Solvent deasphalting

Claim 1

A process for producing a paraffinic-waxy fraction, a resin-naphthenic fraction, and a solids-asphaltene fraction from an asphalt-containing heavy hydrocarbon material which comprises the steps of: (a) contacting a hydrocarbon charge stock containing asphaltic materials and resins with a first portion of a selective solvent comprising light paraffins and mixtures thereof at a relatively low solvent-to-hydrocarbon volumetric ratio in the range of 2:1 to 10:1 and under extraction conditions of temperature and pressure sufficient to separate a first solvent-rich extract fraction containing paraffins and waxy materials and a first solvent-lean raffinate fraction containing resins, naphthenes, and asphaltene, (b) separating paraffinic waxy materials from said first solvent-rich extract phase and recovering a paraffinic waxy phase and solvent, (c) contacting said first solvent-lean raffinate fraction with a second portion of said selective solvent at a solvent-to-hydrocarbon volumetric ratio higher than said ratio in (a) and at a temperature and pressure lower than in (a) such that asphaltic solids are formed in the presence of a large excess of solvent and that substantially all soluble materials are dissolved in a second solvent-rich extract phase, (d) passing the admixture formed in (c) to a liquid-solids phase separation zone and allowing the admixture to phase separate into a heavy solids-containing phase and a solvent-hydrocarbon phase relatively free from asphaltenes, (e) separating a resin extract fraction from said solvent-hydrocarbon phase of (d) and recovering a resin fraction and solvent, and (f) passing said heavy solids-containing phase to a flashing zone and therein subjecting same to flashing conditions of temperature and pressure sufficient to separate residual solvent therefrom and yield a powdered asphaltic product comprising asphaltenes.