Fuel Science & Technology International, Vol.12, No.2, 211-228, 1994
SELECTIVE REMOVAL OF ORGANIC SULFUR FROM COAL BY TRICHLOROETHANE EXTRACTION
Desulfurization of coal involves removal of both organic and inorganic forms of sulfur. In this paper, the process feasibility of organic desulfurization of coal using 1,1,1-trichloroethane (TCA) as the solvent, is established. Sulfur solubility curve in trichloroethane was obtained. The process conditions of this novel process were critically assessed. From the solubility curve it was concluded that the process should be carried out at or near the normal boiling point of the solvent. Comparisons between the TCA extraction and the perchloroethylene (PCE) process have been presented. Since the boiling point of trichloroethane is quite low, the process conditions are very mild in comparision to the PCE process. It was found that the TCA process is capable of removing organosulfur from coal more selectively than the PCE process. The sulfur containing organic species in the extract obtained from the TCA desulfurization process have been completely characterized using GC/MS techniques and compared to the extracts obtained from the PCE process. This study provides an additional confirmation to the catalytic mechanism proposed for the PCE extraction desulfurization.