Abstract:
Bioethanol is the principal fuel used as a petrol substitute for road transport vehicles. The high price of crude oil makes biofuels attractive. Brazil has been a front-runner in the use of renewable fuels. Currently the largest producers in the global biofuel industry are the United States and Brazil, where millions of tons of sugar are processed. Bioethanol fuel is mainly produced by the sugar fermentation process, although it can also be manufactured by the chemical process of reacting ethylene with steam. Domestic production and use of ethanol for fuel can decrease dependence on foreign oil, reduce trade deficits, create jobs in rural areas, reduce air pollution, global climate change and carbon dioxide buildup. Disadvantages of bioethanol include its lower energy density than gasoline, its corrosiveness, low flame luminosity, lower vapor pressure (making cold starts difficult), miscibility with water and toxicity to ecosystems. The main sources of sugar required to produce ethanol are derived from fuel or energy crops. These crops are grown specifically for energy use and include corn, maize and wheat crops, waste straw, willow and poplar trees, sawdust, reed canary grass, cord grasses, Jerusalem artichoke, miscanthus and sorghum plants, wheat grains and/or straw. Although, each source of biomass represents a technological challenge, the diversity of raw materials will allow the decentralization of fuel production with geopolitical, economical and social benefits. This study presents a global overview of bioethanol production, highlighting different feedstocks already in use, their qualities and limitations, also suggesting other potential ones.
|