Microporous membrane absorbers were used for the separation of carbon dioxide–nitrogen mixtures. The
membranes applied were made of polytetrafluoroethylene (PTFE) and the absorbents included aqueous solutions of
different kinds of amines. We determined the separation efficiency and the overall mass transfer coefficient of carbon
dioxide of the membrane modules, and evaluated the separation performance under different absorbent concentrations
and temperatures. Absorption rates through the PTFE hollow fiber membranes were measured at temperatures
ranging from 2 to 60°C, and the removal rate of carbon dioxide was found to increase with the increase of the
volumetric flow rate of an absorbent. We also conducted a theoretical model analysis to predict the separation
efficiency. The results showed that the theoretical model agreed well with the experimental observation for the case
of aqueous amine solutions. © 2000 Elsevier Science B.V. All rights reserved.