Clean-burning aviation gasoline additive to eliminate valve seat recession and deposits

Abstract

A fuel additive for fuel formulations comprising calcium sulfonates in an amount effective to limit or eliminate valve seat recession in engines utilizing such fuel formulations. The fuel additive may also include a detergent, particularly in an amount to enhance the VSR limiting effect of the calcium sulfonates. Also included are fuel formulations containing calcium sulfonates in a concentration effective to limit vale seat recession in engines utilizing the fuel formulations. Methods for treating VSR in piston engines are also provided.

1 . A fuel additive for use in gasoline fuels comprising:
 one or more calcium sulfonates in an amount, upon addition to the gasoline fuel, to be effective to limit valve seat recession in an engine using the fuel.   
     
     
         2 . The fuel additive of  claim 1  in which the calcium sulfonates comprise calcium petroleum sulfonates. 
     
     
         3 . The fuel additive of  claim 2  which further comprises;
 a detergent present in an amount to provide enhanced limiting of the VSR over that achieved with the calcium sulfonates, the calcium sulfonates and the detergent being formulated for direct addition to a final fuel formulation. 
 
     
     
         4 . The fuel additive of  claim 3  in which the detergent is polyolefin alkyl phenol alkyl amine. 
     
     
         5 . The fuel additive of  claim 4  which further includes an antioxidant. 
     
     
         6 . An aviation gasoline fuel formulation comprising:
 aviation gasoline;   one or more calcium sulfonates in an amount effective to limit valve seat recession in an engine using the fuel.   
     
     
         7 . The aviation gasoline fuel formulation of  claim 6  comprising at least 5 ppm of calcium petroleum sulfonates. 
     
     
         8 . The aviation gasoline fuel formulation of  claim 6  that includes calcium petroleum sulfonates in an amount effective to eliminate valve seat recession in an engine using the fuel. 
       comprising calcium petroleum sulfonates and present in the aviation gasoline at a Ca 2+  concentration of at least 10 ppm. 
     
     
         9 . The fuel formulation of  claim 6  and which further includes a detergent present in the aviation gasoline fuel formulation at a concentration effective to provide enhanced limiting of the VSR over that achieved with the calcium petroleum sulfonates. 
     
     
         10 . The fuel formulation of  claim 6  which further includes 50 to 250 ppm of the detergent polyolefin alkyl phenol alkyl amine to prevent intake coking and reduce post combustion deposits. 
     
     
         11 . The fuel formulation of  claim 10  which further includes the antioxidant 2,6-ditertiary butyl-4-methylphenol in an amount up to 20 mg/L. 
     
     
         12 . The fuel formulation of  claim 11  which further includes the anti-microbial agent 4, 4, 6-trimethyl-1, 3, 2-dioxaborinane in an amount up to 40 mg/L. 
     
     
         13 . The fuel formulation of  claim 12  which further includes a dye for quality control and color calibration for fuel safety. 
     
     
         14 . The fuel formulation of  claim 6  comprising calcium petroleum sulfonates in solution with a liquid carrier, the calcium petroleum sulfonates being present in an amount of at least 10 ppm calcium, the aviation gasoline comprising a clean-burning aviation gasoline with at least a 99.6 MON octane rating comprised of at least one C 4  to C 8  aliphatic hydrocarbon and at least one oxygenated-compound and with no more than 5% m/m aromatic hydrocarbons, and no more than 1.5% m/m amines and/or no more than 0.005% m/m organometallic compounds, which formulation upon combustion prevents valve seat recession and intake coking, and reduces post-combustion deposits. 
     
     
         15 . A method for treating VSR in a piston aircraft engine using an aviation gasoline, comprising:
 blending with the aviation gasoline an amount of calcium petroleum sulfonates to provide a concentration of 10 ppm in the aviation gasoline as used.   
     
     
         16 . The method of  claim 15  which further comprises adding a detergent to be present in an amount to provide enhanced limiting of the VSR over that achieved with the calcium petroleum sulfonates. 
     
     
         17 . The method of  claim 16  which further comprises adding the detergent to provide 50 to 250 ppm of the detergent in the aviation gasoline. 
     
     
         18 . The method of  claim 17  in which the detergent is polyolefin alkyl phenol alkyl amine. 
     
     
         19 . The method of  claim 18  and which further includes adding to the aviation gasoline an antioxidant. 
     
     
         20 . The method of  claim 19  which includes adding the antioxidant 2,6-ditertiary butyl-4-methylphenol in an amount up to 20 mg/L.