K-Promoted Hydrotalcites for CO2 Capture in Sorption Enhanced Reactions

Potassium-promoted hydrotalcite-like material was prepared with potassium nitrate as the K precursor. The highest ever reported CO2 adsorption capacity (1.13molkg1) was obtained at 656K with pCO2=0.5bar at humid conditions. A mathematical model was developed and it satisfactorily simulated the adsorption and desorption processes. The stability of the material was tested with repeated adsorption/desorption cycles; the CO2 adsorption capacity decreased around 7% after ten cycles. In addition, regeneration was performed with temperature swing operation (from 656K to 708K), where a complete regeneration was achieved within 60min, which reduced to half the time required for regeneration under isothermal conditions.