CO₂Capture with Membrane Contactors

This paper summarizes the development work for membrane gas/liquid contactors used for natural gas sweetening (CO2 and H2S removal), dehydration and CO2 removal from exhaust gas. Membrane gas/liquid contactors operate with liquid on one side of a membrane and gas on the other. Unlike gas separation membranes, where differential pressure across the membrane provides the driving force for separation, here the pressure is essentially the same on both sides of the membrane. Absorption into the liquid provides the driving force. The increased specific area of the membrane gas/liquid contactor allows for a 65-75% reduction in weight and size compared to conventional towers. The latest work has been a gas dehydration field test at a Duke Energy Field Services compressor station in Colorado. The project was performed in co-operation with Gas Technology Institute (GTI).