Abstract: An experimental packed tower was set up to study the absorption of high-concentration CO2 in aqueous solutions of blended organic amine with diethanolamine (DEA) as base solvent, and N-methyldiethanolamine (MDEA), (N-2-hydroxyethyl) ethylenediamine (AEE), diethylenetriamine (DETA) and triethylenetetramine (TETA) as additives respectively. The effects of concentration and species of additives on the mass transfer performance, such as conversion rate of CO2 h, volumetric overall mass transfer coefficient KGae, and gas and liquid phase mass transfer resistance, were systematically examined. The results show that KGae and h increase with increasing of additive concentration when AEE, DETA and TETA are taken as additives. And the gas phase mass transfer coefficient kG and gas phase mass transfer resistance decrease, but liquid phase mass transfer resistance increases. For the additive of MDEA, the trends were just contrary to the above. In the absorption process of CO2 in two-component blended organic amine solutions, the values of KGae and h increase along the tower packing height, which follow the order of DEA-TETA > DEA-DETA > DEA-AEE > DEA-MDEA.

Key words: biogas purification, CO2, absorption, packed tower, blended organic amine, mass transfer

摘要： 在填料塔中，对以二乙醇胺(DEA)为基础溶剂，以N-甲基二乙醇胺(MDEA)、(N-2-羟乙基)乙二胺(AEE)、二乙烯三胺(DETA)、三乙烯四胺(TETA)为添加剂的二元混合胺溶液吸收沼气中高浓度CO2的传质性能进行了实验研究，考察了添加剂浓度及种类对吸收过程中CO2脱除率h、总体积传质系数KGae、气液相传质阻力的影响. 结果表明，双组分混合有机胺溶液中，以AEE, DETA和TETA为添加剂时，KGae和h随添加剂浓度增加而增大，气相传质系数kG及气相阻力占总阻力的分率减小，液相阻力占总阻力的分率增大；以MDEA为添加剂时趋势相反. h和KGae沿塔高方向增大，其在4种溶液中的大小为DEA-TETA>DEA-DETA>DEA-AEE>DEA-MDEA.

关键词: 沼气提纯, CO2, 吸收, 填料塔, 混合有机胺, 传质