Composition and method for enhancing the stability of jet fuels

Abstract

A composition comprising about 5 to about 95 weight percent of one or more dispersants selected from the group consisting of polyalkenyl substituted succinic acid esters and α-olefin maleic anhydride copolymers and mixtures thereof and about 0.1 to about 25 weight percent of one or more metal deactivators, method of using the composition to stabilize jet fuels and jet fuels comprising the composition.

1 . A composition comprising about 5 to about 95 weight percent of one or more dispersants selected from the group consisting of polyalkenyl substituted succinic acid esters and α-olefin maleic anhydride copolymers and mixtures thereof and about 0.1 to about 25 weight percent of one or more metal deactivators.  
   
   
       2 . The composition of  claim 1  wherein the polyalkenyl substituted succinic acid esters are selected from the group consisting of polyisobutenyl succinic acid esters.  
   
   
       3 . The composition of  claim 2  wherein the polyisobutenyl substituted succinic acid esters are selected from the group consisting of polyisobutenyl substituted succinic acid esters of monohydric alcohols, polyhydric alcohols, phenols and naphthols.  
   
   
       4 . The composition of  claim 3  wherein the polyalkenyl substituted succinic acid esters are selected from the group consisting of polyisobutenyl pentaerythritol succinates.  
   
   
       5 . The composition of  claim 1  wherein the α-olefin maleic anhydride copolymer is composed of one or more α-olefins having about 10 to about 36 carbon atoms and maleic anhydride wherein the weight ratio of the α-olefin to maleic anhydride is about 1:1 to about 5:1.  
   
   
       6 . The composition of  claim 5  wherein the molecular weight of the copolymer is from about 5,000 to 100,000.  
   
   
       7 . The composition of  claim 6  wherein the α-olefins have from about 24 to about 28 carbon atoms.  
   
   
       8 . The composition of  claim 7  wherein the α-olefin-maleic anhydride copolymers have a molar ratio of α-alpha olefins to maleic anhydride of about 1:1 to about 5:1.  
   
   
       9 . The composition of  claim 8  wherein the α-olefin-maleic anhydride copolymers have an average molecular weight of about 5,000 to about 20,000.  
   
   
       10 . The composition of  claim 9  wherein the α-olefin-maleic anhydride copolymers have a weight ratio of α-olefins to maleic anhydride of from about 1:1 to about 4:1.  
   
   
       11 . The composition of  claim 1  wherein the metal deactivators are selected from N,N′-salicylidene-1,2-propanediamine, N,N-disubstituted aminomethyl-1,2,4- triazoles, alkyl phenol-monoethylene diamine and polyethylene polyamine-formaldehyde resin polymers, and mixtures thereof.  
   
   
       12 . The composition of  claim 11  wherein the metal deactivator is N,N′-salicylidene-1,2-propanediamine.  
   
   
       13 . The composition of  claim 1  comprising about 10 to about 60 weight percent of one or more dispersants selected from the group consisting of polyalkenyl substituted succinic acid esters and α-olefin maleic anhydride copolymers and mixtures thereof and about 1.0 to about 20 weight percent of one or more metal deactivators.  
   
   
       14 . The composition of  claim 1  comprising about 10 to about 40 weight percent of one or more dispersants selected from the group consisting of polyalkenyl substituted succinic acid esters and α-olefin maleic anhydride copolymers and mixtures thereof and about 5.0 to about 10 weight percent of one or more metal deactivators.  
   
   
       15 . The composition of  claim 1  further comprising one or more hydrocarbon solvents.  
   
   
       16 . The composition of  claim 1  further comprising one or more antioxidants.  
   
   
       17 . A method of stabilizing jet fuel comprising adding to the fuel an effective stabilizing amount of the composition of  claim 1 .  
   
   
       18 . The method of  claim 17  wherein the effective stabilizing amount is about 0.1 to about 5,000 parts per million.  
   
   
       19 . The method of  claim 17  wherein the effective stabilizing amount is about 1 to about 1,000 parts per million.  
   
   
       20 . A stabilized jet fuel comprising jet fuel and an effective stabilizing amount of the composition of  claim 1.