The effect of nitrogen adsorption on vacuum swing adsorption based post-combustion CO2 capture

Abstract

The importance of nitrogen adsorption, an often neglected topic, on post-combustion CO2 capture using vacuum swing adsorption is evaluated. Several hypothetical adsorbents are generated by parametrizing their affinities using the Langmuir adsorption isotherm. By performing detailed process simulation and optimization, it is found that N2 affinity has a strong impact on the ability of the process to concentrate and recover CO2. It is also demonstrated that the energy required to remove N2 can play an important role in determining the total parasitic energy of the process. Lower parasitic energies are obtained for adsorbents that show weak N2 affinity and high CO2/N2 selectivity.