负载型K_2CO_3/Al_2O_3吸收剂吸收CO_2反应机理  

Reaction mechanism of K_2CO_3/Al_2O_3 sorbents for CO_2 absorption

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

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

出　　处：《化工学报》2014年第10期4101-4109,共9页CIESC Journal

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

摘　　要：利用热重分析仪、扫描电镜和氮吸附仪对不同粒径的K2CO3颗粒和负载型K2CO3/Al2O3二氧化碳吸收剂的碳酸化特性进行研究。负载后的吸收剂比表面积和孔隙结构得到较大改善,使得碳酸化反应速率和转化率均提高,吸收剂碳酸化特性得到改善。纯K2CO3颗粒吸收剂的反应速率和转化率随着粒径的增加而减小,负载型吸收剂的反应速率和转化率随着粒径的增加略增大。研究了不同粒径和反应时间对K2CO3/Al2O3颗粒微观结构的影响,结果表明K2CO3/Al2O3颗粒具有较稳定的微观结构。采用负载型粒子模型对K2CO3/Al2O3吸收剂吸收CO2碳酸化过程进行研究,所建立的粒子模型计算结果与试验值吻合较好。利用建立的模型对不同CO2浓度下K2CO3/Al2O3吸收剂碳酸化反应特性进行模拟计算,模拟结果具备一定的合理性和准确性,为开展进一步研究提供了基础。The carbonation characteristics of K2CO3 sorbents and K2CO3/Al2O3 supported sorbents for CO2 capture were investigated with thermogravimetric apparatus （TGA）, scanning electron microscopy analysis （SEM） and N2 adsorption. The surface areas and porosities of the sorbents were greatly improved after loading, which led to increase of reaction rate and conversion percent. It meant that carbonation characteristics of sorbents were improved. The reaction rate and conversion percent decreased with increasing diameter of pure K2CO3 sorbents, and slightly increased with increasing diameter of K2CO3/Al2O3sorbents. The influence of different diameters and reaction times on the particle micro structure was studied, and the result showed a steady micro structure of the particle. A supported particle model was used to describe the carbonation process of K2CO3/Al2O3sorbents and the model results agreed well with experimental data. The influence of different CO2 concentrations on K2CO3/Al2O3 sorbents carbonation was computed by the model. The simulation result was reasonable and accurate, providing a foundation for further study.

关 键 词：CO2捕集 K2CO3/Al2O3 吸收剂 碳酸化反应 粒子模型 动力学 

分 类 号：TK09[动力工程及工程热物理]