Recovery of carbon dioxide from combustion exhaust gas

Abstract

An electric generating power plant and a method of operation thereof wherein the boiler (1) produces steam to a turbine driven-generator (2), carbon dioxide from combustion exhaust gas emitted from the boiler is simultaneously absorbed in an absorbing solution in an absorber (7), the absorbing solution with the absorbed carbon dioxide is passed through a regenerator (10) where the carbon dioxide is stripped from the absorbing solution, the regenerated absorbing solution is returned to the absorber (7), and steam from either the boiler (1) or turbine of the turbine-driven generator (2) is supplied to a reboiler (13) to provide heat for operation of the regenerator (10). During periods of high demand for electric power steam extraction from the boiler or turbine is discontinued, operation of the regenerator (10) is discontinued and the absorbing solution from the absorber (7) is stored in a first storage unit (15). During periods of low power demand steam is supplied to the reboiler (13) from the boiler (1) or turbine and absorbing solution from the first storage unit (15) is fed to the regenerator (10) for operation thereof, and absorbing solution stripped of carbon dioxide from the regenerator (10) is stored in a second storage unit (16). Absorbing solution from the second storage unit (16) is fed to the absorber (7) during periods of high power demand.