Increasing fuel smoke point

Abstract

The present invention relates to processes for increasing smoke point of a fuel. The process can be carried out using an upgrading catalyst that contains at least one noble metal supported on an inorganic, porous crystalline phase material. The catalyst is particularly effective in increasing smoke point, while minimizing reduction in total aromatics content, particularly naphthalene content.

1 . A process for increasing smoke point of a fuel, comprising:
 providing a feedstock fuel having a smoke point from 18 mm to below 25 mm and a total aromatics content of A r ≧68−2.6S m , wherein A r  is vol % total aromatics of the feedstock and S m  is the smoke point of the feedstock, provided that A r  is at least about 4 vol %; and   contacting the feedstock fuel with a smoke point upgrading catalyst comprised of at least one noble metal hydrogenation component disposed on a support having an inorganic, porous crystalline phase material to provide a fuel product having a smoke point of at least 25 mm.   
     
     
         2 . The process of  claim 1 , wherein the feedstock fuel has an initial and final boiling point within the range from about 90° C. to about 360° C. 
     
     
         3 . The process of  claim 1 , wherein the feedstock fuel has an ASTM D86 10% distillation point ‘within the range from. about 110° C. to about 190° C. 
     
     
         4 . The process of  claim 1 , wherein the feedstock fuel has a total aromatics content of at least about 6 vol %. 
     
     
         5 . The process of  claim 4 , wherein the feedstock fuel has a smoke point of at least 19 mm. 
     
     
         6 . The process of  claim 1 , wherein the feedstock fuel has a total aromatics content of not greater than about 25 vol %. 
     
     
         7 . The process of  claim 1 , wherein the feedstock fuel has a sulfur content of not greater than about 3000 wppm. 
     
     
         8 . The process of  claim 1 , wherein the smoke point upgrading catalyst comprises a support material comprising an inorganic, porous crystalline phase material having pores with diameters of at least about 13 Å and exhibiting, after thermal treatment, an XRD spectrum having at least one peak corresponding to a d-spacing greater than about 18 Å with a relative intensity of about 100, and having an equilibrium benzene sorption capacity of at least about 15 grams of benzene per 100 grams of material at about 50 torr (about 6.7 kPaa) and at about 25° C. 
     
     
         9 . The process of  claim 1 , wherein the at least one noble metal is selected from the group consisting of Pd, Pt, Rh, Ru, Ir, and combinations thereof. 
     
     
         10 . The process of  claim 1 , wherein crystalline phase material is a metallosilicate or an aluminosilicate. 
     
     
         11 . The process of  claim 1 , wherein the at least one noble metal is present on the catalyst in an amount from about 0.01 wt % to about 5 wt %, based on total catalyst weight. 
     
     
         12 . The process of  claim 1 , wherein the at least one noble metal is bound by a refractory inorganic oxide selected from the group consisting of alumina, silica, silica-alumina, titania, zirconia, magnesia, and combinations thereof. 
     
     
         13 . The process of  claim 1 , wherein the smoke point upgrading catalyst is a Pt/Pd-containing M41S catalyst or a Pt/Pd.-containing MCM-41 catalyst. 
     
     
         14 . A process for increasing smoke point of a fuel, comprising:
 hydrocracking a mineral oil feedstock;   providing from the hydrocracked mineral oil feedstock a first fuel having a smoke point from 18 mm to below 25 mm and a total aromatics content of A r ≧68−2.6S m , wherein A r  is vol % total aromatics of the feedstock and S m  is the smoke point of the feedstock, provided that A r  is at least 4 vol %; and   contacting the first fuel with a smoke point upgrading catalyst comprised of at least one noble metal hydrogenation component disposed on a support having an inorganic, porous crystalline phase material to provide a fuel product having a smoke point of at least 25 mm.   
     
     
         15 . The process of  claim 14 , wherein the first fuel has in initial and final boiling point within the range from about 90° C. to about 360° C., 
     
     
         16 . The process of  claim 14 , wherein the first fuel has an ASTM D86 10% distillation point within the range from about 110° C. to about 190° C. 
     
     
         17 . The process of  claim 14 , wherein the first fuel has a total aromatics content of at least about 6 vol %. 
     
     
         18 . The process of  claim 14 , wherein the first fuel has a total aromatics content of not greater than about 25 vol %. 
     
     
         19 . The process of  claim 14 , wherein the feedstock fuel has a sulfur content of not greater than about 3000 wppm. 
     
     
         20 . The process of  claim 14 , wherein the smoke point upgrading catalyst is a. Pt/Pd-containing M41S catalyst or a Pt/Pd-containing MCM-41 catalyst.