汽爆秸秆漆酶协同作用提取木质素

Synergistic mechanism of steam explosion combined with laccase treatment for straw delignification

组分分离是秸秆炼制的关键技术。本文建立了汽爆耦合漆酶协同作用工艺,研究其对秸秆物理形态、化学组成以及木质素碱提取过程的影响。研究结果表明汽爆破坏秸秆表面致密结构,提高比表面积,促进漆酶对秸秆木质素的氧化作用;红外分析表明,漆酶破坏了汽爆秸秆中半纤维素酯键,且愈创木基吸收峰减弱,漆酶削弱了木质素与纤维素间相互作用;汽爆漆酶协同作用后的秸秆木质素提取率提高约20%(70℃,120 min)。Nuclei Growth模型分析温和条件下秸秆木质素提取过程,动力学结果表明,汽爆漆酶协同预处理增加了汽爆秸秆木质素碱提过程中反应起始作用位点,并提高了该过程对温度的敏感性。汽爆-漆酶协同预处理是一种有效的分离木质素的方法,将在木质纤维素原料的生物炼制中发挥重要作用。

Components separation is the key technology in biorefinery. Combination of steam explosion and laccase wasused, and synergistic effect of the combined pretreatment was evaluated in terms of physical structure, chemical components and extraction of lignin. The results showed that steam explosion can destroy the rigid structure and increase the specific surface area of straw, which facilitated the laccase pretreatment. The laccase pretreatment can modify the lignin structure based on the Fourier transform infrared test, as a result the delignification of straw was enhanced. Nuclei Growth model with a time dependent rate constant can describe the delignification, and the kinetics parameters indicated that the combined pretreatment improved the reaction sites and made the delignification reaction more sensitive to temperature. The combined pretreatment enhanced delignification, and can be a promising technology as an alternative to the existing pretreatment.