Characterization of the Prepared CaO-Based Sorbents for Hydrogen Production through Ethanol Steam Reforming

Abstract

Sorbents for CO2 capture based on CaO have been synthesized and tested for sorption-enhanced steam reforming (SESR) via the co-precipitation method. Various stoichiometries of MgO and CeO2 have been utilized along with Cao and an optimum stoichiometry was identified providing the highest capacity and stability over cycling. The as-synthesized sorbents were structurally characterized by means of XRD and SEM. The thermal characterization was obtained via TGA. The porosity of the synthesized samples was measured by the N2 adsorption and mercury porosimetry. Based on the outcomes of the current work, the sorbents with the highest capacities presented a highly porous structure with a porosity level higher than 65%. The sorbents were tested at high temperatures over repeated cycling (carbonation/decarbonation) to identify the stability of the synthesized sorbents over cycling. The results showed that the stoichiometry of 6:2:1 (CaO, MgO, CeO2) could retain a capacity up to 25 wt% even after 45 cycles.

Keywords

• hydrogen production
• steam reforming
• CaO-based sorbent
• co-precipitation method
• sorbent characterization
• CO₂ uptake capacity