Biofuels PDF
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This document provides an overview of biofuels, including their types, advantages, disadvantages, and production processes. It covers different types of biofuels, including liquid biofuels, biogas, and solid fuels, and also details the production of ethanol. The document analyzes characteristics of industrial strains used in the production of alcohol and studies on microalgae as a source of biofuel.
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Biofuels Bio 121: Industrial Microbiology Why do we need biofuels? BIOFUEL bioenergy manufactured from biological raw materials. Liquid biofuel major transportation fuels Ethanol, biodiesel, biobutanol TYPES OF BIOFUELS Biogas biomethane and biohydrogen Solid Fuels wood pellets and chips ADVANTAGES...
Biofuels Bio 121: Industrial Microbiology Why do we need biofuels? BIOFUEL bioenergy manufactured from biological raw materials. Liquid biofuel major transportation fuels Ethanol, biodiesel, biobutanol TYPES OF BIOFUELS Biogas biomethane and biohydrogen Solid Fuels wood pellets and chips ADVANTAGES OF BIOFUEL PRODUCTION renewable recycles CO2 reduce dependence on imported crude oil Environment friendly PROBLEMS ON BIOFUEL PRODUCTION large portion of land large quantities of water raw materials are large components of human and animal food ETHANOL PRODUCTION Ethanol -colorless, neutral, mobile flammable liquid with sharp burning taste -intoxicating component of alcoholic beverages ETHANOL PRODUCTION ETHANOL PRODUCTION ETHANOL FERMENTATION Substrate Characteristics of Industrial Strains of Alcohol Producers Can ferment broad range of substrate rapidly Can tolerate ethanol Has low-levels of by-products With osmotolerance Temperature tolerance High cell viability Appropriate flocculation and sedimentation characteristics Saccharomyces spp. Substrate Limited substrate range Substrate utilization Embden-Myerhoff pathway Osmotolerance Glycerol pH (4-6) Ethanol tolerance Modification of cell membrane composition Sterol, long-chain unsaturated fatty acids, cytochrome P-450 Temperature : 35 C Flocculence for easier cell separation Zymomonas mobilis Substrate Causes cider sickness Anaerobic, gram (-) rods Limited substrate range Varied substrate utilization Glucose: Entner-Doudoroff pathway Other substrate: varied by-products High osmotolerance High ethanol tolerance hopanoids Substrate Substrate Clostridium spp. Substrate Thermophilic anaerobes Simultaneous saccharification and fermentation Cellulase production Varied substrate range Large amount of by-products Lower ethanol tolerance BIODIESEL Esterification of triglycerides with methanol Sources: plant lipids, animal fats, cooking oils, microbes MICROALGAE High oil content Rapid growth Carbon dioxide fixation Reduce greenhouse gas emission Increase lipid accumulation High iron concentration Nitrogen starvation CULTIVATION Open System ⚬ pond system ⚬ larger scale production ⚬ wastewater can be used Closed System ⚬ photobioreactors ⚬ easier control of process, less environmental factor interferences, higher biomass, easier prevention of contamination
