Analysis of availability and accessibility of hydrogen production: An approach to a sustainable energy system using methane hydrate resources
It is considered that use of hydrogen as an energy source may contribute to environmental improvement and provide an alternative energy system. Moreover, it is anticipated that hydrogen will be in great demand in the near future for use in such vehicles as fuel cell-based cars. Research and development of a number of advanced methods of hydrogen production (OTEC, water photolysis using a semiconductor, a municipal waste gasification—smelting system, etc.) is currently under way. A comparison of different hydrogen-rich fuels in this paper shows that methane is advantageous for hydrogen production from the viewpoint of energy efficiency as measured by thermodynamic analysis. This paper therefore proposes combining existing technology for hydrogen production with an unconventional methane source in order to facilitate the realization of a hydrogen energy system: i.e., this paper proposes combining the process of steam reforming, which is commercialized worldwide, with use of untouched natural gas hydrate (NGH) resources. Gas hydrate deposits, which are distributed worldwide, hold great amounts of methane gas and have hardly been touched. This paper presents the economic parameters of NGH development and discusses the concept of devising useful applications of NGHs, with consideration given to (1) independence from current fossil fuels, (2) energy transport using the hydrate system, (3) CO2 sequestration — replacement of methane hydrate with CO2 hydrate in the submarine layer and (4) improvement of current steam reforming of methane by CO2 reuse and zeolite application. This paper thus proposes a new solution that will make a key contribution to the systematic development of a new sustainable energy structure.