Calorimetric and Densimetric Data to Help the Simulation of the Impact of Annex Gases Co-Injected with CO2 During Its Geological Storage

Most of the industrialized countries have started to significantly reduce their greenhouse gases emissions. CO 2 capture and geological storage processes entered an operational phase with the emergence of several pilot-sites where different technologies are tested. The gas mixture composition to be stored can vary considerably both qualitatively and quantitatively, based on the origin of CO 2 , the chosen process of capture and the concerned industrial sector. Indeed, in addition to CO 2 , several components can be present at various concentration levels, including O 2 , N 2 , SO x , H 2 S, N y O x , that are a concern to the energy industry. These impurities can have an impact on the chemical reactivity with water, reservoir or cap-rock forming minerals, and the materials constituting injection or monitoring wells installed in a repository site. Moreover, some impurities (SO x , H 2 S, N y O x , CO) are toxic for human health and the environment, even at low concentrations. This work is part of the objectives of the French ANR program SIGARRR : Simulation of the Impact of Annex Gases (SO x , N y O x , O 2 ) co-injected with CO 2 during its geological storage on the Reservoir-Rocks Reactivity. Based on the technical experience of the consortium, it was appropriate to propose a project to study the behavior of co-injected gases mixtures under storage conditions. This chapter will focus on the determination of two key properties for the mixtures containing pure gases: Enthalpies of mixing, solubility, and Molar volumes at infinite dilution of aqueous solutions of salts, loaded with different gases, namely CO 2 and SO 2 .