A comprehensive modeling of the hybrid temperature electric swing adsorption process for CO 2 capture

Adsorption technologies provide high selectivity and low energy consumption making this technique very attractive to be employed in post-combustion carbon capture. In this publication, a material made of activated carbon and zeolite 13X is considered for a hybrid process termed Temperature Electric Swing Adsorption (T/ESA). This hybrid T/ESA can work as a traditional Temperature Swing Adsorption (TSA) heated by hot gas, but can also increase the temperature of the adsorbent very fast by Joule effect as long as the activated carbon provides a continuous conductive matrix for electricity. This paper discusses a detailed modeling of the T/ESA process when applied to three cases. The first case is the simulation of the T/ESA process with exhaust with 12% of CO2 concentration, which has been chosen to validate the model against literature results. The second and third case studies consider the T/ESA application in a natural gas combined cycle (NGCC) traditional power plant, and in a NGCC plant with exhaust gas recycle (EGR). These cases were selected to investigate the adsorption technology at low CO2 concentration and quantify the benefit of the EGR for carbon capture applications. Starting from an NGCC overall electric efficiency of 58.3% LHV based, the efficiency of the NGCC with T/ESA technology reduces to 35.3% while with EGR is 38.9% against the 49.9% with the MEA absorption plant. The same results are confirmed by the SPECCA index 13.05 MJLHV/kgCO2 to 9.64 MJLHV/kgCO2 against the reference of 3.36 MJLHV/kgCO2. The energy penalty of the T/ESA is significant because of electric consumptions required for the heating and fast cooling of the adsorbent.