红麻秸秆高效预处理方法的选择

Efficient Pretreatment of Kenaf Stalk for Fuel Ethanol

利用地球上储量最大的可再生的植物纤维质转化制备燃料乙醇,对于减少温室效应,缓解能源紧张,提高环境质量具有重大意义。红麻是一种传统的速生高产的纤维作物,为提高红麻纤维质的糖转化率,采用H2O、H2SO4、NaOH溶液(121℃,60min)或白腐真菌P.sajor-caju固态培养的方法,对红麻秸秆进行预处理,比较了后续的纤维素酶催化红麻秸秆水解的纤维素转化率。结果表明,NaOH预处理样品的纤维素转化率达到82.24%,说明碱性预处理比较适合于红麻秸秆。微生物法预处理能有效去除红麻秸秆的木质素,提高样品的纤维素转化率,但耗时较长,糖分有所损失,可作为辅助预处理方法。

Bioconversion of fuel ethanol from lignocellulose,the most abundant renewable raw materials on earth,is significant to reduce the greenhouse effect,relieve the energy crisis and enhance the environmental quality.Kenaf is a traditional quick-growing fiber crop with high yields and is considered one of potential materials for fuel ethanol.Four different pretreatment methods for kenaf stalk were studied.Hot water （121℃,60 min）,dilute H2SO4 （3% v/v,121℃,60 min）,aqueous sodium hydroxide （1.5% w/v,121℃,60 min） and microbial pretreatment in solid state cultivation by the white-rot fungus P.sajor-caju were employed in this study to determine how each method affected the digestibility of kenaf stalk during subsequent enzymatic hydrolysis.The results showed that the average conversion rate of NaOH pretreated kenaf sample to fermentable reducing sugar was 82.24%,and alkaline pretreatment was considered more suitable for kenaf stalk,compared to other three methods.Although efficient delignification and considerable improvement of cellulose digestibility had been reported from kenaf lignocellulose pretreated by the white-rot fungus P.sajor-caju,long pretreatment time and loss of holocellulose still remained as the major weakness of microbial pretreatment,used as an auxiliary pretreatment process for kenaf stalk.