Method and apparatus for improving the oxidative thermal stability of distillate fuel

Abstract

The present invention provides methods of improving the thermal oxidative stability of a distillate fuel which comprise selectively reducing the active concentration in the fuel of N—H containing heterocyclic aromatic compounds in which the nitrogen atom of the N—H group is part of the aromatic system, and wherein said fuel also contains an active concentration of metal compounds or will be exposed to active metal compounds in storage or in use. The present invention also provides methods of determining the thermal oxidative stability of a distillate fuel and apparatus for performing said methods.

1 - 46 . (canceled)  
     
     
         47 . A method for improving the thermal oxidative stability of a jet fuel which contains an active concentration of metal compounds or will be exposed to active metal compounds in storage or in use, which method comprises selectively reducing the active concentration in the fuel of N—H containing heterocyclic aromatic compounds in which the nitrogen atom of the N—H group is part of the aromatic system, by treatment with a suitable adsorbent material comprising a compound having a benzaldehyde functionality supported on a suitable support wherein the benzaldehyde is a 4-aminobenzaldehyde functionality which is chemically part of a suitable support as an end group or pendant group on a polymer backbone that forms the support material.  
     
     
         48 . The method according to  claim 47 , wherein said fuel contains an active concentration of metal compounds, and which method further comprises reducing the active concentration of metal compounds present in the fuel.  
     
     
         49 . The method according to  claim 47 , wherein the N—H containing heterocyclic aromatic compounds comprise one or more of pyrrole, indole, pyrazole, carbazole, substituted pyrroles, indoles, pyrazoles and carbazoles.  
     
     
         50 . The method according to  claim 47 , wherein the N—H containing heterocyclic aromatic compounds comprise one or more of pyrrole, indole, substituted pyrroles and substituted indoles.  
     
     
         51 . The method according to  claim 48 , wherein the N—H containing heterocyclic aromatic compounds comprise one or more of pyrrole, indole, pyrazole, carbazole, substituted pyrroles, indoles, pyrazoles and carbazoles.  
     
     
         52 . The method according to  claim 48 , wherein the N—H containing heterocyclic aromatic compounds comprise one or more of pyrrole, indole, substituted pyrroles and substituted indoles.  
     
     
         53 . The method according to  claim 47 , wherein the metal compounds comprise compounds of transition metals.  
     
     
         54 . The method according to  claim 47 , wherein the metal compounds comprise copper and/or iron compounds present in the fuel.  
     
     
         55 . The method according to  claim 48 , wherein the metal compounds comprise copper and/or iron compounds present in the fuel.  
     
     
         56 . The method according to  claim 51 , wherein the metal compounds comprise copper and/or iron compounds present in the fuel.  
     
     
         57 . The method according to  claim 52 , wherein the metal compounds comprise copper and/or iron compounds present in the fuel.