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. 12, 2000
Filed:
Sep. 08, 1997
Alexander D Daspit, Dallas, TX (US);
Martin MacDonald, Plano, TX (US);
Thomas G Murray, Aubrey, TX (US);
Probex Corporation, Carrollton, TX (US);
Abstract
A process for recovering a base oil of lubricating viscosity from used oil in which, following optional pretreatment, used oil is re-refined by distilling it in distillation apparatus having multiple theoretical plates. Impurities are then extracted from the lube range distillate fraction or fractions with a liquid extractant such as N-Methyl-2-Pyrrolidone (NMP) at a temperature below the temperature, if any, of complete miscibility of the extractant and the oil. The oil and extractant are then separated whereupon the extractant is re-used in the process and the oil is subject to further treatment, as necessary, for targeted uses.