Mixing calorimetry in aqueous solutions: energetic properties for CCS concerns

International audienceCarbon Capture and Storage (CCS) is a solid option for CO2 mitigation in the atmosphere. One option is the CO2 capture on the industrial site of production followed by storage in secured sites. Capture processes are based on absorption/desorption cycles of selected gas in aqueous solutions of amines[1]. One of the options for storage is the dissolution of gas in deep aquifers. The optimization of the capture processes as well as the safety of the storage induced the knowledge of thermodynamic properties for the dissolution of CO2 in aqueous media. The experimental thermodynamic study of CO2 dissolution in such aqueous solutions will then allow the correlation and the prediction of absorption capacities and energy cost depending on chemical composition of the solution, temperature, and pressure. These studies have to combine experimental measurements [2-4] and modeling developments [5-6]. This work will present the thermodynamic data experimentally accessible in our laboratory and necessary for the development of predictive models. The enthalpies of mixing of gas in aqueous solutions are obtained using mixing cells, developed in our laboratory, and used in BT2.15 and C80 differential calorimeters from SETARAM. This equipment allows determining simultaneously the enthalpy of dissolution and the solubility of the gas in aqueous solutions over a wide range of temperatures and pressures.The results obtained with such measurements will be illustrated through some examples coming from researches on aqueous solutions of amines and aqueous solutions of electrolytes