An octane-enhancing additive includes a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether, and a C4-dimer, the mixed butanol composition comprising sec-butanol and tert-butanol, and the C4-dimer comprising di-isobutylene, 2,2,4 trimethylpentane, 2,3,3 trimethylpentane, or a combination comprising at least one of the foregoing.

An octane-enhancing additive includes a mixed butanol composition, sec-butyl ether, methanol, methyl tert-butyl ether, and a C4-dimer, the mixed butanol composition comprising sec-butanol and tert-butanol, and the C4-dimer comprising di-isobutylene, 2,2,4 trimethylpentane, 2,3,3 trimethylpentane, or a combination comprising at least one of the foregoing.

Unleaded aviation gasoline. An aviation gasoline fuel blend includes an unleaded aviation gasoline base fuel, with an effective amount of selected alkyl benzenes to improve the functional engine performance to avoid harmful detonation sufficient to meet or exceed selected standards for detonation performance requirements in full scale aircraft piston spark ignition engines designed for use with Grade 100LL avgas. Suitable alkylated benzenes may include a mixture of xylene isomers. Aromatic amines, such as m-toluidine, may also be added to increase MON. Base fuels may be a high quality aviation alkylate, or may be a commercial iso-octane, or a mixture of high quality aviation alkylate enhanced by iso-octane, or by commercial iso-octane mixtures, and may include iso-pentane or butane or both iso-pentane and butane in sufficient quantity to provide appropriate vapor pressure for the final fuel blend.

Unleaded aviation gasoline. An aviation gasoline fuel blend includes an unleaded aviation gasoline base fuel, with an effective amount of selected alkyl benzenes to improve the functional engine performance to avoid harmful detonation sufficient to meet or exceed selected standards for detonation performance requirements in full scale aircraft piston spark ignition engines designed for use with Grade 100LL avgas. Suitable alkylated benzenes may include a mixture of xylene isomers. Aromatic amines, such as m-toluidine, may also be added to increase MON. Base fuels may be a high quality aviation alkylate, or may be a commercial iso-octane, or a mixture of high quality aviation alkylate enhanced by iso-octane, or by commercial iso-octane mixtures, and may include iso-pentane or butane or both iso-pentane and butane in sufficient quantity to provide appropriate vapor pressure for the final fuel blend.

The present disclosure discloses a water-hydrocarbon fuel emulsion comprising: a) 87-99% by weight of at least one hydrocarbon fuel with respect to the emulsion; b) 0.1-10% by weight of water with respect to the emulsion; c) 1-3% by weight of an emulsifying blend with respect to the emulsion; and d) 0.05-1% by weight of at least one inorganic hydride with respect to the emulsion, wherein the emulsifying blend comprises i) at least one oil-soluble nonionic surfactant; ii) at least one water-soluble nonionic surfactant; and iii) at least one ionic surfactant. The present disclosure also reveals a convenient preparation process of the water-hydrocarbon fuel emulsion.

Processes for producing high-octane-number fuel components, particularly those useful for AvGas blends, can be advantageously produced from hydrocarbon feed streams comprising C8+ aromatic hydrocarbons. Such feed streams may be produced by, among others, separation and other optional post-processing of an effluent produced from a steam cracker (e.g., a liquid feed steam cracker cracking liquid feeds such as naphtha and/or other crude fractions, a gas steam cracker cracking gas feeds such as ethane and/or propane), hydrocarbon reforming of a crude fraction or steam cracker effluent fraction, C6-C7 aromatic hydrocarbon methylation, transalkylation between C6-C7 aromatic hydrocarbons and C9+ aromatic hydrocarbons, isomerization of C8 aromatic hydrocarbons, and toluene disproportionation processes.

Processes for producing high-octane-number fuel components, particularly those useful for AvGas blends, can be advantageously produced from hydrocarbon feed streams comprising C8+ aromatic hydrocarbons. Such feed streams may be produced by, among others, separation and other optional post-processing of an effluent produced from a steam cracker (e.g., a liquid feed steam cracker cracking liquid feeds such as naphtha and/or other crude fractions, a gas steam cracker cracking gas feeds such as ethane and/or propane), hydrocarbon reforming of a crude fraction or steam cracker effluent fraction, C6-C7 aromatic hydrocarbon methylation, transalkylation between C6-C7 aromatic hydrocarbons and C9+ aromatic hydrocarbons, isomerization of C8 aromatic hydrocarbons, and toluene disproportionation processes.

Methods for preparing an octane-boosting fuel additive having the following formula: are provided. In a first aspect, the method may comprise carrying out the following reaction: (i), (ii) In a second aspect, the method may comprise: (1) preparing the fuel additive; and (2) purifying the product of step (1) by: (a) dissolving the fuel additive in a water-insoluble solvent to form a solution; (b) washing the solution with water; and (c) separating the fuel additive product from the water-insoluble solvent using distillation. Steps (i) and (1) of the methods are carried out in the presence of butylated hydroxytoluene. ##STR00001##

Methods for preparing an octane-boosting fuel additive having the following formula: are provided. In a first aspect, the method may comprise carrying out the following reaction: (i), (ii) In a second aspect, the method may comprise: (1) preparing the fuel additive; and (2) purifying the product of step (1) by: (a) dissolving the fuel additive in a water-insoluble solvent to form a solution; (b) washing the solution with water; and (c) separating the fuel additive product from the water-insoluble solvent using distillation. Steps (i) and (1) of the methods are carried out in the presence of butylated hydroxytoluene. ##STR00001##

A fuel mixture includes a fuel and an octane overboosting additive. Methods of preparing and using such mixtures are disclosed. In particular, the mixture includes an additive that provides octane boosting that produces peak octane at or before a 40% blend and produces at least a 1 octane boost at 10% volume of additive to fuel mixture.