Abstract: The invention relates to a method and a device for increasing the enthalpy of a medium, in which energy is withdrawn from a first heat carrier (W) consisting of a first flue gas (5) and a second heat carrier (W) comprising water and flue gas and, in each case, is transmitted to the medium via indirect heat exchange, wherein a second flue gas (3) is injected into a water-containing system of matter for formation of the second heat carrier (W). The first heat carrier (9) that is cooled against the medium is used for formation of the second heat carrier (W).