Effects of Ionic Liquids/AMP Mixture on CO2 Absorption

摘要

Ionic liquids are known as environmentally benign solvents because of their immeasurably low vapour pressure which essentially eliminates the opportunity for solvent release to the atmosphere. Recently they have been proposed for CO2 capture as alternative solvents to the more established alkanolamine systems. The use of mixtures of ionic liquids with alkanolamines is an interesting alternative since it combines the advantages of both systems.In this work, an experimental investigation is carried out in order to evaluate the effects of two ionic liquid [bmim][acetate] and [bmim][BF4] addition on the absorption of CO2 in AMP a sterically hindered alkanolamine. The [bmim][acetate] is a chemical absorbent and [bmim][BF4] is a Physical one. The solubility studies were carried out in a semi-batch stirred cell reactor operated under various operating conditions. The reaction of CO2 with the mixture was monitored using online pH measurement system. The addition of ionic liquid resulted in a decrease of CO2 solubility. This reduction in CO2 loading was accompanied by an increase in the overall rate of reaction. The results showed that CO2 absorption of [bmim][acetate]/AMP mixture was more than [bmim][BF4]/AMP which confirms high reactivity of chemical absorbent comparing with physical absorbent.