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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 chemical composition and enzymatic hydrolysis efficiency of wheat straw were investigated under different temperature, alkali concentration and degree of sulfuration. With the increase of alkali and sulfuration degree, the removal rate of lignin increased with pretreatment, but it also aggravated the degradation of carbohydrates and led to the decrease of wheat straw yield. The pH value of the green liquor pre-treatment waste liquid is less than 9.5. The weak alkali medium can reduce the degradation of the carbohydrate, and meanwhile avoid the silicon with higher content of grass raw material from being dissolved in the black liquor, which is favorable for the alkali recovery and utilization of the waste liquor. After pretreatment, the slurry was hydrolyzed by a mixed enzyme solution composed of cellulase, xylanase and β-glucosidase, and when the amount of cellulase increased from 5 FPU / g to 10 FPU / g, Rate and conversion rate increased significantly. Under the conditions of enzyme dosage of 10 FPU / g, the total sugar yield of the pretreatment slurry reached 43% at the maximum of 130% with 8% of alkali and 40% of the degree of sulfide after enzymatic hydrolysis for 48 h Sugar conversion was 73.1%.