Biodiesel: Production Technologies and Perspectives

Transcription

1 Biodiesel: Production Technologies and Perspectives Martin Mittelbach Institute for Chemistry (IFC) Working Group Renewable Resources Karl-Franzens-University Graz A-8010 Graz Austria Renewable Resources and Biorefineries, , Ghent

2 Agenda: Chemical principles of BD-production Current technologies single feedstock, multi feedstock New Trends heterogenous catalysts, enzymes ethyl esters, supercritical conditions Future perspectives: synthetic fuels Summary

3 Newsweek: August 8, 2005

4 Triacylglycerides Vegetable oils, animal fat, microbial oils Transesterification Biodiesel: Fatty Acid (M)ethyl Esters from natural origin Esterification Fatty Acids Hydrolysis, veg. oil raffination, soap stock

5 Biodiesel : Publications and Patents 400 Source: Sci-Finder, CAS-Service Source: 350 Sci-Finder, CAS-Service 300 Patents Publications

6 Transesterification of Triglycerides CH 2 CH O O COR 1 COR 2 CH3OH CH 2 CH O O COR 1 COR 2 + R 3 COOCH 3 CH3OH CH 2 O COR 3 CH 2 OH CH 2 CH O OH COR 1 CH 2 CH3OH + R 2 COOCH 3 CH OH OH + R 1 COOCH 3 CH 2 OH CH 2 OH

7 Catalysts for Current Technologies Sodium methylate: Na + OCH 3 - 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

8 Main Chemical Reactions Formation of methoxide: Na (K)+ OH - + CH 3 OH Na (K)+ OCH H 2 O Main side reactions: hydrolysis and saponification R 1 COOR 2 + Na + OH - R 1 -COO - Na + + R 2 OH R COOH + Na + OH - R-COO - Na + + H 2 O

9 Equilibrium Hydroxide - Alkoxide Formation of methoxide: Na (K)+ OH - + R-OH Na (K)+ RO - + H 2 O % Water in Alcohol [OH - ] [CH 3 O - ] [C 2 H 5 O - ] E.F.Caldin, C.Long, 1954 M.L.Bender, W.A.Glasson, 1958

10 History of Alcoholysis of Triacylglycerols 1852 P.Duffy: Alcoholysis of fats: J.Chem.Soc G.B.Bradshaw: US 2,360,844 preparation of pure glycerol: 2-step reaction 1950 ff Fatty alcohol production for nonionic detergents high temperature and pressure process 240 C; 100 bar; NaOCH 3 ; distillation 1986 Mittelbach et al. AT low temperature and pressure process for biodiesel production: KOH; purification with IER 1990 ff over 200 patents on biodiesel production

11 Biodiesel Production Technologies 1) Single Feedstock Technologies Feedstock Fully refined vegetable oils, FFA < 1 % Catalyst Reaction conditions Purification ME-Ester Glycerol treatment Capacity NaOCH 3, NaOH, KOH C, batch or continous water washing, drying, no distillation removal H 2 O+MeOH, opt.: distillation 500 t t/a

12 Biodiesel Production Technologies 2) Multi Feedstock Technologies Feedstock FFA: up to 100 % Crude vegetable oils, animal fat, waste oils Catalyst Reaction conditions Purification ME-Ester Glycerol treatment Capacity Preesterif.: H + ; Transesterif.: KOH C, batch or continous water washing, drying, distillation acidification, salt separation: crude glycerol t t/a

13 1985: 1 st pilot plant worldwide for RME Silberberg, Styria, Austria

14 1986: Mittelbach, Junek, Andreae: AT

15 Multi-Feedstock Production Scheme (simplified) BDI Anlagenbau Ges.m.b.H. KOH Glycerine phase Methanol Catalyst Preparation After- treatment Fertilizer Fertilizer Oil / Fat Oil Pretreatment Fully automatic Transesterification Separation Free Fatty Acid Methylester Recovery Methanol-Recovery Crude Glycerine Crude Glycerine Acid Methylester Purification Distillation Methanol-Recovery Quality Control Pharmaceutical Pharmaglycerine Glycerine Production BioDiesel Distillation side-product

16 Biggest Multifeedstock Biodiesel Plant in Austria Arnoldstein, t

17 First Biodiesel Plant in a European Capital Ground-breaking, Vienna, Capacity: Ghent, t/a; September First 19, 2005 production: 09/06

18 Biggest Biodiesel Plant in Germany ADM, Hamburg, t

19 J.Connemann

20 New Trends: Heterogenous Catalysts Metal oxides (Mg, Ca, Al, Fe) Carbonates: CaCO 3 Ion exchange resins (acidic, alkaline) Enzymes Silicates + easy separation, reusable pure glycerol, no side products (salts) first industrial application 2006? - high temperature and pressure, high investment costs incomplete conversion, distillation necessary

21 New Trends: Enzymes as Catalysts Lipases (Triacylglycerolhydrolases) main task: lipid hydrolysis in organic solvents: esterification, transesterification Alcoholysis of sunflower oil with MeOH, EtOH Mittelbach et al., ff: 88 publications on enzymatic alcoholysis

22 Immobilization of Lipases on Corn Cob Granulate Fabrik der Zukunft, BMVIT Aim: Biodiesel production process with lipases Immobilization: 93 % physical adsorption at ph = 4.7 Enzymes: Thermomyces lanuginosus, Pseudomomas sp.

23 Immobilization of Lipases on Corn Cob Granulate % Alkylester h Methanol Ethanol, 96% iso-propanol 1-Butanol Batch: mol.ratio triglyceride:alcohol= 1:4.5; 50 C, no solvent, 10 % lipase R.Uitz, S.Schober, M.Müller, M.Mittelbach; 2005, submitted

24 Enzymes as Catalysts: Summary + High catalytic activity, no solvents necessary Transesteriifcation and esterification in 1 step High conversion also with ethanol Easy separation and purification of products Saving of chemicals - Slow reaction rates High price of enzymes Deactivation with glycerol: washing step Economic evaluation Enzyme: 10 /kg and h lifetime

25 New Trends: Fatty Acid Ethyl Esters Today s biodiesel production worldwide: approx. 2 mill. t/a Almost 100 % fatty acid methyl esters why?

26 Prices for Methanol and Ethanol [ /t] 300 Ethanol Rape seed oil 520 /t 200 Methanol

27 Fatty Acid Ethyl Esters % biofuel bioethanol production increasing worldwide higher Cetane Number - price of ethanol anhydrous ethanol necessary: via zeolites slower transesterification; lower conversions no separation of glycerol with common technologies higher viscosity no EN specifications no additional tax benefits

28 New Trends: Supercritical Solvents Definition: no differentiation between gas and liquid no liquid phase over T c Conditions: Methanol Ethanol Water T c K K 647.1K P c 80.9 bar 61.4 bar bar

29 Vapor Pressure Methanol Pressure [bar] P c = 80.9 bar T c = C Temperature [ C]

30 Alcoholysis with Supercritical Methanol Typical reaction conditions: reaction temperature: 350 C optimum molar ratio: oil : methanol = 1 : 40 reaction time: 2 min conversion: > 95 % + no catalyst, no purification - high excess of methanol, high energy input investment costs, equipment D.Kusdiana, S.Saka, Fuels 2001

31 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

32 Future Perspectives of Biodiesel New 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 pinnata used frying oil Animal fat: tallow, grease, SRM-material Waste oils and fat, soap stock, trap grease

33 Future Perspectives of Biodiesel New Feedstocks

34 New Trends: Synthetic Biodiesel Pyrolysis Fuels: any carbon source: plastic, sewage sludge pyrolysis with/without catalysts mixture of alkanes, alkenes, aromates gas, gasoline, diesel, residue GTL Fuels: Gas to liquid fuels sources: natural gas, biogas synthesis gas, synthesis with catalysts products: methanol, gasoline, diesel BTL Fuels: Biomass to liquid fuels; Sun Fuels gasification, Fischer-Tropsch synthesis sources: cellulose, wood, straw tailor made Diesel fuels

35 Fischer-Tropsch Synthesis Inventors: F.Fischer, H.Tropsch, 1925, Mülheim Main goal: coal liquefaction CO + 2 H 2 -(CH 2 )- + H 2 O H = -165 kj/m C, 25 bar, Fe, Co catalyst Reaction products: straight chain hydrocarbons: ideal diesel fuels

36 Biomass to Liquid Fuels Advantages: almost unlimited sources designer fuel, chemical composition variable low engine emissions Disadvantages: high production costs only industrial scale possible

37 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 heterogenous catalysis, enzymes, supercritical alcohols Fatty acid ethyl esters will be produced in the future due to the availability of cheap ethanol

38 Conclusions, 2 Biodiesel (FAME and FAEE) is a well established fuel and will represent the most important market share of biofuels in the next decades Limiting factor: availability of feedstock Synthetic biofuels (GTL, BTL) are taylor made products with excellent Diesel properties. There is almost unlimited availability. However, due to the high production costs the time of market penetration depends on mineral oil price

39 Bianca Bergler Mag. Firoozeh Alavian Mag. Adina Fodor Sigrid Lagarde Mag. Tobias Madl Mag. Mario Müller Mag. Bernd Nebel Mag. Bernd Pokits Florian Reder Mag. Sigurd Schober Ingrid Seidl Mag. Renate Uitz

40 Publication date: 11/ pages Publisher: Martin Mittelbach