Low-sulfur diesel fuel and use of fatty acid monoalkyl esters as lubricant improvers for low-sulfur diesel fuels

Abstract

The invention relates to a low-sulfur diesel fuel containing a maximum amount of 0.2% by weight of sulfur and fatty acid monoalkyl esters in an amount of between 10 and 50,000 ppm as lubricity improvers, with the fatty acid moieties of the fatty acid monoalkyl esters originating from saturated fatty acids by at least 50%, in particular by at least 70%. It has been shown that said fatty acid esters show a substantially better lubricity improvement in a low-sulfur diesel fuel than a biodiesel made of rape oil and soy bean oil.

1 . A low-sulfur diesel fuel containing a maximum amount of 0.2% by weight of sulfur and fatty acid monoalkyl esters in an amount of between 10 and 50,000 ppm as lubricity improvers, 
 characterized in that    the fatty acid moieties of the fatty acid monoalkyl esters originate from saturated fatty acids by at least 50%, in particular by at least 70%.    
   
   
       2 . A diesel fuel according to  claim 1 , characterized in that the fatty acid monoalkyl esters are provided as fatty acid methyl esters.  
   
   
       3 . A diesel fuel according to  claim 1 , characterized in that the fatty acid monoalkyl esters were produced from vegetable fats and/or oils.  
   
   
       4 . A diesel fuel according to  claim 1 , characterized in that it additionally contains one or more additives for improving the cetane number or for improving the low-temperature behaviour.  
   
   
       5 . An agent for improving the lubricity of diesel fuels containing fatty acid monoalkyl esters, characterized in that the fatty acid moieties of the fatty acid monoalkyl esters originate from saturated fatty acids by at least 50%, in particular by at least 70%.  
   
   
       6 . A process for the production of a fatty acid monoalkyl ester whose fatty acid moieties originate from saturated fatty acids by at least 50%, in particular by at least 70%, characterized in that a fatty acid monoalkyl ester whose fatty acid moieties originate from saturated and unsaturated fatty acids is subjected to fractional crystallization or distillation.  
   
   
       7 . The use of fatty acid monoalkyl esters as lubricity improvers for low-sulfur diesel fuels, characterized in that the fatty acid moieties of the fatty acid monoalkyl esters originate from saturated fatty acids by at least 50%, in particular by at least 70%.