Removal of mineral material from solvent-refined coal by solvent extractions

Solvent refined coal (SRC), a coal extract which is highly polyaromatic in character and relatively high in N, O and S content, is derived from the direct liquefaction of coal. SRC contains mineral matter in the form of soluble organometallic compounds which can not be removed by filtration. These soluble species can be detrimental to the hydrocracking catalyst used in the upgrading of the SRC to high-value liquid fuels. These species, however, can be separated from the SRC by extraction with benzene or tetralin as solvents so that the mineral matter is mainly concentrated in the solvent-insoluble fraction, the other fraction are then readily hydrocracked, as demonstrated in this work.