Co-production of heavy and light base oils (ExxonMobil)

CATEGORY: DEWAXING 
Co-production of heavy and light base oils (ExxonMobil)

Type	Patent
Inventor	Michel Daage
Inventor	Jason Thomas Calla
URL	Free Full Text Source:  http://www.google.com/patents/US20140042056
Abstract	A suitable feedstock for forming lubricant base oils is separated into at least a lower boiling portion and a higher boiling portion. The lower boiling portion is combined with a feed suitable for use as a fuels hydrocracking feed. The combined feed is hydrocracked and catalytically dewaxed in order to form fuels and Group II, Group II+, or Group III light neutral basestocks. The higher boiling portion of the feedstock is solvent processed in order to form Group I heavy neutral base oils and/or Group I brightstock base oils. The higher boiling portion of the feedstock can correspond to both a bottoms fraction and one or more additional fractions boiling above a fractionation cut point. Dewaxing is a commonly used technique for improving the properties of a petroleum fraction for use in various products, such as fuels or lubricant base stocks. Historically, solvent dewaxing was the first type of dewaxing used for modifying the properties of a feedstock. Solvent extraction and dewaxing allowed for separation of a feedstock into a raffinate fraction for use as a distillate fuel or lubricant, an aromatics fraction, and a waxy fraction. More recently, catalytic dewaxing has been commonly used for improving the properties of feeds for use in fuels or lubricant base stocks. U.S. Pat. No. 4,259,170 describes a process for manufacturing lube basestocks. In the process, one or more lower boiling fractions from a vacuum distillation tower are solvent dewaxed to form lubricant base stocks. One or more higher boiling fractions are catalytically dewaxed in order to provide a pour point improvement for the higher boiling fractions that is greater than the amount that can be achieved by solvent dewaxing. U.S. Pat. No. 6,773,578 describes a process for preparing lubes with high viscosity index values. The process includes obtaining a first feedstock that includes at least 95% of material that boils below 1150° F. (621° C.), and a second feedstock that includes at least 95% of material that boils above 1150° F. (621° C.). The feedstock containing the portion that boils below 1150° F. is catalytically dewaxed. The feedstock containing the portion that boils above 1150° F. is solvent dewaxed and optionally also catalytically dewaxed. Performing solvent dewaxing on the above 1150° F. portion is described as reducing the difference between the cloud point and the pour point for the resulting products. U.S. Pat. No. 7,354,508 describes a process for preparing a heavy and a light lubricating base oil. A feedstock for forming lubricant basestocks is separated into a lower boiling fraction and a higher boiling fraction. The lower boiling fraction and higher boiling fraction are dewaxed under different conditions. Solvent dewaxing is generally mentioned as a type of dewaxing. However, catalytic dewaxing is identified as the preferred type of dewaxing for dewaxing of both fractions.
Assignee	Exxonmobil Research And Engineering Company
Patent Number	US20140042056 A1
Issue Date	Feb 13, 2014