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

Research output: Journal article publicationJournal articleAcademic researchpeer-review

15 Citations (Scopus)


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.

Original languageEnglish
Article number126395
JournalBioresource Technology
Publication statusPublished - Jan 2022


  • Bioenergy
  • Food waste hydrochar
  • Resource recovery
  • Solid fuel
  • Sustainable waste management
  • Yard waste recycling

ASJC Scopus subject areas

  • Bioengineering
  • Environmental Engineering
  • Renewable Energy, Sustainability and the Environment
  • Waste Management and Disposal

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