A novel plasma-assisted hollow fiber membrane concept for efficiently separating oxygen from CO in a CO2 plasma
Plasma-based technologies providing extremely flexible 'turnkey' applications are increasingly attracting interest in renewable energy usage and CO2 conversion into carbon neutral fuels. Here, we report a breakthrough concept combining plasma and mixed ionic-electronic conductor hollow fiber membranes for significantly enhancing the oxygen permeability which may stimulate the CO2 conversion by product separation. Structure and composition of La0.6Ca0.4Co0.5Fe0.5O3−d (LCCF) hollow fiber membranes were characterized before and after oxygen permeation tests in a CO2 plasma. The oxygen permeation flux can be increased by one order of magnitude via this new plasma-assisted hollow fiber membrane concept, reaching up to 4 ml min−1 cm−2 in a CO2 containing atmosphere. Long-term operation did not lead to an apparent decrease of the oxygen permeation flux even with fast heating and cooling cycles by switching the plasma repeatedly on and off. Thus, we consider this plasma-assisted hollow fiber membrane concept a promising process for flexible and economical CO2 conversion.