CO2 separation with polyolefin membrane contactors and dedicated absorption liquids:: performances and prospects

Evidence continues to mount that the enhanced greenhouse effect is caused by increased emissions of infrared light absorbing components. Carbon dioxide is the largest contributor as a result of the large amounts emitted in power generation processes. This has brought about a sizeable academic and industrial interest in ways to remove carbon dioxide from various feed gas streams. Membrane gas absorption (MGA) using dedicated absorption liquids (CORAL) in conjunction with porous polypropylene hollow fibre membranes for carbon dioxide removal is discussed in this paper. Mass transfer results achieved in a pilot plant, including regeneration of the absorption liquids, are presented. The impact of carbon dioxide partial pressure, liquid loading and liquid temperature on the carbon dioxide membrane flux is discussed and compared with literature data for other systems. The novel absorption liquids show an excellent performance in terms of system stability and mass transfer, when used in combination with commercially available, inexpensive polyolefin membranes. The largest application under development is the production of carbon dioxide for the horticultural industry. Amongst the spin-off activities the life support applications are prevalent. (C) 2002 Elsevier Science B.V. All rights reserved.