碱性亚硫酸盐耦合低压蒸汽预处理慈竹及其纤维素酶解转化

慈竹作为一种富含纤维素、分布广泛的草类资源,是生产纤维素燃料乙醇的潜在原料。本文采用碱性亚硫酸盐法与低压蒸汽爆破相结合对慈竹原料进行预处理,在保留碳水化合物的同时能够有效脱除大量木质素进而提升后续的纤维素酶水解效率。通过正交试验确定最优工艺条件为反应温度140 ℃、亚硫酸盐用量40%、氢氧化钠用量15%。水解试验中加入质量分数5%的最优工艺条件预处理慈竹原料72 h,纤维素酶解生成葡萄糖得率达到88.54%。在此基础上将碱性亚硫酸盐与低压蒸汽爆破预处理相耦合,有效简化了预处理工艺并降低成本,可实现慈竹原料“一步法”高效预处理,纤维素保留率为89.25%,葡萄糖得率达87.25%。 

Alkaline ;sulfite and low-pressure steam coupled pretreatment on Neosinocalamus affinis and its enzymatic hydrolysis

Neosinocalamus affinis, a widely distributed grassy material rich in cellulose, is a potential resource for cellulose ethanol production. In this study, a coupled pretreatment of low-pressure steam explosion ( SE) and alkaline sulfite ( AS ) was applied to N. affinis in order to protect carbohydrates against degradation and increase delignification, which is useful for subsequent enzymatic hydrolysis. The optimal conditions of SE-AS were explored using the orthogonal experiment. It was found that the optimum condition of SE-AS process was 140 ℃ in 40% dry substrate Na2 SO3 and 15% dry substrate NaOH. A final glucose yield of 88. 54% was achieved during the 72-h enzymatic hydrolysis process ( substrate concentration was 5%) . Further simplification by combining low-pressure SE and AS into one-step pretreatment with a similar glucose yield of 87. 25% was achieved with 89. 25% of cellulose retention rate.