Patent ID: 8486358

Claim:
A method of capturing the CO 2 contained in the combustion fumes produced by a combustion unit, wherein the following stages are carried out: a) contacting combustion fumes with an absorbent solution comprising at least one amine in aqueous solution so as to obtain CO 2 -depleted fumes comprising amine degradation products, and a CO 2 -enriched absorbent solution, b) regenerating at least a fraction of CO 2 -enriched absorbent solution in a regeneration column provided with a reboiler so as to obtain a regenerated absorbent solution and a CO 2 -rich gaseous effluent, regenerated absorbent solution being recycled to stage a) as absorbent solution, c) washing in a first wash section the CO 2 -depleted fumes obtained in stage a) by contacting with a first liquid water stream so as to obtain fumes depleted in amine degradation products and a water stream enriched in amine degradation products, the method being characterized in that at least the value of one of the operating parameters of said method is measured over time, in that the fumes depleted in amine degradation products obtained in stage c) are released to the atmosphere as long as said value is constant and in that, if a variation over time of said value is detected, stage d) hereafter is carried out: d) washing in a second wash section at least part of the fumes depleted in amine degradation products obtained in stage c) by contacting with a second liquid water stream comprising at least one acid whose pKa value is below 6, so as to obtain a treated gas, and releasing said treated gas to the atmosphere.