高校化学工程学报2011，Vol.25Issue(2)：341-346,6.
硫酸铵热分解反应动力学研究
Thermal Decomposition Kinetics of Ammonium Sulfate
范芸珠 1曹发海1
作者信息
- 1. 华东理工大学化学工程系,上海200237
- 折叠
摘要
Abstract
During the production of the eaprolactam, a large amount of ammonium sulfate is produced asbyproduct. While the thermal decomposed products of the ammonium sulfate can be used as the raw materialsagain for the production of caprolactam. So, there is increasing interest in fully using ammonium sulfate for theproduction of caprolactam, and some researchers aim at studying the thermal decomposition of ammoniumsulfate. The present work investigated the thermal decomposition kinetics of ammonium sulfate throughthermo-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 toform ammonium pyrosulfate; 3.the ammonium pyrosulfate decomposes to form the raw materials for theproduction of caprolactam. The mechanisms of each step were limited by using Malek method firstly; then thedifferential integral algorithm was introduced subsequently to confirm the decomposition mechanisms, and thekinetic 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 sphereequation with activation energy E=I10.02 kJ.mol-l, frequency factor lgA=10.36 s-1; The dehydration ofammonium bisulfate is controlled by crystallization growth and nucleation model fitting Avrami-Erofeevequation with E=127.95 kJ.mol-1 and lgA＝9.90 s-1; The ammonium pyrosulfate decomposition is controlled bythe 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 kineticparameters for each decomposition step of ammonium sulfate, which may offer some help for the recyclingutilization of the ammonium sulfate in the production of caprolactam.关键词
硫酸铵分解/热重分析/Malek法/微分-积分法Key words
ammonium sulfate decomposition/TGA/Malek methods/differential integral algorithm分类
化学化工引用本文复制引用
范芸珠,曹发海..硫酸铵热分解反应动力学研究[J].高校化学工程学报,2011,25(2):341-346,6.
