气相第2组分对水溶解CO2过程界面对流影响的LIF观测  

LIF measurement for effect of additive component in gas phase on interfacial convection for water-CO_2 dissolution process

作　　者：胡楠[1] 张会书[1] 傅强[1] 李陆星[1] 袁希钢[1] 

机构地区：[1]化学工程联合国家重点实验室,天津大学化工学院,天津300072

出　　处：《化工学报》2017年第2期584-593,共10页CIESC Journal

基　　金：国家自然科学基金项目(91434204)~~

摘　　要：采用激光诱导荧光(LIF)观测方法考察了在气相中分别添加乙醇和二氯甲烷分别对CO_2在水中溶解过程界面对流的影响,得到了液相中CO_2浓度分布及其演化的观测结果,通过物料衡算得到了相应条件下的液相传质系数。CO_2溶解过程会出现由密度梯度引起的Rayleigh对流。实验结果表明,当添加的乙醇含量小于8.47 mg·L-1时,Rayleigh对流会被增强,进而促进了CO_2的溶解;随着气相中乙醇含量的增大,Rayleigh对流反而被抑制;气相添加二氯甲烷会显著增强Rayleigh对流,提高了CO_2的传质速率,随着气相二氯甲烷含量的增大,CO_2在水中溶解过程的液相传质系数呈现先加强后恒定的趋势。Laser induced fluorescence（LIF） technique was employed to investigate the influence of additive component in gas phase on interfacial convection in the process of water-CO_2 dissolution. CO_2 concentration distributions in the liquid and their evolutions were obtained. Liquid side mass transfer coefficients were estimated using the measurement results. Rayleigh convection in the liquid occurred during water-CO_2 dissolution due to density gradient near the interface. The results showed that with the addition of ethanol of a low concentration（8.47 mg·L-1） in the gas, the Rayleigh convection enhanced and liquid side mass transfer was enforced. With further increase of ethanol concentration in the gas, Rayleigh convection and thus the liquid side mass transfer were inhibited. The experimental results also showed that the addition of dichloromethane in the gas is enhanced by both Rayleigh convection and the liquid side mass transfer for the process of CO_2 dissolution in water. With the increase of the concentration of dichloromethane in the gas, the liquid mass transfer coefficient tended to become constant.

关 键 词：激光诱导荧光 界面Rayleigh对流 传质系数 传质增强因子 

分 类 号：TQ028[化学工程]