A novel facilitated transport membrane module for gas separation 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 module 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 become a lean solution, and the lean solution is returned to the lumen of the capillary module by a pump. This type of capillary membrane module was applied to the separation of CO, from model flue gases consisting of CO2 and N-2 using various amines as carriers or absorbents of CO2. The feed side pressure was atmospheric and the permeate side pressure was controlled at 9-27 kPa. CO2 in the feed was successfully concentrated from 1.5-15 to 98.5-99.8 mol %. When the CO2 mole fraction in the feed was 0.1 and the mean residence time of gas in the module was 0.28 s, the CO2 permeance was 3.8 x 10(-4) mol m(-2) s(-1) kPa(-1) (1.1 x 10(-3) cm(3) cm(-2) s(-1) cmHg(-1)) and the CO2 recovery was 76%. The selectivity of CO2 over N-2 was in the range from about 800 to 8000. The membrane was very stable over a discontinuous 4-month testing period. The energy consumption was found to be much smaller than those of conventional chemical absorption and membrane separation processes. (C) 2004 Elsevier B.V. All rights reserved.