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:
Mar. 22, 1977
Filed:
Oct. 21, 1974
David A Gudelis, Sarnia, CA;
David H Shaw, Sarnia, CA;
Exxon Research and Engineering Company, Linden, NJ (US);
Abstract
A dewaxing process is described wherein a waxy petroleum oil stock such as residual or a broadcut feedstock, characterized by containing at least 10% of residual material boiling above about 1000.degree. F., is mixed with at least about 0.3 volumes of a dewaxing solvent per volume of waxy oil stock, thereby depressing the cloud point of same. In one embodiment of the invention, the resultant mixture is introduced into a cooling zone, at a temperature above the depressed cloud point of the oil. Precooled dewaxing solvent is incrementally added to the cooling zone which is divided into a plurality of stages with agitation means present in each of the stages. The resultant solvent-oil mixture is cooled and agitated as it passes through the cooling zone, thereby reducing the temperature of the oil to below its depressed cloud point and precipitating at least a portion of the wax therefrom. An oil stock of diminished wax content is thereafter recovered. In a second embodiment of the invention, the waxy oil stock is introduced into the cooling zone in the absence of solvent at a temperature above the cloud point of the oil. Precooled dewaxing solvent is introduced incrementally into the initial stages of the cooling zone, coming into contact with the waxy oil and depressing its cloud point. The oil is gradually cooled to a temperature no less than the depressed cloud point of the oil whereupon additional precooled dewaxing solvent is added to the oil in the remaining stages of the cooling zone, thereby gradually cooling the oil to a temperature below the depressed cloud point and precipitating at least a portion of the wax therefrom.