Study On Alcohol Production With Simultaneous Saccharification And Fermentation By Rice Straw

Ethanol is an important renewable energy. Currently, corn and other crops has often been used as raw material for ethanol production. But with the growing world population, food scarcity is becoming increasingly serious, so that China's grain ethanol production has begun to be gradually restricted. Straw is very rich in resources in China and most of them have not been the development and use of. Now technology is not well developed, it is not possible to carry out the industrial production of ethanol straw.At present, there are some problems in the ethanol production, for example: the pretreatment of straw is ineffective, the requirements for the equipment is high, cellulase activity is low and the fermentation process is long. In this paper, the rice straw was pre-treated with microwave, and the high-yield cellulase was producted by the Aspergillus niger which was preserved in our laboratory, the ethanol was produced with simultaneous saccharification, the experiment could provide an reference for ethanol production efficently using rice straw.1. Pretreatment of rice straw. Two pre-treatment methods of straw have been compared. Be processed by lye only, appropriate concentration of lye is 8%, the reducing sugar content was 11.53mg/mL. Be processed by lye and microwave, appropriate dose of microwave is 4.8w/g, compared with be processed by lye only, The efficiency of saccharification increased 27.02%.2. Studies on screening of strains Aspergillus niger and conditions of producing cellulase. From the laboratory to preserve the four strains of Aspergillus niger with high filter paper enzyme activity were selected, and M34 is the best strain. Through single factor tests, we could achieve the orthogonal factors level to test. The optimum condition was 30℃, pH5.5, 200r/min for 5 days, and filter paper enzyme activity was 44.34U/mg.3. Studies on simultaneous saccharification and fermentation. The conditions of the orthogonal experiments were that the temperatures, pH, cellulose dosage and saccharomyces cerevisiae inoculation amount. By orthogonal experiment, optimizing SSF condition was gotten. The optimum condition of simultaneous saccharification and fermentation was 40℃, pH 4, cellulose dosage 25U/g, saccharomyces cerevisiae inoculation amount 8%. The extracting rate in ethanol was 69.22% and ethanlo yield was 15.58%.