Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system

Solomon Inalegwu Okopi; Jianfei Zeng; Xuetong Fan; Jiaxin Lu; Jiahao Cui; Yang Hu; Jiayu Wang; Jiaxin Chen; Oraléou Sangué Djandja; Yingqun Ma; Lei Che; Gu Zhaolin; Fuqing Xu

doi:10.1016/j.wasman.2024.01.038

Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system

Waste Manag. 2024 Apr 30:179:130-143. doi: 10.1016/j.wasman.2024.01.038. Epub 2024 Mar 11.

Authors

Solomon Inalegwu Okopi¹, Jianfei Zeng², Xuetong Fan¹, Jiaxin Lu³, Jiahao Cui¹, Yang Hu¹, Jiayu Wang¹, Jiaxin Chen⁴, Oraléou Sangué Djandja⁵, Yingqun Ma⁴, Lei Che⁶, Gu Zhaolin¹, Fuqing Xu⁷

Affiliations

¹ School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
² Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
³ School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China.
⁴ Shaanxi Key Laboratory of Energy Chemical Process Intensification, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
⁵ Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes, Guangdong Provincial Key Laboratory of Distributed Energy Systems, Dongguan University of Technology, Dongguan, Guangdong 523808, China.
⁶ College of Engineering, Huzhou Normal University, No. 759, East 2nd Road, Huzhou 313000, China.
⁷ School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China. Electronic address: xufuqing@xjtu.edu.cn.

PMID: 38471251
DOI: 10.1016/j.wasman.2024.01.038

Abstract

This research conducted an environmental life cycle assessment (LCA) to evaluate an anaerobic digestion-co-pyrolysis (ADCo-Py) system in which pyrolysis was added to traditional food waste (FW) anaerobic digestion (AD) systems to treat the solid fraction and impurities separated from FW. The solid fraction, including impurities such as wooden chopsticks, plastics, eggshells, and bones, is usually incinerated, while pyrolysis can be a viable alternative to optimize FW treatment. The environmental impact of ADCo-Py was compared with stand-alone AD, pyrolysis, and ADCo-INC (AD with incineration of separated solids). The results indicated that both ADCo-Py (-1.726 kg CO₂-Eq/kg_FW) and ADCo-INC (-1.535 kg CO₂-Eq/kg_FW) outperform stand-alone AD (-0.855 kg CO₂-Eq/kg_FW) and pyrolysis (-0.181 kg CO₂-Eq/kg_FW) in mitigating global warming potential (GWP). Additionally, pretreatments were found to have the most significant influence on GWP, ecotoxicity potential (ETP), and acidification potential (AP). The two-step pretreatment in ADCo-Py, including the separation of solids and drying, significantly improved the environmental sustainability of the system when compared with standalone pyrolysis.

Keywords: Bioenergy; Bones; Impurities; Integrated systems; Life cycle assessment; Plastics; Resource recovery.

MeSH terms

Anaerobiosis
Carbon Dioxide
Food
Food Loss and Waste
Pyrolysis
Refuse Disposal* / methods
Waste Management* / methods

Substances

Food Loss and Waste
Carbon Dioxide