The use as a piston varnish controlling additive in a fuel composition for a spark-ignition internal combustion engine or a compression-ignition gasoline internal combustion engine of a combination of: a. a hydrocarbyl-substituted aromatic compound; and b. a polyalkylene amine. The fuel composition may also be used for controlling power output, fuel economy, engine wear, piston ring sticking and blow-by.

A quaternary ammonium compound of formula (I): ##STR00001##
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.

A quaternary ammonium compound of formula (I): ##STR00001##
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.

Disclosed herein are antifouling compositions including a combination of one or more dispersant polymers and one or more inhibitors, the one or more dispersant polymers including the polymerized residues of one or more α-olefins and maleic anhydride, further wherein the maleic anhydride residues are reacted with a primary amine; and the one or more inhibitors including a functionalized p-phenylene diamine. Concentrates of the antifouling compositions in solvents are stable and pourable at temperatures of 0° C. to −40° C. The antifouling compositions are added to a petroleum product to form a treated petroleum product, wherein fouling by the treated petroleum product is reduced and a stable dispersion is formed over a wide range of processing conditions.

Disclosed herein are antifouling compositions including a combination of one or more dispersant polymers and one or more inhibitors, the one or more dispersant polymers including the polymerized residues of one or more α-olefins and maleic anhydride, further wherein the maleic anhydride residues are reacted with a primary amine; and the one or more inhibitors including a functionalized p-phenylene diamine. Concentrates of the antifouling compositions in solvents are stable and pourable at temperatures of 0° C. to −40° C. The antifouling compositions are added to a petroleum product to form a treated petroleum product, wherein fouling by the treated petroleum product is reduced and a stable dispersion is formed over a wide range of processing conditions.

A process of removing at least one metal contaminant, such as copper, from a fluid hydrocarbon, for example, crude oil or a liquid hydrocarbon fuel, such as an aviation fuel. The process involves contacting the metal-contaminated fluid hydrocarbon with a sorbent selected from graphene oxide or a functionalized graphene oxide, particularly, a graphene oxide treated with a polycarboxylic acid, such as a saccharide polycarboxylic acid or a salt thereof, examples of which include alginic acid and Group IA and IIA salts thereof. The process removes greater than 99 percent of the metal contaminant without reducing concentrations of advantageous fuel additives, such as, antioxidants, icing inhibitors and corrosion inhibitors. Also described are a purified fluid hydrocarbon composition and a metal contaminant filter system.

A process of removing at least one metal contaminant, such as copper, from a fluid hydrocarbon, for example, crude oil or a liquid hydrocarbon fuel, such as an aviation fuel. The process involves contacting the metal-contaminated fluid hydrocarbon with a sorbent selected from graphene oxide or a functionalized graphene oxide, particularly, a graphene oxide treated with a polycarboxylic acid, such as a saccharide polycarboxylic acid or a salt thereof, examples of which include alginic acid and Group IA and IIA salts thereof. The process removes greater than 99 percent of the metal contaminant without reducing concentrations of advantageous fuel additives, such as, antioxidants, icing inhibitors and corrosion inhibitors. Also described are a purified fluid hydrocarbon composition and a metal contaminant filter system.

The subject matter of the present invention is a fuel composition which comprises —at least 85% by weight of one or more fractions of hydrocarbons having a distillation range within the range extending from 100 to 400° C. and having a paraffin content greater than or equal to 90% by weight; —at least a first additive consisting of a particular quaternary ammonium salt; and —at least a second additive consisting of a phenolic antioxidant. The subject matter of the invention is also the use of a composition of additives comprising said first and second additives, for improving at least one property of a paraffin-rich fuel composition.

Use of a wax anti-settling agent (WASA), in an automotive fuel composition, for the purpose of improving the acceleration performance of an internal combustion engine into which the fuel composition is or is intended to be introduced or of a vehicle powered by such an engine.

Use of a wax anti-settling agent (WASA), in an automotive fuel composition, for the purpose of improving the acceleration performance of an internal combustion engine into which the fuel composition is or is intended to be introduced or of a vehicle powered by such an engine.