A gas flow absorber comprises an absorption vessel, having a vessel wall defining a cylinder including an absorption material, the cylinder having a cylinder wall bearing, at the bottom thereof, in a circumferential slot formed on a support plate including a channel therethrough a gas mixture flow is conveyed, the channel having a channel hole passing through an enlarged portion of the support plate, the enlarged portion being coupled to a flat chamber substantially extending through the overall extension of the vessel bottom, the chamber being covered by a disc-like body made of a sintered material.