Mass transfer analysis of CO2 capture by PVDF membrane contactor and ionic liquid

Abstract

Post-combustion processes based on ionic liquids (ILs) and membrane contactors are attractive alternatives to traditional systems. Here, a gas stream composed of 15% CO2 and 85% N2 flowed through the lumen side of a hollow-fiber membrane contactor containing poly(vinylidene fluoride)-IL (PVDF-IL) fibers. The IL 1-ethyl-3-methylimidazolium acetate [emim][Ac] served as an absorbent due to its high chemical absorption and CO2 solubility. The overall mass transfer coefficient (Koverall), activation energy (Ea), and resistances of the hollow-fiber membrane were quantified. The Koverall value was one order of magnitude higher than those reported in previous works with conventional solvents, and the Ea was lower than formerly stated values for other solvents. A theoretical simulation was conducted to estimate the operational parameters required for 90% CO2 capture and to quantify intensification effects related to CO2 absorption in a packed column.