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.

Fuel compositions comprising at least 10 ppm by weight of a succinic ester acid amine salt or a succinamide acid amine salt (both “amine salt(s)”). The amine salt is the product of (a) and (b), wherein: (a) is an amine with (i) at least one tertiary nitrogen and (ii) at least one hydroxy alkyl functional group and/or at least one secondary amine functionality; and (b) is a hydrocarbyl-substituted succinic acid/or anhydride. The molar ratio of (a) to (b) may range from 3:1 to 1:3. The fuel composition may comprise gasoline, oxygenate, or mixtures thereof. Methods and uses for reducing carbonaceous deposits in an engine comprising operating the engine using the fuel composition having an amine salt therein.

The present invention relates to a composition for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams, the composition comprising an oxazolidine compound and a synergistic additive.

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.

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##

The present disclosure provides a fuel composition that includes hydrocarbon-based fuel boiling in the gasoline or diesel range; an amine-based detergent given by formula R.sub.1—O—(CH.sub.2).sub.m—NHR.sub.2, wherein the additive is present in about 10 ppm to about 750 ppm by weight based on total weight of the fuel composition; wherein R.sub.1 is a hydrocarbylgroup having 8 to 20 carbons, R.sub.2 is hydrogen or (CH.sub.2).sub.nNH.sub.2 moiety, and wherein m, n are independently integers having a value of 3 or greater; and one or more nitrogen-containing detergent.

The present disclosure provides a fuel composition that includes hydrocarbon-based fuel boiling in the gasoline or diesel range; an amine-based detergent given by formula R.sub.1—O—(CH.sub.2).sub.m—NHR.sub.2, wherein the additive is present in about 10 ppm to about 750 ppm by weight based on total weight of the fuel composition; wherein R.sub.1 is a hydrocarbylgroup having 8 to 20 carbons, R.sub.2 is hydrogen or (CH.sub.2).sub.nNH.sub.2 moiety, and wherein m, n are independently integers having a value of 3 or greater; and one or more nitrogen-containing detergent.

The present disclosure relates to a method of reducing regeneration frequency of a diesel particulate filter in a vehicle combusting diesel fuel. The method includes combusting a diesel fuel in a vehicle engine having a diesel particulate filter and wherein the diesel particulate filter requires regeneration thereof. The diesel fuel has less than about 50 ppmw of sulfur and one or more select additives to reduce a measured frequency of regeneration of the diesel particulate filter.

A quaternary ammonium salt of formula (I): (I) where in X is a linking group; Y is O, NH or NR.sup.1 wherein R.sup.1 is H or an optionally substituted hydrocarbyl group; Q.sup.+ is a moiety that includes a quaternary ammonium cation; A.sup.− is an anion; R.sup.2 is an optionally substituted alkylene group; R.sup.3 is hydrogen or an optionally substituted hydrocarbyl group; and n is 0 or a positive integer; provided that n is not 0 when R.sup.3 is hydrogen. ##STR00001##

A quaternary ammonium compound of formula (I): (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, R5 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 R5 is hydrogen. ##STR00001##