Formulating fuel compositions

Abstract

A method of preparing a fuel composition containing a distillate fuel, a detergent additive and a cold flow additive, of a further additive selected from (a) acids and mixtures thereof; and (b) lubricity enhancing additives are provided, for the purpose of reducing the effect of the detergent additive on the cold flow performance of the composition, and/or improving the cold flow performance of the composition, and/or reducing the amount of cold flow additive in the composition, and/or increasing the concentration of detergent additive in the composition without undue impairment of the cold flow performance. The further additive is preferably selected from carboxylic acids, more preferably fatty acids, and mixtures thereof. The distillate fuel is preferably a middle distillate fuel. The overall fuel composition is preferably an automotive fuel composition, more preferably a diesel fuel composition.

1 . A method for formulating a fuel composition, the method comprising (i) blending together a distillate base fuel, a detergent additive and a cold flow additive, (ii) measuring the cold flow performance of the resultant blend and (iii) incorporating a further additive selected from:
 (a) acids and mixtures thereof; and   (b) lubricity enhancing additives,   
     in an amount effective to improve the cold flow performance of the blend. 
   
   
       2 . The method of  claim 1  wherein the distillate fuel is a middle distillate fuel. 
   
   
       3 . The method of  claim 1  wherein the fuel composition is a diesel fuel composition. 
   
   
       4 . The method of  claim 1  wherein the further additive is a carboxylic acid or mixture thereof. 
   
   
       5 . The method of  claim 2  wherein the further additive is a carboxylic acid or mixture thereof. 
   
   
       6 . The method of  claim 1  wherein the further additive is a fatty acid or mixture thereof. 
   
   
       7 . The method of  claim 2  wherein the further additive is a fatty acid or mixture thereof. 
   
   
       8 . A fuel composition made by the method of  claim 1 . 
   
   
       9 . A method of operating a fuel consuming system, which method involves introducing into the system a fuel composition of  claim 8 .