Analysis of energy utilization on digestion biogas tri-generation in sewage treatment works

Zhiyi Wang, Hongxing Yang, Jinqing Peng, Lin Lu

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)


This paper presents a combined heating, cooling, and power generation (tri-generation) system using sewage treatment digestion biogas according to the principle of energy gradient utilization technology. The tri-generation scheme adopts Lithium Bromide (LiBr) absorption cooling technology for office air conditioning, a biogas power generator, a heating system for digestion tanks. The performance analysis demonstrates that the scheme is practical in Hong Kong. Surplus cooling of the chiller is used to cool the inlet air of the generator for increasing the biogas power generator output. The electricity generation capacity can be increased by around 7 % annually owing to the inlet air cooler. For a case study of a local sewage water treatment work, the cooling capacity is equal to 422.72 MWh. The hot water meets the digester heating load at the same time. It is estimated that the economic payback period will be about 2 years.
Original languageEnglish
Title of host publicationProceedings of the 8th International Symposium on Heating, Ventilation and Air Conditioning
Subtitle of host publicationHVAC and R Component and Energy System
Number of pages9
EditionVOL. 2
Publication statusPublished - 24 Feb 2014
Event8th International Symposium on Heating, Ventilation, and Air Conditioning, ISHVAC 2013 - Xi'an, China
Duration: 19 Oct 201321 Oct 2013

Publication series

NameLecture Notes in Electrical Engineering
NumberVOL. 2
Volume262 LNEE
ISSN (Print)1876-1100
ISSN (Electronic)1876-1119


Conference8th International Symposium on Heating, Ventilation, and Air Conditioning, ISHVAC 2013


  • Absorption chiller
  • Biogas generator
  • Inlet air cooling
  • Sewage treatment plant

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering

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