Bioethanol (Biofuel)

Rice straw is one of the potential sources for bio-ethanol production. It gives a clean energy solution to fulfill the energy demand on sustainable basis and would also assure additional income and sustainable utilization of rice straw which is otherwise being burned and cause tremendous air pollution. Rice straw contains significant amount of hexose (C6-compound) and pentose (C5-compound) sugars that make it potentially valuable lingo-cellulosic source for bio-ethanol production. The three basic processes required for generation of bio-ethanol from rice straw are, (i) liberation of cellulose and hemicelluloses from the straw-matrix through delignification (through pre-treatment); (ii) production of simple sugars by deploymerization of carbohydrate-polymers (through hydrolysis/ saccharification); and (iii) production of ethanol through fermentation of mixed pentose and hexose sugars. Generally, 220 to 300 litres of bioethanol can be produced from 1 ton of rice-straw.

Establishment cost of the bioethanol plant involved with upgraded and latest technologies, operational cost and requirement of trained personnel with suitable backgrounds are of immense importance. If not limitation or gap, this technical knowhow remains of utmost importance to enhance the bio-ethanol production at best possible extent. Standard pretreatment technique is another major technical gap, and that involves constant effort of researchers to meet the challenge.

There is a huge potential to offsets fossil fuel by generating ethanol from bulk crop residues in general and rice straw in particular, with efficient commercial technologies.