Sorption of carbon dioxide by the composite sorbent “potassium carbonate in porous matrix”

Sorption of CO2 in the presence of water vapor by the K2CO3—γ-Al2O3 composite sorbent was studied by IR spectroscopy in situ, X-ray diffraction analysis, and the differentiating dissolution method and reasons for a decrease in its dynamic capacity are given. The samples containing K2CO3·1.5H2O in pores are characterized by the maximal dynamic capacity. A mechanism for CO2 sorption was proposed, which qualitatively explains the obtained dependence of the capacity on the water content in the composite sorbent. A high dynamic capacity can be maintained by regeneration of the sorbents by water vapor at 170 °N. The capacity of the sorbents decreases during the first 10 sorption—regeneration cycles due to the formation of an inactive phase of potassium aluminum carbonate.