Carbon dioxide capture using chemical absorbents: a thermodynamic approach
Résumé
Greenhouse gases are responsible for the global warming. Anthropic emission of carbon dioxide represents about 70% of the total effect. One option to fight against this environmental problem consists in reducing CO2 emissions in industrial effluents. Industrial CO2 capture processes are based on repeated absorption-desorption cycles of CO2 in selective absorbents such as amine aqueous solutions. These solutions are known for being efficient chemical solvents for the CO2 capture. A first pilot plant has already been tested in Denmark (CASTOR project). This installation uses monoethanolamine aqueous solutions to capture CO2 from power plant emissions. This plant is efficient but cannot be used in industrial sites because of economical reasons. Researches are actually carried out on both absorbent selection [1,2,3] and process optimization in order to reduce total cost of CO2 capture. Thermodynamic properties are essential to study gas dissolution and to design capture process units. Reliable experimental thermodynamic data of absorbent solution, such as excess properties and equilibrium constants, and of gas dissolution, such as solubility and enthalpy of dissolution of CO2, are needed to optimize the processes. Moreover, the development of thermodynamic models is essential to correlate and predict vapour-liquid equilibria and enthalpic data. This presentation will focus on the acquisition of thermodynamic data. Those data will be used to optimize the semi-empirical parameters in the thermodynamic representation of the gas - absorbent systems. References [1] L. Rodier, K. Ballerat-Busserolles, J-Y. Coxam, J. Chem. Thermodynamics, 42 (2010) 773-780 [2] H. Arcis, L. Rodier, K. Ballerat-Busserolles, J-Y. Coxam, J. Chem. Thermodynamics, 40 (2008) 1022-1029 [3] H. Arcis, L. Rodier, K. Ballerat-Busserolles, J-Y. Coxam, J. Chem. Thermodynamics 41 (2009) 836-841