Catalytic dewaxing process
US4921593A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 1987 |
| Grant date | May 1, 1990 |
| Priority date | — |
| Expiry date | Aug 20, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G65/043
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A lubricant dewaxing process which is useful with difficult feeds, especially highly waxy feeds having paraffin contents in excess of 25 weight percent of feeds with high nitrogen levels, employs two-step dewaxing in which the first stage is carried out under relatively mild conditions to obtain extended catalyst cycle life between successive reactivations with a constant temperature for the duration of each dewaxing cycle. The second stage dewaxing is carried out under conditions which maintain the target pour point for the product with a progressively increasing temperature during each dewaxing cycle. More than one preliminary dewaxing stage may be provided in order to reduce severity in each stage with mild conditions and constant temperature being maintained in the preliminary steps. Using this process, extended catalyst cycle lives may be obtained with difficult feeds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.