Carbon dioxide capture by [emim][Ac] ionic liquid in a polysulfone hollow fiber membrane contactor

Abstract

CO2 emissions have to be controlled and reduced in order to avoid greenhouse effect. This work reports an analysis of the efficiency of CO2 separation using a hollow fiber membrane contactor and an ionic liquid. This process configuration contributes to the process intensification approach in the field of CO2 capture and storage. In this study, the ionic liquid 1-ethyl-3-methylimidazolium acetate, [emim][Ac], was used as absorbent due to its high CO2 solubility. The module selected was polysulfone (Ps) because it is a well characterized polymer that allows to operate at moderate temperatures. Results were compared to previous studies with a polypropylene module. The gas stream flowed through the inside of the hollow fibers. The CO2 removal efficiency was obtained from experimental data, showing a temperature dependence: from 30 to 45.0%, corresponding to 291 K and 348 K respectively, when the Ps contactor was used. The overall mass transfer coefficient Koverall has also been evaluated. In addition, a numerical analysis was carried out to study the performance of the membrane contactor for the CO2 capture in order to estimate the process conditions to accomplish 90% CO2 capture as a target to be competitive with the conventional absorption process.