Device for capturing an acid gas contained in the combustion fumes of a thermal power plant comprising a steam circuit, the device comprising: - means for absorbing the acid gas by bringing the fumes into contact with a capture fluid which is poor in acid gas, - a regenerator in which the acid gas-enriched capture fluid and steam from a regeneration fluid are brought into contact in order to regenerate the capture fluid, - first means for introducing the steam of the regeneration fluid into the regenerator, - first means for condensing (2, 3, 4) into a medium containing a liquid phase of the regeneration fluid and a gaseous phase rich in acid gas, arranged at the top of said regenerator, - means for separating the liquid phase of the regeneration fluid from the acid gas-rich gas phase, wherein - the first condensation means (2, 3, 4) are means of a first evapo-condenser and are in heat exchange with first evaporation means of the first evapo-condenser, which evaporate a working fluid, and - the device comprises first reintroduction means (13, 16) of the the working fluid steam thus obtained into a first turbine, characterized in that: - the regeneration fluid steam introduced in order to regenerate the capture fluid is a superheated steam, - the regenerator comprises contact means between the acid gas enriched capture fluid and the superheated steam of the regeneration fluid, limiting the contact time between the two so that the steam flow rate of the regeneration fluid is substantially maintained, and wherein the first regeneration fluid steam introduction means are first means for introducing steam from: - the first turbine, the first turbine being a turbine of said steam circuit or - a second turbine, the second turbine being a turbine of said steam circuit. - means for absorbing the acid gas by bringing the fumes into contact with a capture fluid which is poor in acid gas, - a regenerator in which the acid gas-enriched capture fluid and steam from a regeneration fluid are brought into contact in order to regenerate the capture fluid, - first means for introducing the steam of the regeneration fluid into the regenerator, - first means for condensing (2, 3, 4) into a medium containing a liquid phase of the regeneration fluid and a gaseous phase rich in acid gas, arranged at the top of said regenerator, - means for separating the liquid phase of the regeneration fluid from the acid gas-rich gas phase, wherein - the first condensation means (2, 3, 4) are means of a first evapo-condenser and are in heat exchange with first evaporation means of the first evapo-condenser, which evaporate a working fluid, and - the device comprises first reintroduction means (13, 16) of the the working fluid steam thus obtained into a first turbine, - the regeneration fluid steam introduced in order to regenerate the capture fluid is a superheated steam, - the regenerator comprises contact means between the acid gas enriched capture fluid and the superheated steam of the regeneration fluid, limiting the contact time between the two so that the steam flow rate of the regeneration fluid is substantially maintained, and - the first turbine, the first turbine being a turbine of said steam circuit or - a second turbine, the second turbine being a turbine of said steam circuit.