豆浆热絮凝脱除玉米秸秆水解液中木质素的研究

Research on the Removal of Lignin from Corn Stalk Hydrolysate Using Thermal Coagulation of Soymilk

关键词:  玉米秸秆水解液  可生化性  豆浆  絮凝工艺

Key Words:corn stalk hydrolysate  biodegradability  soymilk  flocculation process

摘要:为了有效脱除木质素以提升玉米秸秆水解液的可生化性，本研究分析了高温热处理豆浆（Soymilk-TC）絮凝工艺对玉米秸秆水解液中木质素脱除的影响及其反应机理。结果表明，Soymilk-TC絮凝工艺可脱除玉米秸秆水解液中85.38%胶体木质素及28.14%可溶性木质素，优于使用阳离子聚丙烯酰胺及聚合氯化铝絮凝工艺的胶除效果。通过分析热处理前后豆浆的化学结构、表面电荷、表面疏水性、游离巯基含量等，对Soymilk-TC絮凝工艺中蛋白与木质素及其蛋白自絮聚过程中的热力学变化进行定量分析。结果表明，高温导致豆浆中大豆蛋白发生变性，增强了豆浆的表面疏水性，促进了豆浆与木质素通过疏水反应结合；同时巯基-二硫键反应促使木质素的豆浆分子聚合形成大分子聚集体，便于其从玉米秸秆水解液中分离。玉米秸秆水解液经Soymilk-TC絮凝工艺处理后可生化性显著提升，沼气得率及沼气生产速率分别提升了207.65%和34.32%。

Abstract:This study investigated the impact of high-temperature thermal soymilk （Soymilk-TC） flocculation process on lignin removal from corn stalk hydrolysate and elucidated its reaction mechanism， aming to enhance the biochemical characteristics of the hydrolysate. The results showed that the Soymilk-TC flocculation process effectively removed 85.38% of colloidal lignin and 28.14% of dissolved lignin from the hydrolysate， outperforming the Cationic polyacrylamide and Polyaluminium chloride coagulation methods. By analyzing the chemical structure， surface charge， surface hydrophobicity， free thiol content， etc. of soymilk before and after heat treatment， the thermodynamic changed of protein and lignin and the self-flocculation process of protein in the Soymilk-TC flocculation process were quantitatively analyzed. The results showed that high temperature causes denaturation of soy protein in soymilk and enhanced the surface hydrophobicity of soymilk. It promoted the combination of soymilk and lignin through hydrophobic reaction. Meanwhile， the thiol-disulfide bond reaction promoted the formation of macromolecular aggregates of soymilk molecules combined with lignin， facilitating their separation from the hydrolysate of corn stalks. The biodegradability of the hydrolysate was significantly enhanced by the Soymilk-TC flocculation process， resulting in increases of 207.65% in biogas yield and 34.32% in biogas production rate.