Modeling and Kinetic Study on Absorption of CO2 by Aqueous Solutions of N-methyldiethanolamine in a Modified Wetted Wall Column  

作　　者：钱智 郭锴 

机构地区：[1]Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029, China

出　　处：《Chinese Journal of Chemical Engineering》2009年第4期571-579,共9页中国化学工程学报（英文版）

基　　金：Supported by China Petroleum&Chemical Corporation(105044)

摘　　要：To get more accurate kinetic data of the absorption of CO2 into aqueous solution of N-methyldiethanolamine,a wetted wall column was modified to more uniformly distribute the liquid on the column surface and gas in the absorbing chamber and change the length of the column.The average liquid film thickness and the liquid-phase mass transfer coefficient were measured,and a correlation for the Sherwood number,Reynolds number and Schmidt number was obtained for the modified wetted wall column.The equilibrium concentrations in chemical reactions were calculated with a minor absolute error for calculating the rate constant more accurately.A mathe-matical model for the CO2 absorption was established based on the diffusional mass transfer accompanied with parallel reversible reactions,and the partial differential equation was solved by Laplace transform.An analytical ex-pression for the concentration of carbon dioxide as a function of time and penetration depth in liquid film and the average interphase mass transfer rate was obtained.This model was also used to calculate the rate constant for a second-order reaction,which was in good agreement with reported data.To get more accurate kinetic data of the absorption of CO2 into aqueous solution of N-methyldiethanolamine, a wetted wall column was modified to more uniformly distribute the liquid on the column surface and gas in the absorbing chamber and change the length of the column. The average liquid film thickness and the liquid-phase mass transfer coefficient were measured, and a correlation for the Sherwood number, Reynolds number and Schmidt number was obtained for the modified wetted wall column. The equilibrium concentrations in chemical reactions were calculated with a minor absolute error for calculating the rate constant more accurately. A mathe- matical model for the CO2 absorption was established based on the diffusional mass transfer accompanied with parallel reversible reactions, and the partial differential equation was solved by Laplace transform. An analytical expression for the concentration of carbon dioxide as a function of time and penetration depth in liquid film and the average interphase mass transfer rate was obtained. This model was also used to calculate the rate constant for a second-order reaction, which was in good agreement with reported data.

关 键 词：ABSORPTION carbon dioxide N-METHYLDIETHANOLAMINE kinetics mass transfer 

分 类 号：O65[理学—分析化学]