Patent ID: 6274108
Filing Date: 2001-08-14
Classification: B01D,Y02A,Y02C

Abstract:
In a method for recovering carbon dioxide from combustion exhaust gas by passing the exhaust gas from a cooler to an absorbing column; passing a scrubbing solution of aqueous monoethanolamine through the absorbing column where the scrubbing solution counter-currently contacts the exhaust gas and absorbs the carbon dioxide out of the exhaust gas; discharging the cleaned exhaust gas from absorber; transferring the carbon dioxide-loaded scrubbing solution from the absorbing tower to a regenerator where the carbon dioxide is stripped out of the scrubbing solution, replenishing the scrubbing solution by injecting a supplemental, aqueous solution of monoethanolamine into the carbon dioxide-loaded scrubbing solution at a location between the absorbing column and the regenerator, and returning the regenerated scrubbing solution back to the absorbing column, the improvement comprises:using an aqueous solution containing from about 70% to about 75% by weight of monoethanolamine as said supplemental, aqueous solution of monoethanolamine, andinjecting water into the carbon dioxide-loaded scrubbing solution at a location between the location where the supplemental, aqueous solution of monoethanolamine is injected and the regenerator.