Analysis of Biogas Produced from Switchgrass by Anaerobic Digestion
Hongzhi Niu,
Xiaoying Kong,
Lianhua Li,
Yongming Sun,
Zhenhong Yuan,
Xianyou Zhou
Affiliations
Hongzhi Niu
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS, Key Laboratory of Renewable Energy, Guangzhou 510640, Guangdong China; b: University of China Academy of Sciences, Beijing 100049, China; China
Xiaoying Kong
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS, Key Laboratory of Renewable Energy, Guangzhou 510640, Guangdong China; China
Lianhua Li
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS, Key Laboratory of Renewable Energy, Guangzhou 510640, Guangdong China; China
Yongming Sun
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS, Key Laboratory of Renewable Energy, Guangzhou 510640, Guangdong China; China
Zhenhong Yuan
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS, Key Laboratory of Renewable Energy, Guangzhou 510640, Guangdong China; China
Xianyou Zhou
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS, Key Laboratory of Renewable Energy, Guangzhou 510640, Guangdong China; China
Material flow analysis (MFA) was applied to study the process of biogas production from switchgrass using a mid-temperature (35 ± 1 °C) batch anaerobic digestion process. The flow distributions of energy and material, including carbon (C) and nitrogen (N), were analyzed, as were the material and energy conversion efficiencies. The results showed that biogas and CH4 production were 268.80 and 135.31 NmLgVS-1 added, respectively, and the average CH4 content in biogas was 50.34%. Based on the MFA of the anaerobic digestion process, 30.6%, 3.6%, and 65.8% of C was converted into biogas, biogas slurry, and biogas residue, respectively; and 11.7% and 88.3% of N was converted into biogas slurry and biogas residue, respectively. The conversion efficiencies of the material and energy from switchgrass to biogas were 36.1% and 30.1%. Because of the low conversion efficiencies of matter and energy during biogas production, it is necessary to strengthen the secondary use of the fermentation residue. This study provides a basis for the optimization of the anaerobic digestion process and efficient utilization of resources and energy of energy-grass.
