Heterocyclic sulfur removal of coal based on potassium tert-butoxide and hydrosilane system

The present work investigated the feasibility of heterocyclic sulfur (HS) removal for coal utilizing potassium tert-butoxide and hydrosilane system. Changes of sulfur forms with treatment time in Xinyu (XY) coal were determined by XANES. Results showed that reductions of total sulfur and organic sulfur for XY coal were 55% and 53%, respectively. >85% sulfoether and thiophene sulfur were removed after treated for 4 h, suggesting that the HS could be removed to a high extent from coal. However, contents of sulfonate and sulfonic ester increased with treatment time due to the hydrolysis and oxidation of intermediate products containing SiS bands. Furthermore, it indicated that the HS could be removed selectively from coal without destroying the macromolecular structure of coal based on analysis of desulfurization mechanism. These findings suggested that the desulfurization of refractory HS in coal could be obtained using the potassium tert-butoxide/hydrosilane reductive system, which provided a reference for desulfurization of high organic sulfur coal.