Abstract
The objective of this study is to develop an advanced desulfurization process for clean fuel production from coal with the use of ionic liquid that can be carried out under mild condition. Ionic liquids were prepared by adding dialkylsulfates to alkylimidazoles in toluene. Coal soluble was prepared by applying Miura's process. A mixture of coal sample and 1-methylnaphthalene was heated at 350℃ for 1 h in an autoclave. Sulfur K-edge X-ray absorption near edge structure spectroscopy was applied to specifying the forms of sulfur in raw coal and its soluble. Sulfur in the soluble was mainly composed of thiophenic sulfur according to XANES analysis. Organic sulfur in the coal soluble was successfully extracted by using one of ionic liquids, dimethyl imidazole methyl sulfate (MMIMMeSO_4) which showed phase change from solid to liquid above 70℃. With repeated extraction by MMIMMeSO_4, the sulfur content in the coal soluble could be decreased considerably.
