K_2CO_3颗粒吸收CO_2反应机制模型  

Reaction Mechanism Model of the CO_2 Absorption With K_2CO_3 Sorbents

作　　者：张中林[1] 陈晓平[1] 刘道银[1] 董伟[1] 吴烨[1] 孟庆敏[2] 

机构地区：[1]能源热转换及其过程测控教育部重点实验室(东南大学),江苏省南京市210096 [2]南京工程学院电力仿真与控制工程中心,江苏省南京市210013

出　　处：《中国电机工程学报》2014年第23期3865-3873,共9页Proceedings of the CSEE

基　　金：高等学校博士学科点专项科研基金资助项目(20130092110006)~~

摘　　要：颗粒粒径对气固化学反应速率有着重要的影响,利用改造后的热重分析仪对K2CO3颗粒吸收CO2的化学反应机制进行分析,获得了不同粒径吸收剂转化率随反应时间的变化规律。采用缩核反应模型对K2CO3颗粒吸收CO2的化学反应过程进行研究,利用热重试验数据分别计算出产物层扩散系数和反应速率常数等关键参数,并建立了产物层扩散系数与固体转化率的关联式。研究结果表明,不同粒径的颗粒均存在由化学反应控制向内扩散控制转变的现象,颗粒粒径增大不利于气固化学反应的进行,同时产物层扩散系数随着转化率的增加而不断减小。所建立的颗粒反应机制模型计算结果与试验值吻合较好,揭示了一定粒径范围内K2CO3颗粒吸收CO2的反应机制,为开展反应器模型研究提供参考。The particle diameter had an important influence on the rate of gas-solid reaction. The chemical reaction mechanism of K/CO3 sorbents absorbing CO2 was analyzed in a reconstructive thermogravimetric analyzer and the effect of the diameter on the sorbents conversion rate was investigated. A shrinking core model was developed to describe the reaction of CO2 with K2CO3 particles. The inner diffusion coefficient and reaction rate were calculated through thermogravimetric data, which were key parameters in the model. Meanwhile, an association relationship between diffusion coefficient and conversion rate was created. The result shows that the transformation from reaction control step to inner diffusion control step is observed in sorbents with all sizes. The increase of diameter is harmful to the reaction and the diffusion coefficient decreases with the increase of the conversion rate. The accordance of model data and experiment data verified the accuracy of model which provided a basis for a further study.

关 键 词：碳酸钾 二氧化碳 吸收 缩核模型 

分 类 号：TK09[动力工程及工程热物理]