Fuel compositions

Abstract

Use of a Fischer-Tropsch derived fuel component, in a fuel composition, is provided reducing the tendency of the composition to dissolve metals; increasing its thermal stability; reducing the concentration of a metal deactivator, antioxidant or detergent additive in the composition; or increasing the storage stability of the composition. The composition is preferably a diesel fuel composition.

1 . A method for formulating a fuel composition, which method comprising blending together a non-Fischer-Tropsch derived base fuel and a Fischer-Tropsch derived fuel component, optionally with other fuel components, in which the JFTOT breakpoint of such fuel composition is greater than 300° C. 
     
     
         2 . The method of  claim 1  which the JFTOT breakpoint is greater than 350° C. 
     
     
         3 . The method for formulating a fuel composition, which method comprising blending together a non-Fischer-Tropsch derived base fuel and a Fischer-Tropsch derived fuel component, optionally with other fuel components, the peroxide level of such fuel composition is 10 mg/kg or less after a period of storage of 8 weeks under storage temperature of at least 40° C. 
     
     
         4 . A method of operating a fuel consuming system, which method involves introducing into the system a fuel composition prepared according to  claim 1 . 
     
     
         5 . A method of operating a fuel consuming system, which method involves introducing into the system a fuel composition prepared according to  claim 2 . 
     
     
         6 . A method of operating a fuel consuming system, which method involves introducing into the system a fuel composition prepared according to  claim 3 . 
     
     
         7 . The method of  claim 2  wherein the concentration of the Fischer-Tropsch derived fuel component in the fuel composition is from 5 to 30% v/v.