The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 07, 1993
Filed:
Apr. 01, 1991
Theodore C Mead, Port Neches, TX (US);
Avilino Sequeira, Jr, Port Arthur, TX (US);
Texaco Inc., White Plains, NY (US);
Abstract
In a solvent refining process a naphthenic lubricating oil feedstock is solvent extracted to yield a primary aromatics-lean raffinate and a primary aromatics-rich extract. Polynuclear aromatic content of primary raffinate is controlled by manipulating extraction temperature and solvent dosage. Primary extract is separated (settled) to form a secondary raffinate and a secondary extract. Secondary raffinate is recycled to solvent extraction. The refractive index of secondary raffinate is controlled by manipulating settling temperature and antisolvent dosage. The refractive index of secondary raffinate is maintained at or below the refractive index of feedstock. An improved yield of primary raffinate of a specified polynuclear aromatic content is achieved.