Pressure liquefaction of coal - with extn. of prod. by supercritical gas

摘要

After hydrogenation of powdered coal as a slurry in oil under heat and pressure in presence of catalyst, an extraction agent is added in the upper range of the reaction zone or in the subsequent gas/liquid hot separator, to achieve supercritical extraction of distillate oils. The extraction agent is pref. a benzine fraction with boiling range up to 200 degrees C from the process. Used for conversion of coal to benzine, fuel oil and other fractions. Most of the oil is extracted from the solid residue from liquefaction, so that expensive vacuum distn. of the latter is unnecessary. The residue from extraction, contg. 25% ash, 25% coal and 50% non-distillable bitumen, is similar to that from vacuum distn.