Fate of Sulfur During Carbothermal Reduction of SO_2(g) Using Oil-sands Fluid Coke

摘要

Aiming at the development of an oil-sand fluid coke-based sulfur-producing flue gas desulfurization (SP-FGD) technology, the reduction of SO_2 by the coke at high temperatures was investigated. It was established that a carbothermal reduction of SO_2 with coke was a fast reaction and could be completed within seconds. Elemental sulfur was the predominant product if the over reduction was prevented. The present paper focuses on the fate of sulfur during the carbothermal reduction. Sulfur balance is analyzed with data obtained using a total sulfur analyzer and a gas chromatograph (GC-TCD). A scanning electron microscope (SEM-EDS) was used to characterize the surface and cross section of coke particles before and after the reaction. An ash layer, which is low in sulfur, was found on the surface of partially reacted coke particles surface. At the ash-coke interface, however, there was a build-up of sulfur. In addition, an x-ray photoelectron spectroscope (XPS) was utilized to identify the chemical state of sulfur in the coke and the ash layer.