Production of ethanol from agro-industrial wastes: ii - optimizing variables for ethanol production from rice straw and beet pulp hydrolyzates

Due to increasing commercial significance of ethanol production from lignocellulosic biomass, this study was conducted in an attempt to evaluate the process for ethanol production from the rice straw (rs) and sugar beet pulp (sbp) wastes as a cheap substitute of molasses using saccharomyces cerevisiae thereby, reduce the cost of ethanol production, at the same time eliminates environmental impact of waste via open burning. this investigation has been carried out to study the influences of substrate concentration, ph, nitrogen source and incubation period on ethanol fermentation from (rs) and (sbp) hydrolzates. the results revealed that, the optimum conditions for ethanol production were attained at cultivation conditions being: 100g/l (w/v) sugar concentration; ammonium sulfate as nitrogen source, 5.0 ph and 48 hr incubation period at 30 ˚c. at previous fermentation conditions, ethanol yield was 44.42 g/l and 42.72 g/l with 88.24 and 88.09 (%) percentages of the theoretical yield for (rs-h) and (bp-h), respectively. and in this work, a good yield of ethanol was observed after 48 hr of fermentation using rice straw hydrolyzate medium, which shows a satisfactory performance and a potential for lowering ethanol production costs.