Catalytic tar reforming with sewage sludge char of a producer gas from fluidized bed co-gasification of sewage sludge and wood

Lukas von Berg*, Cevdet Doğan, Ebubekir Sıddık Aydın, Stefan Retschitzegger, Robert Scharler, Andrés Anca-Couce

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review


Fluidized bed gasification of sewage sludge is a promising method for its valorisation due to the fuel flexibility of the process. The main drawbacks are the impurities present in the producer gas, with a high tar content, and its low calorific value. In this study, sewage sludge and wood mixtures are gasified in a fluidized bed. A tar cracking reactor is used to reduce the amount of tars and to increase the calorific value of the producer gas. Sewage sludge char is employed for tar cracking with a real producer gas, showing the feasibility of the process with a tar conversion of about 80% at the beginning. The test was conducted for several hours and tar deactivation was observed, which lead to a decrease of tar conversion to about 35% after 5 hours. Reactivating the char with steam increases again the tar conversion up to 84%, however, the subsequent deactivation was found to be faster compared to the one for fresh char. First tests using char from the gasification process in the tar cracking unit also show promising results.

Original languageEnglish
Pages (from-to)523-526
Number of pages4
JournalEuropean Biomass Conference and Exhibition Proceedings
Publication statusPublished - 1 Jan 2019
Event27th European Biomass Conference and Exhibition: EUBCE 2019 - Lisbon, Portugal
Duration: 27 May 201930 May 2019
Conference number: ISSN 2282-5819


  • Char
  • Fluidized bed
  • Gas cleaning
  • Gasification
  • Sewage sludge
  • Tar removal

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Forestry
  • Renewable Energy, Sustainability and the Environment
  • Waste Management and Disposal

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