Dynamic behaviour of a K-doped Ga substituted and microwave aged hydrotalcite-derived mixed oxide during CO2 sorption experiments

Abstract

A potassium impregnated magnesium–aluminum–gallium hydrotalcite, aged under microwave irradiation (K-HTCGa MW), was tested for CO2 capture during a long term breakthrough experimental campaign. Higher total pressures, CO2 concentrations in the feed and temperatures resulted in higher outstanding sorption capacities. The presence of H2O was considerably advantageous for increasing the CO2 capture. Finally, it was observed that higher total pressures, temperatures and H2O contents allowed higher bed usage efficiencies. EDS elemental distribution mapping showed that potassium and gallium were mobilized towards the sorbent surface under wet conditions, which could have contributed to the enhanced behavior of the sorbent under such conditions.