Process for the working up of salvage oil
AssigneeKrupp-Koppers GmbH
InventorsRolf Wetzel, Hubert Coenen, Winfried Kreuch
Life of this patent
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Abstract
A process is disclosed for the working up of salvage oil, in which the salvage oil is subjected to an extraction under supercritical conditions. The halogen compounds contained in the produced extract are removed by catalytic hydrogenation. The extraction residue is eliminated by deposition or thermal treatment (gasification). In the case of a thermal treatment of the extraction residue, other residues can be simultaneously converted, so that the process is performed without yield of environmentally burdensome residues or by-products. Ethane in particular and/or propane is employed as solvent for the supercritical extraction.
Claims20
Process for the working up of salvage oil, by subjecting previously dewatered salvage oil to an extraction under supercritical conditions with a solvent which is gaseous at normal conditions and separating extracted components from a separated supercritical gas phase through lowering of pressure or alteration of temperature, comprising
- (a) removing solid impurities present in said salvage oil by filtration;
- (b) subjecting filtered salvage oil to an atmospheric distillation;
- (c) subjecting previously distilled salvage oil to a supercritical extraction, thereby producing a separated supercritical gas phase containing extract components, and separating said extract components from said separated supercritical gas phase in a single step or fractionally;
- (d) removing from separated extract components any solvent residue still remaining therein through single or multiple stage relaxation;
- (e) subjecting solvent-free extract components to a catalytic hydrogenation, thereby producing a gas stream, and purifying said gas stream by pressurized washing with water or caustic soda;
- (f) removing from an extraction residue produced by said extraction any solvent dissolved therein by single or multiple stage relaxation;
- (g) eliminating said solvent-free extraction residue through thermal treatment composed of gasifying the solvent-free extraction residue in a flame reaction in the presence of oxygen or air and removing from a gas so produced, composed essentially of CO, H.sub.2, CO.sub.2, H.sub.2 O and N.sub.2, any undesirable components by a subsequently disposed gas purification;
- and
- (h) combining solvent recovered from said extraction residue with solvent recovered from said extract components, condensing said solvent and adding said condensed solvent to a main solvent stream which is led back to said extraction stage.
Dependencies are inferred from the claim text.