WP-3 Optimisation of secondary processing (i.e biodiesel production) Coordinator – Prof. Gyula Marton Deputy coordinator – Zsanett Herseczki University

WP-3 Optimisation of secondary processing (i.e biodiesel

production)

Coordinator – Prof. Gyula MartonDeputy coordinator – Zsanett Herseczki

University of Pannonia - UP

Foggia, 24.04.2009

Objectives and Tasks

•To review novel routes to biodiesel (e.g. heterogeneous catalysis, biocatalysis, etc.)

by UCO and SENECA (Task 1)•To review and assess the different technologies available to refine and purify glycerol

by UP and NEC (Task 2)


•To develop a portfolio of most promising speciality (among chemicals and adhesives through green chemistry) can be obtained from crude glycerol as a platform chemical

by UoY and CHIMAR Task 3 and Task 4


•To carry out a technical-economic assessment of the production of triacetin from crude glycerol by UP and NEC (Task 5)•To develop methods of pretreatment, hydrolysis and fermentation of glycerol for ethanol production by DTU (Task 6)

Program

1. Novel routes to biodiesel that incorporate glycerol – Rafael Loque – University of Cordoba (Spain)

2. Glycerol from biodiesel production – Existing and new glycerol purification - Zsanett Herseczki- UP

3. Production of Triacetin from crude glycerol – Zsanett Herseczki- UP

4. Application of glycerol in adhesives for wood panels – Dr. Katsampas Ilias – CHIMAR HELLAS (Greece)

5. Transformation of glycerol into high-quality products through green chemistry and biotechnology – Abbas Kazmi – UoY (UK) (presented by Zsanett Herseczki)

6. Assessment of various methods of pre-treatment, fermentation and downstream processing of alcohol production from glycerol fermentation – John Woodley DTU (Denmark) (presented by Zsanett Herseczki)

Glycerol from biodiesel production – Existing

and new glycerol purification technologies

Zsanett Herseczki, Gyula MartonUniversity of Pannonia, Cooperative Research Centre for

Environmental and Information Technology, H-8200 Veszprem, POB 158, Hungary

Phone/Fax: +36-(88) 624-986, e-mail: [email protected]

Sándor Ember2657 TOLMÁCS, Arany J.u.2.

Tel: (35)-550-153, 550-038, 350-089Fax:(35)-550-154, 350-190

e-mail: [email protected]

mailto:[email protected]


Introduction Recently

•Increases in crude oil prices •Limited resources of fossil oil•Environmental concerns

renewed focus on vegetable oils and animal fats

10 % Problem?

Crude glycerol

•glycerol•fatty acid methyl ester •methanol•salt•soaps•water•other impurities

Problems: foaming, high boiling point components (deep vacuum, high temperature)

Crude glycerolG-phases obtianed from Hungarian biodiesel factories contain

Glycerol ~45%

Water, methanol ~10-15%

Salt ~10-15%

Soaps ~30%

•Poor quality

•Requires expensive refining

•Current technologies require significant economies of scale to be economical

Processes for refining glycerol•The following technologies may be used to purify glycerol (after the soap splitting step)

•The glycerol soap splitting followed by a combination of methanol recovery/drying, fractional distillation, ion-exchange (zeolite or resins) and adsorption (active carbon powder) seems to be the most common purification pathway.

fractional distillation

ion-exchange

adsorption

precipitationextraction

crystallisation

dialysis

Conventional processes for glycerol purification Pretreatment - to remove colour and odour matters as well as any remaining fat components from crude glycerol (activated carbon )

Concentration step - removal of ionic substances using ion exclusion chromatography

Ion-exchangers – to remove inorganic salts, fat and soap components, colour and odour causing matters

Multiple vacuum flash evaporators - results in 90-95% concentration (10-15kPa vacuum) or

Thin film distillation - final concentration of glycerol to 99.5% is carried out in vacuum (0.5-1kPa)

a) Feed heater; b) Evaporator; c) Separator with demister; d) Water Condenser; e) Glycerol heater; f) Glycerol heater/final product cooler; g) Falling film evaporator; h) Glycerol condenser

Continuous glycerol Concentration – Multiple vacuum flash evaporators

a) Economizer; b) End heater; c) Thin-film distillation; d) Fractionating Column; e) Reboiler; f) Reflux Condenser; g) Glycerol condenser; h) Water condenser

Continuous glycerol distillation - Thin film distillation

Recent development in glycerol purification processes (>99,5% glycerol)

Chromatography and regenerative column adsorption•Activated carbon - The main components to separate are:

Glycerol Water Ions (like K+) Saponification residues and Methanol traces

•Expensive regeneration

•High operational costs due to the high viscosity of the crude glycerol and the high pressure drop

•New developments on chromatography separation - some possible chromatography techniques:

•Gel permeation

•Ion exchange chromatography

•Hydrophobic interaction

•Reversed phase

•Affinity chromatography

Partly purified G-phase

G-phases obtianed from Hungarian biodiesel factories contain

Glycerol ~45%

Water, methanol

~10-15%

Salt ~10-15%

Soaps ~30%Refining process

Acid treatment (H3PO4 ), pH~3, stirring at 80°C, 1 hour

Neutralization of excess acid, (Ca(OH)2), pH~4,8

Distillation to remove water, methanol (under vacuum)

Free fatty acidsCrude glycerol

Ca3PO4

Crude glycerol

Water, methanolGlycerol

containing salt

Glycerol alkyl esters – Production of Triacetin from crude glycerol

Zsanett Herseczki, Gyula MartonUniversity of Pannonia, Cooperative Research Centre for

Environmental and Information Technology, H-8200 Veszprem, POB 158, Hungary

Phone/Fax: +36-(88) 624-986, e-mail: [email protected]

Sándor Ember2657 TOLMÁCS, Arany J.u.2.

Tel: (35)-550-153, 550-038, 350-089Fax:(35)-550-154, 350-190

e-mail: [email protected]



Triacetin – Properties, field of applicationProperties

Field of application

•Food additive (e.g. butter) - E1518

•Antifungal agent in external medicine

•Potential green solvent and fuel additive

Molar mass 218,2 g/mol

Boiling point 258-260 °C

Melting point -78 °C

Density 1,16 g/ml at 25°C

Production of TriacetinTriacetin is commonly prepared by

•Esterification of glycerol with acetic anhydride or acetic acid

•Reacting ketene with glycerol

•Oxidation of allyl acetate in the presence of acetic acid

Purification of crude triacetin - Crude triacetin typically contains acetic acid, acetic anhydride and smaller quantities of other impurities

•Acetic anhydride and acetic acid are usually removed by distillation

•Remaining triacetin is then usually distilled to remove nonvolatile impurities and to eliminate color and odor

Ionic liquid as a green catalytic reaction medium for triacetin synthesis

Esterification of carboxylic acids with alcohols in room temperature ionic liquids as a catalyst and reaction media was studied

Molar ratio of aluminium chloride/butylpyridine chloride is less than 1.0 (Lewis basic) - the mechanism of esterification in ionic liquid may be different from that in sulfuric acid

Selectivity of triacetin was ~ 3,6-26% (conversion ~100%)

Outstanding advantage: resultant esters may not dissolved in the ionic liquid and therefore they could be isolated easily

The ionic liquid is suitable to those esterifications between aliphatic acids and alcohols at mild reaction conditions (30-75°C)

Production of triacetin from partly purified glycerol

OH OH

OH

+ 3 + 3 H2OH3C

O

OH

O

O

O

O

O

O

Azeotropic distillation

Used in excess

Cat.

Used catalysts•H2SO4

•H3PO4

•Ion exchange resins – Amberlyst type (Amberlyst 15 and Amberlyst 36)

Entraining solvents•n-Hexane•MIBK•Toluene

Raw material•Partly purified glycerol

Best catalyst: H2SO4

Best entraining solvent: toluene

Product purification:

•removal of excess acetic acid by distillation

•removal of salt by filtration

Purity >96%

Color: pale yellow

Distillation of glycerol, triacetin is not necessary!

Production of triacetin from partly purified glycerol

Scheme for production of triacetin from crude glycerol

Dilution, acid

treatment

Phase separation Decolorization Filtration

Free fatty acid, salt

Glycerol containing water, salt, methanol

Crude glycerol

Water, phosphoric acid

Activated carbon

Acetic acid

Water, toluene

Phase separation

Toluene

Esterification

Water

Filtration

Salt

Triacetin

Triacetin, acetic acid, catalyst, salt

Distillation

Acetic acid

Triacetin, catalyst,

salt

Methanol

Neutralization

NaOH solution

Activated carbon

Program







Dr. Abbas KazmiGreen Chemistry Centre of Excellence, University of York,

York, UK

Transformation of glycerol into high-quality products through green chemistry

and biotechnology

The biodiesel industry currently regards glycerol as a waste by-product however with novel methods glycerol has the potential to be converted into high value products

Glycerol transforming processes

Valuable Chemicals from Glycerol

Transformation of glycerol into high-quality products through green chemistry

and biotechnology

Aqueous phase Reforming - Fischer-Tropsch•Conversion of glycerol to hydrogen and carbon monoxide (Synthesis Gas)

• The process conditions are 250˘C using a Pt-Re catalyst in a single reactor

•The synthesis gas can be used as a building block for chemicals and fuels using the Fischer-Tropsch reaction

Selective reduction•The main processes used to reduce glycerol to glycols are hydrogenolysis, dehydroxylation and bacteria

Halogenation•1,3-dichloro-2-propanol can be produced directly from glycerol using HCl as a catalyst and subsequent dehydrochlorination using NaOH to generate epichlorohydrin and NaCl


Dehydration

•The dehydration of glycerol can produce important chemicals such as acrolein, 3-hydroxypropionaldehyde and acrylic acid.

Etherification

•Glycerol alkyl ethers can be synthesised by etherification of alkenes such as isobutylene in the presence of an acid catalyst at temperatures from 50°C-150°C.

Esterification

•Glycerol can be esterified with carboxylic acids or via carboxylation and nitration and reaction of glycerol with dimethyl carbonate produces a high yield of glycerol carbonate


Selective oxidation•Oxidation products include glyceraldehydes, glyceric acid, glycolic acid, hydroxypyruvic acid, oxalic acid and tartronic acid

•The oxidation of glycerol can be catalysed using highly active aerobic catalysts such as platinum and palladium

Pyrolysis•Typical products include carbon monoxide, hydrogen, carbon dioxide, methane and ethane

•At lower temperatures (steam or supercritical water) longer molecules such as acrolein, formaldehyde and acetaldehyde are observed

Biotransformation•Glycerol can be converted to a very large number of chemicals using micro-organisms and enzymes (e.g. 3-hydroxypropionaldehyde )


Hydrogen

Succinic acid

Ethanol

Propylene glycol

Dihydroxyacetone

Acrolein

Glycerol Tertiary Butyl Ether (GTBE)

Mono- and Di-acylglycerol (DAG)

Citric acid

Valuable Chemicals from Glycerol

Market for glycerol is likely to remain volatile in the near future

Chemical industries need to be approached at a local, national and international level to determine their requirements and then research needs to be conducted on glycerol in association with biodiesel producers, chemists, biologists and engineers to provide a solution

Future vision

Program







Yuan Xu (DTU) Denmark

Assessment of various methods of pre-treatment, fermentation and downstream processing of

alcohol production from glycerol fermentation

The fermentation production of value-added alcohols from glycerol offers an attractive opportunity of stimulating the biofuel industry due to the relatively low price of glycerol and some advantages over glucose fermentation, such as the production of 1,3-propanediol (PDO), which could not be produced from glucose fermentation.

Dilution of the crude glycerol is necessary because of the inhibition effect of impurities and high substrate concentration on some species, like the ethanol producing strain Enterobacter aerogenes. It has little effect on 1,3-PDO producing species Clostridium butyricum and Klebsiella pneumoniae.

Assessment of various methods of pre-treatment, fermentation and downstream processing of alcohol production from glycerol fermentation

The glycerol fermentation has been mostly studied under anaerobic conditions

Micro-aerobic or aerobic processes have also been reported on 1,3-PDO production by some species to simplify the process

Fed batch fermentation could result in high product concentration up to 70 g/L of 1,3-PDO

Continuous fermentation and immobilized cell fermentation could enhance the productivity over 8 g/L h of 1,3-PDO.

The scale-up production of 1,3-PDO has been found both in anaerobic and microaerobic operations up to 2 m3 and 1 m3, respectively

It is worth attention that the increasing volumetric scale-up factor resulted in the decrease of final PDO concentration.


The downstream processing of the alcohols from fermentation is costly owing to the low final product concentration and coexistence of by-products

Most separation methods in use are energy-consuming and expensive.

To increase the economic viability of industrial application, the metabolic engineering technology could be adopted on the microorganisms to increase their product specificity or improve their tolerance to the impurities and high substrate concentration of the crude glycerol.


Discussion!

Documents

WP-3 Optimisation of secondary processing (i.e biodiesel production) Coordinator – Prof. Gyula Marton Deputy coordinator – Zsanett Herseczki University