Simulation of a Novel Chemical Looping System for Recovering Elemental Sulfur from Acid Gases Using Ca-Based Oxygen Carriers

Abstract:

In this paper, a novel chemical-looping process is developed for converting sulfur dioxide (SO₂) in the flue gas generated from industries to elemental sulfur using Ca-based oxygen carriers. The system is mainly composed of a bubbling bed gasifier, a bubbling bed reactor and a circulating fluidized bed reactor. The high-purity sulfur vapor can be obtained from the reaction between SO₂ and calcium sulfide and then be cooled into solid sulfur particles. From the thermodynamic analysis, the reactions between CaS and SO₂ is much more easier to reach equilibrium than Claus reaction between H₂S and SO₂. When the temperature ranges from 500 to 600 °C, the major sulfur vapor is diatomic sulfur vapor while the solid product is mainly CaSO₄, representing the regenerating of the oxygen carrier. In the system, the required heat in the coal gasification comes from the strongly exothermic oxidation of oxygen carrier, by circulating the oxygen carrier particles in the system. The effects of reacting temperature, SO₂/CaS molar ratio on the yield of sulfur particle and conversion of SO₂ to elemental sulfur are all discussed. The favorable temperature of the reactor to generate elemental sulfur should be between 500 and 600 °C.

• Periodical: Advanced Materials Research (Volumes 724-725)
• Pages: 1136-1139
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.724-725.1136
• Online since: August 2013
• Authors: Jing Chang, Ming Dong Han, Hong Jing Tian
• Keywords: Acid Flue Gas, Calcium Sulfide, Elemental Sulfur, Oxygen Carrier

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