Determining the Potentials of PSA Processes for CO2 Capture in Integrated Gasification Combined Cycle (IGCC)

The adoption of a Pressure Swing Adsorption (PSA) process emerged as a promising method for CO2 capture in pre-combustion application. This paper aims to analyse PSA potentials in this framework and to point out the advancements necessary in order to become competitive with other more mature techniques, absorption in the first instance. The methodology for integrating a PSA unit into an Integrated Gasification Combined Cycle (IGCC) is presented and the resulting plant has been modelled and simulated. Different process configurations have been tested. The attained performance suggests that the optimum operating configuration is depending on the specific requirements of the system, either prioritising the separation efficiency, the energy efficiency or the footprint of the plant. An analysis of the adsorbent material leads to similar considerations. Simulations of the adsorbent with targeted properties modifications demonstrate that there is room to attain performance improvements thanks to advancements in material science. Neither by investigating the process nor the material it was possible to completely fill the gap with the benchmark absorption process. Approaching an energy efficiency of 37%, to be competitive with absorption, could be obtained only accepting CO2 recoveries significantly lower than 90%. Conversely higher CO2 recoveries would hinder PSA efficiency on an energy point of view. However, the analyses provide some guidelines on the most feasible directions where to address further investigations.