Other Compounds
Most fuels contain additional material beyond the carbon, hydrogen, and oxygen discussed above. Sulfur in the fuel is converted into H2S and COS, and the nitrogen into elemental nitrogen, NH3, and HCN. Generally speaking, the quantities of sulfur and nitrogen in the fuel are sufficiently small that they have a negligible effect on the main syngas components of hydrogen and carbon monoxide. Nonetheless it is necessary to consider the fate of sulfur and nitrogen because of the effect of the resulting compounds downstream of the gas production, for example, environmental emissions, catalyst poisons, and so on.
Details concerning the formation of sulfur and nitrogen compounds are included in Section 6.9. Since the amounts of sulfur and nitrogen converted into the various product molecules are not large, the distribution of sulfur and nitrogen compounds is usually estimated in advance (for example, H2S/COS = 9-9.5, NH3 = 25%, and HCN = 10% of fuel nitrogen, respectively), and interaction with carbon, hydrogen, and oxygen is then limited to mass and heat balance calculations.
