文献类型：期刊文献

中文题名：液相苯加氢反应的内扩散阻力分析

英文题名：Analysis of Internal Diffusion Resistance for Benzene Hydrogenation in the Liquid Phase

作者：谭靖琳[1];程振民[1];周志明[1];束忠明[1];张文里[1]

机构：[1]华东理工大学化学工程联合国家重点实验室,上海200237

年份：2011

卷号：37

期号：1

起止页码：20

中文期刊名：华东理工大学学报（自然科学版）

外文期刊名：Journal of East China University of Science and Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2008】；CSCD:【CSCD2011_2012】；

基金：国家自然科学基金(20876043;21076072);长江学者和创新团队发展计划基金(IRT0721);高等学校学科创新引智计划基金(B08021)

语种：中文

中文关键词：苯加氢;环己烷;动力学;有效扩散系数;内扩散阻力

外文关键词：benzene hydrogenation; cyclohexane; kinetics; effective diffusion coefficient; internal diffusion resistance

摘要：采用NCG工业新型苯加氢催化剂（Ni/Al2O3）,通过消除外扩散和内扩散影响,在反应温度433-473 K和氢压0.6-3.3 MPa下,对液相苯催化加氢制环己烷的反应动力学进行了研究。结果表明,液相反应中苯的反应级数为0,氢的反应级数几乎为1,因此氢在催化剂内的传质过程是形成内扩散阻力的主要原因。由内部效率因子和Thiele模数可知,粒径小于0.150 mm时才能消除内扩散影响,说明该催化剂具有较高本征反应活性。通过Thiele模数的定义式,求得氢液相有效扩散系数。由Wilke-Chang方程得到综合扩散系数,进而通过Thiele模数定义式求得催化剂曲节因子为3.12。通过模拟得到液相中氢在不同粒径颗粒内的浓度分布曲线,说明氢的内扩散阻力是苯加氢反应的控制因素。
The kinetics of the hydrogenation of benzene to cyclohexane in liquid-phase is studied by using a new kind of Ni/Al2O3 catalyst after eliminating the external and internal diffusion influence at the temperature range of 433-473 K and pressure range of H2 of 0.6-3.3 MPa.Research shows that the reaction is zero-order for benzene while first-order for hydrogen.Therefore,the main reason of the internal diffusion resistance comes from the hydrogen diffusion in catalysts.The internal efficiency factor and Thiele modulus demonstrate that the internal diffusion resistance can only be eliminated when the particle diameter is smaller than 0.150 mm,which implies the high activity of the catalyst.The effective diffusion coefficient of hydrogen in the liquid phase is determined from the definition equation of the Thiele modulus.The comprehensive diffusion coefficient for hydrogen in the liquid is calculated by the Wilke-Chang equation,and the tortuosity factor of the catalyst is obtained to be 3.12 from the definition equation of the Thiele modulus.The radial distribution profile of hydrogen concentration in the liquid phase in the particles with different sizes indicates that the internal diffusion resistance of hydrogenation is the controlling factor.