超低浓度气氛中CO_2吸附动力学影响因素分析  

Analysis on influence factors of CO_2 adsorption kinetics under ultra-low CO_2 atmosphere

作　　者：刘军[1] 孟桂祥[1] 姚胜[1] 王祝成[1] 徐凯[1] 韩国庆[1] LIU Jun;MENG Guixiang;YAO Sheng;WANG Zhucheng;XU Kai;HANG Guoqing(Xi’an Thermal Power Research Institute Co.,Ltd.,Suzhou Branch,Suzhou 215011,Jiangsu,China)

机构地区：[1]西安热工研究院有限公司苏州分公司,江苏苏州215011

出　　处：《化工进展》2017年第8期3092-3099,共8页Chemical Industry and Engineering Progress

摘　　要：为对抗全球变暖并控制CO_2排放,针对超低浓度气氛中CO_2吸附速率慢、动力学性能差等问题,基于湿法再生技术,系统分析了湿法再生技术中CO_2吸附动力学若干影响因素。通过实验分析与理论模型相结合的方法,研究结构参数、温度及湿度对CO_2吸附的多重影响机制。采用相转化法制备CO_2吸附薄膜,并通过优化及筛选,获得界面结构可控、官能团可调的异相吸附多孔薄膜,实现了CO_2的可逆吸附。针对异相结构吸附剂吸附CO_2过程中传质步骤复杂,描述困难的问题,对传统的缩核模型进行改进,用来描述CO_2吸附反应过程,得到CO_2吸附过程中各部分阻力大小,同时试验获得了结构参数、温度、湿度等对总传质系数及单个步骤(扩散和反应)传质系数的影响规律。结果表明CO_2吸附过程中产物层扩散阻力所占份额较大,而膜扩散阻力所占份额较小,表明下一步吸附剂的优化应重点降低产物层扩散阻力。To fight against global warming and control the CO2emissions,several factors influencing the kinetics of CO2adsorption during moisture swing technology are systematically analyzed to solvethe problem of slow CO2adsorption rate and poor kinetic performance under ultra-low CO2atmosphere.The multiple influencing mechanisms of structure parameter,temperature and humidity on CO2adsorption kinetics were studied through experimental analysis and theoretical model.Firstly,the CO2adsorption membrane was prepared by phase inversion technique,and then the porous and heterogeneous membrane with controllable structure and adjustable functional groups was obtained after optimization and screening,through which the reversible adsorption of CO2was realized.In light of the complex mass transfer steps of CO2adsorption for heterogeneous adsorbents,the traditional Shrinking Core Model was modified to describe the CO2adsorption process and all resistance during CO2adsorption was obtained.Meanwhile,the effects of the structure parameters,temperature and humidity on total mass transfer coefficient and individual step(diffusion and reaction)were studied by experiments.The results showed that the product layer diffusion resistance dominated the total mass transfer during CO2adsorption,indicating that the optimization of the adsorbent should focus on reducing product layer diffusion resistance.

关 键 词：二氧化碳捕集 空气捕集 湿法再生吸附 动力学 

分 类 号：TK09[动力工程及工程热物理] X5[环境科学与工程—环境工程]