (waste

and natural gas). The same emission level is achieved with injection of four

kg of urea per ton of waste.

3

CONTENTS

FOREWORD SUMMAR Y

l u 1.2 1.3 1.4

2 2.1 2.2

3 3.1 3.2 3.3

4 4.1 4.2 4.3 4.3 4.4.1 4.4.2

5 5.1 5.2 5.3 5.4 5.5

6 6.1 6.2 6.3

Rcferences

Appendix l Appendix2 Appendix 3

IN1RODUCTION General Objective The project Final report

BACKGROUND- REBURNING The reburning process The Olmsted tests

THE SYSA V PROJECf Background Conceptual design of gas rebuming Predieted NOcreduction

REALIZA TION OF THE PROJECf Design Calculation results Construction and planning Operating resnits Test-run l Test-run 2

CONCLUSIONS Primary combustion The reducing zone Bomout Operating experience Target compliance for the project

ALTERNATIVE METHODS FOR REDUCING NO, SNCR for NOcreduction METHANE de NO, Combination SNCR!Rebuming

Financing Organizations Technical data P&! diagram

4

Page 2 3

5 5 5 6 6

7 7 9

JO ]0 12 13

]5 15 17 18 19 21 23

26 26 27 28 28 28

29 29 30 33

l INTRODUCITON

l.l General

Acidification and the fertilizing effect of the nitrogen oxides (NOJ emitted

during combustion have been ascertained, and measures to reducc NOx

emissions are high-priority environmental targets. Wastc incineration plants

contribute only to a small proportion of the emissions in Swedcn, but tbese

days demands for severe rcstrictions are being stipulated as conditions for the

license. From 1992, environmcntal charges wcre also introduced on NOx

emissions. There is therefore a great interest in finding cost-effcctive methods

of NDx reduction.

SYSA V (Sydvästra Skånes Avfallsaktiebolag [The South-wcst Scania Waste

Co. Ltd. J) has a waste-to-cnergy plant in Malmö with two grate-fired

incinerator units, incinerating an annual total of 220,000 tonnes of municipal

and industrial waste. In the hoilers approximately 500 GWh ofthermal energy

is recovered and sopplied ~o Malmö's district heating network.In the course of

1991, SYSA V iostalled a SNCR system with urea dosage on both units in

order to reduce NO x emissions. These have been in operation since December

1991.

SYSA V was also interested in having one of its fumaccs act as an evaluation

plant for a full-seale trial with NOx reduction using rebuming. Reburning

involves natural gas being dosed into the fumace to create a secondary

combustion zone, with reducing conditions in which the nitrogen oxides

formed above thegrateare decomposed. In 1991, the Nordie Gas Technology

Centre ha d drawn up a report (1) demoostrating the applicability of the

rebuming technique on SYSA V's fumaces and, taking this as their basis, it

was decidcd that a project should be carried out with full-seale trials.

1.2 Objective

The aim of the project was to demonstrate, by converting one of the units at

SYSA V's facil ity, that the emissions of nitrogen oxides can be reduced by at

least 50% from 350 mglm3 to 175 mglm3 (m3 refers to standarddrygas

corrected to 10% C02). This was to be achieved without increasing the

emissions of other harmful substances or creating operational problems (2).

5

ln order to obtain these conditions in the fumace, natural gas and landtill gas

were to be used as the rebuming fuel. Landtill gas is of local interest, being

recovered from SYSA V's main landtill site very ncar to the waste incineration

plant.

1.3 The project

The projcct was budgeted at SEK 8.5 miiL Besides funding from SYSA V, the

project was financed by eight organizations in collaboration. Appendix l gives

a summarized presentation of these.

The project plan for implementation was divided into eight stages:

l. Establishing basic prercquisites.

2. Design studies.

3. Retrofitting the fumace.

4. Test-running.

5. Optimizing the rebuming process.

6. Evaluating results.

7. · Long-terin perfonnance.

8. Final repnrting.

The project schcdule encompasscd the period from J une 1991 up to and

including November 1992. A 90-day-long operating period for investigating

the Iong tenn perfonnance was included. That part was not cornpleted because

the short tenn trial periods were judged to provide sufficient information. No

test were carried out using landtill gas because of limited supply.

1.4 Final repnrt

The project has produced a number of reports and additional reports have been

used to complete the final report. The reports are Iisted as references.

This final report was compiled by Miljökonsultema. It presents the results and

an assessment of the project. In the concluding chapter three different methods

forachicving NOx-reduction in waste incinerations plants are discussed.

6

2 BACKGROUND- REBURNING

The concept of rebuming employed in this report is a term derived from the

natural gas rebuming technology. To facilitate an understanding of the project

planning and the interpretation of the results obtained, we give a description

here of rebuming as a tcchnique and of the process variables affecting NOx

reduction. We also report on the full-seale trials which were carricd out at the

Olmsted Waste-to-Energy Facility in Rochester, Minnesota, USA

2.1 The rebuming process

The description of the procedure enabling natural gas to reduce NOx­

cmissions through rebuming is taken from a Nordie research project. This

involved researchers from four Nordie universities and is outlined in a project

report published by NGC entitled "Rebuming" (3).

It has Iong been known that hydrocarbon radieals rapidly rcact with the

nitrogen monoxide in combustion gases, and i t was attempted to exploit this

during the 1980s in the form of low-NOx engineering. By actding gaseous

fuel, reducing conditions are created in the fumace before actding combustion

air prior to final combustion. This generates combustion in three stages. Figurc

l shows rcbuming uscd for pulverized coal hoilers in which 20% of the heat

input is accounted for by natural gas.

Overfire air -

--80% coal --

Figure l

-w- 60% NOx reductlon

'---'~- Burnout Zone Nonnal excess air

--f--Reburnlng Zonc Sllghtlyfuelrtch NO x reduced to N2

Prlmary Combustlon Zon e

Reduced flring rate low excess air Lower NO x

The rebum technology applied to a wall fired hoiler

7

In the initial combustion stage, coal is fired with enough excess air to avoid

large quautities of combustible matter. Natural gas is subsequently mixed into

the hot combustion gases in sufficient arnount to make a fuelrich gas with

hydraearbon radieals but without oxygen. The best NO reduction isachicved

at air depletion corresponding to a stoichiometric ratio (SR) of about 0.9. At a

suitable distance from thelevelat which the natural gas is introduced,

combustion air is supplied in whatever volorne is required to achieve complete

humout with a controlied excess of air.

This three-stagc combustion is an effectivc method of reducing the NO

content, especially in coal-fircd boilers. Coal oftcn yields a high NO content

directly in the first stage of combustion. By mixing natural gas into the

combustion gas, the excess oxygen is consurned and the natural gas

contributes methane radieals which react with the oxygen in the NO at the

same time as N2 is formed. If reduction takes place at a high temperature with

sufficient residence time, NOx emission can be reduced by up to 70%.

The composition of the main fuel and its actmixture with the combustion air

determinc the temperature leveland excess air prevailing in the combustion

gas emitted from the primary stage. If the excess air is not greaterthan SR=

1.1, natural gas equivalent to 20% of the total heat input will be sufficient to

give SR = 0.9 in the reducing zone.

The rcsidence time of the gas in the reducing zone often imposes a constraint

when the reburning tcchnique is applied in existing bo il ers. The survcys

available from laboratory and pilot studies using pulverized coal firing show

that 0.5 secs is a sufficient residence time. In practical combustion terms,

however, it is obvious that the necessary residence time is greatly detennined

by the mixture ratios between the natural gas and the combustion gas from the

primary zone.

An clcvated gas temperature in the reducing zone prometes NOx reduction,

though there are reports showing a good effect at temperatures as low as

woo•c.

8

2.2 The Olmsted tests

A comprchcnsive research programme started in 1987 in the USA in order to

stud y the possibilities of reducing the NOx emission from waste incineration.

The aim was to minimize NOx emission by dosing natural gas above the grate

and optimizing operations by minimizing excess air during the final

combustion. The research programme was conducted by the Institute of Gas

Technology (IG1) and Riley Stoker Corporations (Riley) in association with

the Olmsted Waste-to-Energy Facility in Rochcster. The work carried out

included laboratory tests at IGT, pilot trials at Riley Research and full-seale

testing at Olmsted. The full-seale trials on rebuming- or as it is called

nowadays, the METIIANE de NOx System - were performed in Olmsted in

December 1990 and January 1991. A final report was made out in December

1992 (4).

The results from Olmsted were very promising; reductions in NOx and CO are

summarized in Figure 2.

20 L--------------+ CO, ppm 10 20 30 40 50 60 70 80 90

Figure 2

NOx and CO reduction at Olmsted

The officers supervising the SYSA V Project visited Olmsted (5). The

converted fumacc was 12 MW and produced an operating rcsult

corresponding to those found in the pilot-seale trials. By mixing in 12-15%

of the heat input as natural gas and 8% flue gas recirculation (FGR) to the

9

fumace to improve the mixing, it was possible to cut the total excess air from

100% to 40%. Combustion was rcndered more stable, halving the average

content of CO from a leve! of 50-60 ppm to 20-30 ppm. Togethcr, these

measures resulted in the NOx emission being rcduced by 60%. The flue gas

emitted bad a NOx content levet of approx. 50-60 ppm (at 12% 0 2).

The METHANE de NOx System is further diseossed later in this report.

3 THE SYSA V PROJECf

3.1 Background

At the time it was decided to go ahead with the project, there were preliminary

studies from EER (l) and experiences from full-seale trials at Olmsted bad

been obtained through the study visit (5).

EER found that the SYSA V facility was an ideal site for demonstration of

rebuming on a mass bum municipal waste incinerator. The design of the

facility and the romposition of the waste make the result potentially

applicable to many installations. Th~ design of the fumace and boiler in

Malmö is shown in Figure 3. A picture of the flow pattem for the entire

installation is shown in Appendix 2.

EER indicates that one potential concem with rcspect to application of gas

rcbuming to the SYSAV facility is the presencc of the wingwall (heat transfer

surface) in the upper fumace since this surface reduces the available residence

time for the process. However, this effect ma y be offset by the lower excess air

levels and higher fumace temperatures which the Malmö incinerator has in

comparison to units in the United States.

EER refers to the studies which have been referenced here, as these detail the

conditions under which NOx reduction is achieved. The volorne of natural gas

which is needed is statedas 15-25% of the total heat input.

10

13.1 m

.5m

Figure 3

Wingwall -

Grate .,.... Width = 4.7 m Length =8m

Fumace and hoiler at SYSA V.

3.6m o

3.9 m

The significance of an efficient mixing of gases, both in the rebuming zone

and in the bum out zone, is stressed. It is estimated that a good mixing can

reduce the total excess air and still yield low contents of CO in the flue gas

and unbumt in the fl y as h.

A high fumace temperature in the rebuming zone promates NO~ reduction,

hut dosing of natural gas must be done at a levet where the primary air is able

to oxidize the bulk of the volatile hydrocarbons from the fuel bed. The

temperature of the gas at the point where the bum out air is fed in does not

affect the reburning process, but it must be high enough to produce oxidation

of earbon monoxide and hydrocarbons from the reburning zone.

11

The significance of the residence time in the rebuming zone is emphasized. It

must allow adequate time for mixing of the gases and for rebuming, and is

given as 0.3-0.5 seconds. EER refers to the longer residence time indicated by

the IGT/Riley studies on waste combustion but notesthat this result depends

on reactions other than rebuming.

3.2 Conceptual design of gas reburning

Having outlined the underlying concept, EER presenteda design for

conversion of the facility. The principle is illustraled in Figurc 4.

MSW

Figure 4

---o, Fumace Width- 4.6 m

Bumout Zone

Rebuming Residance Ttme- 500 msec

c;~·········z········"-'._ .... ·-Il'= _L

Primary Gombustian Zone

Conceptual design for application of gas rcbuming

12

The EER concept includes

natural gas will be introduced from the front and rear wall of the

incinerator at an elevation slightl y a bo ve the current row of

upper overfire air jets

flue gas will be recycled to the rebuming fuel nozzles

the overfire air used to complete oxidation of the products from

the rebuming zone will be injected in new rectangular over fire

air ports at an elevation above the rebuming fuel jets correspon­

ding to a rebuming zone residcnce time of approximatel y 0.5

see

the existing lower overfire airjetson the rear wall will be kept

in operation. The existing lower overfire airjetson the front

wall will be taken out of service. It may be necessary to recycle

flue gas to the airjetstaken out of service to kecp them from

overheating

i t may be necessary to recyclc flue gas to the grate if it is found

that the undergrate air flow can not be reduced to the desired

design conditions without resulting in overheating of the grate.

At fullload the rebuming system will use natural gas corresponding to

approximately 23% of the total heat input. Approximately 3% of the flue gas

will be recycled to the rebuming fuel nozzles to enhance mixing of the natural

gas with the products from the primary combustion zone.

3.3 Predieted NOx-reduction

The estimated reduction of NOx-emissions are based on three factors.

l. Reduced thermal input to the grate. The capacity of the hoiter is

limited which means the heat input with the rebuming fuel must

be compensated with reduced heat input to the grate.

13

400

~300

~

"' 'O 200 M

E z o .s

• ~ 100

o

2.

3.

Lowering the excess air ratio in the lower fumace and the

overall excess air in the bumout zone.

The application of gas rebuming

Predieted overall NOx-emissions are shown in figure 5.

Baseine

Figurc 5

Load Reduction Excess Air Reduc:OOn

NO x Errissions after

Preliminary estimate of gas reburning perforrnance

Gas Rebuming

The reduced heat input to the grate is expected to lower the NOx-concentra­

tion from 350 to 300 mg/nm3. Although the final NOx-emissions levet de­

pends upon the absolute reductions in NOx contributed by each factor, this fi­

gure shows that the anticipated emissions levet due to applying gas rebuming

is below the target value of 175 mglnm3 (dry corrected to 10% C02) at even

the lowest valuc of anticipated NOx reduction. Therefore i t is expected that the

projcct goal is casily achievable with gas rebuming.

14

4 REAUZATIONOFTHEPROJEIT

4.1 Design

When the project was set up, EER, together with SYSAV, carried out the

studies at the facility on which the design and projection of the rebuming

systern bad been based. That work is detailed in a separate report (6).

The design of the rebuming facility was complicated samewhat by the fact

that SYSAV simultaneously iostalled a SNCR system (urea dosage in the

fumace) with the airn of reducing NOx emissions.

Baseline data for the design of the rebuming system were generaled by rneans

of mcasurements at the facility. The contro l strategy u sed at the facility

involve controlling the excess air within a given range with a low CO content

by centrolling the feed of waste flow to the grate. The interrelation of 0 2 , CO

and fumace temperature is illustraled in Figure 6.

Temp c o

c o

_-_-_-_-_-_-~ _-_-_-_-1::=::(

Figure 6

Optimal operating excess air

Furnace Temperature

Excess Air (Optimal)

Excess o,

The process design was established by studying the flow behaviour in the

furnacc as rcalized in a physical plexiglass model. At the same time, thermal

conditions in the furnace were described together with the thermalload on the

hcating surfaces in a mathematical modets.

15

With the aid of the result from the model studies, the design and position of

the jets were determined in order to supply recirculated flue gas, natural gas

and combustion air to the fumace. The main dimensioning data as prescribed

by EER are shown in Figure 7.

UPPER FRONTWALL OFA PORTS o Elevation- 14.7 m

6 ports 156l( 405 mm 15' downward Wt Velacity-16m/s

FRONTWALL AEBURNING FUELJETS

Elevation- 12.6 m 6jets046mm 30' downward Velacity- 73 m/s FGR2%

LOWEA FRONTWALL OFAJETS

Elevation- 11.6 m 14 jets 0 50 mm

o Coo~ng FGA flow

Undergrate Air Plenums

FifWre 7

UPPER BACKWALL OFA JETS o Elevation- 14.7 m

6jets 0 52 mm 45' downward Vetocity-58 m/s

BACKWALL REBURNING FUELJETS

Elevation -12.7 m 5jets052mm 30' downward Velacity- 49 m/s FGR 1.5%

LOWER BACKWALL OFA JETS SR 1 = 1.07 o Elevation- 8.0 m

/

FGR-4%

)b=e:J 0105~ts (4 jets out of service)

"mm

c__vc'c"'cc''c-c"::"':'~------_j

Sommary of specifications for the reburning system

Figure 8 shows the design of the jets for natural gas and flue gas on the front

wall.

16

Jet design and position were selected to give the best distribution of air, flue

gas and natural gas on the basis of the modet trials that werc carried out.

MO

Figurc 8

) Sel Scl-@ 120' Tu H<>ld PD&Itlon

Conceptual design of the reburning fuel injector

4.2 Calculation results

EER computed the temperature profile in the fumace for a number of different

operating modes. One example is shown in Figure 9.

;:; ';! oo:L:; ~ =;3&:~ ~ ~ec ; ~ o

z .s 900

Reduced Load Cases:

u800 _:-:_ ~ ~ 5) Baseline - ' ' - '-. 7) Rebuming, SRg= !.05, SR1 = 1.15 o

100 o

Figure 9

~- · 8) Rebummg, SRg= l.OO, SR1= 1.10 \ - 9) Rebuming, SRg= l. lO, SR1 = l. !O

5 10 15 Mode! Height from Backwall OFA Nozzles (m)

Effects of reburning variations at rcduccd load on surface temperatures

17

The mathematical mode! shows no elevated temperature in the top of the

fumace in front of the wing wall, while the temperature is raised approx.

100°C in the lower part of the fumace. The temperature level increases with

the thermalload but the profile remains roughly the same.

In parallel with EER's efforts, mathematical modelling was done at SINTEF in

Nmway (7). Six different operating modes were simulated for rebuming in

SYSA V's fumace. The results showed that gases could be expected to be weil

mixed in the reducing zone but worsc in the burn out zone. The model pre­

dieled that high temperature peaks would occur near the wing wall concurrent

with high contents of CO.

4.3 Construction and planning

A detailed structural design was finalized, producing guidelinesfor natural gas

pipelines, landfilt gas, flue gas ducts, safety equipment and measuring and

control system. The work was carried out by SYSA V in cooperation with

Sydkraft Konsult AB in Malmö. A P&l diagram for the process is outlined in

Appendix 3. A detailed functional description was compiled by Sören Lundh

Konstruktionsbyrå AB for the control system of the facility (8).

The installation work was demanding, as the space available for piping was

restricted at the facility. Trimming in the system and getting the process

computer function for the measuring and control equipments operational was a

time-consurning process. The facility was ready for shake down tests in May

and for test-running in Jul y 1992.

In conjunction with the planning work, a plan was designed by NGC for

testing the rebuming system. The measuring programrue was designed to

clarify the limits for utilizing the rebuming technique in the facility and to

establish optimized operating conditions (9). The principal parameters to be

studied were fumace load, excess air in the primary zone and the stoichio­

metry of the rebuming zone. The trial was planned as a complete factor trial

with 27 operating modes.

18

The programme included extensive sampling and measurements of all

parameters which might be of interest in evatoating the rebuming and

determining optimized operating conditions as well as clarifying whether it

producedan y change in gas composition or unbumt material in the fly ash.

For all operating modes, part of the testing programrue involved analyzing the

occurrence of dioxins in the combustion gas leaving the boiler. Optimized

conditions for long-term testing were to be detennined by assessing the

results of the testing programme carried out.

Testing according to planning were not accomplished duc to the fact that

sufficient stable buming conditions could not be established.

4.3 Operating resulls

In April1992, the modified facility was put into service according to the

project plan. As mentioned before, calibration of the measuring equipments

and shake down of the control system Iasted longer than planncd. Then the

first trial with natural gas could not start until July 1992.

In order torunthe modified fumace solelywith waste, new baselinc operation

conditions bad to be established directl y after the rcconstruction. The new

design of the jets and the air ports did not result in acceptable bum out with

flue gas recycling. Air and flue gas ducts were thercfore rearrangcd in such a

way that air and flue gas was mixed and injected in the jets for fluc gas

recirculation.

An acceptable base Iine operation was established by supplying the major part

of the primary air to the two first zones of thegrateand only air to the jets.

Table l shows typical base Iine data.

The change in air distribution in the fumace occurring as a result of air jet

modifications renders fumace operations less stable. The frequency of time

with bad bum out was increased and was recorded by the number of CO

peaks. Particulart y when the fumace is not operated at maximum grate load.

19

Table l

Basline operation

Boiler output 28 MW

Primary air 33000 run3/h

Over fire air

upper frontwall OF A ports 3300 run3/h

upper backwall OF A jets 1500 nm•!h

FGR-jets (with air)

lower backwall OFAjets 5000 nm•!h

lower frontwall OF A jets 1000 run3/h

frontwall rebuming fuel jets 1900 nm•!h

backwall rebuming fuel jets 1100 run3/h

Furnace temperature 850 •c

Heat input

waste 35 MW

natural gas o MW

Flue gases:

flow 69500 nm3/h temperature 260 •c

o. 6.6 vol %wet gas

mo is ture 13.5 vol %wet gas

co 66 mg/run3 wet gas

NO 210 mg/nm3 wet gas

No. 3 mg/nm3 wet gas

At the same time the NO, emission was found to be 275 mg/nm3 (as N02 dry

gas corrected to 10% C02). The new air and flue gas distribution in the fur­

nace resulted in reduced NOx emission but less stable combustion compared

with before retrofitting the furnace.

1\vo test runs were carried out to study the influence of flue gas recirculation

and natural gas injection. A great nomber of data were collected and eva­

luated. The first test run were carried out in July/Augost 1992 by SYSAV and

Miljökonsultema. The seeond test run were carried out in November 1992 by

SYSA V and EER.

20

4.4.1 Test-run l

The instruments for measurement and control were calibrated in connection

with the test-ron. The capacity of the process computer made it possible to

stud y and evaluate the different modes of operation directly during the test

periods. A great nomber of operationalmodes were tested in a few days time.

(lO)

According to the figurcs shown in table l, 9000 m3/h combustion air sopplied

in the lower FGR-jets achieved sufficient oxygen and creatcd enough

turbulence for complete bum out of the flue gas. When the air is replaced by

recirculated flue gas, the vetocity in thejetson the fumace wallsis definitcly

maintained, but the mass flow of gas decreases as the temperature of the gas

rises. The flue gas also contains less oxygen than air. As a result, it is

impossible to bum out the CO in the flue gas to attain the level required.

Despite systematic attempts to optimize the distribution of recirculated flue

gas, the CO content could not be brought down under 100 mg!m3. This fact

makesthat particular operationalmode unacceptable at this facility. Nor did it

prove possible to achieve satisfactory final combustion by increasing the

amount of bum out air in the airports high up in the fumacc. During those

operating periods when it was attempted to optimize final combustion by

FGR, the presencc of a low NOx content was ascertained w hen CO was high.

This observation is of no practical interest since the facility cannot be run with

an elevated content of CO in the flue gas. The earrelation between CO and

NOx is shown by Figure 10.

21

450

• 400 ...

\:: • 350

• .300 ' ..... •

o .. -. • • if' • • o •

250 • • 1ii .. • • • o E • c

"' E 200 x • o z

150

o "r - • o 500 1000 1500 2000 2500

CO in Flue Gas mglnm3

Figure 10

The correlation bctween CO and -NO x content

Natural gas injection does not produce better bum out conditions. It was not

possible to findamode of operation with FGR and natural gas with stable

bum out in the flue gas and CO below 100-150 mglrun3,

The periods of testing carried out using natural gas demoostrate reduced NOx

contents. With the proportion of natural gas forming 15% of the heat input, the

NOx content was measured to be the equivalent of 150 mg!nm3 at 10% C02.

However, the CO level in this case was 400 mglnm3. Natural gas and the gas

recirculation created conditions when the NOx reduction was betterthan the

target 50% but the bum out was not acceptable. It can be eaused by the gas

temperature in the fumace.

The temperatures measurcd in the fumace are low. Under basic operating

conditions, 850-900°C is recorded as the highest temperature at a boiler

output of 30 MW. The recorded fumace temperature increases by approx. 8°C

per MW of hoiler output - see Figure 11. 'The gas temperature drops as a result

of heat being transferred to the hoiler walls, sothat it is appreciably lower

when the flue gas reaches the wingwall at the top of the fumace.

22

"'"" 950

""" 650

""' u "'

700

650

600

sso

500

"' "

• • •

• • . .

22 25 JO " MW

Figure 11

Fumacc temperature as a function of hoiler load.

The fumace temperature is recorded with an unprotected thermocouple. The

gas temperature might therefore be a hundred °C higher. However, the fact

remains that to a !arge extent heat transfer to the hoiler walls already takes

place in the bottom part of the fumace, and those reactions promoted by a high

gas temperature, e.g. final oxidation of CO, do not occur to any notable extent

in the top section of the fumace.

The supply of natural gas in the fumacc does not increase the temperature

materially. 6 MW natural gas, making up 15% of the heat input, increases the

recorded fumace temperature only 80°C at the inlet to the wingwall. The

prevailing low temperature makes it difficult to ensure satisfactory bum out of

co.

4.4.2 Test-ron 2

The mcasuring results obtained during test-run l were evaluated by EER, who

conducted a series of complementary measurements and evaluations during

fourdaysin November 1992 (11). Thesetests were focused on both

23

400

ON 350 o

"' o o

300

"' ~ 250 M E z 200 -"' E

'" 150 c o

'" 100 ~

E w

" 50 o z

o 10:00

combustion air and FGR distribution effecting the burn out of CO and how

amount and distribution of natural gas influenced the NOx-reduction.

The tests confinned t hat sta bl e combustion condition on l y we re

obtained with air in the lower FGR -jets. With this mode of operation a

numbcr of tests were carried out with gas rebuming. Figure 12 shows NOx and

CO concentration in the flue gas during five hours of operation .

" ' ' ~-il j "

!

11:00

! ! ! tests

12:00

Figure 12

•

• o

!

13:00 Time ol Day

NOX

c o

! !

14:00

Gasrebuming with air through the lower BW jets.

24

! ! !

15:00

3000

2625

c 2250 u

M E

1875 z

1500 -"' E ~ c Q

1125 ~

750

375

o 16:00

E

"' o o

3000

~2500 ~

n

~ 2000 c, E vi 1500 c o

" -~ 1000 w o () 500

o 0.8

l l l l • l T l l

0.9

In order to obtain sufficient bum out with low CO-contents in the flue gas

excess air is required in the primary zone over the grate also with gas

rebuming. Air must earrespond to at least SR = 1.1 which means significant

amounts of natural gas must be injected to create reducing conditions in the

fumace. Figure 13 show SR in the primary zone with different amounts of

natural gas.

- 400 N • o

() 350

"' o o

o 300

"' :s 250 n

00 E o l z 200 c, k o

E

"' 150

c o

" 100 ~

E w 50

' ~ o

z o 1.0 1 1 1.2 13 14 0.8 o 9 1.0 1 1 1 2 1.3 1 4

Primary Zone Stoichiometry Primary Zone Stoichiometry

Figure 13

• Non GR Operation

n GR operation@ 1 O% NG input

" GR operation@ 15% NG input

o GR operation@ 20% NG input

The stoichiometry of the primary zone.

Figure 14 shows NOx and CO measured with SR between 1.1 and 1.2 in the

primary zone. Low CO-content is maintaincd also with reducing conditions in

the rebuming zone. The NOx content is reduced as the proportion of natural

gas increases.

The maximal natural gas flow corresponding to 8 MW or 20% of the total heat

input reduced the NOx to about 160 mglnm3 (drygas 10% C02) without an y

increase in CO content when SR in the primary zone were 1.1

25

400 n

N o 350 o

"/

"' O Q Il~ • ~ 300 () dl ) /l

"' Q]J~t~~ Il ~ 250

o~J~: "" " E ~ 200 }.-t\- cb rr Il

1 ۤJ 111 E o u

"' 150 c -~ • 100 ·~

•• w o" 50 • • • z • • • • .... LJ

o

load: 25-30 MW Out SRg =0.9-1 10 sR 1 = 1.1 -'-2

3000 400

N o 350

2500 u

' l'

" ~ 300

2000 ""E "' ~

~ 250 " E

1500 • z 200 c i> o E

" 150 ~ • c 1000 o w " • wo o e o

500 w o" 50 z

o o

Basel1ne NO emo<SIQM ---- _.__-- ---

o

"o

"' -"-f-~ _!ar.'!!I~•S~ns_tfä __ (~ _:(j_-, o

0_85 0.90 0.95 1.001.05 110 115 1 20 1 25 o 5 10 20 25 Reburniog Zone Sloich1ome1ry

Il NO ' • co

Fil;ure 14 NOx emissions at 25 to 30 MW load range.

5 CONCLUSIONS

NG Heatlnpul (%o! Tolal)

Realization of this project has resulted in one of SYSA V's units being

cquipped with a measuring system and process calculation resources, enabling

combustion results to be monitored inadear and lucid fashion. lt is therefore

possible to draw conclusions despite the fact that the total operating time with

natural gas is not extensive.

5.1 Primary combustion

The gas composition and excess air from the waste on the grate varles

significantly both with time and in different parts of the primary zone. The

combustion is very different from coal firing where gas rebuming first was

applied. In the homogeneous pulverized coal flame the temperature is high

and thennal NO contributes to a major part of the total nitrogen oxides.

Waste firedon the grate results in relatively low temperatures and fluctuating

excess oxygen. The limitedamount of overfire air or flue gasthat is possible

to add to the fumacc will not create sufficient mixing before the reburning

zone.

26

Stable combustion conditions in the primary zone are achieved when the gratc

load is high and the SR at !east 1.1. This is due to the combined effect of the

fuel bed covcring the grate and the higher temperatures which are obtained in

the combustion gas. The large-scale transfer of heat to the fumace walls

provides a quick drop in temperature. When the planning of the project were

carried out the significance of this was underestimated, and during the project

it has not been possible to improve the primary combustion conditions

enough.

The NOx emission increases with the increase in waste load. The evaluations

made of the data from test -run l show that in the rang c 26-34 MW, the bo il er

load increases the NOx content by 10 mg/nm3 per MW, all other conditions

being equal.

5.2 Tbe redodog zone

The natural gas which is dosed in eonsornes the excess oxygen in the

combustion gas and raises the gas temperature through the input of heat.

However, heat transfer to the fumace wallstakes place quickly, preventing

temperatures in excess of 1000°C from occurring in the rebuming zone. The

gas temperature is lower than predicted in the models by EER and SINTEF. In

the fumace the highest recorded gas temperature is between 850 and 900°C.

Compared with successful rebuming in coal fired hoilers it is considerably

lower.

The project result shows NOx-reduction with use of natural gas. The NDx­

reduction is the same when natural gas lower SR from high level eg 1.2 to 1.1

compared with SR from 1.0 to 0.9. Consurning oxygen with natural gas

corresponding to SR 0.1 gives a NOx-reduction of 60 mglnm3 which can be

seen in figure 14.

Whether there would be a better reduction in NDx if the residence time were

incrcased above the 0.5 secs provided for by the fumace is beyond

clarification in this project.

27

5.3 Burn out

When the gas mixture from the reducing zone is mixed with bum out air, the

temperature is too low. Natural gas only contribute to a marginal increase in

gas tcmperature. The final excess oxygen levet to reach low CO in the flue gas

is the same both with and without natural gas in the fumacc. Excess oxygen is

nonnally 6-7% (by volume wet gas).

Increasing the 0 2 content from 5 to 8% only serves to raise the NO x content by

25-40 mg!nm3 at JO% co2.

5.4 Operating experience

The operating conditions have changed due to installation of the gas reburning

system. After trimming, a base linemode of operation was obtained. Calibra­

tion of the process instruments and the experience from the first test -run made

the facility operating wcll.

The recirculatcd flue gas, taken from the dust precollector outlet, still

contained considerable amounts of dust as result of which:

the FGR jets have to be cleaned;

occasionall y coating of dust eauses disruptive speils of vibration

in the FGR-fao;

dust deposits occur in the FGR ducts;

dust coatings accumulate on the flow transmitters at low flue

gas temperatures.

5.5 Target compliance for tbe project

The project successfully completed the installations and realized the set-ups at

the facility, as planned. The facility has since functioned in ordinary operating

mode. The prime target of rcducing NOx emission with 50% from the original

Icvel of 350 mg/nm3 was achieved. The changcd operating mode due to mo­

dified air distribution reduced the NOx emission to the level of 275 mg!nm3.

With natural gas accounting for 20% of the total heat input, the NOx content is

28

reduced to a levet of 160 mfVnm3. NOx is always calculated as equivalent N02

calculated in dry gas corrected to 10% co2.

The modifications to the air distribution in the furnace have resulted in a less

stable Combustion. The incidence of cases where difficultics in achieving

satisfactory complete burn out have increased. It has not been tested if the

emissions of other harmful substances have been affected, bu t Iikely there is

no increased emission of arornatics in the flue gas after the fabric filter.

6 ALTERNATIVE METHODS FOR REDUCING NOx

Instead of gas rebuming reduced NOx emissions can be achieved using a

selective noncatalytic reduction (SNCR) system with urea injection or the

METIIANE de NOx system developed byIGT and tested at the Olmsted

Facility in the USA.

As a general principle, selective catalytic reduction (SCR) systems can be

iostalled but considerably greater costs arethen entailed the NOx-reduction

both for investment and operation. It is also possible to combine SNCR and

gas rebuming.

In the following section the SNCR, METHANE de NOx and the combined

system are described in slightly greater detail.

6.1 SNCR for NOx-reduction

Since December 1991, both fumaccs at SYSA V Plant have been fittcd with

equipment toprepare the urea solution and dose this into the fumaces with

nozzles at two levels. Appreciable NOx reduction is thus achieved. At the time

of the periodic inspection of the installation (12) in August 1992, a NOx

content of 125 mfVnm3 drygas at 10% co2 was measured in the flue gas from

unit 2. This corresponds to 60 ~g!MJ fuel input.

The urea dosage, which rises to something in the order of 4 kg/ tonne wastc,

results in a measurable emission of ammonium in the flue gas. On inspection,

the content of N~-ions in the flue gas was 13-19 mg/nrn3 drygas at 10%

C02• The annual mcan valne of the NOx emissions at the plant is somewhat

greaterthan the inspcction value, rising to a Ievel of 80 mg/MJ fuel input.

29

Similarly, the measurements show that the ammonium slip is lower than it was

during inspection.

6.2 METHANE de NOx

The conversion of the waste-to-heat facility in Olmsted and the installation of

natural gas yielded a result of up to 60% reduction in NOx emissions. At the

same time, the excess air in the flue gas was hal ved, as was the content of CO.

The results achieved in the development work carried out over several years

are shown in Table 2.

Table 2

Averagc operating data -1990/1991 field evaluation tests (13)

FGR + NGas At Normal A<

19!!7 Normal Basel in.: 1991

Ba~e!tn.: MSW Input Basdine

!987 1991 (Averag.: MSW Input

Test Test FGR Only Data} Test

MSW,· lb/h 6,450 7,900 7,400 6,650 7,100

Natural Gas,% o Il Il 14.8 \2.9

Total Heat Input," 106 Bw/h 33.5 41.2 JH.6 40.5 42.5

FGR,% o o 7.9 8.7 10.6

Total Flue Gas, lb/h 46,000 59,000 46,0()() 48,000 45,400

Stcam Flow, lb/h 23,500 2H,2SO 27,300 28,600 JO,SOO

Economtzer Exit Tempera ture, °F 417 425 4){} 422 422

Precipitator lnlet

o.,% _, 9.3 10.5 H.9 6.5 5.9

CO, vppm, at 7% Oz 47 72 ]{)() 35 33

NOx, vppm, at 7% Oz 210 IR5 150 75 75

"Estimated.

The ME1HANE de NOx system stems from the fundamental expcrience

gained from the rebuming developed for pulverized coal boilers. Rebuming

involvcs that NO formed primarit y at a high temperature are being reduced in

the flue gas at a high temperature when reducing conditions are created

through the addition of natural gas. The development work has however

shown that other factors have great importance for waste combustion.

ln waste incinerators, only a minor portion of the nitrogen oxides are formed

primarily as NO above the bed. The creation of an oxygen-free combustion

30

gas at a high temperature is thus not essential to the final result. Instead, the

natural gas which is doscd in is instrumental in reducing the 02 content

downstream of the primary combustion zone and thus in minimizing the

formation of NO x from other nitrogen compounds such as N~ and HCN.

Figure 15 illustrates the METHANE de NOx approach for waste incinerators

iostalled at the Olmsted facility. Natural gas and recirculated flue gas are

injected above thegrateand the secondary overfire air is injected at a higher

elevation in the furnace.

Undergrate Air

Figure 15 The METIIANE de NO, process

Natural Gas/ Recirculating Flue Gases

ln order to derive the most favorable effect from the natural gas, combustion

on the grate needs to tak e p~ace in a controlied way, minimizing the

differenccs in excess air between the various parts of the grate exterior.

Natural gas together with recirculated flue gas for mixing provide an oxygen

deficient secondary combustion zone that promotes the destruction of NOx

precursors as weil as NOx. In the Olmsted facility the good results were

obtained with 12 to 14% of the flue gas recirculated.

31

Figure 16 shows that the flue gas in the reducing zone is not oxygen free, yet

NOx-reduction still takes place. [t is the same result found in the full scale test

at the SYSA V facility

=.------------------------------------.

180 O BASEUNE

N o

'"' "rf!. 140 ,._

E "' o_ o_ > x- 100

o z •

e METHANE de·NOX

•• •

• •

•

• •

eo • • • •

•o L_----~----L-----~----"-----"------i_----~-----J

' • ' w

SECONDARY ZONE OXYGEN,%

Figure 16

Effect of excess oxygen concentration on NOx-formation

The residence time of the combustion gas in the reducing zone is of crucial

importance to NOx reduction. In the Olmsted fumace, the residence time was

1.1-2 seconds. When the air for bum out was mixed in earlier, NOx reduction

was less good.

The mixture ratio of the combustion gas already in the primary zone and the

actmixture of natural gas to form a homogeneons gas in the reducing zone are

decisivefor the successful exploitation of the ME11lANE de NOx system.

The results achieved through the project at the SYSA V facility tall y with

those from Olmsted, although the impact of the residence time cannot be

verified. The great importance of the mixtureratio in generating a

homogeneons gas in the reducing zone means that each separate fumace and

32

each operating mode must be optimized separately in order to achieve

maximum NOK reduction by means of the natural gas injected.

6.3 Combinatlon SNCR/Reburnlng

lnjection of natural gas may be combined with injection of urea in the fumace.

The combined system may provide higher NOK-reductions than expected by

the individual reductions. EER has patentedthis combination and narned it:

"Advanced rebuming". The system is developed for coal firing. In a pilot

plant, 80% NOx reduction is demonstrated with 10% of the total fuel heat

input being natural gas and urea injected with the bum out air. (14)

Injection of nitrogen containing compounds like urea in the fumace forther

reduces NO in the hum out stage. The earobined effect of gas rebuming and

SNCR as NOx-reducing methods will be very effective in tbose situations

where it is possible to modify the fumace, so the rigth temperature zones and

residential times are obtained.

The METHANE de NOx, full scale tests with waste incinerations show that

the NOx-reducing effect of natural gas injection in the fumace is not primaril y

a rebuming effect. Natural gas mainly contributes to create homogeneons gas

mixture with low oxygen content. in which the NOx-precursors like N~ and

HCN are prevenled from destruction, before they enter temperature zones

suitable for SNCR-reactions. It is not known, if an addition of urea improve

the NOK reduction in the same way as demonstrated for pulverized coal firing.

Obviously, the SYSA V facility has most of the installations necessary in order

to test the additional effects of the combined systems for NOx-reduction.

33

REFERENSER

l

2

3

4

5

6

7

Technical Support for Field Evaluatian of MSW Combustion with Natural Gas Rebuming Phase l - Final Report Energy and Environmental Research Corporation June 1991

NOx reduktion genom Reburning med naturgas/deponigas Fullskaleförsök vid SYSA Vs avfallsvärmeverk i Malmö Projektbeskrivning Nordisk Gastekoisk Center (NGC) Juni 1991

Rebuming Process Parameters, Implementation and NOx-reduction Potential Peter Glarborg, Technical University of Denmark Bent Karll, Nordie Gas Technology Centre September 1991

Emissions Reduction from MSW Combustion Systems Using Natural Gas Task 3, Field Evaluatian Harnid A. Abbasi, Institute of Gas Technology Frank J. Zon e, Riley Stoker Corporation December 1992

Reserapport, D nr SGD-91 04-12 Besök på- Olmsted Waste -to Energy - Municipal solid Waste U nit, Rochester, Minnesota, USA Lan; Nilsson, Sydgas Erik Nord, Sysav Maj 1991

Technical Support for Field Evaluation of MSW Combustion with Natural Gas Rebuming Phase II - Final Report Energy and Environmental RCscarch Corporation November 1991

Mathematical Modelling and Numerical Simulation of the Rebuming Process in Waste Incinerators Description of Methods and Application to the SYSA V Incincrator B. Lakså, S. Byggst0yl, S. Aune, B.F. Magnussen, S!NTEF December 1992

34

8 SYSA V AB Malmö Avfallsverk Funktionsredovisning Rebuming Panna 2 Sören Lundh konstruktionsbyrå AB April1992

9 Choice of Operating Parameters and Test Design for Phase 5 Peter Blinksbjerg, dkTEKNIK Bent Karll, Gas Technology Center Henrik Madsen, DPI September 1991

10 SYSA V REBURNING Lägesrapport juli/augusti 1992 PM/MKS-92/1598 Jan Bergström, Miljökonsultema i Studsvik AB Augusti 1992

11 Technical Support for Field Evaluation of MSW Combustion with Natural Gas Rebuming Energy and Environmental Research Corporation November 1992

12 Periodisk besiktning 1992 MKS-92/128 Per-Åke Gustafsson, Miljökonsultema i studsvik AB December 1992

13 Field Evaluation of Mcthane de-NOx at Omsted Waste-to-Energy Facility Richard Biljetina and Harnid A. Abbasi, Institute of Gas Technology Michael E. Cousino and Rob Duonett e, Olmsted County, Minnesota January 1992

14 Large Pilot Scale Testing Results of the COMBINO" Process J.N. Pont, A.B. Evans, G.C. England, R.K. Lyon and W.R. Seeker, Energy and Environmental Research Corporation Charles Schmidt, Department ofEnergy-Pittsburgh Energy Technology Center

35

Financing Organizations

Nordie Gas T echnology Centre r s owned by a number of large energy cancerns rn Norway. Sweden. Finland and Denmark_ NGC's mandaters to promate the usc of natural gas rn the Nordie reg1on through Nordrc research proteets

The Gas Research Institute. Chrcago. 1s a member organizatron for the natural gas rndustry in the USA_ GRI plans. manages and frnances re­search rnto the recovery, transportation. storage and applicatlon of natural gas.

Swedish Gas Technology Centre rs owned by a number of Swedrsh gas and energy enterpnses and the Swedrsh Gas 1\ssocration SGC"s JOb is to coordinate and rationalize the R& D activ!lres of the Swedish gas rnduslry

Svensk Energ1 Utveckling AB rs a dovet­opment company owned by the Swedish power 1ndustry. 1ts mandate •s to promate the development of env1ronment · fnend!y and economical energy technology

Sweden·s National Board for !ndustnal and T echn•cal Oevelopment

Sweden's Nat•onat Environment Proteetlon Board

The JOint research and development agency of Swedish government. local authonhes and 1ndustry 1n the held of waste and recovery.

The Swed•sh Association for Refuse Collection Interest orgamzat1on for tocal authorit1es and enterpnses with activ1ties afflliated w•th waste management and sanitation in the public seetar

Sydvästra Skånes Avfallsaktiebolag is a municipal undertak1ng in charge of was te management in 9 municipalities w1th a total of 470.000 res1dents and a waste volume of 500,000 tonnes a year

36

Nordisk Gasteknisk Center

SGC~s""'~ Gastekniskt Center AB

SVENSK ENERGI UTVECKLING

=-======= i~ U i;,..;{

''""'"" "·"'""'·'' "'""' '''''"·''""'·'' ·"'·' '··'"'"·'''''"''"''""'"'

Naturvårdsverket

Stiftebcn REFORSK

RY.E

S \"S4\' Sydvaslra Skånes Avlallsakliebolag

Appendix l

Appendix 2

FROM REFUSE TO DISTRICT HEATING SYSAV is responsible forwaste management in South-West Scania. Household and Industrialf commercial waste is incinerated at Malmö Avfallsverk. The plant, which came into operation in 1973, consists of two units.ln order to further reduce emissions the existing cleaning equip­ment was expanded to include advanced flue gas cleaning in 1981. T wo years later additional hot water units were iostalled to increase energy yield from waste.

Malmö Avfallsverk produces 500.000 MWh yearly fordistrict heating. This represents 25% of the total district heating /oad in the City of Malmö. Connected to the incinerator thereareal so a special fur­nace for cremation of dead animals, toxic waste, etc. and a gasfired hot w ater bo il er utilizing landtill gas.

15

13

~~~~J==o="~~~~~Jr~~~~np~1ngl!h:a,:l::::~ 2 Receiving bunker 3 Travelfing crane 4 Feed shaft

7 Slag discharge 8 Hot water boi/er 9 Precol/ector

12 Reactor 13 Bag filter

Location:

Latest permit

Operating Since: Extension:

Capacity: Population in operation area: Incineration: Operating time: Weighing bridges: Bunker capacity: Travelling cranes: Incineration g rate:

5 Operator ca bin 6 lncinerator fumace

10 Hot water ecnomizer 1 and 2

11 Limesilo

14 Fluegasfan 15 Slack 16 Dust si/o

TECHNICAL DATA Spillepeng. Phone (040) 93 64 55 licence from Board for Environment Proteetian Sept1986

1973 {2 u nits) 1981 (flue gas cleaning) 1983 (hot water economizer) 2 x 14 ton/h

470,000 220,000 ton/year 8000 h/fumace {Continuous three-shitt operation)

5Fiintab

11,000m'

3 x Aarhus, 1 x Kone Martin (reverse grate) gross thermalload 2 x 40 MW

Bo i lers:

Energy recovery: Energy yield: Slagashes:

Fluegas cleanlng: stack: Emissions:

Incineration temp, approx. 1000"C Wagner-Bira 2 x 32 MW Generator 2 x 3.75 MW Pressure 16 alm, hot water temp. in 120GC, out 160°C, flue gas temp. a fler stack 140°C District heating, approx. 500,000 MWh/year 2.4 MWhfton refuse Martin slag discharge. Slag to sarting plant approx. 60,000 ton/ year . .Ashes to landtill approx. 4,000 ton/year Precollector, lime reactor(dry system) and bag filter by Fläkt Concrete, 74 m high Dust 10 mg/nm' Hydrochloric acid 150mgfnm' Mercuty0.005 mg/nm' Oioxines less.'than 0.1 nglnm'

Sydvästra Skånes Avfallsaktiebolag Östergatan 30, S-211 22 Malmö, Sweden. In t. teL + 46-4010 19 20

37

-

38

Appendix 3

l Il !i Il III

' '

'!;t

' ' ,, '

10;~~ 11!!•

~L:.~ _ej ~ ·~~.~ > l c==~:!d_ L~~ J: 41}

Publikationer fra Nordisk Gasteknisk Center/ Publications from Nordie Gas Technology Centre:

1: Titei/Dato/Forfatter: ISBN nr.: l Titei/Dato/Forfatter: ISBN nr.:

~ Konferencerapporter/Conference reports: l Naturgasfyrade decentrale kraft/-varmevcerker - 1988

Naturgas i industrin - 1988

Forskning och utveckling inom naturgasanvändning - 1988

Forskning og utvikling innanfor naturgassanvendelse - 1988

Naturgas och milj0 - 1989

Industrielle t0rringsprocesser- 1989

Naturgasanvändning inom kraftvärme-saktom - 1990

Naturgas og Milj0 - 1992

Fuel Cell Workshop l - 1989

Reburning Workshop - 1990

Fuel Cell Workshop Il- 1991

Nordisk FUD-Workshop "Naturgasanvendelse" - 1991

Nordisk FUD-Workshop "Naturgasanvendelse" - 1992

Workshop Paper Drying with Gas - 1992

Nordisk FUD-Workshop "Naturgasanvendelse" - 1993

'*' 87-89309-00-6 ~ 87-89309-02-2 ~~

f~

87-89309-04-9

87-89309-13-8

87-89309-06·5

87-89309-08-1 ~:>

~ 87-89309-19-7 i: 87-89309-92-8 1.~ .. ': .. :' 87-89309-27-8 ~!j

87-89309-33-2 f;:: X•: ::::::::::::: l

87-89309-84-7 l ~ 87-89309-90-1 """ ~ w ~>.~

87-89309·95-2 w

Motorer och kraftvärmeaggregat för naturgasdrift - 6/91 E. Danielsson, AF-Energikonsult Syd AB

Cheng Cycle -Et nyt kraftvarmesystem • 9/91 M. Straarup, Axel Nielsen as Rådg. /ng.

Drift· och underhållskostnader vid gasturbinanläggningar i Mellaneuropa • 9/91 H. Gährisch & J. Sjödin, AF-Energikonsult

Användning av gasturbiner vid torkprocesser • Gyprocs gipsskivafabrik i Varberg · 12/91 L. Eriksson & L. De/in, AF Energikonsult

Gasturbinteknologi · Nuläge och utvecklingstrender· 7/92 Jyrl<i Ha/me, Ekono Oy

Kraftvärme med liten gasturbin • Utveckling av koncept för moduluppbyggning • 2/93 A. Sihvola, IVO Intern. Ltd.

Uppgradering av kraftverk • Komplettering med gasturbin • 8/93 Jussi Manninen, Endat Oy

Gasturbineanvendelse ved industriel wrreproces • T0rring af grces- og fjernvarmeproduktion l 01god · 8/93 B. Holm Christensen, dk· TEKNIK

87-89309-48-0

87-89309-78-2

87·89309-41 -3

87-89309-4 7 ·2

87-89309-69-3

87 -89309-83·9

87-89990-00-5

87-89990-02-1

i ~ lndustrlelanvendelsellndustrlal Appllcatlons: r/

Projektrapporter/Research reports: t j

l Industriell gasanvändning i Norden -En branschanalys.

Kraftvarme/Co·Generatlon:

Gasturbinernas tekniska nivå och utvecklingsriktningar - 7/89 Ekono Oy

Erfarenheter från finska gasturbinanläggningar • 4/90 Vesa Junttila, CTS-Engineering Oy

Erfaringer med danske og andre europceiske naturgasdrevne gasmotoraniceg • 1 0/90 Jan de Wit, Dansk Gastekn. Center

Små gasturbiners tekniska nivå och utvecklingsriktningar • 2/91 Ekona Oy

Energiproduktionskostnader med naturgas· 2/91 JP-International Oy

Gassmotorer for kraft/varmeproduksjon: Teknologler for emisjonsbegrensninger - 2/91 O. Stenersen, Marintek!Sintef

Utredning av små gasturbin· och motorkraftverksanläggningar · 2/91 J. Hittunen et al., Neste Oy

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l Bind 1 : Uvsmedelsindustri • 4/90 dk-Teknik et al.

i 87-89309-24-3 $ ~:~

Industriell gasanvändning l Norden • En branschanalys. Bind 2: Massa- och pappersindustri • 4/90 dk-Teknik et al. t

~ 87 -89309·15·4 ~

~

l Industriellgasanvändning i Norden -En branschanalys. Bind 3: Kemisk industri • Jord- og stenvaruindustri • Verkstadsindustri - 4/90 dk· Teknik et al. 87-89309-29-4 ~]

~:

87-89309-37-5

87-89309-35-9

87-89309-39-1

87 -89309-40·5

,,.. Autoprofiling with Gas lnfrared t Paper Dryer- 7/91 i ALemaitre & D. G/ise, C. Techn. du Papier

t~ Möjligheten till cogenerering .:~ vid direkttorkning - 8/91 ~ C. Rehn, Lunds Tekniska H6gskola ,;.;:

i~

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Luftkvaliteter i lokaler vid direktutsläpp av rökgaser från naturgasförbranning - 8/91 U. Jantze & M. Jedeur-Palmgren Theore/1 + VBB Energikonsulter AB

=i: Naturgas vid betongelementtillverkning - 8/91 )~ T. Ehrstedt, Sydkraft Konsult

87 -89309-05· 7

87-89309-11 -1

87-89309-07-3

87-89309-56-1

87-89309-58-8

87 -89309-62·6

87-89309-64-2

.. 21

Publlkatlonerne kan erhverves ved henvendelse tll Nordisk Gasteknisk Center/ The publications are available from the Nordie Gas Technology Centre.

@;:;:;:::::w;;~;::::;:':::::::::::':''"":!l:~:r.-w..m;::::~-w.;;;:;:~;;:::::::'~~~~=~:::;;;:::~;;,~~''':':'''"'''::;m.:<:;:m=.t;;~;~:m,~:'''''~;;:';'T~'*;;;;:~;~:;':'m::?:!m;::;:~~!jj:~i?i!W.~~~==~=:::::::::::''''''''~'~<<i:'::m::~~=~''''::m:<:S?.<;~~~,:::;;;:::::::::::::::r::::

Gasformiga bränslen i glasugnar - 8/91 S. Linzander, Glafo 87-89309-66-9

Mätprogram. Arbetsmiljöförhållanden vid förbränning av naturgas för koldioxidgödsling l växthus- 2/91 A-B. Antonsson, lnst. för Vatten- och Luftv. 87-89309-70-7

Mätprogram. Arbetsmiljöförhållanden vid förbränning av naturgas för koldioxid­gödsling i växthus. Kortversion- 2/91 A-B. Antonsson, lnst. för Vatten- och Luftv. 87-89309-72-3

Konvertering av aluminiumsmältugnar -Förstudie - 12/91 O. Hall & C. Rehn, Sydkraft Konsult 87-89309-49-9

Optical Properties of Wet Paper and Simulation of the Effect of Autoprofiling on Gas-flred IR Drying- 12/91 K. T. Oja/a & M.J. Lampinen, Helsinki University of Technology 87 -89309-51 ·0

Användning av en gasturbin för tillverkning av raffinör- (TMP) och slipmassa (PGW)- 1/92 R. Askola & V. Junttila, CTS Engineer/ng OY 87-89309-55-3

Användning av en gasdriven dieselmotor för tillverkning av raffinör- (TMP) och slipmassa (PGW)- 1/92 R. Askola & V. Junttila, CTS Engineer/ng OY 87-89309·59·6

Naturgasanvändning l schaktugn för blysmältning - 3/92 B. Lundborg, Sydkraft Konsult 87·89309-61-8

Diract Gas Firad Cylinder Heater for Paper Drying - 9/92 Vesa Junttila, Jamcon Oy 87-89309-77-4

Gas-lA på wellpappmaskin - Försök vid SCA Emballage AB, Värnamo - 9/92 T. Gustafsson, SCA Research AB & l. Gunnarsson, Energi Analys AB 87-89309-79-0

Rekuperativa naturgasbrännare - Utvärdering av konvertering från olja till naturgas i en vagnugn hos Svedala Arbrå- 11/92 B. Leden & A. Rensgard, MEFOS-BTF 87-89309-82-0

Koldioxidgödsling i växthus med hjälp av naturgas · 11/92 S-A. Moten, Mäster Grön, Hetsingborg 87-89309-86-3

Forbramdlngsteknlk/Combustlon Technology:

Modeling and Chemical Reactions - Review of Turbulence and Combustion Models • 7/89 N.!. Lilleheieetal., SINTEF 87-89309-10-3

Modellering og Kemisk Reaktion -Statusrapport: Reaktionskinetisk databaset Den kemisk kinetiske modal- 7/89 P. G/arborg & S. Hadvig, DTH 87-89309-16-2

The Fuei-Rich Hydrocarbon/Nitrogen Chemistry - lmplications for Reburning with Natural Gas - 11/89 P. Glarborg & S. Hadvig, DTH 87-89309-32-4

ti ~ i Modelling and Chemical Reactions -f Development and Test of a Kinatic Modal ~~ for Natural Gas Combustion - 3/91

'_.l_,k_,;_,~_,l ~·o~~~~:::: ~~:~~~~~~=lons -. Development and Test of Reduced Chemical i Kinatic Maehanism for Combustion of ~,' Mathane - 5191 -~

l N./. Lillehele et al., SINTEF ;.i!:

*~ Reburnlng - International Experiences with Reburning with Special Emphasis on Reburning Fuellnjection and Mixing- 7/89 S. Byggsteyl et al., SINTEF l

~ Reburning - Status over internatlonale ~® erfaringer- 7/89 w P. Glarborg & S. Hadvig, DTH

l~=~ Reburnlng - Reburning using Natural Gas • Polentialin Finland • 2/90

t;· S. Boström & M. Hupa, Abo Akademi

Reburning • Reburning med naturgas på ifiii kulsltavsfyrede kedler -!if~ Polantiale i Danmark - 2/90

~~~ ~~~~;~~~a~=~:::~~:n:ad naturgas -~® Potential l Sverige - 2/90

l :=~n~:·. ~~:~;i:::~~:~:~olan if Analy1ical and Experimental Study - 4/90

87 ·89309-36-7

87-89309-31-6

87 ·89309-44-8

87-89309-50-2

87-89309-14-6

87-89309-18-9

87·89309-34-0

87-89309-01-4

87 ·89309-03-0

a.:.:···.:·::· !~::~~:~~ ;:~~~:~:'·s~~;::~:~b:t:~~:olm 87-89309-17-0

\~= teknikkan på kulst0vsfyrede kedler- 8/90 :§: A. N0rregaard, dk-Teknik .f '''~ Reburning - Injektion av strålar i en

r-.,~_,',~.'.;_',: ~~~~~::'e~ :~~~ung/iga Tekn. Högskolan

Reburning • Parametric Study of Natural

~~! ~~~~l~nb~~s~:Oemistry using Kinatic

jj)j P. Kilpinen et al., Abo Akademi Univ.

:_._,i_~.·._f,i HDevelopment Projaet in Limhamn District . eating Central. - Reburning, Modelling {' Wand Experiments in a 125 MW Hot ·· ater Boiler - 3/91 .] R. Go/lin, Kungliga Tekniska Högskolan ) t !l'{ i§·

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Mathematlcal Modelling of Reburnlng -Oescrlption of Methods and Appllcation to the Limhamn Boiler andAmager Boller . 7/91 B. Laksb et al., SINTE F

87-89309-21·9

87-89309-23-5

87-89309-25-1

87-89309-42-1

87 ·89309-54-5

... 31

Publikationerna kan erhverves ved henvendeJsa t11 Nordisk Gasteknisk Center/ The publications are available from the Nordie Gas Technology Centre.

Reburnlng - Process Parameters, lmplementation and NO.-reductlon Potential - 9/91 P. Glamorg, DTH & B. Karl, NGC

Technlcal and Economic Feaslbllity of Reburnlng using Natural Gas in Finland - 9/91 A. Ahola et al., Neste Oy

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87-89309-76-6 ~~ ~

l f;

Naturgas tll Fur Fmrgen- Teknisk/0konomlsk studium af mulighederne for N-gas drift af fmrgen Branden-Fur- 7/92 L Nielsen, Dansk Teknologisk lnst.

Bedrift0konomisk analyse av naturgass­drift av busser l Norden • Fase Il. Delprosjekt: Marked - 8/92

87 ·89309-75-8

Rebumlng Simulator- Implementallan of a General Formalism for the Eddy Dissipation Concept in KAMELEON Il • 5/92

87-89309-45-6 ~ K.-E. Hagen et al., Transportekon. lnst., Oslo 87-89309-73-1

N./. L/lleheie et al., SINTE F

Reburnlng Rlch-Lean Kinatics -Annual Report 1991 - 6/92

87-89309-63-4

Gas Research Institute 87-89309-65-0

statusrapport for methanudslip fra naturgasanlmg i de nordiske lan de - 10/89 K. Christiansen, dk-Teknik 87-89309-20-0

status Report concerning Mathane Release from Natural GasSystems in the Nordie Countries - 1 0/89 K. Christiansen, dk-Teknik 87-89309-38-3

Energi og Milj0 i Norden - 5/91 B. Holm Christensen, dk· Teknik 87-89309-46-4

Reduction of Np from Combustion in Circulating Fluidized Beds with Afterbumlng of Gas - 11192 L Gustavsson & B. Leckner, Chalmers Univ. 87-89309-80-4

Modellng and Reburning Actlvities 1992 • 6/93 N./. Lillehele et al., SINTEF 87-89309-89-8

Modellng of the Holstebro-Struer furnace • 6/93 N./. Lillehele et al., SINTEF 87 -89309-93-6

Reburnlng Rich-Lean Kinatics -Annual Report 1992 - 6/93 Gas Research Institute 87-89309-97-9

Reduktion af NO.-emission fra naturgasfyreda industrikedler- 7/93 Jan de Wit et al., DGC 87-89309-99-5

NO. Reduction using Reburning with Natural Gas - Final Report from Fuii-Scale Trial at SYSAV's Waste Incineration Plant in Malmö - 9/93 Jan Bergström, Miljökonsulterna 87-89990-04-8

Energi- og mlljsanalyser/ Energy and Envlronmental Analyses :

Naturgas l kelaprocesser - 12/91 G. Minds et al., Dansk Teknologisk lnst.

Gas as Vehicle Fuel in the Nordie Region -Ongolng Field Tests invalving Natural Gas, Biogas and Propane - 8/92 A.M. Hansen, NGC

87-89309-53-7

87-89309· 71 -5

C02-Teknologi- Litteraturstudie om utskilling

J og deponering - 3/93 M. Matre et al., Berdal Stremme a. s.

Metanreduktion i katalysatorer för ~ naturgasmotorer - 3/93

m. ~ H. Boman, Vattentall Energisystem

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NGAS Database:

Nordie R& D Projaets within the field of Natural Gas Oownstream Technologies­Dlrectory 1990 -

Nordiske FUD projakter lndenfor naturgas­anvandeisa - Katalog 1992

87-89309-85-5

87-89309-87-1

87-89309-30-8

87-89309-67.7

20.993