Patent ID: 6554995
Filing Date: 2003-04-29
Classification: B01D,C10G

Abstract:
A method of separating a petroleum-containing material into at least two fractions, including the steps of:introducing into an extraction column petroleum-containing material as well as a solvent mixture comprising 50%-99% by volume sub-critical carbon dioxide and 1%-50% by volume of at least one co-solvent selected from the group consisting of propane, ethane, butane, propylene, 2 methylpropane, 2,2 dimethylpropane, propadiene, dimethylether, chlorodifluoromethane, difluoromethane and methylfluoride; operating said extraction column at 0Â° C. or less; allowing the petroleum-containing material to percolate down through said extraction column; removing from said extraction column a fraction containing solvent mixture and solvated petroleum-containing material; withdrawing from a bottom portion of said extraction column a dense fraction of said petroleum-containing material; and conveying said removed fraction of solvent mixture and solvated petroleum-containing material to a recovery unit for separating solvent mixture from solvated petroleum-containing material.