Method and apparatus for removing carbon dioxide from flue gas

Abstract

A method of removing carbon dioxide from flue gas is disclosed. The method comprises mixing the flue gas with ammonia; and contacting the gas mixture with calcium nitrate solution to produce calcium carbonate precipitates and ammonium nitrate solution; or contacting the gas mixture with sodium nitrate solution to produce sodium carbonate precipitates and ammonium nitrate solution. The carbonate/bicarbonate precipitates are recovered by separating the carbonate/bicarbonates (s) from said solutions. An apparatus for performing the above method is also disclosed. The apparatus comprises a reaction vessel with an inlet to receive said solution and an inlet to receive and deliver a flue gas-ammonia mixture to a gas-liquid contactor which is configured to diffuse said gas mixture into either calcium nitrate or sodium nitrate solution. The reaction vessel is also provided with an impellor and draft tube configured to circulate the diffused gas mixture throughout the calcium nitrate or sodium nitrate solution for a period of time sufficient to produce carbonate/bicarbonate precipitates locking the CO2 into a solid form.

Dependencies are inferred from the claim text.