MDEA水溶液脱碳平衡溶解度和动力学研究

EQUILIBRIUM SOLUBILITY AND KINETICS OF CO_2 ABSORPTION IN AQUEOUS ACTIVATED METHYLDIETHANOLAMINE SOLUTIONS

针对烯胺为活化剂的混合胺水溶液脱碳需求,为满足工程计算和动力学研究之需,研究了以三乙烯四胺(TETA)为活化剂的N-甲基二乙醇胺(MDEA)水溶液吸收CO2的反应机理,采用动态吸收法测定了CO2在MDEA和TETA(2.7molMDEA+0.3molTETA/L)混合胺水溶液中的平衡溶解度和吸收速率。根据实验数据建立了以机理为基础的该混合胺水溶液吸收CO2的简化气-液平衡模型及吸收速率动力学方程,并通过计算得到简化气-液平衡模型及吸收速率动力学方程中各相关参数的关联式。与实验值比较,CO2平衡分压、CO2在混合胺水溶液中的平衡溶解度以及CO2吸收速率的模型预测值相对误差均<10%,所得到的模型和方程可满足工程设计的需要。

The mechanism study on CO2 absorption in aqueous solution of TETA and MDEA has been conducted.The solubility and absorption rate of CO2 in MDEA-TETA-H2O(2.7 mol MDEA/L + 0.3 mol TETA/L)are studied by using a dynamic absorption technique.A simplified gas-liquid equilibrium model for the CO2-TETA-MDEA-H2O system and the rate equation of CO2 absorption in the solution are developed.Predicted and experimental CO2 equilibrium solubility,CO2 equilibrium partial pressures and CO2 absorption rate are all in good agreement,and the relative error is less than 10%.The model and equation are reliable for commercial unit design.