Abstract:
This invention covers a process for reducing the sulfur content of coal and coal char and the ignition temperature of coal char. Coal is converted into char at temperatures not in excess of about 1600.degree. F. The char is introduced into a caustic system which is maintained at a temperature between about 500.degree. F. to about 750.degree. F. Intimate contact is maintained between the caustic and the char for a period of about 2 to 30 minutes to leach the sulfur from the char. The desulfurized char is thereafter separated from the caustic and washed.
Abstract:
A method is provided for combining coal as a colloidal suspension within a heavy petroleum fraction. The coal is broken to a medium particle size and is formed into a slurry with a heavy petroleum fraction such as a decanted oil having a boiling point of about 300.degree.-550.degree. C. The slurry is heated to a temperature of 400.degree.-500.degree. C. for a limited time of only about 1-5 minutes before cooling to a temperature of less than 300.degree. C. During this limited contact time at elevated temperature the slurry can be contacted with hydrogen gas to promote conversion. The liquid phase containing dispersed coal solids is filtered from the residual solids and recovered for use as a fuel or feed stock for other processes. The residual solids containing some carbonaceous material are further processed to provide hydrogen gas and heat for use as required in this process.
Abstract:
This invention covers a process for reducing the sulfur content of carbonaceous fuels by treatment at elevated temperatures in a system comprised of aqueous caustic and oxygen.