Overbased metallic salt diesel fuel additive compositions for improvement of particulate traps

Abstract

A fuels additive metallic salt composition effective in improving the operation of diesel engine particulate traps when added to a diesel fuel so as to provide 1-25 ppm metal in the fuel which comprises an oil soluble or oil dispersible overbased metal salt of an acidic organic compound, said salt composition containing 5-85 wt. % of a stoichiometric excess of metal over that required to neutralize the anionic portion of the salt, the metal being selected from the group consisting of Ca, Fe, Mg, Sr, Na, Ti, Zr, Mn, Zn and Ce.

1 . A method of improving the operation of a diesel engine particulate trap which comprises the steps of (a) fueling a diesel engine provided with a particulate trap with a fuel composition containing a fuel additive metallic salt composition comprising at least one oil soluble or oil dispersible overbased metal salt of an acidic organic compound, said salt composition containing 5-85 wt. % of a stoichiometric excess of metal over that required to neutralize the anionic portion of the salt, the metal being selected from the group consisting of Ca, Fe, Mg, Sr, Na, Ti, Zr, Mn, Zn and Ce, in an amount providing from about 1 to about 25 ppm of metal to the fuel, and (2) operating said diesel engine.  
   
   
       2 . The method of  claim 1  wherein the salt is selected from the group consisting of sulfonates, phenates, sulfurized phenates, thiophosphonates, salicylates, naphthenates and carboxylates.  
   
   
       3 . The method of  claim 1  wherein the metal is cerium or iron.  
   
   
       4 . The method of  claim 1  wherein the excess metal is in the form of an oxide, carbonate or hydroxide.  
   
   
       5 . The method of  claim 1  wherein the metal is iron, the salt is a neocarboxylate or naphthenate.  
   
   
       6 . The method of  claim 1  wherein the excess metal is present in an amount of 20-50 wt. %.  
   
   
       7 . The method of  claim 1  wherein the salt is a carboxylate.  
   
   
       8 . The method of  claim 1  wherein the salt is a neocarboxylate or naphthenate.  
   
   
       9 . The method of  claim 1  wherein the salt is iron neodecanoate.