The fate of carbon in two-stage anaerobic digestion of vegetable waste

2019 5th International Conference on Environment and Renewable Energy

生态环境科学;能源学

Dinh, P.V.^1 ; Fujiwara, T.^1 ; Giang, H.M.^2 ; Pham Phu, S.T.^1^3

Okayama University, 3-1-1 Tsushima, Kita Ward, Okayama

700-8530, Japan^1

National University of Civil Engineering, 55 Giai Phong, Ha Noi, Viet Nam^2

University of Danang, University of Technology and Education, 48 Cao Thang Road, Hai Chau District, Danang City

550000, Viet Nam^3

关键词: Inorganic carbon;    Large amounts;    Mesophilic temperature;    Retention time;    Suspended solids;    Two-stage anaerobic digestions;    Vegetable wastes;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/307/1/012019/pdf
DOI  :  10.1088/1755-1315/307/1/012019

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

This study aims to investigate the fate of carbon in two-stage anaerobic digestion (TAD) of vegetable waste. The TAD including a hydrolytic reactor and a methane reactor were controlled at mesophilic temperature (36 ± 1°C) with a retention time (RT) of 9 days and 20 days, respectively. Carbon tracking was conducted step by step throughout the system. Non-hydrolysable carbon accounted for a significant proportion of total initial carbon (25%). Meanwhile, a large amount of carbon in the feedstock (23.5%) was hydrolysed but remained in the effluent including water and suspended solids. It was mostly inorganic carbon which is not harmful to the environment. The only 41.3% initial carbon was converted to biogas in both reactors. In the hydrolytic reactor, biogas was mainly carbon dioxide (99%), accounted for 11.3% of total biogas and 35.8% of total CO2 product. In the methane reactor, biogas was 373.9 Nml/g-VS including 73.3% CH4, 21.9% CO2 and 4.8% others. Non-hydrolysable materials can be a source of thermal energy. Meanwhile, a large amount of hydrolysed carbon was not converted into biogas, was still in the effluent, it was a significant energy loss. Therefore, how to further increase the effectiveness of TAD is an issue that needs to study.