CO₂ separation membranes and carbon capture and storage (CCS)

An explosive increase of atmospheric concentration of greenhouse gas, particularly CO₂, causes global warming and climate change. One of the effective solutions should be mitigation of CO₂ emission through the air by Carbon Capture and Storage, CCS. CO₂ is separated over other gaseous components at the mass emission sources, such as thermal power plants, and then stored under ground or seabed after transportation by pipeline or tanker truck. For implementation of CCS, the capture cost should be drastically reduced, which is equivalent to develop novel CO₂ capture technologies with much lower energy consumption. Among various CO₂ capture technologies, membrane separation is promising because difference in pressure or chemical potential between feed and permeate sides drives the separation, and basically additional energy, such as heating in liquid amine scrubbing technology, is not required at all. A number of CO₂ separation membranes have been investigated, and herein, the recent progress and the potentiality of membrane separation in CO₂ capture are reviewed.