Development of carbon-based vacuum, temperature and concentration swing adsorption post-combustion CO2 capture processes

Vacuum, temperature and concentration swing adsorption processes, have been designed to capture 85% of the CO2 emitted by an advanced supercritical coal fired power plant of 800 MW taken as reference, and to produce a concentrated product with 95% of CO2 (dry basis) using a sustainable carbon adsorbent inside the tubes of a tube-bundle adsorber. Indirect heat transfer is used to increase productivity and to conserve energy within the process. Two different configurations of the cyclic process have been evaluated at cyclic steady state through dynamic process simulation, using a detailed non-isothermal non-equilibrium fixed bed adsorption model that takes into consideration competitive adsorption between the main flue gas components: N-2, CO2 and H2O. Simulation results indicate that the purity and recovery constraints can be met with a specific heat duty of 2.32 MJ(th) kg(-1) CO2 and a specific electric consumption of 0.66 MJ(e) kg(-1) CO2. The main advantage of this process is that the specific heat duty, which is lower than the benchmark amine absorption technology, could be satisfied using waste heat.