Fluid catalytic cracking and hydrotreating processes for fabricating diesel fuel from waxes

Abstract

A method for obtaining a petroleum distillate product is provided, the method including subjecting a paraffin-based wax, such as a Fisher-Tropsch wax, to the process of cracking at a pressure less than, or equal to, about 7 Kg/cm 2 in the presence of a first catalyst to obtain an olefinic intermediate, the cracking being carried out in a fluid catalytic cracking apparatus, followed by hydrogenating the olefinic intermediate at a pressure less than, or equal to, about 35 Kg/cm 2 , in the presence of a second catalyst, and recovering the petroleum distillate product. An apparatus for carrying out the method is also provided.

1 . A method for obtaining a petroleum distillate product comprising:
 (a) in a fluid catalytic cracking apparatus, cracking a paraffin-based wax at a pressure less than, or equal to, about 7 Kg/cm 2  in the presence of a first catalyst to obtain an olefinic intermediate;   (b) hydrogenating the olefinic intermediate in the presence of a second catalyst; and   (c) recovering the net reactor effluent comprising at least about 50 mass % distillate boiling range product,   
       to obtain the distillate product thereby. 
     
     
         2 . The method of  claim 1 , wherein the wax is at least one selected from the group consisting of a Fisher-Tropsch wax and a slack wax. 
     
     
         3 . The method of  claim 1 , wherein the step of hydrogenating is conducted at a pressure less than, or equal to, about 35 Kg/cm 2    
     
     
         4 . The method of  claim 3 , wherein the Fischer-Tropsch wax is comprised of substantially 100 mass % of a paraffin composition. 
     
     
         5 . The method of  claim 4 , wherein the paraffin composition is comprised of at least one straight-chained paraffin and at least one branched paraffin. 
     
     
         6 . The method of  claim 5 , wherein the paraffin composition further comprises at least one cycloparaffin, oxygenate, or aromatic. 
     
     
         7 . The method of  claim 1 , wherein the cracking is carried out at the pressure between about 3 and about 5 Kg/cm 2 . 
     
     
         8 . The method of  claim 1 , wherein the first catalyst comprises a first metallic composition embedded within an amorphous substrate. 
     
     
         9 . The method of  claim 8 , wherein the first metallic composition comprises scandium, yttrium or a metal selected from the lanthanide series of the periodic chart. 
     
     
         10 . The method of  claim 1 , wherein 0 to 500 mass % of unconverted wax is recycled to the fluid catalytic cracking apparatus. 
     
     
         11 . The method of  claim 1 , wherein the second catalyst comprises an amorphous substrate having a second metallic composition impregnated therein 
     
     
         12 . The method of  claim 11 , wherein the amorphous substrate comprises aluminum oxide. 
     
     
         13 . The method of  claim 11 , wherein the second metallic composition comprises a base metal composition or a noble metal composition. 
     
     
         14 . The method of  claim 13 , wherein the base metal composition is at least one selected from the group consisting of a nickel-molybdenum composition and a cobalt-molybdenum composition. 
     
     
         15 . The method of  claim 13 , wherein the noble metal composition comprises at least one noble metal selected from the group consisting of platinum and palladium. 
     
     
         16 . The method of  claim 1 , wherein the distillate boiling range product comprises a combination of jet fuel and diesel fuel. 
     
     
         17 . The method of  claim 1 , wherein the net reactor effluent further comprises naphtha, liquefied petroleum gas or at least one light end product selected from the group consisting of methane, ethane, ethylene, and hydrogen. 
     
     
         18 . The method of  claim 1 , wherein the step of cracking is carried at a temperature that is less than about 500° C. 
     
     
         19 . The method of  claim 1 , wherein the step of hydrogenating is carried at a pressure between about 10 and about 20 Kg/cm 2 . 
     
     
         20 . A system for obtaining a distillate boiling range product from a paraffin-based wax, comprising:
 (a) a fluidized catalytic cracking reactor for cracking a paraffin-based wax at a pressure less than, or equal to, about 7 Kg/cm 2  to obtain an olefinic intermediate;   (b) a fractionator in fluid connection with the fluid catalytic cracking reactor for recovering a distillate from the olefinic intermediate; and   (c) a hydrotreating unit in fluid connection with the fractionator for hydrogenating the distillate to obtain the net reactor effluent comprising of at least about 50 mass % petroleum distillate boiling range product.