Effects of carbonization and solvent-extraction on change in fuel characteristics of sewage sludge

► Combustible components are extracted from sewage sludge through the carbonization process and the solvent-extraction process. ► The extract is composed of 99.7% combustible components and 0.3% ash. ► Similar to coal within the coal band and the FT-IR thereof. ► DTG analysis showed that the ignition temperature and the burnout temperature were higher than those of coal. ► Carbonization and solvent extraction proved suitable processes for improving the fuel rank.