Conversion of agricultural biomass into ethanol

Rice, banana and corn processing generates a large volume of rice straw, banana plant waste and corn cobs. Disposal of wastes are critical for both agricultural profitability and environmental protection. Agricultural residues are renewable resources that can be used to produce ethanol and many other value-added products. The current research investigates the utilization of rice straw, banana plant waste and corn cob as a feedstock to produce a value-added product - fuel ethanol, where ethanol is nowadays an important product in the fuel market. Agricultural residues are considered to be a lignocellulosic material. Lignocellulosic materials are renewable, largely unused, and abundantly available sources of raw materials for the production of fuel ethanol. The three main chemical constituents are cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are polysaccharides of primarily fermentable sugars, glucose and xylose respectively. Hemicellulose also includes small fractions of arabinose, galactose, and mannose, all of which are fermentable as well. The main issue in converting rice straw, banana plant waste and corn cob to fuel ethanol is the accessibility of the polysaccharides for enzymatic breakdown into monosaccharides. Different pretreatment methods such as chemical pretreatment process using alkaline pulping, microwave treatment as well as steam explosion were applied in this study to pre-treat the lignocellulosic biomass, which acts as physical barrier to cellulolytic enzymes. Yeast Saccharomyces cerevisiae, was used in the experiment to ferment the pre-treated materials into ethanol. Ethanol production in the culture sample was monitored using high performance liquid chromatography. The results indicate that ethanol can be made from the above mentioned residues in a different yield according to the pre-treatment method.