UPGRADING OF AN ASPHALTENIC COAL RESIDUE - THERMAL HYDROPROCESSING

A residue from deasphalting a syncrude obtained by direct coal liquefa ction of a subbituminous Spanish coal was processed by thermal hydrotr eatment. Kinetic study of the cracking reaction and coke formation rea ction has been performed. The viscosity, coke content, boiling point d istribution, elemental analysis, and aromaticity of the reaction produ cts have been determined. The experimental data fits with the first-or der kinetic model proposed. The main effects observed with the thermal hydrotreatment have been a large decrease of the viscosity that varie s from 4608 cSt in the feedstock to 147 cSt in the products. The conve rsion of the heavy fraction (bp > 350 degrees C and soluble in toluene ) and asphaltenes increased with the temperature and residence time, a nd the formation of coke was inhibited even at the hardest reaction co nditions used. At 425 degrees C a kinetic control conducts the reactio n, the cracking reaction with lower activation energy was more favorab le and the coke formation (condensation) remained almost completely in hibited.