食品廃棄物のメタン発酵及び水素･メタン二段発酵

Hydrogen and methane fermentation of solid wastes from food industry

Nakashimada Yutaka

Nishio Naomichi

Foods Food Ingredients Journal of Japan

To treat and recover energy from food industrial solid wastes, methane fermantion is very altractive, in this article, therefore, researches on methane fermentation of solid wastes from a Japanese Sake brewery, bread manufacture and soy sauce brewery were reviewed. To solubilize and acidify the waste from a Japanese Sake brewery, hyperthemophilic archaeon Pyrococcus furiosus could be applied. A perfusion culture developed to increase cell concentration gave 0.4 g/l/h of acetate production rate from rice powder. Futhermore, a continuous culture using the cells fixed on a porous ceramic carrier gave 0.14 g/l/h of acetate rate at the dilution rate of 0.4 h-1. By using a microbial consortium, when 100 g-wet wt./l of the bread waste was fermented under controlled pH7 conditions, 91(null)S was reduced after 24h and 240 mM H2 was produced. When the diluted culture broth after the hydrogen fermentation was supplied continuously into a UASB methanogenic reactor, the optimum loading of 9.5 g-TOC/l/day gave 80% TOC removal, 408 mmol/l/day of methane production rate and ca. 0.6 methane yield as carbon base. To reduce MLSS in soy source refuse (SSR) and produce methane successfully, thermophilic methanogenic suldge obtained from a municipal wastewater treatment plant could be used as seed. At 25 g-wet wt./l of SSR, 120 mM CH4 production and 50% (w/v) MLSS reduction were observed after 35 d. Acclimatization of the sludge to the waste was effective to increase the methane production rate in the pH-controlled fed-batch culture using the stirred tank reactor. Development of high rate production of hydrogen-methane in two-stage process was also discussed.

Chemical technology [ 570 ]

jpn

[NCID] AN10455343

[ISSN] 0919-9772