Pillared clays, affordable and scalable adsorbent for efficient (V)PSA processes to capture CO2 from cement flue gases

Gas-solid adsorption is emerging as a promising technology for carbon capture. Pillared clays (PILCs) were considered as they are physical adsorbents known for their thermal and chemical stability. The synthesis process was optimized for scale-up 50 L reactors where the synthesis time and water consumption (75%) were significantly reduced. The PILCs performance was studied under common flue gas impurities. The presence of moisture proved to favor CO 2 adsorption/separation and no significant reduction in the performance after one-year-equivalent exposure to impurities, namely SO 2 , NH 3 , and HCl, was observed. Dynamic adsorption with mixtures was measured and the adsorbed amounts agreed with that calculated from pure equilibrium adsorption isotherms. The dynamic adsorption was modeled and the set of equations/relations used to model adsorption was validated. Subsequently, several pressure swing adsorption (PSA) and vacuum pressure swing adsorption (VPSA) configurations were implemented in industrial-scale process simulator with a two-stage six-bed PSA process to enhance the final purity. To enhance recovery, the strategy of recycling the product stream of the second stage to the first stage was studied. Two-stage VPSA process proved to be equally effective in recovery with no need to recycle the product stream of the second stage. Operational-cost assessment was conducted to estimate the competitiveness of the different processes' parameters from economic point of view. The results indicated that the VPSA/VPSA process configuration is the most appealing, yielding 97% and 98% purity and recovery of CO 2 respectively, at energy consumption of 0.4 MWh/ton CO 2 removed. The developed work demonstrated the scale-up feasibility of the adsorbent and its effective performance in (V)PSA processes presenting a real opportunity for implementation at an industrial scale. • Scale-up synthesis process optimization from economic and scale-up point of view. • Effect of moisture on the adsorption process. • Material Stability in the presence of noxious impurities always present in flue gases. • Dynamic characterization and modeling. • PSA and VPSA different processes configurations. • Operational-cost analysis was performed.