LUBRICANT PRODUCTION PROCESS

• Main Authors: LE, QUANG N, WONG, STEPHEN S, GARWOOD, WILLIAM E
• Format: Patent
• Language: English; Korean
• Published: 22.12.1993
• Edition: 5
• Subjects: CHEMISTRY; CRACKING HYDROCARBON OILS; FUELS; INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATINGCOMPOSITIONS; LUBRICANTS; LUBRICATING COMPOSITIONS; METALLURGY; MINERAL WAXES; PEAT; PETROLEUM, GAS OR COKE INDUSTRIES; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVEHYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, ORGASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; TECHNICAL GASES CONTAINING CARBON MONOXIDE; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATINGINGREDIENTS IN A LUBRICATING COMPOSITION

A process for producing lubricant oils of low pour point and high viscosity index by partial dewaxing of a lubricant base stock by isomerization dewaxing followed by a selective dewaxing step. The isomerization dewaxing step is carried out using a large pore, high silica zeolite dewaxing catalyst such as high silica Y or zeolite beta which isomerizes the waxy components of the base stock to less waxy branch chain isoparaffins. The severity is controlled to effect only a partial removal of the waxy components. Further removal of the waxy components is effected during a subsequent dewaxing step which selectively removes of the more waxy n-paraffin components, leaving the branched chain isoparaffins which contribute to a high VI in the product. The selective dewaxing step may be either a solvent, e.g., MEK dewaxing operation or a catalytic dewaxing, preferably using highly shape selective zeolite such as ZSM-22 or ZSM-23. Isomerization dewaxing may be controlled to effect a net increase in the content of isoparaffins and because of the selective nature of the solvent dewaxing step, this increased isoparaffins concentration may be retained, producing a product of high VI. The pour point of the feedstock is preferably reduced by isomerization dewaxing to a value which is no lower than 6 DEG C and preferably no lower than 12 DEG C, above the target pour point for the products. Generally, this will entail a reduction of at least 6 DEG C and preferably at least 12 DEG C in the pour point of the feed.