Method for the separation of carbon dioxide from an exhaust gas of a fossil-fired power plant (55, 56), in which a) a fossil fuel is burnt in a combustion process, an exhaust gas containing carbon dioxide being generated, b) the exhaust gas containing carbon dioxide is brought into contact with an absorption medium in a separating apparatus in an absorption process in an absorption unit, carbon dioxide being taken up by the absorption medium, a laden absorption medium and a purified exhaust gas being formed, c) the laden absorption medium is regenerated in a desorption process in a desorption unit using heating energy in the form of heating vapour from the power plant (55, 56) via a heat exchanger, a regenerated absorption medium being formed, and a condenser, which condenses out a condensate from the gas-vapour mixture, is arranged downstream of the desorption unit, characterized in that - the laden absorption medium is divided into a first part stream and into a second part stream, and delivered to the desorption process, wherein the first part stream of the desorption unit is delivered to a process stage in which, in the desorption process, there is predominantly exhaust vapour, so that the exhaust vapour condenses, and wherein the process stage in the desorption unit is higher than a process stage at which the second part stream is delivered to the desorption process, - in an expansion process with a pressure tank which is configured for vacuum and the pressure P 1 of which is lower than a pressure P 2 in the desorption process, regenerated absorption medium from the desorption unit is expanded, wherein vaporous absorption medium is formed and a regenerated absorption medium is separated, and wherein the vaporous absorption medium is compressed in a compressor and is recirculated into the desorption process, and the regenerated absorption medium is recirculated via an absorption medium recirculation line into the absorption process, and - the regenerated absorption medium is made to exchange heat only with the second part stream (40, 202) in a heat exchanger in order to heat the laden absorption medium in the second part stream. a) a fossil fuel is burnt in a combustion process, an exhaust gas containing carbon dioxide being generated, b) the exhaust gas containing carbon dioxide is brought into contact with an absorption medium in a separating apparatus in an absorption process in an absorption unit, carbon dioxide being taken up by the absorption medium, a laden absorption medium and a purified exhaust gas being formed, c) the laden absorption medium is regenerated in a desorption process in a desorption unit using heating energy in the form of heating vapour from the power plant (55, 56) via a heat exchanger, a regenerated absorption medium being formed, and a condenser, which condenses out a condensate from the gas-vapour mixture, is arranged downstream of the desorption unit, - the laden absorption medium is divided into a first part stream and into a second part stream, and delivered to the desorption process, wherein the first part stream of the desorption unit is delivered to a process stage in which, in the desorption process, there is predominantly exhaust vapour, so that the exhaust vapour condenses, and wherein the process stage in the desorption unit is higher than a process stage at which the second part stream is delivered to the desorption process, - in an expansion process with a pressure tank which is configured for vacuum and the pressure P 1 of which is lower than a pressure P 2 in the desorption process, regenerated absorption medium from the desorption unit is expanded, wherein vaporous absorption medium is formed and a regenerated absorption medium is separated, and wherein the vaporous absorption medium is compressed in a compressor and is recirculated into the desorption process, and the regenerated absorption medium is recirculated via an absorption medium recirculation line into the absorption process, and - the regenerated absorption medium is made to exchange heat only with the second part stream (40, 202) in a heat exchanger in order to heat the laden absorption medium in the second part stream.