Review -importance of ethanol as a fuel, advances in technology and reduction of production cost

Abstract

Abstract: Renewable energy is a key component supporting our journey towards the sustainable development. About 80% of the liquid fuel refined is consumed in transportation and hence, the challenging question is, "what is the best substitute liquid fuel instead of gasoline and diesel?" The answer is bio-ethanol and bio-diesel, respectively where ethanol is more interested. Brazil and USA are the world leaders producing ethanol with a percentage share of approximately 40% and 60% of the world total of 20,000 million gallons respectively. Brazil has been keen on sugarcane having a production cost of 365 US$/m3 while USA has been practicing com with 430 US$/m3. However with the ethical question of using edible feedstock for fuel production, lignocellulose material has recently gained a growing interest. Forest residues, agricultural wastes such as com straw & rice straw and dedicated energy plants as Poplar, Miscanthus, Switchgrass & etc. are under consideration. Feedstock pre-treatment cost and high hydrolysis cost (enzyme synthesis & low hydrolysis rate) are the main barriers in commercializing cellulose ethanol. Development of microbiology has played a major role in cost reduction and improving plants to have high feedstock production with reduced lignin 1 percentage is also in interest.