磷酸丙酮预处理中木质素的产生机理研究  

Research on mechanism of lignin production in phosphoric acid-acetone pretreatment

作　　者：康鹏[1] 覃吴[1] 郑宗明[1] 杨勇平[1] 董长青[1] 

机构地区：[1]华北电力大学可再生能源学院,北京102206

出　　处：《华北电力大学学报（自然科学版）》2013年第4期96-101,共6页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家自然科学基金(51106051;51206044;51276062);国家科技支撑计划(2012BAA09B01;2012BAD30B01);北京市自然科学基金(3101001);国家重点基础研究发展计划(2009CB219801);中央高校基本科研业务费专项资金(09ZG03;11ZG08;12MS15);教育部新世纪优秀人才计划(NCET-10-0374)

摘　　要：基于分子动力学模拟和密度泛函计算,针对愈创木基甘油-β-O-松柏醇醚(CAGG),研究木质素在磷酸、丙酮中的沉降、溶解变化过程,揭示磷酸-丙酮法预处理中木质素溶解分离的内在机理。结构和特性分析表明,CAGG的2p电子在费米能级(0 eV)及其左边发生离域,具有较强的化学活性。对比CAGG在磷酸和丙酮中的总能量、溶解能、空穴表面积、空穴体积及木质素片段体积,发现丙酮溶液中木质素的内部作用力较为松散,形成的空穴表面积(634.21 cm2/mol)比其在磷酸中大,且它在磷酸中的溶解能是在丙酮中的1.58倍,因此木质素在磷酸中较难溶解。低温时CAGG的β-O-4键不易断裂,在磷酸、丙酮中均可保持完整。木质素在磷酸、丙酮中的溶解性差异和稳定性是预处理中实现木质素分离的前提条件。Based on molecular dynamics simulation and density functional theory calculations, coniferyl alcohol guaia- cyl glycerol （CAGG） is considered as model to research lignin dissolution and precipitation in acetone and phosphoric acid. h could help explain inner mechanism of lignin separating in phosphoric acid-acetone pretreatment. It is showed that CAGG 2P electronics delocalize in Fermi level （E = 0 eV） and the left of Fermi level, suggesting a strong chemi- cal activity. Etotal , Edissolution , Scavity , Veavity and Vmolecale of CAGG in phosphoric acid and acetone are analyzed and com- pared. It is found that the internal force of CAGG piles are more loose in acetone, so Scavity（634. 21 cm2/mol） in ac- etone is bigger than that in phosphoric acid. Edissolution of CAGG in phosphoric acid is 1.58 times of that in acetone, so lignin dissolves more easily in acetone.β-O-4 bond cleavage in CAGG is very hard, molecule structure could keep sta- ble and intact in these two solvents. Chemical stability and different solubility of lignin in the two solvents enable feed- stock pretreatment and lignin separating simultaneously.

关 键 词：预处理 磷酸-丙酮 木质素 密度泛函理论 分子动力学 

分 类 号：TQ35[化学工程]