Process simulation of co-HTC of sewage sludge and food waste digestates and supercritical water gasification of aqueous effluent integrated with biogas plants

Niloufar Ghavami, Karhan Özdenkçi and Cataldo De Blasio

Energy, 2024, vol. 291, issue C

Abstract: The objective of this article is to investigate the integration of a digestate treatment with a biogas plant processing sewage sludge and food waste via process simulations: co-HTC of mixed digestates and supercritical water gasification (SCWG) of the aqueous effluent. The optimum co-HTC conditions are selected based on the energetic yields, comparing relative equipment sizes besides the hydrochar product. The selected conditions are 200 °C, 30 % solid load, and 1-h residence time for the mixing ratios in scope: energetic yields of 3.58–3.59 MJ/kg reactor inlet. These conditions result in more than 60 % K, P, and N recovery on hydrochar. SCWG of the aqueous effluent provides complete mineral recovery in the solid form and surplus energy production through syngas while causing some nitrogen loss as N2 gas. Although the co-HTC data is calculated from individual HTC results, the synergetic effect on the energetic yield does not affect the selection of optimum conditions as investigated through co-HTC of sewage sludge and food waste (the origins of the digestates). Consequently, biogas plants can evolve into multi-product biorefineries through the proposed integration. Meanwhile, this study can guide future co-HTC experiments of food waste and sewage sludge digestates and reduce the required runs.

Keywords: Biorefinery; Co-hydrothermal carbonization; Integration of hydrothermal processes; Nutrient recovery; Process simulation (search for similar items in EconPapers)
Date: 2024
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544223036150
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:291:y:2024:i:c:s0360544223036150

DOI: 10.1016/j.energy.2023.130221

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().