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U.S. Department of Energy
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Solvent treatment of used lubricating oil to remove coking and fouling precursors

Technical Report ·
OSTI ID:6540201
Coking and fouling problems encountered with direct distillation of used lubricating oils indicate the need for a pretreatment step in re-refining processes which employ distillation. A systematic, detailed study of pretreatment by solvent precipitation is presented. After many solvents were tested, the optimum system is shown to be a mixture of 2-propanol, 1-butanol, and methylethyl ketone in a ratio of 1:2:1 by volume. The minimum solvent-to-oil ratio is 3:1. Sludge separation and settling rates are noted for static reactors, and data for centrifuged samples are also included. The effects of container shape, pH, and impurities are studied and shown to be minimal. Pilot plant data show this pretreatment to be effective and prove solvents can be recycled for continued use. The solvent pretreatment in conjunction with dehydration, distillation, and a finishing process, produces a high-quality lube oil.
Research Organization:
Department of Energy, Bartlesville, OK (USA). Bartlesville Energy Technology Center
OSTI ID:
6540201
Report Number(s):
BETC/RI-78/20
Country of Publication:
United States
Language:
English