Air co-gasification of coal and dried sewage sludge in a two-stage gasifier: Effect of blending ratio on the producer gas composition and tar removal

Yong Seong Jeong, Young Kon Choi, Ki Bum Park, Joo Sik Kim

Research output: Contribution to journalArticlepeer-review

40 Scopus citations

Abstract

The co-gasification of coal and dried sewage sludge (DSS) was conducted using a two-stage gasifier consisting of a fluidized bed gasifier and a tar-cracking reactor. In this study, the effect of the blending ratio of coal and DSS was investigated. Producer gases that were obtained from the tar-cracking reactor filled with active carbon contained high levels of hydrogen (maximum H2: 27.7 vol%) and low tar contents (minimum tar: 0 mg/Nm3). Upon gasification of the coal/DSS blends, the hydrogen content decreased and tar content increased with increasing DSS. Blends with coal/DSS ratios of 70/30 and 50/50 showed a synergetic effect on tar reduction, which could be attributed to the high ash content of the DSS. The gasification of the 70% DSS blend increased the condensed tar yield by only 0.1 wt%, compared to coal gasification. Lastly, a hot filter filled with Fe-impregnated active carbon was applied to completely remove tar from producer gas, which led to the production of a tar-free and hydrogen-rich gas (30 vol%). Furthermore, the Fe-impregnated active carbon reduced the H2S content to 229 ppmv. In summary, it was possible to produce a clean gas from coal and DSS blends in the UOS gasification process.

Original languageEnglish
Pages (from-to)708-716
Number of pages9
JournalEnergy
Volume185
DOIs
StatePublished - 15 Oct 2019

Keywords

  • Co-gasification
  • Coal
  • Dried sewage sludge
  • Hydrogen
  • Tar
  • Two-stage gasification

Fingerprint

Dive into the research topics of 'Air co-gasification of coal and dried sewage sludge in a two-stage gasifier: Effect of blending ratio on the producer gas composition and tar removal'. Together they form a unique fingerprint.

Cite this