Study On Production Process Of Fuel Ethanol By Fermentation Of Corn Straw

Recent years,bioethanol technology based on corn straw fermentation to produce fuel alcohol is a hot spot since it combines with the existing technology in China.It is a challenge to break up the compact structure of lignocellulose by enzyme hydrolysis,and the cost of pretreatment process is high.This work is aimed to find an ideal production process by researching on corn straw hydrolysis pretreatment,saccharification and fermentation conditions.Based on genetic recombinant yeast S.cerevisiae ZU-10 strains,this work studied the key technology of alcohol fermentation by using the coupling pretreatment process of dynamic extrusion and dilute alkali to treat wood fiber raw material,meanwhile,the fermentation process of glucose and xylose mixture also researched.The optimal conditions of enzyme hydrolysis in batches are listed as follows:the corn straw pretreated by dynamic extrusion and sodium hydroxide was used as raw material,the initial substrate concentration was 80 g/L,the enzyme dosage was 12 CBIU/g and 20 FPIU/g,respectively,and the reaction time kept at 48 h.The enzymatic hydrolysis of substrate reached 83.7%under this optimal condition.The optimal simultaneous saccharification fermentation technology was applied on the fermentation process of 30 thousand tons production line.The corn straw pretreated by dynamic extrusion and sodium hydroxide was also used as raw material,also the liquid glucose treated by 20 FPIU/g cellulase and 12 CBIU/g cellobiase was added as substrate,the temperature and pH was 32 ?,5.0,respectively.Finally,the ethanol concentration reached to 30 g/L after 72h fermentation.This research possesses great academic value as well as considerable benefits in the application of industrial production.Obvious improvement is obtained with the application of the optimal technology.The economic analysis of raw material and energy consumptions indicates that this novel technology has a production cost reduction of 17.69%compared with the traditional technology,and the price is close to the selling price of grain ethanol on market.