Urea dewaxing of naphthene oils
AssigneeTexaco Inc.
InventorsTheodore C. Mead, James H. Wright
Life of this patent
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Abstract
In an improved urea dewaxing process a urea/alcohol slurry chilled to 60.degree. F. to 65.degree. F. is added to a naphthenic distillate chilled to 60.degree. F. to 65.degree. F. to produce a refrigerator oil with improved low temperature properties.
Claims6
In a process for dewaxing a naphthenic lubricating oil distillate charge stock containing less than 2 wt% n-paraffin the process comprising mixing the naphthenic oil with urea in the presence of an organic solvent and forming solid, n-paraffin-urea adducts, separating the adducts from the solution thereby producing dewaxed naphthenic oil, decomposing or extracting the separated adducts, recovering and recycling the urea and optionally, recovering the n-paraffins, the improvement which comprises:
- a. chilling the naphthenic lubricating oil distillate charge stock to a temperature of 60.degree. F. to 65.degree. F.;
- b. admixing granulated, solid urea with urea dewaxing solvent, the amount of urea being a multiple of the amount required for the complete conversion of the n-paraffin to n-paraffin-urea adduct;
- to form a slurry;
- c. chilling the slurry to 60.degree. F. to 65.degree. F.;
- d. vigorously mixing the naphthenic lubricating oil distillate charge stock with the slurry for 3 to 4 hours to form an n-paraffin-urea adduct;
- e. separating from the mixture of step (d) a solids-free solution of dewaxed lubricating oil.
Dependencies are inferred from the claim text.