摘要
主要探讨在不同温度、用碱量和硫化度条件下绿液预处理对麦草化学成分及酶水解效率的影响。随着预处理用碱量和硫化度的提高木质素的脱除率增加,但同时也加剧了碳水化合物的降解,导致麦草浆得率下降。绿液预处理废液的pH值小于9.5,弱碱介质可以减少碳水化合物的降解,同时避免禾草原料含量较高的硅溶解在黑液中,有利于废液的碱回收利用。预处理后浆料经过由纤维素酶、木聚糖酶和β-葡萄糖苷酶组合而成的混合酶液水解,纤维素酶用量从5 FPU/g增加到10 FPU/g时,总糖得率及转化率显著增加。在酶用量为10 FPU/g条件下经过48 h的酶水解后,温度130℃、用碱量8%、硫化度40%条件下的预处理浆料总糖得率达到最大值43%,总糖转化率为73.1%。
The effects of green liquor pretreatment on the enzymatic hydrolysis of wheat straw for production of ethanol was investigated at different temperatures,total titrateable alkali（TTA） charges and sulfidity.Lignin can be effectively removed with the increasing amount of TTA charge and sulfidity in GL pretreatment while pulp yield drops with the increasing amount of TTA charge and sulfidity.The final pH was controlled to be lower than 9.5 in order to prevent the severe loss of carbohydrates and to ensure little silica dissolved in the black liquor.The pretreated materials were hydrolyzed by the enzyme cocktail which was a mixture of cellulase,xylanase and β-glucosidase to evaluate the improvement of sugar recovery.Compared with the cellulase loading of 5 FPU/g,sugar yield was significantly increased by the loading of 10 FPU/g.After 48 h enzymatic hydrolysis under a cellulase loading of 10 FPU/g pulp,the total sugar yield of pulp pretreated by 8 % TTA and sulfidity 40% at 130 ℃ was the highest among all pretreated pulps,and the highest enzymatic hydrolysis sugar recovery was 73.1 %.These results provided evidences that the enzymatic hydrolysis efficiency of wheat straw can be significantly improved by GL pretreatment.
出处
《林产化学与工业》
EI
CAS
CSCD
北大核心
2011年第5期48-54,共7页
Chemistry and Industry of Forest Products
基金
国家自然科学基金资助项目(31070512)
国家重点基础研究发展计划项目(2010CB732205)
江苏省高校自然科学研究重大项目(10KJA22020)
关键词
麦草
绿液
化学成分
木质素脱除率
酶水解
糖
wheat straw
green liquor pretreatment
chemical compositions
lignin removal
enzymatic hydrolysis
sugar
