Effect of CaSO4 pelletization conditions on a novel process for converting SO2 to elemental sulfur by reaction cycles involving CaSO4/CaS - part II: Reduction of SO2 with CaS

摘要

A new process for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium sulfide and calcium sulfate without generating secondary pollutants, developed at the University of Utah, was described in Part I of this series. In this process, sulfur dioxide is reacted with calcium sulfide to produce elemental sulfur and calcium sulfate; the latter is reduced by hydrogen to regenerate calcium sulfide. Here, in Part II, the effects of different pelletization conditions for the initial reactant calcium sulfate on the reactivity of CaS pellets produced from calcium sulfate pellets toward sulfur dioxide were studied. Experiments were performed to investigate the effects of temperature in the range 1023-1173 K, pellet size, cycle repetition, and water vapor or carbon dioxide content in the sulfur dioxide stream. The binder amount and the presence of nickel catalyst did not significantly affect the reaction rate.