Production Of Fuel Ethanol By Synchronous Saccharification And Fermentation From Straws

In this paper, crop straws are pretreated for synchronous saccharification and fermentation(SSF) with different methods adding complex enzyme and microorganism to improve the ethanol yield in maximum limit and lay the foundation of the technical basis of the fiber fuel ethanol industrial production. On the basis of these trials, by orthogonal experiment, the optimal conditions are obtained and further verification test are made using this conditions.The main results are shown as follows:(1) Using corn straws as raw materials, regard temperature, pH, the liquid-solid ratio and time of the fermentation as factors, the best cultivation condition is: the incubation temperature was 34℃, fermentation pH 5.5, he solid-liquid ratio is 1:8, fermentation time is 108 h. The ethanol concentration can reach 8.33 g/L. 8.99 g/L is obtained by adding Tween-80(0.005 g/g straws).(2) Soak the corn straws in H2SO4 (1%, w/w), the liquid-solid ratio (v/w) is 10:1, kept 1.5 h at 121℃. After 12 h and 24 h in saccharification, ferment with P-01 in different inoculation at 37℃, pH 5.5, the ethanol concentration is 7.31 g/L.(3) Soak the corn straws in H2SO4 (1 %, w/w), the liquid-solid ratio (v/w) is 10:1, kept 1.5 h at 121℃. According to the mode of different strains accession, at 32℃, pH 4.5, add P-01 when saccharify 12 h and yeast when 24 h, the ethanol concentration can reach 7.19 g/L. With the optimal condition using C hybrid strains scheme for SSF, the ethanol concentration can reach 6.85 g/L using corn stalk and 16.52 g/L using straw stalk.(4) Soak the corn straws in H2SO4 (1 %, w/w), the liquid-solid ratio (v/w) is 10:1, kept 1.5 h at 121℃. Feed materials in different time, the results show that kind of H(double times feed materials), the ethanol concentration reach maximum of 10.09 g/L. In bp mode the ethanol concentration can reach 8.20 g/L on the basis of the optimal conditions using different pretreatment methods and feed materials fermentation.