A method for reclaiming CO2 absorbing chemical(s) from a lean aqueous CO2 absorbent leaving a regeneration column (8), where lean absorbent (30) is withdrawn and flashed (31) to generate a vapor that is compressed (34) and returned into the regeneration column as stripper gas (37), where a part of the lean absorbent (20) is withdrawn and introduced into a reclaimer (21) in which the lean absorbent is boiled to generate a gas phase (23) that is withdrawn and returned into the regeneration column as reclaimed absorbent, and a liquid phase containing impurities (24), wherein the gaseous phase that is withdrawn from the reclaimer is compressed (34) together with the vapor part (33) from the flashing of the lean absorbent, to generate a pressure in the reclaimer that is lower than the pressure in the regeneration column, and a reboiler (11) for carrying out the method, are described.