Biodiesel - RRB Conference Martin.pdf · • Biodiesel production technologies today use homogenous, alkaline catalysis like alkali alkoxides or hydroxides • For low quality feedstocks

Ghent, September 19, 2005

Biodiesel:Production Technologies and Perspectives

Martin Mittelbach

Institute for Chemistry (IFC)

Working Group Renewable ResourcesKarl-Franzens-University Graz

A-8010 GrazAustria

Renewable Resources and Biorefineries, 19.09.2005, Ghent


Agenda:

• Chemical principles of BD-production• Current technologies

single feedstock, multi feedstock• New Trends

heterogenous catalysts, enzymesethyl esters, supercritical conditions

• Future perspectives: synthetic fuels• Summary


Newsweek:

August 8, 2005


TriacylglyceridesVegetable oils, animal fat, microbial oils

Transesterification

Biodiesel:Fatty Acid (M)ethyl Esters

from natural origin

Esterification

Fatty AcidsHydrolysis, veg. oil raffination, soap stock


„Biodiesel“: Publications and Patents

Source: Sci-Finder, CAS-Service

0

50

100

150

200

250

300

350

400

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Patents

Publications

Source: Sci-Finder, CAS-Service


Transesterification of Triglycerides

CH2

CH

CH2

O

O

O

COR1

COR2

COR3

CH3OHCH2

CH

CH2

O

O

OH

COR1

COR2 R3 COOCH3+CH3OH

CH3OH+ R2 COOCH3

CH2

CH

CH2

O

OH

OH

COR1 CH2

CH

CH2

OH

OH

OH

R1 COOCH3+


Catalysts for Current Technologies

Sodium methylate: Na+OCH3-

preparation: solution of Na in methanol+ commercially available, no additional step

almost water free, no saponification- high price, only fully refined oils

Sodium hydroxide, potassium hydroxide: Na+OH- , K+OH-

preparation: exothermic dissolution of solid in methanol+ lower price, oils with up to 2,5 % free fatty acids- additional step necessary, water content: saponification??

KOH vs. NaOH

faster reaction, better glycerol separation, utilization as fertilzer


Main Chemical Reactions

Formation of methoxide:

Main side reactions: hydrolysis and saponification

R1 – COOR2 + Na+OH- R1-COO-Na+ + R2OH

R – COOH + Na+OH- R-COO-Na+ + H2O

+ CH3OH Na (K)+ OCH3-Na (K)+ OH - + H2O


Equilibrium Hydroxide - Alkoxide

Formation of methoxide:

+ R-OH Na (K)+ RO -Na (K)+ OH - + H2O

% Water in Alcohol [OH-] [CH3O-] [C2H5O-]

0 3.7 96.31 6.8 93.230 92.0 48.0

E.F.Caldin, C.Long, 1954M.L.Bender, W.A.Glasson, 1958


History of Alcoholysis of Triacylglycerols1852 P.Duffy: Alcoholysis of fats: J.Chem.Soc.

1944 G.B.Bradshaw: US 2,360,844preparation of pure glycerol: 2-step reaction

1950 ff Fatty alcohol production for nonionic detergentshigh temperature and pressure process240°C; 100 bar; NaOCH3; distillation

1986 Mittelbach et al. AT 386.222low temperature and pressure process forbiodiesel production: KOH; purification with IER

1990 ff over 200 patents on biodiesel production


Biodiesel Production Technologies1) Single Feedstock Technologies

Feedstock Fully refined vegetable oils, FFA < 1 %

Catalyst NaOCH3, NaOH, KOH

Reaction conditions 40-100°C, batch or continous

Purification ME-Ester water washing, drying, no distillation

Glycerol treatment removal H2O+MeOH, opt.: distillation

Capacity 500 t – 250.000 t/a


Biodiesel Production Technologies2) Multi Feedstock Technologies

Feedstock Crude vegetable oils, animal fat, waste oils

Catalyst Preesterif.: H+; Transesterif.: KOH

Reaction conditions 40-60°C, batch or continous

Purification ME-Ester water washing, drying, distillation

Glycerol treatment acidification, salt separation: crude glycerol

Capacity 5.000 t – 50.000 t/a

FFA: up to 100 %


1985: 1st pilot plant worldwide for RMESilberberg, Styria, Austria


1986: Mittelbach, Junek, Andreae: AT 386.222


MultiMulti--FeedstockFeedstock ProductionProduction SchemeScheme ((simplifiedsimplified))

© BDI Anlagenbau Ges.m.b.H.

CatalystPreparation

Methanol

KOH

Fully automatic

TransesterificationOil Pre-

treatmentOil / Fat

MethylesterMethanol-Recovery

MethylesterPurification – Distillation

Quality Control

Glycerine phaseAfter- treatment

FertilizerSeparation

Free Fatty AcidRecovery

Crude GlycerineMethanol-Recovery

PharmaceuticalGlycerine Production

Fertilizer

Pharmaglycerine

BioDiesel

Acid

Crude Glycerine

Distillation side-product


Biggest Multifeedstock Biodiesel Plant in AustriaArnoldstein, 25.000 t


First Biodiesel Plant in a European Capital Ground-breaking, Vienna, 15.09.05

Capacity: 95.000 t/a; First production: 09/06


Biggest Biodiesel Plant in Germany ADM, Hamburg, 200.000 t

Ghent, September 19, 2005© J.Connemann


New Trends: Heterogenous Catalysts

Metal oxides (Mg, Ca, Al, Fe)Carbonates: CaCO3Ion exchange resins (acidic, alkaline)EnzymesSilicates

+ easy separation, reusablepure glycerol, no side products (salts)first industrial application 2006 ?

- high temperature and pressure, high investment costsincomplete conversion, distillation necessary


New Trends: Enzymes as CatalystsLipases (Triacylglycerolhydrolases)

main task: lipid hydrolysisin organic solvents:

esterification, transesterificationAlcoholysis of sunflower oil with MeOH, EtOH

Mittelbach et al., 19901990 ff: 88 publications on enzymatic alcoholysis


Immobilization of Lipases on Corn Cob GranulateFabrik der Zukunft, BMVIT

Aim: Biodiesel production process with lipases

Immobilization: 93 % physical adsorption at pH = 4.7Enzymes: Thermomyces lanuginosus, Pseudomomas sp.


Immobilization of Lipases on Corn Cob Granulate

0

20

40

60

80

100

% A

lkyl

este

r

Methanol Ethanol, 96%

iso-Propanol 1-Butanol

1 3 6 12 24 48 h

Batch: mol.ratio triglyceride:alcohol= 1:4.5; 50°C, no solvent, 10 % lipase

R.Uitz, S.Schober, M.Müller, M.Mittelbach; 2005, submitted


Enzymes as Catalysts: Summary

+ High catalytic activity, no solvents necessaryTransesteriifcation and esterification in 1 stepHigh conversion also with ethanolEasy separation and purification of productsSaving of chemicals

- Slow reaction ratesHigh price of enzymesDeactivation with glycerol: washing step

Economic evaluation

Enzyme: 10 €/kg and 1.700 h lifetime


New Trends: Fatty Acid Ethyl Esters

Today‘s biodiesel production worldwide: approx. 2 mill. t/a

Almost 100 % fatty acid methyl esters

why ?


0

100

200

300

400

500

600

700

2002 2003 2004 2005

[€/t]

E thanol

Methanol

Prices for Methanol and Ethanol

Rape seed oil520 €/t


Fatty Acid Ethyl Esters

+ 100 % biofuelbioethanol production increasing worldwidehigher Cetane Number

- price of ethanolanhydrous ethanol necessary: via zeolitesslower transesterification; lower conversionsno separation of glycerol with common technologieshigher viscosityno EN specificationsno additional tax benefits


New Trends: Supercritical Solvents

Definition: no differentiation between gas and liquidno liquid phase over Tc

Conditions:

Methanol Ethanol WaterTc 512.6 K 513.9 K 647.1KPc 80.9 bar 61.4 bar 220.6 bar


Vapor Pressure Methanol

0

50

100

150

200

250

300

350

0 50 100 150 200 250 300 350 400

Temperature [°C]

Pres

sure

[bar

]

Tc = 239.5°C

Pc = 80.9 bar


Alcoholysis with Supercritical Methanol

Typical reaction conditions:

reaction temperature: 350°Coptimum molar ratio: oil : methanol = 1 : 40reaction time: 2 minconversion: > 95 %

+ no catalyst, no purification- high excess of methanol, high energy input

investment costs, equipment

D.Kusdiana, S.Saka, Fuels 2001


Future Perspectives of Biodiesel

• Biodiesel production capacities are exploding worldwide

• New process technology: low production costs

• New challenge for developing countries: agriculture, labour

• Full acceptance of engine manufacturers for 5 % blend of biodiesel in mineral fuel

• Well established, harmonized specifications

Drawback: limited quantity of feedstocks


Future Perspectives of BiodieselNew Feedstocks

• Vegetable food oils: palm, soybean, sunflower„New“ seed oils: cuphea, crambe.....

• Single cell oils: yeast, funghi, algae• Genetically modified seed oils• Non-edible seed oils

Jatropha curcas, Castor oil, Pongamia pinnataused frying oil

• Animal fat: tallow, grease, SRM-material• Waste oils and fat, soap stock, trap grease


Future Perspectives of BiodieselNew Feedstocks


New Trends: Synthetic BiodieselPyrolysis Fuels: any carbon source: plastic, sewage sludge

pyrolysis with/without catalystsmixture of alkanes, alkenes, aromatesgas, gasoline, diesel, residue

GTL – Fuels: Gas to liquid fuelssources: natural gas, biogassynthesis gas, synthesis with catalystsproducts: methanol, gasoline, diesel

BTL – Fuels: Biomass to liquid fuels; Sun Fuelsgasification, Fischer-Tropsch synthesissources: cellulose, wood, strawtailor made Diesel fuels


Fischer-Tropsch Synthesis

Inventors: F.Fischer, H.Tropsch, 1925, MülheimMain goal: coal liquefaction

CO + 2 H2 -(CH2)- + H2O ∆H = -165 kJ/M

200 – 250°C, 25 bar, Fe, Co catalyst

Reaction products: straight chain hydrocarbons: ideal diesel fuels


Biomass to Liquid Fuels

Advantages:almost unlimited sourcesdesigner fuel, chemical composition variablelow engine emissions

Disadvantages:high production costsonly industrial scale possible


Conclusions, 1

• Biodiesel production technologies today use homogenous, alkaline catalysis like alkali alkoxides or hydroxides

• For low quality feedstocks with higher content of FFA an additional esterification step is necessary: strong acids

• Purification of biodiesel includes water washing and distillation,if necessary (waste oils etc.)

• New trends in biodiesel production includes heterogenouscatalysis, enzymes, supercritical alcohols

• Fatty acid ethyl esters will be produced in the future due to theavailability of cheap ethanol


Conclusions, 2

• Biodiesel (FAME and FAEE) is a well established fuel and will represent the most important market share of biofuels inthe next decadesLimiting factor: availability of feedstock

• Synthetic biofuels (GTL, BTL) are taylor made products withexcellent Diesel properties. There is almost unlimited availability. However, due to thehigh production costs the time of market penetrationdepends on mineral oil price


Bianca Bergler Mag. Bernd Nebel Mag. Firoozeh Alavian Mag. Bernd PokitsMag. Adina Fodor Florian RederSigrid Lagarde Mag. Sigurd SchoberMag. Tobias Madl Ingrid SeidlMag. Mario Müller Mag. Renate Uitz


Publication date: 11/04

340 pages

Publisher: Martin Mittelbach

Documents

Biodiesel - RRB Conference Martin.pdf · • Biodiesel production technologies today use homogenous, alkaline catalysis like alkali alkoxides or hydroxides • For low quality feedstocks