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Research Topics

by Karine Ballerat - 6 November 2012

All the versions of this article: English , français

The development of technologies for the capture of CO2 is a major research front, requiring thermodynamic knowledge on solubility, selectivity and diffusion of gases in absorbing media. The originality of the group’s research on CO2 absorption is the measurement of energetic quantities, which are crucial for the steps of regeneration of the absorbent: too strong a binding of CO2 makes the capture process hardly reversible. The challenge resides in the search for the optimum compromise, reconciling the highest possible CO22load with an energetically (and economically) acceptable regeneration of the absorbent. The group’s studies of gas sorption calorimetry contribute to characterize and develop new absorbent media for industrial capture and also for geological sequestration. Thermodynamic models are formulated in order to describe the physical and chemical equilibria in these multi-component systems containing ions, gaseous and liquid species.

The geological storage of CO2 is then a very logical complement to the group activities. Indeed, when CO2 is separated from industrial effluents, it must be either used or stored in secure storage areas. One of the solutions is the geological storage in deep aquifers. The knowledge of geological, geochemical and thermodynamic properties is fundamental to avoid serious environmental problems (brutal spill of a large amount of gas for example). In this context, the study of variations in physicochemical (pH,...) and thermodynamic properties (enthalpies of dissolution of gas, solubility,...) of the medium in presence of dissolved gas is fundamental. Experimental studies realized in the laboratory at conditions close to storage sites conditions (high temperatures and high pressures) will be fundamental for the development or adjustment of rigorous thermodynamic models describing those environments, in order to predict the behavior of the sites in the presence of dissolved gases.

Finally, if the CCS (carbon capture and storage) is a major pathway for reducing greenhouse gas emissions of fixed sources using fossil fuels, it is important to contribute to the development of "clean" processes for energy production, for example using biomass. The Group has started recently a thermodynamic study of molecules associated with the bio-conversion, in collaboration with Ecole des Mines of Fontainebleau (CEP/TEP). This work, which is essential in the design and development of new processes is currently poorly studied and documented.