High power fuel compositions

Abstract

A fuel composition is prepared by blending a petroleum derived low sulphur diesel with a Fischer-Tropsch derived gasoil and a Fischer-Tropsch derived base oil wherein the amount of the petroleum derived low sulphur diesel is from 60% up to 80% v/v of the total composition; the amount of Fischer-Tropsch derived gasoil is from 10% up to 30% v/v of the total composition; the amount of Fischer-Tropsch derived base oil is from 10% up to 30% v/v of the total composition; the amounts of the Fischer-Tropsch derived gas oil and Fischer-Tropsch derived base oil together being at least 20% v/v of the total composition. The fuel compositions of the invention have improved properties, in terms that they display increased power when compared to fuel compositions in which the Fischer-Tropsch derived base oil component is not present.

What is claimed: 
     
         1 . A fuel composition prepared by blending a petroleum derived low sulphur diesel comprising <50 ppm of sulphur with a Fischer-Tropsch derived gasoil and a Fischer-Tropsch derived base oil wherein the amount of the petroleum derived low sulphur diesel is from 60% up to 80% v/v of the total composition; the amount of Fischer-Tropsch derived gasoil is from 10% up to 30% v/v of the total composition; the amount of Fischer-Tropsch derived base oil is from 10% up to 30% v/v of the total composition; the amounts of the Fischer-Tropsch derived gas oil and Fischer-Tropsch derived base oil together being at least 20% v/v of the total composition; and wherein the petroleum derived low sulphur diesel has a density of 0.81 to 0.865 g/cm 3  at 15° C. and a kinematic viscosity (ASTM D445) from 1.5 to 4.5 mm 2 /s at 40° C.; the Fischer-Tropsch derived gasoil has a density of 0.76 to 0.80 g/cm 3  at 15° C. and a kinematic viscosity (ASTM D445) from 2.0 to 4.5 mm 2 /s at 40° C.; the Fischer-Tropsch derived base oil has a density of 0.79 to 0.82 g/cm 3  at 15° C. and a kinematic viscosity (ASTM D445) from 7.5 to 12.0 mm 2 /s at 40° C.; and wherein the composition has increased power performance in a diesel engine when compared to fuel compositions comprising only a petroleum derived low sulphur diesel comprising <50 ppm of sulphur and a Fischer-Tropsch derived gasoil. 
     
     
         2 . The fuel composition of  claim 1 , wherein the Fischer-Tropsch derived gasoil consists of at least 95% w/w of paraffinic components. 
     
     
         3 . The fuel composition of  claim 1 , wherein the Fischer-Tropsch derived base oil consists of at least 98% w/w of paraffinic components. 
     
     
         4 . The fuel composition of  claim 1 , wherein the amount of the Fischer-Tropsch derived base oil is at least 15% v/v of the total composition. 
     
     
         5 . The fuel composition of  claim 1 , wherein the amount of the Fischer-Tropsch derived gasoil is from 10% v/v of the total composition. 
     
     
         6 . The fuel composition of  claim 1 , wherein the amount of the Fischer-Tropsch derived gasoil is between 10 and 20% v/v and the amount of the Fischer-Tropsch derived base oil is between 20 and 30% v/v. 
     
     
         7 . The fuel composition of  claim 1 , wherein Fischer-Tropsch derived gasoil has a density of 0.77 to 0.79 g/cm 3  at 15° C. 
     
     
         8 . The fuel composition of  claim 1 , wherein Fischer-Tropsch derived gasoil has a kinematic viscosity from 2.2 to 4.2 mm 2 /s at 40° C. 
     
     
         9 . The fuel composition of  claim 1 , wherein Fischer-Tropsch derived base oil has a density of 0.800 to 0.815 g/cm 3  at 15° C. 
     
     
         10 . The fuel composition of  claims 1 , wherein Fischer-Tropsch derived base oil has a kinematic viscosity from 8.0 to 11.0 mm 2 /s at 40° C. 
     
     
         11 . A method for increasing power performance of a diesel engine, the method comprising providing to the diesel engine a fuel composition comprising a petroleum derived low sulphur diesel comprising <50 ppm of sulphur, a Fischer-Tropsch derived base oil and a Fischer-Tropsch derived gasoil, wherein the amount of the petroleum derived low sulphur diesel is from 60% up to 80% v/v of the total composition; the amount of Fischer-Tropsch derived gasoil is from 10% up to 30% v/v of the total composition; the amount of Fischer-Tropsch derived base oil is from 10% up to 30% v/v of the total composition; the amounts of the Fischer-Tropsch derived gas oil and Fischer-Tropsch derived base oil together being at least 20% v/v of the total composition; and wherein the petroleum derived low sulphur diesel has a density of 0.81 to 0.865 g/cm 3  at 15° C. and a kinematic viscosity (ASTM D445) from 1.5 to 4.5 mm 2 /s at 40° C.; the Fischer-Tropsch derived gasoil has a density of 0.76 to 0.80 g/cm 3  at 15° C. and a kinematic viscosity (ASTM D445) from 2.0 to 5.0 mm 2 /s at 40° C.; and the Fischer-Tropsch derived base oil has a density of 0.79 to 0.82 g/cm 3  at 15° C. and a kinematic viscosity (ASTM D445) from 7.5 to 12.0 mm 2 /s at 40° C.