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| TITLE | Development of Energy-Saving Technology for Food Wastes Treatment by a
Two-Phase Circulating Dilution-Free Methane Fermentation Process (Joint Program to Promote Technological Development with the Private Sectors) |
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RITE - KYOTO KIZU LABORATORY |
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| ABSTRACT | In the fiscal year of 2005, a pilot test was conducted in a demonstration plant which has a capacity of 1 ton of food wastes per day by Two-Phase Circulating Dilution-Free Methane Fermentation Process. CODCr loading rate was gradually raised and three levels of capacity had been tested with low capacity of 0.8 ton per day, standard capacity of 1.0 ton per day, high capacity of 1.2 ton per day. It was verified that with no water added for dilution in system, food wastes could be treated effectively and more than 80 % of organic decomposition rate was achieved. 150-180Nm3 biogas was generated from 1 ton of net food wastes, from which plastic wastes had been removed previously. Biogas contained 58-63% of methane gas so that it can be utilized in fuel cell or gas engine. Study shows that this system is economically feasible. Compared with the case of incineration for all combustible wastes, the case of methane fermentation for food wastes in combustible wastes can reduce some maintenance cost for kinds of scale plants (55 ton/day, 110 ton/day, 220 ton/day). Study also shows that this system can be taken as a countermeasure to global warming by reducing carbon dioxide. Due to the supply of electricity from methane fermentation plant, carbon dioxide can be reduced in the power plant. Due to methane fermentation of food wastes, kerosene for incineration can saved and carbon dioxide can be reduced accordingly. Study shows that 9,700ton-CO2 can be reduced every year at a big scale plant (220 ton/day). |
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