纤维质原料高浓度酶解技术研究现状及机理分析

Study on Enzymatic Hydrolysis Technology and Mechanism Based on High Solids Cellulose Substrate

高浓度酶解体系能够获得高糖浓度,显著提高单位设备利用率,减少酒精蒸馏等生产成本,具有较好的应用价值。本文在介绍高固含量底物酶解技术相关研究基础上,主要对高底物浓度水解体系下抑制因素进行了分析,同时对高浓高效酶解反应器的设计及开发进行探讨。高浓度酶解体系伴随水解液中高糖浓度和高的酒精得率,但是酶解转化率随着底物浓度增加而降低,这种抑制效应的出现受多种因素的影响,包括纤维素酶吸附量的下降、产物抑制、搅拌不均使传质传热受限体系粘度增大、水与底物的作用等,可通过改变反应温度、搅拌方式、添加表面活性剂、利用分批补料等酶解技术以改善体系酶解效率,使底物高效转化同时提高产物乙醇浓度,节约燃料乙醇生产成本。

High solids hydrolysis is a direct and convenient technology to produce high concentration sugars, which can dramatically improve the utilization of the unit equipment and reduce purification costs. This review analyzed the inhibitory factors in high solids enzymatic hydrolysis system and discussed the reactors design operated at high solids loading for improving the system efficiency. Enzymatic hydrolysis at high solids loading can obtain high concentration sugars and ethanol, however, the enzymatic conversion efficiencies were decreased with the solids increasing. There were several factors contributed to this inhibitory effect, including the decline adsorption of the cellulase, inhibition from the hydrolysates, high viscosity caused by stirring and mixing difficulty, and lack of available water, etc. Enzymatic efficiency can be improved by altering the reaction temperature and stirring mode, using of surfactant and fed-batch saccharification strategy. The ethanol yield is therefore enhanced the production cost is saved.