Establishment of sustainable electric power supplement system by system design tool using EUD

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In this study, we proposed the PEACE (Peaceful East-Asia Centered Electricity) Network to supply the electricity stably in the East Asia region. Hydroelectric power and low quality natural gas was used as primary energy source. Hydrogen gas was produced by the electrolysis of water and DME (dimethylester) was produced by the catalytic reaction process with low quality natural gas and hydrogen gas. DME was used as an energy-transfer material, which is suitable for the long-distance transfer of energy. For the establishment of PEACE network, the development of reasonable DME synthesis process is required. The conventional DME synthesis systems (direct synthesis and methanol dehydration) were analyzed by EUD (Energy Utilization Diagram) method and the improvement of these systems was discussed. From these results, a new DME synthesis system using hydrogen and oxygen generated by the electrolysis of water was proposed.The methanol dehydration system was complicated, but both energy and exe … More rgy efficiencies were larger than those of direct synthesis system. This is because the carbon conversion yield is higher than that of direct method. The methanol dehydration system is more excellent than the direct synthesis system. From these results, we proposed a new DME synthesis system with high reaction conversion, in which the methanol synthesis column was divided to 5 columns and the pressure and temperature of these columns were optimized. As a result, the carbon conversion yield was increased to 99.5% and the exergy loss per 1mol DME production was reduced up to 60% of that for the direct synthesis and 40% of that for the methanol dehydration system.A chemical-looping combustor was developed and operated by a pilot-scale reactor. The chemical-looping combustion system can separate CO_2 from the outlet gas without any additional energy. In this system, two reactors are used to perform the combustion. In the reduction reactor, the reduction of metal by the fuel gas is performed, and the oxidation of the reduced metal by the air is performed in the oxidation reactor. A Fe_2O_3-AI_2O_3 composite powder is used as oxygen-transfer material between the reduction column and oxidation column. By the improvement of the separation of composite powder and gas in the reduction column, high CO_2 recovery more than 90% was attained successfully. Less