Catalytic co-hydrothermal carbonization of food waste digestate and yard waste for energy application and nutrient recovery

Mingjing He; Xiefei Zhu; Shanta Dutta; Samir Kumar Khanal; Keat Teong Lee; Ondrej Masek; Daniel C W Tsang

doi:10.1016/j.biortech.2021.126395

Catalytic co-hydrothermal carbonization of food waste digestate and yard waste for energy application and nutrient recovery

Bioresour Technol. 2022 Jan;344(Pt B):126395. doi: 10.1016/j.biortech.2021.126395. Epub 2021 Nov 22.

Authors

Mingjing He¹, Xiefei Zhu¹, Shanta Dutta¹, Samir Kumar Khanal², Keat Teong Lee³, Ondrej Masek⁴, Daniel C W Tsang⁵

Affiliations

¹ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; Research Centre for Resources Engineering towards Carbon Neutrality, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
² Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Honolulu, HI, USA.
³ School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Seri Ampangan, Nibong Tebal 14300, Pulau Pinang, Malaysia.
⁴ UK Biochar Research Centre, School of Geosciences, University of Edinburgh, Alexander Crum Brown Road, Crew Building, EH9 3FF, Edinburgh, UK.
⁵ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China; Research Centre for Resources Engineering towards Carbon Neutrality, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China. Electronic address: dan.tsang@polyu.edu.hk.

PMID: 34822987
DOI: 10.1016/j.biortech.2021.126395

Abstract

Hydrothermal carbonization (HTC) provides a promising alternative to valorize food waste digestate (FWD) and avoid disposal issues. Although hydrochar derived from FWD alone had a low calorific content (HHV of 13.9 MJ kg^-1), catalytic co-HTC of FWD with wet lignocellulosic biomass (e.g., wet yard waste; YW) and 0.5 M HCl exhibited overall superior attributes in terms of energy recovery (22.7 MJ kg^-1), stable and comprehensive combustion behaviour, potential nutrient recovery from process water (2-fold higher N retention and 129-fold higher P extraction), and a high C utilization efficiency (only 2.4% C loss). In contrast, co-HTC with citric acid provided ∼3-fold higher autogenous pressure, resulting in a superior energy content of 25.0 MJ kg^-1, but the high C loss (∼74%) compromised the overall environmental benefits. The results of this study established a foundation to fully utilize FWD and YW hydrochar for bioenergy application and resource recovery from the process water.

Keywords: Bioenergy; Food waste hydrochar; Resource recovery; Solid fuel; Sustainable waste management; Yard waste recycling.

MeSH terms

Carbon
Food*
Nutrients
Refuse Disposal*
Temperature

Substances

Carbon