Electron-Transfer-Induced Desulfurization of Organic Sulfur from Sub-bituminous Coal

The intent of this paper is to investigate the effects of leaching time and temperature on the level of desulfurization of organic sulfur by an electron-transfer process involving the transition-metal ion Ni2+ from a sub-bituminous Indian coal. The electron-transfer process was accomplished both in the presence and the absence of naphthalene with unoxidized and oxidized samples. Desulfurization has been determined to be greater in oxidized samples. The presence of naphthalene enhanced the amount of desulfurization both in unoxidized and oxidized samples, revealing that it serves as an excellent electron-transfer agent. Increases in reaction time and temperature increased the level of desulfurization. The electron-transfer process, in the presence of naphthalene, succeeded in removing a maximum of 16.3 wt % organic sulfur from unoxidized coal and 18.7 wt % from oxidized coal at 50 °C and 4 h. Study of a model sulfur compound indicated that the desulfurization is primarily due to aliphatic-type compounds, s...