【Paper】
Analysis of the Operation Data of a Methane Fermentation Facility that Treats Manure and Tofu Refuse
Yukimasa Ogawa*, Masanori Fujita** and Yoshiteru Nakagawa***
* Obayashi Corporation Ecology Engineering Department
** Osaka University Graduate School of Engineering
*** Yagi Town Office Agricultural and Forestry Promotion Division
† Correspondence should be addressed to Yukimasa Ogawa:
Obayashi Corporation Ecology Engineering Department
（2-15-2, Konan, Minato-ku Tokyo, 108-8502 Japan）


Abstract
Yagi Bio Ecology Center（Yagi BEC）in Yagi Town, an agricultural town in Kyoto Prefecture, treats the manure of cows and pigs and tofu refuse by mesophilic methane fermentation and generates electric power by biogas produced from anaerobic digester. This facility also has a dewatering machine for digested sludge, a waste water treatment and compost plant for the dewatered cake and manure of beef cows. Yagi BEC has operated since April 1998. According to the operation data from Jan. 2000 until Dec. 2001, the average VTS loading rate was 1.6kg/m3/d and VTS removal was 44.4％. The volume of produced biogas averaged 32.4Nm3 per ton of received manure and tofu refuse, while CH4 concentration was 52〜60％. The volatile organic acid concentration in the digester was mostly less than 500mg/L. This paper also shows the performance of biogas co-generation and the ratio of heating calorie for the digester to the recovered calorie from the generators.


Key words: methane fermentation, biogas co-generation, biogas, manure treatment, food processing waste treatment