Use of mixtures of monocarboxylic acids and polycyclic hydrocarbon compounds for increasing the cetane number of fuel oils

Abstract

The use of mixtures of (A) aliphatic saturated or unsaturated monocarboxylic acids having 12 to 24 carbon atoms or the dimerization or trimerization products thereof, which may be present in the form of free carboxylic acids and/or in the form of ammonium salts, amides, esters and/or nitriles, and (B) polycyclic hydrocarbon compounds which are obtainable from distillation residues of natural oils, which have been extracted from tree resins, for increasing the cetane number of fuel oils which comprise at least one additive with detergent action and at least one cetane number improver, the mixtures of components (A) and (B) being used in a concentration of 10 to 500 ppm by weight, based on the total amount of the fuel oil.

1 . The use of mixtures of
 A) aliphatic saturated or unsaturated monocarboxylic acids having 12 to 24 carbon atoms or the dimerization or trimerization products thereof, which may be present in the form of free carboxylic acids and/or in the form of ammonium salts, amides, esters and/or nitriles, and   B) polycyclic hydrocarbon compounds which are obtainable from distillation residues of natural oils, which have been extracted from tree resins,
 for increasing the cetane number of fuel oils which comprise at least one additive with detergent action and at least one cetane number improver, the mixtures of components (A) and (B) being used in a concentration of 10 to 500 ppm by weight, based on the total amount of the fuel oil. 
   
     
     
         2 . The use according to  claim 1 , in which the fuel oils comprise at least one additive with detergent action which is selected from
 (i) compounds with moieties derived from succinic anhydride and having hydroxyl and/or amino and/or amido and/or imido groups;   (ii) nitrogen compounds quaternized in an acid-free manner, obtainable by addition of a compound comprising at least one oxygen- or nitrogen-containing group reactive with an anhydride and additionally at least one quaternizable amino group onto a polycarboxylic anhydride compound and subsequent quaternization;   (iii) polytetrahydrobenzoxazines and bistetrahydrobenzoxazines.   
     
     
         3 . The use according to  claim 2 , in which the fuel oils comprise at least one polyisobutenyl-substituted succinimide as an additive with detergent action. 
     
     
         4 . The use according to  claims 1  to  3 , in which the fuel oils comprise 2-ethylhexyl nitrate as a cetane number improver. 
     
     
         5 . The use according to  claims 1  to  4 , in which the carboxylic acids (A) and the polycyclic hydrocarbon compounds (B) are present in the mixtures in a weight ratio relative to one another of 65 to 99.9:0.1 to 35, especially of 90 to 99.9:0.1 to 10. 
     
     
         6 . The use according to  claims 1  to  5 , in which the mixtures of carboxylic acids (A) and polycyclic hydrocarbon compounds (B) used are tall oil fatty acid or dimerized tall oil fatty acid. 
     
     
         7 . The use according to  claims 1  to  6  for use in fuel oils, which consist
 (a) to an extent of 0.1 to 100% by weight of at least one biofuel oil based on fatty acid esters, and 
 (b) to an extent of 0 to 99.9% by weight of middle distillates of fossil origin and/or of vegetable and/or animal origin, which are essentially hydrocarbon mixtures and are free of fatty acid esters. 
 
     
     
         8 . The use according to  claims 1  to  6  for use in fuel oils which have at least one of the following properties:
 (α) a sulfur content of less than 50 mg/kg; 
 (β) a maximum content of 8% by weight of polycyclic aromatic hydrocarbons; 
 (γ) a 95% distillation point (vol/vol) at not more than 360° C.