Selection and Pilot Plant Tests of New Absorbents for Post-Combustion Carbon Dioxide Capture

Post-combustion capture of carbon dioxide is the only technique that can be rapidly and safely employed for substantially reducing carbon dioxide emissions from existing power plants and may also be the best choice for power plants to be built in the near future. For large scale post-combustion capture, absorption is the method of choice. The key question of the absorption/desorption technique for removal of carbon dioxide from flue gases is not its technical feasibility or conceptual process design but process economics, which again are dominated by the choice of the solvent. In the framework of the integrated project CO2-CASTOR (Castor, 2004) a solvent selection procedure was carried out. In this work, a consistent criterion for comparison of thermodynamic equilibrium data has been developed and applied to a list of potential solvents. Furthermore, experimental work for screening of solvent degradation has been performed. After the solvent selection procedure based on lab experiments is completed the operation of the absorption/desorption process has to be tested for the most promising solvents. For that purpose, a gas fired mini plant with a complete absorption/desorption cycle was built at University of Stuttgart.