NOVELTY - The process comprises contacting the gas to be treated with an absorbent solution comprising an amine in aqueous solution to obtain a gas depleted in acid compounds and comprising amine and an absorbent solution enriched in acid compounds, regenerating a fraction of absorbent solution enriched in acid compounds in a regeneration column to obtain a regenerated absorbent solution and a gaseous effluent rich in acid compounds, and washing the resultant gas in a first washing section with a first liquid flow for obtaining a gas depleted in amine and a flow of water enriched in amine.    USE - The process is useful for capturing acid compounds comprising carbon dioxide and hydrogen sulfide contained in a gas to be treated including combustion smoke, natural gas, gas obtained from Claus process, syngas, conversion gas used in integrated combustion of carbon and wood, heavy crude oil or natural gas, gas from the fermentation of biomass, and an effluent from cement or steel plant, where the acid includes nitric acid, nitrous acid, sulfuric acid, phosphoric acid and orthophosphoric acid, or citric acid, oxalic acid, malonic acid, succinic acid, malic acid, tartaric acid or ortho-phthalic acid (all claimed).    ADVANTAGE - The process is capable of economically, rapidly, accurately and automatically capturing the acid compounds comprising carbon dioxide and hydrogen sulfide contained in the gas to be treated with less consumption of energy and without affecting the environment.    DETAILED DESCRIPTION - The process comprises contacting the gas to be treated with an absorbent solution comprising an amine in aqueous solution to obtain a gas depleted in acid compounds and comprising amine and an absorbent solution enriched in acid compounds, regenerating a fraction of absorbent solution enriched in acid compounds in a regeneration column to obtain a regenerated absorbent solution and a gaseous effluent rich in acid compounds, washing the resultant gas in a first washing section with a first liquid flow for obtaining a gas depleted in amine and a flow of water enriched in amine, and washing the resulting gas in a second washing section with a second liquid flow comprising an acid whose dissociation constant (pKa) is lower than 6 for obtaining a treated gas and a water flow enriched in salts. A part of water enriched in amine and amine degradation products obtained in bottom of the first section is cooled and recycled for constituting a portion of the first liquid flow. The water flow enriched in amine is recycled by mixing the water flow with the regenerated absorbent solution, introducing the part of water flow in the regeneration column, and mixing the water flow with the regenerated absorbent solution enriched in acid compounds. The water flow enriched in salts is removed, and then distilled into fractions for obtaining vapor phase and liquid phase enriched in salts. A base such as sodium hydroxide and potassium is introduced in the fractions for neutralizing the salts.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a process for capturing acid compounds comprising carbon dioxide and hydrogen sulfide contained in a gas.    Line for introducing a gas to be treated (1)    Line for introducing a gas to be treated in the absorption section (2)    Gas evacuation line (3)    Gas heating line (4)    Line for introducing heated gas to the regeneration column (5)    Absorbent solution evacuation line. (6)