A composition is provided that includes a carbonaceous feed material to be combusted to generate an off-gas and an identifier. The identifier is associated with a predetermined composition, characteristic or property of the feed material or the off-gas.

Method of marking a hydrocarbon liquid includes adding to the liquid, a tracer compound of Formula I or II: ##STR00001##
wherein at least one of R.sup.1-R.sup.6 in Formula I and at least one of R.sup.7-R.sup.14 in Formula II is selected from: i. a bromine or fluorine atom; ii. a partially or fully halogenated alkyl group; iii. a branched or cyclic C.sub.4-C.sub.20 alkyl group; iv. an aliphatic substituent linking two positions selected from R.sup.1-R.sup.6 in Formula I to one another or two positions selected from R.sup.7-R.sup.14 in Formula II to one another; or v. a phenyl group substituted with a halogen atom, an aliphatic group or halogenated aliphatic group and none of R.sup.1-R.sup.6 and none of R.sup.7-R.sup.14 being a sulphonate group or COOR.sup.15, where R.sup.15 represents H, C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkenyl, C.sub.2-C.sub.20 alkynyl, C.sub.3-C.sub.15 cycloalkyl or aryl.

A marking method which is a method of marking a product having a distillation range is disclosed. The method comprises the step of adding to said product a first marker, a second marker and optionally one or more further markers. Each marker has a distillation range including a minimum boiling point (Min BP), a maximum boiling point (Max BP) and a maximum distillation boiling point (Max DBP) which is the temperature at which the maximum volume of the marker distils. Each marker has a different distillation range from each other marker and at least one marker has a Max DBP which is within the distillation range of the product. The first marker has a distillation range in the marked product which extends over the whole of the product distillation range.

The present invention relates to markers for liquids that can be used to authenticate the origin and genuineness of a liquid, preferably a bulk liquid such as fuel. For this purpose, the present invention teaches the use of a polymer capable of forming a semiconducting polymer particle (pdot) in the liquid in small amounts. The invention encompasses a liquid comprising a) a polymer that is capable of forming a semiconducting polymer particle (pdot), the concentration of the polymer being 10 ppm by weight or less, and b) an organic substance in an amount of 90% by weight or more. The invention furthermore envisages the use of such a polymer as an authenticating marker in a liquid, preferably a fuel, and a method for authenticating the genuineness and/or origin of a liquid comprising a polymer capable of forming a semiconducting polymer particle (pdot), comprising the steps i. concentrating, isolating and/or extracting the polymer capable of forming a semiconducting polymer particle (pdot); ii. aggregating the polymer or the polymer obtained in Step i. to form semiconducting polymer dots (pdots); iii. irradiating the formed pdots with electromagnetic radiation capable of exciting the pdots to emit electromagnetic radiation by fluorescence and/or phosphorescence, and iv. observing the electromagnetic radiation emitted in response to the exciting irradiation of step iii.

A fuel additive for fuel formulations comprising calcium sulfonates in an amount effective to limit or eliminate valve seat recession in engines utilizing such fuel formulations. The fuel additive may also include a detergent, particularly in an amount to enhance the VSR limiting effect of the calcium sulfonates. Also included are fuel formulations containing calcium sulfonates in a concentration effective to limit vale seat recession in engines utilizing the fuel formulations. Methods for treating VSR in piston engines are also provided.

The invention provides a method of marking a hydrophobic medium with a nucleic acid marker, the method includes: providing a trialkylammonium salt of the nucleic acid marker, a tetraalkylphosphonium salt of the nucleic acid marker or a tetraarylphosphonium salt of the nucleic acid marker; and incorporating the trialkylammonium salt of the nucleic acid marker, the tetraalkylphosphonium salt of the nucleic acid marker or the tetraarylphosphonium salt of the nucleic acid marker into the hydrophobic medium. The hydrophobic medium can be authenticated after shipping or recovery from the stream of commerce by detecting the nucleic acid marker in a sample of the hydrophobic medium.

A method for marking a petroleum hydrocarbon or a liquid biologically derived fuel by adding to the petroleum hydrocarbon or liquid biologically derived fuel a compound having formula C{Ph(R.sup.1).sub.i(OR.sup.2).sub.j}.sub.2{Ph(R.sup.3).sub.m(OR.sup.4).sub.n}{Ph(R.sup.5).sub.o(OR.sup.6).sub.p}, wherein Ph represents a benzene ring, R.sup.1, R.sup.3 and R.sup.5 independently are C.sub.1-C.sub.18 alkyl or C.sub.4-C.sub.18 heteroalkyl; R.sup.2, R.sup.4 and R.sup.6 independently are C.sub.1-C.sub.18 alkyl or C.sub.4-C.sub.18 heteroalkyl, i, j, m, n, o and p independently are zero, one or two. Each compound having formula C{Ph(R.sup.1).sub.i(OR.sup.2).sub.j}.sub.2{Ph(R.sup.3).sub.m(OR.sup.4).sub.n}{Ph(R.sup.5).sub.o(OR.sup.6).sub.p} is present at a level from 0.01 ppm to 20 ppm.

The disclosure provides dyes for marking hydrocarbon compositions. More particularly, the disclosure relates to non-mutagenic dyes for marking hydrocarbon compositions.

The present disclosure provides methods for identifying a hydrocarbon fuel, such as the presence and/or amounts of marker compounds having a fluorescence intensity and, through correlation, the presence and/or amounts of additive package(s) within the hydrocarbon fuel. The methods include obtaining a sample of a hydrocarbon fuel including a marker compound having fluorescence, combining the hydrocarbon fuel with water, and subjecting a water phase thereof to light for observing fluorescence.

Systems and methods for chemically marking dry natural gas and other fluids are provided. In an example, at least 1 ppbv of a first isotopologue of a first hydrocarbon is added to the dry natural gas as a chemical marker. The first isotopologue has at least three deuterium atoms.