High-octane, unleaded aviation fuel compositions

Abstract

In some embodiments, a composition includes isooctane in an amount of about 81 vol % to about 87 vol %. The composition further includes a dialkyl ether compound in an amount of about 10 vol % to about 18 vol %, wherein the dialkyl ether compound is selected from the group consisting of ethyl-tert-butyl-ether, methyl-tert-butyl-ether, and combinations thereof. The composition further includes methanol in an amount of about 1.5 vol % or less. The total oxygen content present in the composition comprises about 3.2 wt % or less of the composition. The figures illustrate comparative testing including compositions of the disclosure.

1 . A composition, comprising:
 about 81 vol % to about 87 vol % of isooctane;   about 10 vol % to about 18 vol % of a dialkyl ether compound, wherein the dialkyl ether compound is selected from ethyl-tert-butyl-ether, methyl-tert-butyl-ether, and combinations thereof; and   about 1.5 vol % or less of methanol;   about 1.8-3.2 wt % total oxygen content as determined in accordance to ASTM D4815.   
     
     
         2 . The composition of  claim 1 , wherein the composition further comprises a manganese containing compound. 
     
     
         3 . The composition of  claim 2 , wherein the composition comprises about 5 mg manganese per liter (mg Mn/L) to about 25 mg Mn/L of the manganese containing compound of. 
     
     
         4 . The composition of  claim 2 , wherein the manganese containing compound comprises methylcyclopentadienyl manganese tricarbonyl (MMT). 
     
     
         5 . The composition of  claim 4 , wherein the composition comprises about 5 mg manganese per liter (mg Mn/L) to about 25 mg Mn/L of MMT. 
     
     
         6 . The composition of  claim 2 , wherein the composition further comprises an oil-soluble alkanoic acid. 
     
     
         7 . The composition of  claim 6 , wherein the oil-soluble alkanoic acid is selected from 2-ethylhexanoic acid, 2-methylhexanoic acid, 3-ethylhexanoic acid, 3-methylhexanoic acid, 4-methylhexanoic acid, 4-ethylpentanoic acid, 4-ethylpentanoic acid, and combinations thereof. 
     
     
         8 . The composition of  claim 6 , wherein the composition comprises about one part by weight of the oil-soluble alkanoic acid per fifteen parts by weight manganese to about one part by weight alkanoic acid per one part by weight manganese. 
     
     
         9 . The composition of  claim 1 , wherein the composition further includes an oil-soluble valve seat recession additive (VSRA). 
     
     
         10 . The composition of  claim 9 , wherein the oil-soluble VSRA is selected from potassium 2-ethylhexyl hexanoate, sodium 2-ethylhexyl hexanoate, and combinations thereof. 
     
     
         11 . The composition of  claim 10 , wherein the oil-soluble VSRA comprises about 10 mg potassium per liter (mg K/L) to about 20 mg K/L potassium 2-ethylhexyl hexanoate. 
     
     
         12 . The composition of  claim 1 , comprising about 0.5 vol % to about 1 vol % of methanol. 
     
     
         13 . The composition of  claim 1 , comprising about 12 vol % to about 15 vol % of the dialkyl ether compound. 
     
     
         14 . The composition of  claim 1 , comprising about 81 vol % to about 84 vol % of the isooctane. 
     
     
         15 . The composition of  claim 1 , wherein the composition has a motor octane number (MON; as determined in accordance to ASTM D2700) greater than 99.6. 
     
     
         16 . The composition of  claim 1 , wherein the composition has a motor octane number (MON; as determined in accordance to ASTM D2700) of about 99.6 to about 105.6. 
     
     
         17 . The composition of  claim 2 , wherein the composition has a motor octane number (MON; as determined in accordance to ASTM D2700) greater than 99.6. 
     
     
         18 . The composition of  claim 1 , wherein the composition is substantially free from aromatic compounds and isopentane. 
     
     
         19 . A composition, consisting essentially of:
 about 81 vol % to about 87 vol % of isooctane;   about 10 vol % to about 18 vol % of a dialkyl ether compound, wherein the dialkyl ether compound is selected from ethyl-tert-butyl-ether, methyl-tert-butyl-ether, and combinations thereof; and   about 1.5 vol % or less of methanol;   about 1.8-3.2 wt % total oxygen content as determined in accordance to ASTM D4815.   
     
     
         20 . A composition, consisting of:
 about 81 vol % to about 87 vol % of isooctane;   about 10 vol % to about 18 vol % of a dialkyl ether compound, wherein the dialkyl ether compound is selected from ethyl-tert-butyl-ether, methyl-tert-butyl-ether, and combinations thereof; and   about 1.5 vol % or less of methanol;   about 1.8-3.2 wt % total oxygen content as determined in accordance to ASTM D4815.