Biofuels and Bioenergy

Bioethanol

Biologically synthesized alcohols, most frequently ethanol, and rarely propanol and butanol, are formed by the reaction of microorganisms and enzymes through the fermentation of sugars or starches, or cellulose. Biobutanol (also called biogasoline) is often asserted to provide a direct stand-in for gasoline, because it can be used precisely in a gasoline engine. Ethanol fuel is the most widely used biofuel worldwide. Alcohol fuels are formed by fermentation of sugars derived from wheat, sugar beets, corn, molasses, sugar cane and any sugar or starch from which alcoholic liquors such as whiskey, can be produced (such as potato and fruit waste, etc.). The ethanol manufacturing methods applied are enzyme digestion (to release sugars from stored starches), distillation, fermentation of the sugars and drying. Ethanol can be used in petrol engines as a substitute for gasoline; it can be blended with gasoline to any concentration. Current car petrol engines can operate on mixes of up to 15% bioethanol alongwith petroleum/gasoline. Ethanol has lesser energy density than that of gasoline; this implies that it takes more fuel to generate the same amount of work. An asset of ethanol is it’s higher octane rating than ethanol-free gasoline accessible at roadside gas stations, which permits the rise of an engine's compression ratio for increased thermal efficiency. In high-altitude locations, some states direct a mix of gasoline and ethanol as a winter oxidizer to lower atmospheric pollution emissions.