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

Abstract

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.

Effect of CaSO4 Pelletization Conditions on a Novel Process for Converting SO2 to Elemental Sulfur by Reaction Cycles involving CaSO4/CaS – Part I. CaSO4 Pellet Strength and Reducibility by Hydrogen

“…This Part I presents the results of the determination of pellet properties that depend on pelletization conditions and a detailed kinetic analysis for the hydrogen reduction of calcium sulfate pellets with the best strengths. The investigation on the reduction of sulfur dioxide with the resulting calcium sulfide pellets is presented in Part II of this series [14].…”

Performance Evaluation of a Gypsum-Based Desulfurizer for Sulfur Recovery from the Smelter Off-Gas: Experimental Analysis and Thermodynamic Performance

“…It seemed probable that even a short-term exposure to the high concentrations of SO 2 in the smelter off-gas would rapidly age the catalyst. Sohn et al − proposed a novel method to recover the elemental sulfur from the high levels of SO 2 using calcium sulfide (CaS) and barium sulfide (BaS) as the desulfurizer, and the method was shown schematically in Figure . The reactions that occurred in the desulfurization reactor (DES) were shown as eq , while those that occurred in the reduction reactor (RED), as eq and eq .…”