膜吸收器吸收CO2的影响因素研究

采用聚丙烯中空纤维膜吸收器,用水、NaOH和K2CO3 水溶液作为吸收剂进行高浓度CO2 吸收试验,考察了气体流率、吸收剂流率、质量分数以及流动方式对吸收率、传质系数和传质速率的影响.结果表明,随着气体流率增大,CO2的吸收率递减,总传质系数和总传质速率增加.在一定的气体流率下,吸收液流率增大,CO2的吸收率、总传质系数和总传质速率增大;吸收液浓度提高,吸收率增大,总传质系数和总传质速率提高.在气体流率较低时,质量分数为5%和8%的NaOH水溶液为吸收剂时的吸收率、总传质系数和总传质速率比较接近.随着气体流率增大,NaOH质量分数为8%时的吸收率、总传质系数和总传质速率增加的值大大超过NaOH质量分数为5%时增加的值.以水为吸收剂时,气体与吸收剂的流动方式为逆流时的吸收率、总传质系数和总传质速率高于并流时的值.

On influencing factors of CO2 absorption by means of membrane contactor

This article is aimed at introducing the authors' investigation of some influencing factors with the membrane absorption, such as the flow rate of the gas and absorbents, their concentration as well as the flow mode. In our investigation we have used microporous membrane contactor made of polypropylene for high concentration CO_2 absorption by means of some few absorbents including water, potassium carbonate solution and sodium hydroxide solution. In the lower gas flow rate, the absorption rate, the overall mass transfer coefficient and the mass transfer rate of 5% and 8% sodium hydroxide solution are approximate. In the higher gas flow rate, the increasing values of above parameter of 8% sodium hydroxide solution are higher than that of 5% sodium hydroxide solution. Using water as absorbent, the absorption rate, the overall mass transfer coefficient and the mass transfer rate with countercurrent flow mode of the gas and absorbent is higher than that with parallel flow mode.