加压氧化气氛下CaO固硫反应和动力学研究  

REACTION AND KINETICS OF SULFATION OF CaO IN OXIDATIVE ATMOSPHERE UNDER PRESSURE

作　　者：李文[1] 韩翔宇[1] 陈皓侃[1] 李保庆[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001

出　　处：《燃料化学学报》2002年第6期487-493,共7页Journal of Fuel Chemistry and Technology

基　　金：国家重点基础研究发展规划项目 (G19990 2 2 10 2 )~~

摘　　要：在加压氧化气氛下研究CaO和SO2 的反应并对该过程进行动力学研究。结果表明 :低温时CaO和SO2 反应的直接产物是CaSO3 ;产物中的CaSO4 是CaSO3 氧化和歧化反应的双重结果。在更高温度 (6 5 0℃ )下发生的是CaO的直接硫酸化反应 ;压力相同时 ,升高温度反应速率和转化率增加 ,但存在一最佳的温度为 85 0℃左右。同一温度下 ,随压力的增加 ,CaO的转化率显著增加。包含可变有效扩散系数的未反应核模型 (EUSCModel)能较好地描述加压下CaO的固硫反应过程。在该模型中 ,用于决定反应速率控制步骤的Thiele模数定义为转化率的函数。Thiele模数和转化率的关系表明整个固硫反应过程是动力学和扩散的共同效应 ;计算得出动力学控制和扩散控制下的表观活化能分别为 43 87kJ·mol-1和 5 6 79kJ·mol-1。Using thermogravimetric technique the reaction of CaO and SO 2 and its kinetics were studied under pressure in oxidative atmosphere. The results show that the direct product of CaO and SO 2 at low temperature is CaSO 3 which is oxidized and disproportionated to form CaSO 4. At high temperature over 650?℃ the direct sulfation of CaO occurred. The conversion of CaO increased with increasing pressure. Under same pressure the reaction rate and conversion were enhanced with increasing temperature which had an optimum valve of 850?℃. The unreacted core model including a variable effective diffusion coefficient well described the sulfation of CaO under pressure. Thiele modulus dominating the reaction rate was defined as the function of conversion. The result indicates that the sulfation of CaO was controlled by both kinetics and diffusion, during which the apparent activation energy was 43.87?kJ·mol -1 and 56.79?kJ·mol -1 respectively.

关 键 词：固硫反应 动力学 CAO 数学模型 氧化气氛 加压氧化 煤 脱硫 

分 类 号：X701.3[环境科学与工程—环境工程]