Petroleum-wax separation
US5620588A · kind A · utility
Inventors
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G73/06
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for dewaxing including the steps of mixing a waxy feedstock near its pour point with an ambient or below ambient temperature solvent essentially free of a selected cosolvent, to form a solvent/feedstock mixture, essentially free of a selected cosolvent, and subsequently adding the cosolvent to the solvent/feedstock mixture to cause instantaneous precipitation of wax on addition of cosolvent with the amount of wax precipitation being controlled by the quantity and temperature of cosolvent added. The cosolvent is essentially completely miscible with the solvent, but immiscible with the oil and wax. For example, alcohols (methanol, ethanol, propanol), ketones (ketene, acetone), amines, etc. The process of the present invention provides the advantages of lower solvent ratios (higher solvent recovery), higher filtration temperatures, "environmentally compatible" solvents, rapid filtration rates, and debottlenecking of existing dewaxing plants.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.