GB1286383A - Preparation of high vi lube oils - Google Patents

Abstract

1286383 Refining lubricating oil stocks SUN OIL CO 26 March 1970 [3 April 1969] 14670/70 Heading C5E A lubricating oil fraction is extracted with a solvent having preferential solubility for aromatics, the raffinate is hydrocracked to increase its viscosity index, the hydrocracked oil is extracted with a solvent having preferential solubility for aromatics and the solvent extract phase, containing solvent and extract, from extraction of the hydrocracked oil is used for the extraction of the lubricating oil fraction prior to the hydrocracking. A feed 1, e.g. a vacuum distillate or residuum which can have been deasphalted with propane, is extracted at 2 with a solvent comprising the solvent and extract phase 10 from the extraction at 7 and additional extractive solvent 15. Solvent contained in the raffinate 3 is removed at 4 by distillation and the raffinate is then hydrocracked at 5. The hydrocracking is carried out at 650-825‹ F. with a hydrogen partial pressure of at least 1500 p.s.i. using a catalyst such as a mixture of nickel sulphide and tungsten sulphide on an alumina, silica or alumina-silica support, or palladium on a molecular sieve support. The hydrocracked oil is extracted in 2-10 stages at 7 with a solvent 14, such as furfural, phenol, acetophenone, acetonitrile, nitrobenzene, aniline, 2,2-dichlorodiethyl ether or dimethylsulphoxide, which can contain water. Solvent contained in the raffinate 8 is recovered by distillation at 9. The extract phase 12 from the solvent extraction 2 is treated at 13 to purify and recover the extractive solvent 14 and 15 and to separate a stream 16 of extracted oil and other impurities which can be cracked to gasoline or used as a rubber processing oil. In an example the feed 1 is vacuum distilled to produce a light vacuum distillate boiling from 775-855‹ F., a heavy vacuum distillate boiling from 855-955‹ F. and a residual oil boiling at 955‹ F. and above and which is deasphalted with propane. The heavy vacuum distillate and the deasphalted residue are separately extracted, the raffinates from these extractions blended with the light vacuum distillate and the blend hydrocracked. The hydrocracked material is extracted to produce an extract phase comprising extract and solvent, which is used to extract the heavy vacuum distillate and the deasphalted residue, and a raffinate which is distilled to produce a 100 neutral oil, a 200 neutral oil, a 500 neutral oil and a bright stock. Low asphalt feeds can be simultaneously deasphalted and solvent extracted by the Duo Sol process.