A synergistic fuel additive composition, the composition having a sulfur additive; and a non-sulfur containing additive, wherein the ratio of the sulfur additive to the non-sulfur additive is about 1:1 to about 1:100. A method of reducing sulfur content in a fuel composition, the method provides adding a fuel additive to a fuel composition, the fuel composition having a silver corrosion inhibitor, the fuel additive having: a sulfur additive and a non-sulfur containing additive, wherein the ratio of the sulfur additive to the non-sulfur containing additive is from about 1:1 to about 1:100; wherein the fuel additive provides less than 5 ppm of sulfur addition to the fuel composition; and wherein the fuel composition does not cause silver corrosion.

A synergistic fuel additive composition, the composition having a sulfur additive; and a non-sulfur containing additive, wherein the ratio of the sulfur additive to the non-sulfur additive is about 1:1 to about 1:100. A method of reducing sulfur content in a fuel composition, the method provides adding a fuel additive to a fuel composition, the fuel composition having a silver corrosion inhibitor, the fuel additive having: a sulfur additive and a non-sulfur containing additive, wherein the ratio of the sulfur additive to the non-sulfur containing additive is from about 1:1 to about 1:100; wherein the fuel additive provides less than 5 ppm of sulfur addition to the fuel composition; and wherein the fuel composition does not cause silver corrosion.

A method of demulsifying an emulsion with an ionic liquid having a nitrogen or phosphorus cation.

A method of demulsifying an emulsion with an ionic liquid having a nitrogen or phosphorus cation.

Lubricity additives for hydrocarbon fuels are provided according to formula I:

##STR00001##

wherein n is 1 or 0; each Q is independently selected from oxygen and sulfur; each R is independently selected from C8-C60 alkenyl groups which are substituted or unsubstituted; and L is a linking group comprising 0-20 carbons which may be substituted or unsubstituted and may optionally comprise catenary heteroatoms. Fuel mixtures comprising a hydrocarbon fuel; and a lubricity additive according to the present disclosure are also provided. Methods of making lubricity additives comprise reacting an alkenyl succinic anhydrides (ASA's) with certain bisamides or bisthioamides.

Lubricity additives for hydrocarbon fuels are provided according to formula I:

##STR00001##

wherein n is 1 or 0; each Q is independently selected from oxygen and sulfur; each R is independently selected from C8-C60 alkenyl groups which are substituted or unsubstituted; and L is a linking group comprising 0-20 carbons which may be substituted or unsubstituted and may optionally comprise catenary heteroatoms. Fuel mixtures comprising a hydrocarbon fuel; and a lubricity additive according to the present disclosure are also provided. Methods of making lubricity additives comprise reacting an alkenyl succinic anhydrides (ASA's) with certain bisamides or bisthioamides.

The capacity of a crude oil to solvate and/or disperse asphaltenes is increased by providing a crude oil which includes an additive comprising (i) a poly(butylenyl)bezene sulphonic acid; or, (ii) a poly(propylenyl)benzene sulphonic acid; or, (iii) a combination of a poly(butylenyl)bezene sulphonic acid and a poly(propylenyl)benzene sulphonic acid.

The capacity of a crude oil to solvate and/or disperse asphaltenes is increased by providing a crude oil which includes an additive comprising (i) a poly(butylenyl)bezene sulphonic acid; or, (ii) a poly(propylenyl)benzene sulphonic acid; or, (iii) a combination of a poly(butylenyl)bezene sulphonic acid and a poly(propylenyl)benzene sulphonic acid.

A quaternary ammonium compound of formula (I): wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group, X is a linking group, R.sup.4 is an optionally substituted alkylene group, R.sup.5 is hydrogen or an optionally substituted alkyl, alkenyl or aryl group, and n is 0 or a positive integer, provided that n is not 0 when R.sup.5 is hydrogen. ##STR00001##

A quaternary ammonium compound of formula (I): wherein R.sup.0, R.sup.1, R.sup.2 and R.sup.3 is each independently an optionally substituted hydrocarbyl group, X is a linking group, R.sup.4 is an optionally substituted alkylene group, R.sup.5 is hydrogen or an optionally substituted alkyl, alkenyl or aryl group, and n is 0 or a positive integer, provided that n is not 0 when R.sup.5 is hydrogen. ##STR00001##