4种木质纤维素预处理方法的比较

Four Kinds of Pretreatment Methods for Lignocellulosics

采用4种方法对玉米秸秆预处理,研究了不同预处理方法对酶水解性能和可发酵性糖得率的影响,分析了预处理物料主要成分,预水解液中糖组成、碳水化合物降解产物及木质素降解产物含量。100 g玉米秸秆经稀酸、稀酸磨浆、中性蒸汽爆破和稀酸蒸汽爆破预处理、洗涤后,物料中纤维素由37.17 g分别降为33.96、33.54、32.63和32.88 g,木聚糖由22.84 g分别降为2.77、2.47、3.56和2.05 g,木质素由18.76 g分别降为17.63、17.42、16.90和17.25 g。稀酸蒸汽爆破预处理物料在底物质量浓度100 g/L、纤维素酶用量20 FPIU/g(以纤维素计,下同)、β-葡萄糖苷酶用量3 IU/g下酶水解48 h,纤维素水解得率为75.91%。玉米秸秆经稀酸蒸汽爆破预处理、纤维素酶水解后可发酵性糖得率为44.93%(以玉米秸秆为基准)。

Corn stalk was pretreated by four kinds of pretreatment methods, namely, dilute acid, dilute acid refining, neutral steam explosion and dilute acid steam explosion. The effects of pretreatment on enzymatic hydrolysis and yield of fermentable sugars were investigated. The components of pretreated corn stalk, sugars in pre-hydrolyzate, carbohydrate and lignin degradation products in pre-hydrolyate were also analyzed. After 100 g corn stalk was pretreated by dilute acid, dilute acid refining, neutral steam explosion and dilute acid steam explosion followed by washing, the cellulose content -dropped from 37. 17g to 33.96, 33.54, 32. 63 and 32.88 g, respectively; the xylan content declined from 22.84 g to 2.77, 2.47, 3.56 and 2.05 g respectively and lignin content reduced to 17.63, 17.42, 16.90 and 17.25 g from 18.76 g, respectively. When dilute acid steam explosion pretreated corn stalk was treated by 20 FPIU/g cellulose cellulase and 3 IU/g cellulose ^-glucosidase for 48 h as the substrate concentration was 100g/L, the hydrolysis yield of cellulose was 75.91% （ based on corn stover）. The yield of fermentable sugars was 4-4.93 % （ based on corn stover） as the corn stover was pretreated by dilute acid steam explosion and enzymatic hydrolysis.