离子液体预处理对奇岗草木素脱除率及酶解效率的影响  

Effect of Ionic Liquid Pretreatment on the Lignin Removal and Enzymatic Hydrolysis of Miscanthus×giganteus

作　　者：周全伟 王超[1] 杨桂花[1] 许凤[1,2] 张凯[1] 陈嘉川[1] ZHOU Quanwei;WANG Chao;YANG Guihua;XU Feng;ZHANG Kai;CHEN Jiachuan(State Key Lab of Bio-based Material and Green Papermaking/Key Lab of Pulp&Paper Science and Technology of Education Ministry of China,Qilu University of Technology(Shandong Academy of Sciences),Ji’nan,Shandong Province,250353;Beijing Key Lab of Lignocellulosic Chemistry,Beijing Forestry University,Beijing,100083)

机构地区：[1]齐鲁工业大学(山东省科学院)生物基材料与绿色造纸国家重点实验室/制浆造纸科学与技术教育部重点实验室,山东济南250353 [2]北京林业大学林木生物质化学北京市重点实验室,北京100083

出　　处：《中国造纸》2020年第6期43-51,共9页China Pulp & Paper

基　　金：国家重点研发计划资助项目(2017YFB0307900);国家自然科学基金资助项目(31670595,31770628);泰山学者工程。

摘　　要：本研究以奇岗草为原料,探讨了不同工艺条件下醇胺类离子液体对奇岗草木素的脱除率,并利用红外光谱、X射线衍射和扫描电子显微镜分析了醇胺类离子液体预处理后奇岗草的官能团、结晶度和微观形貌的变化。结果表明,5种离子液体中乙醇胺醋酸盐([EOA][OAc])预处理对奇岗草木素脱除效果最佳,处理效果优于咪唑类离子液体;[EOA][OAc]预处理较适宜的条件为:预处理温度140℃、预处理时间5 h和固液比1∶10,此条件下木素脱除率可达76.67%;而且经过预处理后奇岗草在50℃、混合酶用量为20 FPU/g条件下酶水解72 h时,葡萄糖和木糖产率分别达到85.78%和79.78%,是未经过预处理奇岗草葡萄糖和木糖产率的5.37倍和12.97倍。经过[EOA][OAc]预处理的奇岗草纤维素含量在最优条件下由37.99%增至52.49%,纤维结构疏松,纤维素晶型不变,结晶度降低,纤维素可及度提高,且[EOA][OAc]循环使用至第5次时,其木素脱除率为(48.46±2.01)%,说明[EOA][OAc]具有良好的循环使用性能。In this study,Miscanthus×giganteus(M×g)was pretreated by alcoholamine-based ionic liquids under different conditions for delignification.The changes of functional groups,crystallinity and microstructure of M×g were analyzed by infrared spectrum,X-ray diffraction and scanning electron microscope.The results showed that ethanolamine acetate([EOA][OAc])among the five ionic liquids was the best for lignin removal of M×g.The[EOA][OAc]pretreatment result was better than imidazole-based ionic liquid pretreatment.The optimal conditions of[EOA][OAc]pretreatment were at 140℃for 5 h with the solid-liquid ratio of 1∶10,in which the highest lignin removal of 76.67%was obtained.The yields of glucose and xylose of the pretreated M×g after using enzymatic hydrolysis mixed enzyme(20 FPU/g)in 50℃for 72 h were 85.78%and 79.78%,respectively.The yields of glucose and xylose were 4.37 and 11.97 times of that of unpretreated M×g,respectively.Under the best conditions after the[EOA][OAc]pretreatment,the cellulose content of M×g increased from 37.99%to 52.49%,and the fiber structure was loose.The crystal structure of cellulose was unchanged,and the crystallinity decreased,as a result accessibility of cellulose was improved.When[EOA][OAc]was recycled and reused for the fifth time,the lignin removal rate was still(48.46±2.01)%indicating that[EOA][OAc]was suitable for recycling.

关 键 词：离子液体 预处理 木素 奇岗草 酶水解 

分 类 号：TS721.3[轻工技术与工程—制浆造纸工程]