Food waste treating by biochar-assisted high-solid anaerobic digestion coupled with steam gasification: Enhanced bioenergy generation and porous biochar production

Jingxin Zhang; Yuxuan Cui; Tengyu Zhang; Qiang Hu; Yen Wah Tong; Yiliang He; Yanjun Dai; Chi-Hwa Wang; Yinghong Peng

doi:10.1016/j.biortech.2021.125051

Food waste treating by biochar-assisted high-solid anaerobic digestion coupled with steam gasification: Enhanced bioenergy generation and porous biochar production

Bioresour Technol. 2021 Jul:331:125051. doi: 10.1016/j.biortech.2021.125051. Epub 2021 Mar 26.

Authors

Jingxin Zhang¹, Yuxuan Cui¹, Tengyu Zhang², Qiang Hu³, Yen Wah Tong⁴, Yiliang He⁵, Yanjun Dai⁶, Chi-Hwa Wang⁴, Yinghong Peng⁷

Affiliations

¹ China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai 201306, PR China.
² Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK.
³ NUS Environmental Research Institute, National University of Singapore, Singapore 138602, Singapore. Electronic address: erihq@nus.edu.sg.
⁴ Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore.
⁵ China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai 201306, PR China; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
⁶ School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
⁷ National Engineering Research Center for Nanotechnology, Shanghai Jiao Tong University, Shanghai 200241, PR China.

PMID: 33812137
DOI: 10.1016/j.biortech.2021.125051

Abstract

A food waste treating system was proposed in this study by combining biochar-assisted high-solid anaerobic digestion and subsequent steam gasification of the digestate. The effect of solid level, biochar dosage in anaerobic digestion on the properties of biogas, syngas, and final biochar products were investigated. Results showed that at a high total solid level and biochar dosage of 25 g/L and 50 g/L, the accumulative methane yield reached 110.3 mL CH₄/g VS and 126.7 mL CH₄/g VS, respectively. From steam gasification of different digestates under 850 °C for 15 min, a maximum of 34.92 mmol/g for the hydrogen yield and 11.44 MJ/m³ for the higher heating value could be obtained for the syngas. Furthermore, the by-product produced from steam gasification was a nutrient-enriched porous biochar, which was suitable to be used as compost. This study demonstrated a pathway for food waste treating to produce methane-enriched biogas, hydrogen-enriched syngas, and nutrient-enriched biochar.

Keywords: Biochar; Food waste; High-solid anaerobic digestion; Steam gasification; Waste-to-energy system.

MeSH terms

Anaerobiosis
Charcoal
Food
Methane
Porosity
Refuse Disposal*
Steam*

Substances

Steam
biochar
Charcoal
Methane