Process for preparing lubricating oil from used waste lubricating oil
US4073719A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1977 |
| Grant date | Feb 14, 1978 |
| Priority date | — |
| Expiry date | Apr 26, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10M175/005
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A re-refining process is described by which high-quality finished lubricating oils are prepared from used waste lubricating and crankcase oils. The used oils are stripped of water and low-boiling contaminants by vacuum distillation and then dissolved in a solvent of 1-butanol, 2-propanol and methylethyl ketone, which precipitates a sludge containing most of the solid and liquid contaminants, unspent additives, and oxidation products present in the used oil. After separating the purified oil-solvent mixture from the sludge and recovering the solvent for recycling, the purified oil is preferably fractional vacuum-distilled, forming lubricating oil distillate fractions which are then decolorized and deodorized to prepare blending stocks. The blending stocks are blended to obtain a lubricating oil base of appropriate viscosity before being mixed with an appropriate additive package to form the finished lubricating oil product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.