摘要:
在功率为120 W、处理时间为30 min的条件下，分别对稻草进行超声波辅助酸碱预处理，与传统化学预处理（碱-预处理、酸-预处理）后稻草的主要化学组成相比较，结果表明超声波技术辅助酸碱预处理可以更为有效地去除半纤维素和木质素，从而提高了稻草基质中纤维素的相对含量，有利于缩短稻草水解时间。在一系列实验研究的基础上，建立了稻草酶水解动力学模型。结果表明，分别经碱、超声波-碱、酸、超声波-酸预处理的稻草在糖化过程中的模型参数（米氏常数KM，速率常数k和抑制常数KI）均不相同，KM分别为17.55、14.14、15.29和15.08 g/L；k分别为15.30、21.32、13.40和15.42 h-1；抑制常数KI变化不明显分别为2.31、2.08、1.81和1.85 g/L。模型及实验方法简便可靠，有较好的拟合性，对稻草酶水解过程工程放大及过程控制都具有一定的参考价值。
Abstract:
In this work, the effect of ultrasound-assisted pretreatment on rice staw was investigated under the condition of 120 W, 30 min, and a simplified kinetic model fitted for the straw enzymatic-saccharification was established to evaluate the pretreatment efficiency. The results showed that most of the hemicellulose and lignin were effectively removed after pretreatment, and the ultrasound-assisted pretreatment was more efficient than the alkali-pretreatment or acidpretreatment alone. The validity of the model developed was confirmed by successfully simulating the time course of saccharification. The values of K, KM, KI for alkali preteatment, ultrasound-assisted pretreatment, acid pretreatment, ultrasoundassisted pretreatment were 15.30，21.32，13.40 and 15.42 h-1; 17.55, 14.14, 15.29 and 15.08 g/L; 2.31, 2.08, 1.81 and 1.85 g/L, respectively. Ultrasound-assisted pretreatment could effectively increase the lignin degradation by decreasing the crystallinity of lignocellulose as destroying the intermolecular hydrogen bonding. Thus it may improve the availability of zymohydrolysis and ultimately increase the saccharification rate.
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