Dilution chilling dewaxing by modification of tower temperature profile
US4146461A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1977 |
| Grant date | Mar 27, 1979 |
| Priority date | — |
| Expiry date | Dec 27, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G73/32
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An improved DILCHILL* dewaxing process wherein waxy lubricating oil stocks are solvent dewaxed by contacting them with successive increments of cold dewaxing solvent at a plurality of points along the height of a vertical tower divided into a plurality of stages while agitating the oilsolvent mixture in each stage to provide substantially instantaneous mixing of the waxy oil and solvent thereby precipitating wax from the oil while avoiding the well known shock chilling effect. The improvement resides in adjusting the cold solvent addition to each stage in a manner so as to modify the temperature profile along the tower to ensure that the temperature drop per stage in the initial stages in which wax precipitation occurs is greater than the temperature drop per stage in the final or later stages in which wax precipitation occurs. FNT * DILCHILL is a registered Service Mark of Exxon Research and Engineering Company.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.