In order to reduce environmental impact of emissions, one possible option is the decarbonation of the effluents coming from fixed sources. A description of the different techniques proposed for a separation of from gaseous effluents is explained with a focus on post-combustion processes. The design of specific separation units will require studies of gas dissolution in various selective absorbent solutions. The thermodynamic approach for dissolution in aqueous solutions of amine is depicted, showing the physicochemical background and the main properties required in this domain. An overview of the main experimental developments for determining the enthalpy of solution of carbon dioxide in absorbent solutions is presented together with some representative results.