A novel type of gas‐liquid contactor for post‐combustion capture cost reduction

A novel gas‐liquid contactor based on a rotating continuous thin liquid sheet is proposed for use in post‐combustion CO 2 capture processes. This rotating liquid sheet (RLS) contactor is capable of providing a surface area equivalent to that of a packed column but without any packing material in the column. A small‐diameter axially located tube provides the liquid feed to the column through thin slots shaped in the form of helices or angled blades and designed in such a way as to create a continuous angled sheet of liquid. Rotation of this device causes the gas to be pumped through the contactor column at velocities comparable to that seen in conventional packed columns. The RLS contactor has the advantage of reducing or eliminating the need for external flue gas pumping, reducing entrainment of liquid droplets and the potential to utilize a wider range of capture solvent viscosities. An optimized design of the new contactor would result in a 30% reduction in the major equipment capital costs for post‐combustion CO 2 capture and a 25% reduction in electrical power requirement. Capital cost reduction occurs as a result of eliminating the packing, reducing or eliminating the need for external flue gas pumping, and in vessel size reduction. Ongoing experimental and modeling work using computational fluid dynamics is addressing scale‐up issues and the development of an optimized design.© 2014 Society of Chemical Industry and John Wiley & Sons, Ltd