| abstract |
Methods are provided for producing lubricant base oils from petrolatum. After solvent dewaxing of a brightstock raffinate to form a brightstock base oil, petrolatum is generated as a side product. The petrolatum can be hydroprocessed to form base oils in high yield. The base oils formed from hydroprocessing of petrolatum have an unexpected pour point relationship. For a typical lubricant oil feedstock, the pour point of the base oils generated from the feedstock increases with the viscosity of the base oil. By contrast, lubricant base oils formed from hydroprocessing of petrolatum have a relatively flat pour point relationship, and some of the higher viscosity base oils unexpectedly have lower pour points than lower viscosity base oils generated from the same petrolatum feed. The base oils from petrolatum are also unusual in yielding both high viscosity and high viscosity index and can be generated while maintaining a high yield. |