PRODUCTION OF BIOETHANOL FROM RICE STRAW USING YEAST EXTRACTS PEPTONE DEXTROSE

Abstract

The production of bio-ethanol from Rice Straw (Oryza sativa) was carried out using rice straw as a feedstock and a combination of Yeast Extracts Peptone Dextrose (YEPD)at 0.2%(w/v) 0.4%(w/v), 0.6%(w/v), 0.8%(w/v) and 1%(w/v) concentrations and Saccharomyces cerevisiae (yeast) at 0.5% (w/v), 1%(w/v), 1.5%(w/v), 2%(w/v) and 2.5%(w/v) concentrations as cells for fermentation. The study determined the most suitable pre-treatment method from the following pretreatment methods; 1M NaOH and heating. IM NaOH pre-treatment gave the highest cellulose and lowest lignin content. The effects of substrate concentration values of 1g/l, 2g/l, 4g/l, 6g/l and 8g/l; with particle size of 300μm and cell loading combination of YEPD at 0.2%(w/v) 0.4%(w/v), 0.6%(w/v), 0.8%(w/v), 1%(w/v) concentrations and Saccharomyces cerevisiae (yeast) at 0.5% (w/v), 1%(w/v), 1.5%(w/v), 2%(w/v), 2.5%(w/v) on the fermentation process were investigated to obtain optimum conditions of fermentation. The optimum conditions of fermentation were obtained at temperature of 33 0 C, pH value of 4.0, substrate concentration of 4g/l, particle size 300μm and YEPD to yeast ratio of 0.8/1.5 after 72 hours of fermentation time. Also substrate concentration of 4g/l, gave highest bioethanol yield of 49.50%. http://dx.doi.org/10.4314/njt.v36i1.36