Acetone hydrogenation in exothermic reactor of an isopropanol–acetone–hydrogen chemical heat pump: effect of intra-particle mass and heat transfer  

作　　者：Yanjun Duan Min Xu Xiulan Huai Xunfeng Li 

机构地区：[1]Institute of Engineering Thermophysics, Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2014年第33期4436-4443,共8页

基　　金：supported by the National Basic Research Program of China(2011CB710705);the National Natural Science Foundation of China(21306192,51276181)

摘　　要：Intra-particle mass and heat transfer plays an important role in performance of the exothermic fixed-bed reactor for an isopropanol–acetone–hydrogen chemical heat pump. In this work, an exothermic fixed-bed reactor model, taking into account the actual packing structure, is established in the commercial software Fluent. A 120°segment of a tube with tube-to-particle diameter ratio(n) of4, where realistic particles are packed and set to porous media, is used to simulate the 3D external flow, concentration and temperature fields in the exothermic packed-bed reactor. The influence of catalyst particle diameter(dp) and micropore diameter(d0) on the intra-particle temperature,species distribution, reaction rate and selectivity is discussed. The appropriate dpand d0 are obtained. Simulation results showed that intra-particle temperature gradient is not obvious. Large dpand small d0 lead to remarkable gradient of reaction rate inside the catalyst particle and the decrease in the catalyst efficiency and reduce the acetone conversion and the selectivity in isopropanol. The optimal results reveal that the spherical catalyst with dpof 1 mm and dporeof 10 nm is appropriate for high-temperature acetone hydrogenation.Intra-particle mass and heat transfer plays an important role in performance of the exothermic fixed-bed reactor for an isopropanol-acetone-hydrogen chemical heat pump. In this work, an exothermic fixed-bed reactor model, taking into account the actual packing structure, is established in the commercial software Fluent. A 120° segment of a tube with tube-to-particle diameter ratio （n） of 4, where realistic particles are packed and set to porous media, is used to simulate the 3D external flow, concen- tration and temperature fields in the exothermic packed-bed reactor. The influence of catalyst particle diameter （dp） and micropore diameter （do） on the intra-particle temperature, species distribution, reaction rate and selectivity is dis- cussed. The appropriate dp and do are obtained. Simulation results showed that intra-particle temperature gradient is not obvious. Large dp and small do lead to remarkable gradient of reaction rate inside the catalyst particle and the decrease in the catalyst efficiency and reduce the acetone conversion and the selectivity in isopropanol. The optimal results reveal that the spherical catalyst with dp of 1 mm and dpore of 10 nm is appropriate for high-temperature acetone hydrogenation.

关 键 词：颗粒直径 化学热泵 异丙醇 丙酮 加氢 热反应器 传热 传质 

分 类 号：TK124[动力工程及工程热物理—工程热物理]