Phosphate assisted integrated carbon dioxide capture and conversion to methane

Phosphate salts have been previously studied as carbon dioxide capture reagents. However, the direct conversion of the captured carbon dioxide species to hydrogenated products is not well studied with phosphate-assisted systems. Herein, we report the conversion of captured carbon dioxide to methane in such a system. When a nickel-based catalyst was used, the reactivity was strongly inhibited due to unwanted interaction of nickel with the phosphate species present in the system. However, with 5% Ru/Al2O3 as the catalyst, 100% conversion of captured CO2 to methane was achieved after 6 hours under 50 bar H-2 at 200 degrees C. 5% Ru/Al2O3 was also able to maintain its reactivity over several capture/hydrogenation cycles.