U.S.Patent 5382267, 1995
R.L.Savage and L.Lazarov,
Method of Desulfurization of Coals
The inorganic and organic desulfurization of solid carbonaceous material at elevated temperatures is increased significantly in the presence of copper. The copper serves as a scavenger for the hydrogen sulfide formed to insure a low hydrogen sulfide concentration for the inorganic desulfurization. In addition, in the presence of ethanol or hydrogen, the organic desulfurization of solid carbonaceous material is improved dramatically by the catalytic influence of the copper on the ethanol dehydrogenization and of the copper sulfide formed on the hydrodesulfurization reactions.