Abstract: A process for removing acid gases from natural or synthesis gases by absorption, comprising the following stages:(a) cooling the natural or synthesis gas to be purified to condense part of the CO.sub.2 contained in said gas;(b) feeding the cooled and partly condensed gas to an absorption column in order to reduce the acid gas content to the required value;(c) regenerating the solvent or solvents used in the acid gas absorption, the solvent or solvents used being chosen from esters, alcohols and ethers of low molecular weight.

Abstract: A cryogenic process for removing acid gases from natural or synthesis gases, comprising the following stages:(a) feeding the natural or synthesis gas to a first absorption column in order to absorb the H.sub.2 S;(b) cooling the substantially H.sub.2 S-free gas to condense part of the CO.sub.2 contained in said gas;(c) feeding the cooled and partly condensed gas to a second absorption column in order to reduce the CO.sub.2 content to the required value;(d) regenerating the solvent or solvents used in the acid gas absorption, the solvent or solvents used being chosen from esters, alcohols or ethers, of low molecular weight.