甘蔗渣的不同预处理方法比较及其酶水解的类分形动力学

Comparison of Different Pretreatment Methods on Sugarcane Bagasse and Fractal-like Kinetics of Enzymatic Hydrolysis

分别采用NaOH(0.45 mol/L aq.)、HCl(0.034 mol/L aq.)和高温液态水(LHW)三种方法对甘蔗渣迚行预处理,幵对其组分变化和酶解效果迚行了比较。NaOH预处理方法获得最高的木质素去除率,达91.1%,糖损失率达23.5%;HCl和LHW预处理结果类似,木聚糖溶解率分别为85.2%和79.7%,糖损失率均约为15%,木质素去除率均小于16%。三种方法处理的甘蔗渣经纤维素酶水解后得到总单糖(葡萄糖+木糖)浓度分别为38.7 g/L(NaOH)、16.1 g/L(HCl)和15.6 g/L(LHW)。综合比较预处理和酶水解工艺,NaOH水溶液预处理法的糖回收率最高,其次为HCl水溶液预处理法,LHW预处理法的糖回收率最低。作为描述纤维素酶反应动力学的有力工具,类分形理论的研究表明,各种预处理后底物的不觃则性依次为:HCl>LHW>NaOH,其与酶的有效吸附大小依次为:NaOH>HCl>LHW。

NaOH （0.45 mol/L aq.）, HC1 （0.034 mol/L aq.） and LHW （liquid hot water） were used to pretreat bagasse, and the composition change and enzymatic saccharification were compared. NaOH pretreatment brought the highest lignin removal （91.1%） and 23.5% sugar loss; the similar composition variation occurred for HC1 and LHW pretreatment, where the xylan dissolution were 85.2% and 79.7%, respectively. The sugar loss and lignin removal was both about 15% and less than 16%, respectively. After enzymatic saccharification, the total obtained sugar （glucose ＋ xylose） concentration were 38.7, 16.1 and 15.6 g/L from NaOH, HC1 and LHW pretreated sugarcane bagasse, respectively. The total sugar yield including the whole pretreatment and saccharification was： NaOH 〉 HC1 〉 LHW. As a persuasive tool, the fractal-like theory was used to study cellulase kinetics. Results showed that the irregularity of pretreated bagasse was： HC1 〉 LHW 〉 NaOH, and the absorbability was： NaOH 〉 HC1 〉 LHW.