High Temperature CaO/Y2O3 Carbon Dioxide Absorbent with Enhanced Stability for Sorption-Enhanced Reforming Applications

To improve the stability of high temperature CO2 absorbent for sorption enhanced reforming applications yttria supported CaO were synthesized using two methods: calcination of mixed salt precursors and wet impregnation of yttria support. According to XRD data, CaO does not interact with the yttria matrix. However, introduction of CaO drastically changes the morphology of primary yttria particles. Increase in CaO concentration results in gradual plugging of the smaller pores and sintering of yttria support. The CO2 absorption uptake in recarbonation-decomposition cycles increases with increase in CaO content and reach 9.6 wt % at CaO content of 19.9 wt %. CaO recarbonation extent varies from 49 to 77%. CaO/Y2O3 absorbents are extremely stable under overheating and maintain their capacity in long series of decomposition-recarbonation cycles even after calcination at 1350 °C. The novel material resists moisture and retains its strength during storage in the air. According to tests, CaO/Y2O3 can be considered as a promising CO2 absorbent for fixed bed sorption enhanced hydrocarbons reforming.