Mass Transfer Analysis of CO2 Capture by PVDF Membrane Contactor and Ionic Liquid

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% N-2 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 (K-overall), activation energy (E-a), and resistances of the hollow-fiber membrane were quantified. The K-overall value was one order of magnitude higher than those reported in previous works with conventional solvents, and the E-a 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.