title: Effect of thermal hydrolysis pre-treatment on anaerobic digestion of municipal biowaste: a pilot scale study in China.
abstract: Co-digestion of wasted sewage sludge, restaurant kitchen waste, and fruit-vegetable waste was carried out in a pilot plant with thermal hydrolysis pre-treatment. Steam was used as heat source for thermal hydrolysis. It was found 38.3% of volatile suspended solids were dissolved after thermal hydrolysis, with digestibility increased by 115%. These results were more significant than those from lab studies using electricity as heat source due to more uniform heating. Anaerobic digesters were then operated under organic loading rates of about 1.5 and 3 kg VS/(m³ d). Little difference was found for digesters with and without thermal pre-treatment in biogas production and volatile solids removal. However, when looking into the digestion process, it was found digestion rate was almost doubled after thermal hydrolysis. Digester was also more stable with thermal hydrolysis pre-treatment. Less volatile fatty acids (VFAs) were accumulated and the VFAs/alkalinity ratio was also lower. Batch experiments showed the lag phase can be eliminated by thermal pre-treatment, implying the advantage could be more significant under a shorter hydraulic retention time. Moreover, it was estimated energy cost for thermal hydrolysis can be partly balanced by decreasing viscosity and improving dewaterability of the digestate.
authors: Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 6158540, Japan. zhouyj03@gmail.com
authors: Yingjun
authors: Y
authors: Zhou
authors: Masaki
authors: M
authors: Takaoka
authors: Wei
authors: W
authors: Wang
authors: Xiao
authors: X
authors: Liu
authors: Kazuyuki
authors: K
authors: Oshita
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D002681:China; D002947:Cities; D005232:Fatty Acids, Volatile / Q000032:analysis; D006358:Hot Temperature; D006868:Hydrolysis; D010865:Pilot Projects; D012722:Sewage; D018505:Waste Management
chemical_list: D056804:Biofuels; D005232:Fatty Acids, Volatile; D012722:Sewage