Production of diesel and base stocks from crude oil

Abstract

A process of producing Group III base oils, along with a naphtha product and diesel product, from whole waxy crude oil is provided. The inventive process omits the typical vacuum distillation stage and separations to form the typical cuts off of the vacuum tower. By selecting a waxy crude oil suitable for processing without separations, the crude oil may be hydroprocessed, dearomatized, dewaxed, and hydrofinished to produce a Group III base oil. Additionally, the dewaxing catalyst will isomerize the naphtha range molecules to increase the octane value to a suitable level for blending into gasoline and the diesel range molecules to reduce the diesel cloud point.

1 . A method for producing lubricant base oils from a whole petroleum crude oil, comprising:
 a. providing a whole petroleum crude oil feedstock comprising less than about 2 wt % of heptane asphaltenes, less than about 2 wt % of Conradson carbon residue (CCR), and less than about 50 ppm of metals;   b. hydrotreating the whole petroleum crude oil feedstock on at least one bed of a hydrotreating catalyst under effective hydrotreating conditions to produce a hydrotreated effluent having less sulfur, nitrogen and aromatics than the whole petroleum crude oil;   c. dewaxing the hydrotreated effluent in the presence of a dewaxing catalyst to produce a naphtha product having an octane value greater than 60, a diesel product having a cloud point less than 0° C., and a lubricant base oil product; and   d. fractionating the lubricant base oil product into at least a low viscosity lubricant base oil product having a viscosity of 2-8 cSt at 100° C. and a high viscosity lubricant base oil product having a viscosity of 6-30 cSt at 100° C.   
     
     
         2 . The method of  claim 1 , wherein the low viscosity lubricant base oil product and the high viscosity lubricant base oil product have a viscosity index of at least 120, a pour point of about −15° C., and less than 300 ppm sulfur. 
     
     
         3 . The method of  claim 1 , wherein the naphtha product has an octane value of greater than 70. 
     
     
         4 . The method of  claim 1 , wherein the diesel product comprises less than 15 ppm of sulfur and a pour point of less than 0° C. 
     
     
         5 . The method of  claim 1 , wherein whole petroleum crude oil feedstock comprises less than 0.5 wt % heptane asphaltenes, less than 20 ppm sulfur and nitrogen, and less than 1 wt % carbonaceous residue. 
     
     
         6 . The method of  claim 1 , wherein at least two beds of hydrotreating catalyst are used in step (b) and the hydrotreating catalyst comprises at least one Group VIII non-noble metal and at least one Group VI metal. 
     
     
         7 . The method of  claim 6 , wherein the Group VIII non-noble metal is selected from Fe, Co, and/or Ni and the Group VI metal is selected from Mo and/or W. 
     
     
         8 . The method of  claim 1 , wherein the hydrotreated effluent comprises less than 15 ppm sulfur, less than 5 ppm nitrogen, less than 2 wt % C 3 — paraffins, and less than 25 wt % of aromatics. 
     
     
         9 . The method of  claim 1 , wherein the dewaxing catalyst of step (c) comprises ZSM-48 having a silica to alumina ratio of about 100:1 or less and 0.5-1.0 wt % of a Group VIII noble metal. 
     
     
         10 . The method of  claim 1 , further comprising hydrofinishing the lubricant base oil product prior to step (d) to remove polynuclear aromatic compounds. 
     
     
         11 . The method of  claim 1 , wherein the low viscosity lubricant base oil product has a viscosity of 3-5 cSt at 100° C. and the high viscosity lubricant base oil product has a viscosity of 8-15 cSt at 100° C. 
     
     
         12 . A method for producing a naphtha product, a diesel product, and a lubricant base oil product from a whole petroleum crude oil, comprising:
 a. supplying a whole petroleum crude oil feedstock, without separation or pretreatment, to a hydrotreating unit, wherein the feedstock comprises less than about 2 wt % of heptane asphaltenes, less than about 2 wt % of Conradson carbon residue (CCR), and less than about 50 ppm of metals;   b. hydrotreating the whole petroleum crude oil feedstock on at least one bed of a hydrotreating catalyst under effective hydrotreating conditions to produce a hydrotreated effluent having less than 15 ppm sulfur, less than 5 ppm nitrogen, less than 2 wt % C 3 — paraffins, and less than 25 wt % of aromatics;   c. dewaxing the hydrotreated effluent in the presence of a dewaxing catalyst to produce a dewaxed effluent;   d. separating the dewaxed effluent into at least a naphtha product having an octane value greater than 60, a diesel product having a cloud point less than 0° C., and a base stock product;   e. subjecting the base stock product to hydrofinishing and/or aromatic saturation to remove polynuclear aromatic compounds and produce a hydrofinished base stock; and   f. fractionating the hydrofinished base stock into at least a low viscosity lubricant base oil product having a viscosity of 2-8 cSt at 100° C. and a high viscosity lubricant base oil product having a viscosity of 6-30 cSt at 100° C.   
     
     
         13 . The method of  claim 12 , wherein the low viscosity lubricant base oil product and the high viscosity lubricant base oil product have a viscosity index of at least 120, a pour point of about −15° C., and less than 300 ppm sulfur. 
     
     
         14 . The method of  claim 12 , wherein the low viscosity lubricant base oil product has a viscosity of 3-5 cSt at 100° C. and the high viscosity lubricant base oil product has a viscosity of 8-15 cSt at 100° C. 
     
     
         15 . The method of  claim 12 , wherein the naphtha product has an octane value of greater than 70. 
     
     
         16 . The method of  claim 12 , wherein the diesel product comprises less than 15 ppm of sulfur and a pour point of less than 0° C. 
     
     
         17 . The method of  claim 12 , wherein whole petroleum crude oil feedstock comprises less than 0.5 wt % heptane asphaltenes, less than 20 ppm sulfur and nitrogen, and less than 1 wt % carbonaceous residue. 
     
     
         18 . The method of  claim 12 , wherein at least two beds of hydrotreating catalyst are used in step (b) and the hydrotreating catalyst comprises at least one Group VIII non-noble metal and at least one Group VI metal. 
     
     
         19 . The method of  claim 18 , wherein the Group VIII non-noble metal is selected from Fe, Co, and/or Ni and the Group VI metal is selected from Mo and/or W. 
     
     
         20 . The method of  claim 12 , wherein the dewaxing catalyst of step (c) comprises ZSM-48 having a silica to alumina ratio of about 100:1 or less and 0.5-1.0 wt % of a Group VIII noble metal.