Bài giảng - Biofuels

BIOFUELS Outlines General Introduction  Biodiesel production  Ethanol production  Acetone-Butanol-Ethanol (ABE)  Hydrogen Production  Biofuels Fossil Fuel: a hydrocarbon fuel, such as petroleum, derived from living matter of a previous geologic time • Coal, Oil, Natural Gas Biofuel: Any fuel that derives from biomass – recently living organisms or their metabolic byproducts • Biodiesel, Butanol, Ethanol, Hydrogen Why Biofuels?     Reduce dependency on fossil-fuels Reduce GHG emissions (reduce impact on health, environment) Improve energy security Contribute to rural development through domestic production BIODIESEL What is Biodiesel Mono-alkyl esters of fatty acids (i.e methyl or ethyl esters) which are produced by transesterification of triglyceride Biodiesel Production • Physical properties very similar to conventional diesel • Must meet the quality requirements of ASTM D6751 • Biodiesel Blend: mixture of biodiesel and petroleum diesel • BXX = volume XX% biodiesel • Most common blends are B5, B20 Sources of Lipids for Biodiesel Production Animals  Plants  Oleaginous microorganisms  Algae  What are Algae?  Algae  Most live in water  Photosynthetic  Capture light energy  Convert inorganic to organic matter  Nonvascular  Use lipids and oils to help float in water  Range from small, single-celled species to complex multicellular species, such as the giant kelps Why Algae? Photosynthetic organisms are capable of efficiently using solar energy and CO2 to create biomass Algae, like terrestrial plants, produce storage lipids in the form of triglycerides Capable of utilizing high nutrients in waste water streams Incredible growth rates (much faster than plants) Ethanol Production Ethanol Production Glycolytic Pathway for Ethanol Production by Saccharomyces cerevisiae CO2 is commonly captured and purified with a scrubber so it can be marketed to the food processing industry for use in carbonated beverages and flashfreezing applications Dried distillers grain (DDG) is commonly used as a high-protein ingredient in cattle, swine, poultry, and fish diets Acetone-Butanol-Ethanol (ABE) Production What is butanol? carbon alcohol C4 H10 O: isomeric structures n-butanol or 1butanol sec-butanol or 2butanol isobutanol tert-butanol How butanol is produced? Biological synthesis (ABE fermentation) Biomass Clostridium spp Acetone: Butanol: Ethanol Chemical synthesis H2 + CO + CH3CH=CH2 → CH3CH2CH2CHO CH3CH2CH2CHO + H2 → CH3CH2CH2CH2OH How butanol is produced from starch? Starch Starch hydrolysis Cl m u i id r t os p p s Glucose Acidogenesis Butyric and acetic Solventogenesi s Acetone: Butanol: Ethanol ABE recovery by Gas stripping  Gas stripping was initiated from about the 36 h by recycling oxygen free N2 gas through the system  The ABE vapors was cooled in a condenser which has been previously fluxed with oxygen free N2  The stripped ABE was collected into the solvents collector (125 mL flask) Co-culturing an amylase producing Bacillus with a Clostridum for ABE production Clostridium butylicum TISTR 1032 Bacillus subtilis WD 161 oTo increase substrate utilization oTo reduce cost of product (no requirement in substrate pretreatment and addition of reducing agent) Fermentation condition design Anaerobic Pretreatment Without anaerobic pretreatment Stirred at 120 rpm during fermentation process Hydrogen Production (i) biomass production by photosynthesis, (ii) biomass concentration, (iii) aerobic dark fermentation yielding mol hydrogen/mol glucose in the algae cell, along with mol of acetates, and (iv) conversion of mol of acetates into hydrogen Clostridium acetobutylicum ... high-protein ingredient in cattle, swine, poultry, and fish diets Acetone-Butanol-Ethanol (ABE) Production What is butanol? carbon alcohol C4 H10 O: isomeric structures n-butanol or 1butanol sec-butanol... General Introduction  Biodiesel production  Ethanol production  Acetone-Butanol-Ethanol (ABE)  Hydrogen Production  Biofuels Fossil Fuel: a hydrocarbon fuel, such as petroleum, derived from... Algae?  As the use of biofuels expands globally, traditional food crops such as corn and soy beans are increasingly being used as feedstocks for the most popular liquid biofuels, ethanol and