Ghent, September 19, 2005 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, 19.09.2005, Ghent
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Biodiesel - RRB Conference Martin.pdf · • Biodiesel production technologies today use homogenous, alkaline catalysis like alkali alkoxides or hydroxides • For low quality feedstocks
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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
Ghent, September 19, 2005
Agenda:
• Chemical principles of BD-production• Current technologies
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
Ghent, September 19, 2005
Main Chemical Reactions
Formation of methoxide:
Main side reactions: hydrolysis and saponification
+ 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
Ghent, September 19, 2005
New Trends: Fatty Acid Ethyl Esters
Today‘s biodiesel production worldwide: approx. 2 mill. t/a
Almost 100 % fatty acid methyl esters
why ?
Ghent, September 19, 2005
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
Ghent, September 19, 2005
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
Ghent, September 19, 2005
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
Advantages:almost unlimited sourcesdesigner fuel, chemical composition variablelow engine emissions
Disadvantages:high production costsonly industrial scale possible
Ghent, September 19, 2005
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
Ghent, September 19, 2005
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