KEY MATERIALS AND SYSTEMS FOR THE USE OF RENEWABLE ENERGY IN THE FORM OF METHANE

Extrapolation of primary energy consumption of the world between 1990 and 2005 to the future revealed the complete exhaustion of oil, uranium, natural gas and coal reserves on the Earth in 2034, 2040, 2040 and 2054, respectively. We have been proposing global carbon dioxide recycling to use renewable energy for all people in the whole world. The electricity converted from renewable energy will be used for production of hydrogen by seawater electrolysis. Hydrogen, for which no infrastructures of transportation and combustion exist, will be converted to methane by the reaction with carbon dioxide captured by energy consumers. Among systems in global carbon dioxide recycling, seawater electrolysis and carbon dioxide methanation have not been performed industrially. We created energy-saving cathodes for hydrogen production and anodes for oxygen evolution without chlorine formation in seawater electrolysis, and ideal catalysts for methane formation by the reaction of carbon dioxide with hydrogen. This paper reviews the characteristics and performance of these materials in the systems.