新型MDEA-TETA混合胺解吸CO_2的动力学研究

Desorption kinetic of CO_2 in mixed amine of MDEA-TETA

以新型MDEA-TETA混合胺为吸收剂,研究CO_2解吸的动力学,计算解吸反应的级数、活化能及指前因子,并探讨温度和溶液组成对CO_2解吸速率的影响。结果表明,新型MDEA-TETA吸收剂解吸CO_2可分为2个阶段,且均为准一级反应,解吸过程的液相阶段为整个解吸过程的控制阶段。TETA的存在能够降低解吸CO_2反应的活化能,使解吸速率加快。相同浓度配比条件下,随着解吸温度的增高,混合胺溶液的CO_2解吸速率增加。温度在90—100℃,浓度配比c(MDEA)∶c(TETA)=2.7∶0.3时CO_2的解吸效果最佳。

A new MDEA-TETA mixed amine was used as absorbent to study the kinetics of CO2 desorption. Desorption reaction order was determined and the value of the activation energy and pre-exponential factor were calculated. The effects of temperature and solution composition on the desorption rate of CO2 were investigated. The results show that the desorption process consists of two stages and the reaction of each stage is a first order reaction. The stage of reaction of the liquid phase is the control stage of the whole process of desorption. TETA can reduce activation energy of desorption of CO2 in the reaction, so as to accelerate the desorption rate. Under the same concentration ratio, with the increase of desorption temperature, the CO2 desorption rate in mixed amine solution was increased. The desorption efficiency of CO2 works best when the temperature is 90-100 ℃, and the concentration ratio is MDEA ： TETA = 2.7 ： 0.3.