Sorption-enhanced thermochemical conversion of sewage sludge to syngas with intensified carbon utilization

Xiaoxia Yang, Sicong Tian*, Tao Kan, Yuxiang Zhu, Honghui Xu, Vladimir Strezov, Peter Nelson, Yijiao Jiang

*Corresponding author for this work

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

(Graphical abstract presents)

Efficient transformation of sewage sludge into bioenergy is currently a promising option to combat the energy crisis and mitigate climate change. Most attention has been paid to thermochemical H2 production, however, effective approaches to utilize the carbon in sludge are lacking. Here we propose a novel two-stage sorption-enhanced thermochemical conversion process, which relies on the integration of a CaO-based CO2 carrying cycle, to intensify the utilization of sludge carbon. In the process, the CO2 generated during sludge pyrolysis at the first stage is captured and stored in the form of CaCO3, and is then released at higher temperatures (the second stage) to gasify the sludge char for CO production. Under the conditions investigated in this study, the proposed process could produce 284.7 NmL of syngas per gram of dry sludge with a gross CO/H2 molar ratio of 2.3, via obtaining a H2-rich gas stream at 550 °C and a CO-rich gas stream at 750 °C, respectively. We conclude that the proposed process offers an efficient option for the production of syngas from sewage sludge with significantly intensified carbon utilization.

Original languageEnglish
Article number113663
Number of pages8
JournalApplied Energy
Volume254
DOIs
Publication statusPublished - 15 Nov 2019

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Keywords

  • Sewage sludge
  • Syngas
  • Carbon utilization
  • Thermochemical conversion
  • CaO

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