A preliminary study was conducted to determine the feasibility of cumulative carbon deposition on zinc ferrite sorbents under conditions relevant to desulfurization of hot coal gas from the KRW fluidized bed gasifier operating in the air-blown mode. Thermodynamic calculations indicated that the range of conditions under which carbon deposition and carbide formation occur can be broadened if the gas contains less than equilibrium levels of methane. These calculations also indicated that dissociation of CO and reduction of CO by hydrogen are potential pathways for carbon deposition on the sorbent.