High octane unleaded aviation gasolines

Abstract

Novel aviation fuel compositions contain a substantially positive or synergistic combination of an alkyl tertiary butyl ether, an aromatic amine and, optionally, a manganese component. The basefuel containing the additive combination may be a wide boiling range alkylate basefuel.

What is claimed is:  
     
         1 . An unleaded aviation fuel composition comprising: 
 (1) an unleaded basefuel and    (2) a substantially positive or synergistic combination of 
 (a) an alkyl tertiary butyl ether, and  
 (b) an aromatic amine having the formula  
                     
 wherein R 1 , R 2 , R 3  and R 4  are hydrogen or a C 1 -C 5  alkyl group.  
   
     
     
         2 . The composition of  claim 1 , wherein the basefuel is a wide boiling range alkylate.  
     
     
         3 . The composition of  claim 1 , wherein the alkyl tertiary butyl ether is methyl tertiary butyl ether.  
     
     
         4 . The composition of  claim 1 , wherein the alkyl tertiary butyl ether is ethyl tertiary butyl ether.  
     
     
         5 . The composition of  claim 1 , wherein the aromatic amine is analine.  
     
     
         6 . The composition of  claim 1 , wherein R 1 , R 2 , R 3  or R 4  is methyl.  
     
     
         7 . The composition of  claim 1 , wherein the aromatic amine is n-methyl aniline, n-ethyl aniline, m-toluidine, p-toluidine, 3,5-dimethyl aniline, 4-ethyl aniline or 4-n-butyl aniline.  
     
     
         8 . The composition of  claim 1 , wherein the composition further comprises manganese.  
     
     
         9 . The composition of  claim 8 , wherein the manganese is provided by methyl cyclopentadienyl manganese tricarbonyl.  
     
     
         10 . The composition of  claim 1 , wherein the composition comprises 0.1 to 40 vol % alkyl tertiary butyl ether, 0.1 to 10 wt % aromatic amine and 0 to 0.5 g manganese.  
     
     
         11 . The composition of  claim 1 , wherein the composition comprises 15 to 32 vol % methyl tertiary butyl ether, 1. 5 to 6 wt % aniline and 0 to 0.1 g manganese.  
     
     
         12 . The composition of  claim 1 , wherein the composition comprises 15 to 32 vol % ethyl tortiary butyl ether, 1.5 to 6 wt % aniline and 0 to 0.1 g managanese.  
     
     
         13 . The composition of  claim 1 , wherein the MON of the composition is at least 94.  
     
     
         14 . The composition of  claim 1 , wherein the MON of the composition is at least 96.  
     
     
         15 . The composition of  claim 1 , wherein the MON of the composition is at least 98.  
     
     
         16 . A method for preparing an unleaded aviation fuel composition comprising: 
 (1) selecting a substantially positive or synergistic combination of 
 (a) an alkyl tertiary butyl ether, and  
 (b) an aromatic amine having the formula  
                     
 wherein R 1 , R 2 , R 3  and R 4  are hydrogen or a Cl-C 5  alkyl group, and  
   (2) combining the combination selected in step (1) with an unleaded basefuel.    
     
     
         17 . The method of  claim 16 , wherein the basefuel is a wide boiling range alkylate.  
     
     
         18 . The method of  claim 16 , wherein the alkyl tertiary butyl ether is methyl tertiary butyl ether.  
     
     
         19 . The method of  claim 16 , wherein the alkyl tertiary butyl ether is ethyl tertiary butyl ether.  
     
     
         20 . The method of  claim 16 , wherein the aromatic amine is analine.  
     
     
         21 . The method of  claim 16 , wherein R 1 , R 2 , R 3  or R 4  is methyl.  
     
     
         22 . The method of  claim 16 , wherein the aromatic amine is n-methyl aniline, n-ethyl aniline, m-toluidine, p-toluidine, 3,5-dimethyl aniline, 4-ethyl aniline or 4-n-butyl aniline.  
     
     
         23 . The method of  claim 16 , wherein the composition further comprises manganese.  
     
     
         24 . The method of  claim 23 , wherein the manganese is provided by methyl cyclopentadienyl manganese tricarbonyl.  
     
     
         25 . The method of  claim 16 , wherein the composition comprises 0.1 to 40 vol % alkyl tertiary butyl ether, 0.1 to 10 wt % aromatic amine and 0 to 0.5 g manganese.  
     
     
         26 . The method of  claim 16 , wherein the composition comprises 15 to 32 vol % methyl tertiary butyl ether, 1.5 to 6 wt % aniline and 0 to 0.1 g manganese.  
     
     
         27 . The method of  claim 16 , wherein the composition comprises 15 to 32 vol % ethyl tortiary butyl ether, 1.5 to 6 wt % aniline and 0 to 0.1 g maganese.  
     
     
         28 . The method of  claim 16 , wherein the MON of the composition is at least 94.  
     
     
         29 . The method of  claim 16 , wherein the MON of the composition is at least 96.  
     
     
         30 . The method of  claim 16 , wherein the MON of the composition is at least 98.  
     
     
         31 . A method for preparing a composition comprising combining a wide boiling range alkylate basefuel and a synergistic amount of all tertiary butyl ether, an aromatic amine and manganese sufficient to raise the motor octane number of the composition to at least 94.  
     
     
         32 . The method of  claim 31 , wherein the synergistic amount is sufficient to raise the motor octane number of the composition to at least 96.  
     
     
         33 . The method of  claim 31 , wherein the synergistic amount is sufficient to raise the motor octane number of the composition to at least 98.  
     
     
         34 . A method for operating a piston driven aircraft which comprises operating the aircraft engine with the aviation fuel composition of  claim 1 .  
     
     
         35 . A method for operating a piston driven aircraft which comprises operating the aircraft engine with the aviation fuel composition made by the method of claim  29 .