文献类型：期刊文献

中文题名：硫酸铵热分解反应动力学研究

英文题名：Thermal Decomposition Kinetics of Ammonium Sulfate

作者：范芸珠[1];曹发海[1]

机构：[1]华东理工大学化学工程系,上海200237

年份：2011

卷号：25

期号：2

起止页码：341

中文期刊名：高校化学工程学报

外文期刊名：Journal of Chemical Engineering of Chinese Universities

收录：CSTPCD;;EI(收录号：20112114007121);Scopus;北大核心:【北大核心2008】；CSCD:【CSCD2011_2012】；

语种：中文

中文关键词：硫酸铵分解;热重分析;Malek法;微分-积分法

外文关键词：ammonium sulfate decomposition; TGA; Malek methods; differential integral algorithm

摘要：己内酰胺生产中副产大量的硫酸铵,而硫酸铵的热分解产物能作为己内酰胺的生产原料。利用热重分析研究了硫酸铵热分解的反应动力学。硫酸铵的热分解包括三个步骤:硫酸铵脱氨生成硫酸氢铵、硫酸氢铵失水生成焦硫酸铵以及焦硫酸铵的分解。研究首先用Malek法限定了各分解步骤机理函数的选择范围,然后用微分-积分法精选机理函数并计算得到了各分解过程的动力学参数。不同的分解步骤遵循不同的反应机理:硫酸铵脱氨为相界面反应机理,符合收缩球体方程,活化能E=110.02 kJ·mol-1,频率因子lgA=10.36 s-1;硫酸氢铵的失水为晶核生成与随后增长机理,符合Avrami-Erofeev方程,E=127.95 kJ·mol-1,lgA=9.90 s-1;焦硫酸铵的分解为三维扩散控制机理,符合反Jander方程,E=161.04 kJ·mol-1,lgA=12.51 s-1。作者研究了硫酸铵各分解步骤的温度、产物、反应机理以及动力学参数,为硫酸铵在己内酰胺生产工艺中的循环利用提供了理论基础。
During the production of the caprolactam,a large amount of ammonium sulfate is produced as byproduct.While the thermal decomposed products of the ammonium sulfate can be used as the raw materials again for the production of caprolactam.So,there is increasing interest in fully using ammonium sulfate for the production of caprolactam,and some researchers aim at studying the thermal decomposition of ammonium sulfate.The present work investigated the thermal decomposition kinetics of ammonium sulfate through thermo-gravimetric analysis（TGA）.The results show that the ammonium sulfate decomposes with three steps： 1.the ammonium sulfate deaminates to form ammonium bisulfate;2.the ammonium bisulfate dehydrates to form ammonium pyrosulfate;3.the ammonium pyrosulfate decomposes to form the raw materials for the production of caprolactam.The mechanisms of each step were limited by using Malek method firstly;then the differential integral algorithm was introduced subsequently to confirm the decomposition mechanisms,and the kinetic parameters were obtained.It was found that each step of the decomposition has different mechanism： The deamination of ammonium sulfate is controlled by phase boundary reaction model fitting shrinking sphere equation with activation energy E=110.02 kJ mol 1,frequency factor lgA=10.36 s 1;The dehydration of ammonium bisulfate is controlled by crystallization growth and nucleation model fitting Avrami-Erofeev equation with E=127.95 kJ mol 1 and lgA=9.90 s 1;The ammonium pyrosulfate decomposition is controlled by the three-dimension diffusion mechanism fitting anti-Jander equation with E=161.04 kJ mol 1 and lgA=12.51 s 1.The paper discussed the decomposition temperature,kinds of product,reaction mechanism and kinetic parameters for each decomposition step of ammonium sulfate,which may offer some help for the recycling utilization of the ammonium sulfate in the production of caprolactam.