Feasibility study of reduction removal of thiophene sulfur in coal

The present work investigated an effective reductive desulfurization method for thiophene sulfur in high organic sulfur coal utilizing the potassium tert-butoxide/hydrosilane. Maximum decreases of 65.8% and 64.2% in organic sulfur for Xinyu coal and Guxian raw coals were, respectively obtained under the optimized conditions of the molar ratio of reductive assistant to sulfur of coal (15), treatment time (80 min), temperature (215 °C). According to the results of XPS, more than 80% mercaptan , sulfoether and thiophene on the raw coals surface were removed without destroying the macromolecular structure of coal. Sulfur on treated coal surface samples mainly existed in the form of sulfonate and sulfone due to the hydrolysis and oxidation of intermediate products generated in the reduction desulfurization reaction. These findings confirmed the possibility of effective removal for thiophene sulfur in coal utilizing the reductive system, which could give a reference for thiophene sulfur removal of high organic sulfur coal.