Abstract: Diheterocyclo diazene dicarboxamides have been found to effectively reduce the ignition delay and/or as effective cetane number improvers in diesel fuels and is suitable for use in modern engines.

Abstract: Mercaptans and/or hydrogen sulfide (H2S) in hydrocarbons, naphthas, gasolines, and the like may be scavenged therefrom by being brought into intimate contact with a mercaptan scavenger formulation containing at least one disubstituted azodicarboxylate of the formula R1OOCN?NCOOR2, where R1 and R2 are independently alkyl groups, alkenyl groups and aromatic groups having from 1 to 18 carbon atoms. These scavengers remove mercaptans and/or H2S from hydrocarbons faster than many conventional mercaptan scavengers. An effective scavenging amount of disubstituted azodicarboxylate in the hydrocarbon fluid ranges from about 5 to about 20 parts by weight based on 1 part as sulfur of mercaptan and/or H2S.

Abstract: Products having the general formula A, particularly useful as non-coloring markers in a process for tagging mineral oils, petroleum derivatives in general and solvents. A method is also described for synthesizing the products by resorting to a classical diazocoupling reaction between a derivative of an aromatic amine and a coupling agent, preferably a functionalized ester. The invention also relates to the use of these tagging and dyeing molecules and mixtures which comprise them. In particular, the mixtures comprise the markers according to the invention and the markers and/or dyes classically used in the petroleum sector.

Abstract: The invention concerns a multifunctional additive enabling fuels to be operable in cold conditions, consisting of copolymers of at least a dicarboxylic compound with at least an olefin, and whereon are grafted nitrogenous functions and/or esters of general formula (1) wherein: R1 and R2, and R4 and R5, R3 and R6 are hydrogen or alkyl radicals, and x is selected among the amine salts and N-alkylpolyalkylenepolyamines and their monohydroxylated and polyhydroxylated derivatives, N-alkylpolyalkylenepolyamine alkylesters and esters, and alkylamines and N-alkylpolyalkylenepolyamines.

Abstract: An emergency fuel for an internal combustion engine comprises a hydrocarbon solvent having a flash point of at least 100° F. (such as about 65-75% paraffins and about 25-35% naphthenes, or about 75-85% paraffins and about 15-25% of C7 or higher alcohols, or an aromatic solvent, or an naphthalene-depleted aromatic solvent) and a cold starting additive. The cold starting additive may be provided in an amount of less than 5,000 ppm, preferably between about 1 ppm and 150 ppm. The cold starting additive is preferably selected from peroxides, azo compounds, cyano compounds, cetane improvers, or combinations of these compounds. When the emergency fuel is added to a cold engine, including one substantially at room temperature, the engine may be easily started.

Abstract: An emergency fuel for an internal combustion engine comprises a hydrocarbon solvent having a flash point of at least 100° F. (such as about 65-75% paraffins and about 25-35% naphthenes, or about 75-85% paraffins and about 15-25% of C7 or higher alcohols, or an aromatic solvent, or an naphthalene-depleted aromatic solvent) and a cold starting additive. The cold starting additive may be provided in an amount of less than 5,000 ppm, preferably between about 1 ppm and 150 ppm. The cold starting additive is preferably selected from peroxides, azo compounds, cyano compounds, cetane improvers, or combinations of these compounds. When the emergency fuel is added to a cold engine, including one substantially at room temperature, the engine may be easily started.

Abstract: An emergency fuel for an internal combustion engine comprises a hydrocarbon solvent having a flash point of at least 100° F. (such as about 65-75% paraffins and about 25-35% naphthenes, or about 75-85% paraffins and about 15-25% of C7 or higher alcohols, or an aromatic solvent, or an naphthalene-depleted aromatic solvent) and a cold starting additive. The cold starting additive may be provided in an amount of less than 5,000 ppm, preferably between about 1 ppm and 150 ppm. The cold starting additive is preferably selected from peroxides, azo compounds, cyano compounds, cetane improvers, or combinations of these compounds. When the emergency fuel is added to a cold engine, including one substantially at room temperature, the engine may be easily started.

Abstract: Colorless markers for petroleum products and methods and composition for detecting them.

Abstract: Amino azoic dyes having general formula (I) wherein: R1 is linear or branched alkyl having from 6 to 20 carbon atoms; R2 and R3 are independently H, CH3, C2H5, OCH3 or OC2H5; R4 and R5 are independently H, CH3 or C2H5; X is H or OH; and Y is hydrogen or poly-isopropxy chain (IA) wherein n is between 1 and 4. They are used as markers of oil distillation product.

Abstract: This invention provides a method for invisibly tagging, for subsequent identification purposes, various liquid petroleum hydrocarbons, such as crude oil, diesel fuel, heating oil, kerosene, lubricating oils, waxes, jet fuel, and in particular gasoline, remarkably using visible dyes by incorporating therein one or more visible dyes at minute levels such that they cannot be visually detected by the human eye. Visible dyes which have high solubility in petroleum hydrocarbons and maximum absorption in the 550-700 nm visible wavelength range are used to impart such invisible markings. The visible dyes, although employed at non-visible levels, are still capable of detection in a relatively quick and simple manner which requires minimal instrumentation, creates no waste products for disposal, and gives true quantitative results of dye concentrations in the field.

Abstract: Azo dyes of the formula ##STR1## where the ring A may be benzofused,n is 0 or 1, and R.sup.1 -R.sup.8 are as defined,as pH-dependent markers for hydrocarbons, hydrocarbons containing the above-mentioned azo dyes, and a method for detecting these azo dyes in hydrocarbons.

Abstract: Leakage in a heat exchanger between two liquids which are in indirect heat exchange relationship is detected by marking one of the two liquids with a colorless chemical marker and detecting it in the second liquid by extraction and conversion to a colored material. The heat exchanger liquids are preferably organic liquids which are immiscible with water. The marker is detected in a heat exchanger liquid by extraction of the marker followed by chemical conversion of the marker to a colored material that can be detected visually. Aminoalkylnaphthalenes are suitable markers which can be extracted by an acidic aqueous solution and converted to a colored material by reaction with a diazotized aromatic amine. Phenylazoalkylphenol derivatives are also suitable markers which can be extracted and simultaneously converted to a colored material with a detection reagent which is comprised of water and a water-soluble amine.

Abstract: Compounds known as "solid dispersed dyes" are synthesized in a two-phase system from which they disproportionate into a water-immiscible solvent phase, providing marker solutions. Marker solution is added to a petroleum fuel to introduce the compound thereto in dissolved form. Subsequently, extraction of the compound with acidic aqueous solution produces a chromophoric reaction which indicates presence of the compound in the petroleum fuel.

Abstract: A dye composition that presents lower mutagenic characteristics useful in coloring petroleum products comprising a substantial amount of the dye of the formula ##STR1##

Abstract: Anilines of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, unsubstituted or substituted alkyl, alkenyl or unsubstituted or substituted phenyl orR.sup.1 and R.sup.2, together with the nitrogen atom linking them are a heterocyclic radical or R.sup.1 may furthermore be unsubstituted or substituted hydroxyl or unsubstituted or substituted amino,R.sup.3 and R.sup.7 are each hydrogen, unsubstituted or substituted alkyl, alkenyl, cyano, nitro, acyl, acylamino, unsubstituted or substituted hydroxyl, unsubstituted or substituted carboxymethyl, unsubstituted or substituted amino, unsubstituted or substituted mercapto or unsubstituted or substituted sulfamoyl or, together with R.sup.2, are alkylene, alkenylene or phenylalkenylene,R.sup.4 is hydrogen, unsubstituted or substituted alkyl, alkenyl, unsubstituted or substituted hydroxyl, unsubstituted or substituted amino, unsubstituted or substituted carboxyl or unsubstituted or substituted sulfamoyl andR.sup.5 and R.sup.

Abstract: Petroleum fuels are tagged with markers having the formula: ##STR1## where R.sup.1 and R.sup.2 are selected from H, methyl, ethyl, methoxy, halogen, cyano and nitro and R.sup.3 is selected from methyl, methoxy methoxyethoxy and morpholino.

Abstract: Method for detecting marked mineral oils by treating the marked mineral oil with an extractant comprising water, a solvent and a base comprises using as marker an azo dye of the formula ##STR1## where ring A may be benzofused,m is from 1 to 4,X.sup.1 is hydrogen, C.sub.1 -C.sub.4 -alkyl, cyano or nitro,X.sup.2 is hydrogen, C.sub.1 -C.sub.4 -alkyl, cyano, nitro, C.sub.1 -C.sub.4 -alkoxy or C.sub.1 -C.sub.16 -alkoxycarbonyl,X.sup.3 is hydrogen, C.sub.1 -C.sub.4 -alkyl, cyano or C.sub.1 -C.sub.16 -alkoxycarbonyl, andX.sup.4 is hydrogen, hydroxyl, substituted or unsubstituted C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.4 -alkoxy, amino, C.sub.1 -C.sub.4 -dialkylamino or substituted or unsubstituted C.sub.1 -C.sub.16 -monoalkylamino,as solvent a partially or completely water-miscible organic solvent, and as base an alkali or alkaline earth metal hydroxide, an alkali metal carbonate or a quaternary ammonium hydroxide, the use of azo dyes as markers for mineral oils, and novel azo dyes.

Abstract: The monoazo compound represented by formula I is excellent in compatibility with, solubility in, and coloring power for, almost all water-immiscible organic liquids, has a low melting point, and is suitable for use to color molten plastics, synthetic fiber spinning solutions, etc., and to color thermal transfer ink. ##STR1## wherein R represents sec-butyl; Cp represents a coupling component residue.The dense solution of at least one kind of said monoazo compound in a hydrocarbon solvent diffuses and dissolves quickly and uniformly in coloring subjects such as petroleum products, and is capable of coloring fuel oil etc. to a desired distinguishable color density with small amounts.

Abstract: Azo dyes useful for marking mineral oils have the formula ##STR1## where R.sup.1 and R.sup.2 are hydrogen, C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -alkoxy,R.sup.3 is hydrogen or C.sub.1 -C.sub.8 -alkyl which may be substituted by hydroxyl and interrupted by from 1 to 3 oxygen atoms,R.sup.4 is C.sub.1 -C.sub.8 -alkyl which may be substituted by hydroxyl and interrupted by from 1 to 3 oxygen atoms, andX is cyano or substituted or unsubstituted C.sub.1 -C.sub.8 -alkoxycarbonyl,with the proviso that the molecule contains at least one hydroxyalkyl radical.

Abstract: Liquid petroleum products are marked with markers having the formula: ##STR1## where the Ws are selected from O--(C.sub.1 -C.sub.3 alkyl) and hydrogen, provided that at least one W is O--(C.sub.1 -C.sub.3 alkyl), the Xs and Ys are the same or different and are selected form hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, aryl, substituted aryl, fused aryl, substituted fused aryl, halogen, nitro, cyano, and alkoxy.

Abstract: Liquid petroleum products are marked with markers having the formula: ##STR1## wherein the R.sub.1 's and the R.sub.2 's are the same or different and are each selected from --H and C.sub.1 -C.sub.7 alkyls; provided that at least one, and preferably both, R.sub.1 's are a C.sub.3 -C.sub.7 alkyl; and provided that the R.sub.3 's are the same or different and are selected from --H, --NO.sub.2, --Br, --F, --CN, and --Me; and provided that at least one R.sub.3 is selected from --NO.sub.2, --Cl, --Br, --F, and --CN.

Abstract: The flame luminosity of a methanol fuel is appreciably enhanced by the addition thereto of at least one azo dye flame luminosity enhancing agent.