Life cycle assessment and cost-benefit analysis of small-scale anaerobic digestion system treating food waste onsite under different operational conditions

Hailin Tian; Alvin W L Ee; Miao Yan; Yong Wei Tiong; Wenxia Tan; Qian Tan; Heng Thong Lam; Jingxin Zhang; Yen Wah Tong

doi:10.1016/j.biortech.2023.129902

Life cycle assessment and cost-benefit analysis of small-scale anaerobic digestion system treating food waste onsite under different operational conditions

Bioresour Technol. 2023 Dec:390:129902. doi: 10.1016/j.biortech.2023.129902. Epub 2023 Oct 21.

Authors

Hailin Tian¹, Alvin W L Ee², Miao Yan³, Yong Wei Tiong⁴, Wenxia Tan⁵, Qian Tan⁵, Heng Thong Lam⁴, Jingxin Zhang⁶, Yen Wah Tong⁷

Affiliations

¹ Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; NUS Environmental Research Institute, National University of Singapore, 1 Create Way, 138602, Singapore.
² Energy Studies Institute, National University of Singapore, 119620, Singapore.
³ NUS Environmental Research Institute, National University of Singapore, 1 Create Way, 138602, Singapore; Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China.
⁴ NUS Environmental Research Institute, National University of Singapore, 1 Create Way, 138602, Singapore.
⁵ Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
⁶ China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai 201306, China.
⁷ NUS Environmental Research Institute, National University of Singapore, 1 Create Way, 138602, Singapore; Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive, 117585, Singapore. Electronic address: chetyw@nus.edu.sg.

PMID: 37871743
DOI: 10.1016/j.biortech.2023.129902

Abstract

This study employed life cycle assessment and cost-benefit analysis to evaluate the environmental and economic profile of a real decentralized small-scale anaerobic digestion (AD) system treating food waste (FW). Different operational conditions, including temperature, biochar addition, biogas engine efficiency, and FW loading, were compared via scenario analysis. Biochar addition could potentially obtain carbon reduction and save fossil fuel. Moreover, at high FW loading and biogas engine efficiency, biochar addition achieved 1-3190% better performance than the system without biochar in all the nine impact categories. The system under mesophilic conditions performed worse than ambient conditions due to high energy demand. All the current scenarios resulted in a monetary loss at US$ 480 k-681 k, while profit was possible if the capital cost and operator salary decreased significantly. Overall, operating the small-scale AD system under ambient temperature with biochar addition was preferred due to its potential environmental benefits and economic profits.

Keywords: Biochar; Biogas; Economic performance; Energy recovery; Environmental impacts.

MeSH terms

Anaerobiosis
Animals
Biofuels
Bioreactors
Cost-Benefit Analysis
Food
Life Cycle Stages
Methane
Refuse Disposal*

Substances

biochar
Biofuels
Methane