Affiliation: | a Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan b CO2 Chemical Utilization Laboratory, Research Institute of Innovative Technology fort the Earth, 9-2 Kizugawadai, Kizu-cho, Soraku-gun, Kyoto 619-0292, Japan |
Abstract: | A novel facilitated transport membrane for gas separation using a capillary membrane module is proposed in which a carrier solution is forced to permeate the membrane. Both a feed gas and a carrier solution are supplied to the lumen side (high pressure side, feed side) of the capillary ultrafiltration membrane and flow upward. Most of the carrier solution which contains dissolved solute gas, CO2 in the present case, permeates the membrane to the permeate side (low pressure side, shell side), where the solution liberates dissolved gas to form a lean solution. The lean solution is circulated to the lumen side. This type of capillary membrane module was applied to the separation of CO2 from model flue gases consisting of CO2 and N2. Monoethanolamine (MEA), diethanolamine (DEA) and 2-amino-2-methyl-1-propanol (AMP) were used as carriers or absorbents of CO2. The feed side pressure was atmospheric and the permeate side was evacuated at about 10 kPa. CO2 in the feed gas was successfully concentrated from 5–15% to more than 98%. The CO2 permeance was as high as 2.7×10?4 mol m?2 s?1 kPa?1 (8.0×10?4 cm3 cm?2 s?1 cmHg?1) when the CO2 mole fraction in the feed was 0.1 and temperature was 333 K. The selectivity of CO2 over N2 was in the range from 430 to 1790. The membrane was very stable over a discontinuous one-month testing period. |