Effective electrodes for electrolysis of seawater for production of hydrogen (H2) without releasing chlorine into atmosphere and catalysts for production of methane (CH4) by the reaction of carbon dioxide (CO2) with H2 have been tailored. Using these novel materials a CO2 recycling plant for substantiation of our proposal has been built on the roof of Institute for Materials Research, Tohoku University. The CO2 recycling plant consists of a desert, a coast close to the desert and an energy consuming district. At the desert electricity is generated by solar cell operation and transmitted to the coast close to the desert. At the coast H2 is produced by electrolysis of seawater using the electricity, and then CH4 is formed by the reaction of H2 and CO2. CH4 is transported to the energy consuming district. At the energy consuming district combustion of CH4 is carried out not by air but by O2 and CO2 is recovered after removing H2O from the exhaust gas composed only of CO2 and H2O. The recovered CO2 is sent again to the coast close to the desert for reproduction of CH4. The CO2 recycling plant has substantiated that the solar energy at the desert can be used by energy consumers in the form of CH4 without emitting CO2 into atmosphere.
