Liquid membranes of triethylenetetramine mixed with ionic liquids were prepared on a hydrophobic microporous membrane using a novel nanoparticle-supported construction. A flat membrane module with the amine/ionic liquid membrane was used for the recovery of CO2 from room air. CO2 was enriched 3-5 times in the sweep air passing through the membrane module. There was an optimum amine/ionic liquid ratio of 10-25 wt% to effectively concentrate the CO2. These permeation results were analyzed in terms of permeability based on a solution-diffusion mechanism. The present membrane process for CO2 separation has proved to be reasonably durable for a greenhouse application.