Hollow Fiber-Type Facilitated Transport Membrane Composed of a Polymerized Ionic Liquid-Based Gel Layer with Amino Acidate as the CO2 Carrier

A hollow fiber-type facilitated transport membrane composed of an ionic liquid-based polymer network gel layer with amino acid as the CO2 carrier and a porous polysulfone support membrane was developed. A polymerized ionic liquid-based gel layer with glycinate was the best amino acidate examined in this study. Filtering the gel particles by the support membrane, a gel layer with a thickness of about 1 μm could be formed on the inner surface of the support. The developed membrane showed promising potential for CO2 capture from air because of its high CO2 permeance of about 1400 GPU and excellent CO2/N2 selectivity of more than 2000 under atmospheric pressure with CO2 pressure of 0.1 kPa at 30 °C. Because the developed membrane showed significant diffusion resistance in the pores of the support membrane, it was suggested that the performance of the composite membrane could be improved by optimizing the support membrane structure.