Chapter 5: Syngas Conditioning (Catalyst, Process: Sulfur and Tar Cl, F)

Synthesis gas (usually referred to as syngas) is a gaseous energy carrier that generally consists of H₂ and CO, which is produced widely via natural gas or biomass reforming and gasification. Based on the feedstock used and also the condition of the gasification method, the syngas produced contains some impurities, including particulate matter, acidic gases (CO₂, H₂S, etc.), nitrogen-containing compounds (N₂, NH₃, HCN), halogen-containing derivatives (HCl, HBr, HF), tar compounds, etc. These should be eliminated stepwise, in order to avoid catalyst poisoning or reducing subsequent conversion processes that use syngas as a feedstock. This chapter introduces different syngas impurities and the associated elimination methods, especially those used for removing sulfur-containing and tar compounds that are based on absorption technology for sulfur compounds or physical and thermal methods used for the removal of tar.