Patent ID: 6524469
Filing Date: 2003-02-25
Classification: C10G

Abstract:
A process for the upgrading of a heavy oil feedstock that comprises the steps of thermally cracking said feedstock in a thermal cracking unit at conditions that will produce a thermally cracked product stream having a lower average molecular weight and boiling point than said feedstock without significant coke formation;volatilizing from said product stream light ends including any water that might be in the stream to form a devolatilized product stream; adding an alkane solvent to said devolitized product stream thereby inducing the formation of asphaltene aggregates and forming a devolatilized product/solvent mixture; passing said devolatilized product/solvent mixture to a first membrane permeation unit; recovering a permeate/solvent stream that is reduced in asphaltenes; heating said permeate/solvent above the solvent critical point; recovering said solvent and recycling it to a discharge of said thermal cracking unit; recovering a substantially deasphalted oil product; mixing a first retentate stream from said first membrane permeation unit, which is increased in asphaltenes, with a portion of the alkane solvent to form a first retentate/solvent mixture; passing said first retentate stream/solvent mixture to a second membrane permeation unit, to recover liquids that are associated with the asphaltenes in said first retentate/solvent mixture as a second permeate, which permeates through the second membrane; and recovering a high-solids retentate stream comprising predominantly asphaltenes, steam stripping said high-solids retentate and recovering the solids.