Patent ID: 6416655
Filing Date: 2002-07-09
Classification: C10G

Abstract:
A method of selectively extracting alkylated mono-aromatic hydrocarbons in a lubricating oil feedstock containing at least about 40 wt. % aromatics by solvent extraction which comprises:(a) contacting the feedstock with a solvent under solvent extraction conditions, the solvent comprising at least one of N-methyl-2-pyrrolidone, furfural and phenol and water wherein said solvent extraction conditions include the amount of water in the solvent, solvent treat rate and temperature; (b) adjusting at least one of the amount of water in the solvent, solvent treat rate and temperature such that paraffinic hydrocarbons and alkylated mono-aromatic hydrocarbons are concentrated in a raffinate phase; (c) separating extracted feedstock into a raffinate rich in paraffinic hydrocarbons and alkylated mono-aromatic hydrocarbons and an extract rich in aromatic hydrocarbons including 2+ multi-ring aromatic hydrocarbons; (d) removing solvent from the raffinate to produce a stripped raffinate; (e) hydrofining the stripped raffinate under hydrofining conditions including a temperature of 150 to 450Â° C., hydrogen pressure of atmospheric to 10,000 psig; and liquid hourly space velocity of 0.1 to 10, (f) solvent dewaxing the hydrofined raffinate under solvent dewaxing conditions to produce a dewaxed hydrofined raffinate; and (g) measuring the VI of the dewaxed hydrofined raffinate and adjusting, if necessary, at least one of the amount of water in the solvent, solvent treat rate and temperature in step (a) to provide a dewaxed hydrofined raffinate having a VI of from about 86 to about 97.