Catalytic dewaxing process
AssigneeFina Technology, Inc.
InventorsJames R. Butler, William P. Licht
Life of this patent
Estimating the term…
Abstract
A process for reducing the pour point of sulfur containing gas oil fractions to produce fractions, including diesel oil of reduced pour point involving sequential hydrotreating and dewaxing of the gas oil feedstock. The hydrotreating step is carried out over a conventional hydrodesulfurization catalyst to remove sulfur. The dewaxing step is carried out over silicalite at mild dewaxing conditions under which the C.sub.3 and lower gas make is no greater than 2 wt. % based upon the gas oil feed.
Claims17
A process for catalytic dewaxing a hydrocarbon feed having an initial boiling point of less than 500.degree. F. and a final boiling point of less than 900.degree. F., comprising passing the hydrocarbon feed through a reaction zone containing a crystalline silica polymorph silicalite catalyst at mild dewaxing conditions under which the C.sub.3 and lower hydrocarbon gas make from said reaction zone is not greater than 2 wt. % based on the feed.
A process for catalytically dewaxing a hydrocarbon feed having an initial boiling point of less than 500.degree. F. and a final boiling point of less than 900.degree. F., comprising passing the hydrocarbon feed through a reaction zone containing a crystalline silica polymorph silicalite catalyst at mild dewaxing conditions under which the liquid yield from said reaction zone is greater than 100% by volume based on the feed.
A process for reducing the pour point of a sulfur containing gas oil boiling in the range of 400.degree.-900.degree. F. comprising the steps of:
- (a) catalytically hydrotreating said gas oil to remove sulfur therein;
- and
- (b) dewaxing said gas oil by passing said gas oil over a crystalline silica polymorph silicalite catalyst at mild dewaxing conditions under which the total C.sub.3 and lower hydrocarbon gas make is no greater than 2 wt. % based on said gas oil feed.
In the dewaxing of hydrocarbons to provide a diesel oil fraction of reduced pour point, the method comprising:
- (a) feeding hydrocarbon fraction having an initial boiling point of less than 500.degree. F. and a final boiling point of less than 900.degree. F. into a first reaction zone operated at a temperature within the range of 550.degree. -800.degree. F. and a pressure of at least 300 psia and within first reaction zone catalytically hydrotreating said fraction to remove sulfur therefrom;
- (b) passing the hydrotreated hydrocarbon fraction from said first reaction zone to a second reaction zone under operating conditions including a temperature within the range of 650.degree.-850.degree. F. to limit the amount of C.sub.1 -C.sub.3 hydrocarbons produced by cracking of said fraction to no more than 2 wt. % of the feed in step (a) and within said second zone dewaxing said fraction over a silicalite dewaxing catalyst to provide a product having a lower pour point than said feed;
- and
- (c) withdrawing a diesel oil product from said second reaction zone.
Dependencies are inferred from the claim text.