甲壳素的液化反应及其动力学模拟  

Chitin liquefaction and kinetics

作　　者：张洁[1] 许文茸 张玉苍[1] 李瑞松[1] 孟繁蓉 ZHANG Jie;XU Wenrong;ZHANG Yucang;LI Ruisong;MENG Fanrong(College of Matericals and Chemical Engingeering,Key Laboratory of Advanced Materials of Tropiacal Island Resources of Ministry of Education,Hainan University,Haikou 570228,Hainan,China)

机构地区：[1]海南大学材料与化工学院,热带岛屿资源先进材料教育部重点实验室,海南海口570228

出　　处：《化工进展》2017年第8期3085-3091,共7页Chemical Industry and Engineering Progress

基　　金：海南省科技项目(ZDYF2017005);海南省高等学校科学研究项目(Hnky2017-13);海南省研究生创新科研课题(Hys2016-01)项目

摘　　要：通过单因素试验法对甲壳素的酸催化液化反应中的影响因素进行了探讨。结合红外光谱(FTIR)、热重分析(TGA)、X射线衍射(XRD)及扫描电子显微镜(SEM)等分析手段分别对液化残渣和液化物的主要官能团、热稳定性、结晶度及表面形貌特征进行了分析,并应用动力学模型探讨了不同温度下反应速率和残渣率的关系。结果表明升高温度、增加催化剂用量和延长反应时间均有利于降低残渣率;动力学研究表明甲壳素的酸催化液化为复杂的多级反应,活化能Ea=34.5kJ/mol,指前因子A=254.17s^(–1),平均活化焓ΔHr=30.86kJ/mol,平均活化熵ΔSr=-210J/mol,整个反应为吸热反应,表观反应速率常数随着温度的升高而增加,在外界能量输入下,体系有序性发生变化。The factors affecting acid-catalyzed liquefaction of chitin were studied by single factor experiments.FTIR was used to examine the major functional groups of liquefied residues and products;SEM,XRD and TGA were employed to investigate the surface morphology,degree of crystallinity and thermostability of residues,respectively.A kinetic model was constructed and used to provide an insight into the relationship between reaction rate and residue content at different temperatures.The results indicated that a higher temperature,a larger catalyst dosage,or a longer reaction time was associated with a lower residue content.Kinetic studies revealed that a complex multistage reaction was involved in acid-catalyzed liquefaction of chitin,having an apparent activation energy Ea=34.5kJ/mol,a pre-exponential factor A=254.17s-1,a mean enthalpy of activationΔHr=30.86kJ/mol,and a mean entropy of activationΔSr=-210J/mol.The reaction on the whole was endothermic and its apparent reaction rate constant increased with raising temperature.The reaction system changed orderly with the input of external energy.

关 键 词：生物质 甲壳素 液化 动力学 

分 类 号：TQ31[化学工程—高聚物工业]