The present invention relates to a method of marking a petroleum hydrocarbon by adding to and uniformly mixing with said petroleum hydrocarbon a chemical marker of general formula (I)

##STR00001##

wherein two of the residues R.sup.1-R.sup.10 are independently of each other selected from C.sub.1-C.sub.4-alkoxy, and eight of the residues R.sup.1-R.sup.10 are independently of each other selected from the group consisting of hydrogen and C.sub.1-C.sub.4-alkyl, as well as to a composition of a petroleum hydrocarbon comprising a petroleum hydrocarbon and at is least one chemical marker of general formula (I). The presence and concentration of the chemical marker of general formula (I) in the composition of the petroleum hydrocarbon can be advantageously determined by laser ionization coupled with mass spectrometry or by laser ionization coupled with ion mobility spectrometry.

A fuel stabilizer formulation includes a hybrid component that acts as an antioxidant, a chelating agent, and lubricant when added to the fuel, one or more vapor suppressants, and a water scavenger. Furthermore, the formulation may include components that bond with gasoline compounds to prevent evaporation of low-end components, form a layer along with the engine metal that prevents condensed water from corroding the metal, prevent corroded metal ions from destabilizing gasoline compounds into resin, and scavenge water to prevent water deposits at the bottom of the tank which limits biological activity, resulting in an overall improvement in oxidation stability over conventional fuel stabilizers.

A gasoline fuel composition for a spark ignition internal combustion engine comprising (a) gasoline blending components, (b) renewable naphtha at a level of 10 to 30% v/v and (c) oxygenated hydrocarbon at a level of 20% v/v or less, wherein the gasoline blending components comprise (a) 0-30% v/v alkylate, (b) from 0 to 15% v/v isomerate; (c) 0 to 20% v/v catalytic cracked tops naphtha; and (d) 20% to 40% v/v of heavy reformate, wherein the total amount of alkylate, isomerate, catalytic cracked tops naphtha and heavy reformate is at least 50% v/v based on the total fuel composition, and wherein the gasoline fuel composition meets the EN228 specification. While the low octane number of renewable naphtha would normally severely restrict its blendability in gasoline to low levels, it has now been found that renewable naphtha can be included in, for example, ethanol-containing gasoline fuel compositions, in surprisingly and significantly high blend ratios of renewable naphtha to ethanol.

The present invention discloses additive package comprising a mixture of (a) 6-10% by weight of fatty acid (b) 7-15% by weight of alkoxy ether and (c) 60-85% by weight of linear or branched chain monohydroxylated aliphatic saturated alcohol (C2-C8) for improving stability of mixtures of methanol-gasoline, ethanol-gasoline blends containing at least 5-15% by volume of short chain alkanol (methanol/ethanol). The additive composition is added to the alcohol-gasoline blends to improve low temperature stability, provides corrosion protection and to normalize vapor pressure of methanol/ethanol-gasoline blends.

The object of the present invention is a fuel composition comprising: (i) from 50 to 79% by mass of a mixture of hydrocarbons comprising: a) from 35 to 55% by mass of aromatic compounds; b) from 30 to 50% by mass of non-cyclic paraffins containing at least 5 carbon atoms; and c) from 5 to 15% by mass of naphthenes; (ii) from 20 to 40% by mass of one or more ethers; and (iii) from 1 to 10% by mass of butane.

This composition is useful for supplying a controlled-ignition engine, in automobile vehicles intended for general-public applications or for competition.

A fuel for an internal combustion engine includes a C.sub.5 to C.sub.30 dialkoxyalkanoate corresponding to formula (I):

##STR00001##

wherein the R.sub.1 group is —H or a —CH.sub.3 group, the R.sub.2 and R.sub.2′ groups are alkyl groups independently selected to have 1 to 9 carbon atoms; and the R.sub.3 group is selected to have 1 to 9 carbon atoms. The compounds described herein may be used as neat fuels or mixed fuels (with diesel, biodiesel, jet fuel, marine fuel or other fuel compounds) in autoignition or spark ignition engines, such as diesel engines, gasoline (spark ignition) engines, MCCI, Homogeneous Charge Compression Ignition (HCCI) engines, or more generally in Low-Temperature Gasoline Combustion (LTGC) engines (using gasoline-like fuels), that have the high-efficiency advantages of HCCI but can operate with some level of charge inhomogeneities. Methods of making these compounds are environmentally friendly and can be done in a continuous manner.

A fuel for an internal combustion engine includes a C.sub.5 to C.sub.30 dialkoxyalkanoate corresponding to formula (I): ##STR00001## wherein the R.sub.1 group is —H or a —CH.sub.3 group, the R.sub.2 and R.sub.2′ groups are alkyl groups independently selected to have 1 to 9 carbon atoms; and the R.sub.3 group is selected to have 1 to 9 carbon atoms. The compounds described herein may be used as neat fuels or mixed fuels (with diesel, biodiesel, jet fuel, marine fuel or other fuel compounds) in autoignition or spark ignition engines, such as diesel engines, gasoline (spark ignition) engines, MCCI, Homogeneous Charge Compression Ignition (HCCI) engines, or more generally in Low-Temperature Gasoline Combustion (LTGC) engines (using gasoline-like fuels), that have the high-efficiency advantages of HCCI but can operate with some level of charge inhomogeneities. Methods of making these compounds are environmentally friendly and can be done in a continuous manner.

A method for preparation of a reagent for reducing hydrodynamic drag of a turbulent flow of liquid hydrocarbons in pipelines, characterized by a high polymer content of at least 75 wt %, including mixing a 0.1-1.5 mm polymer reducing the hydrodynamic drag of a turbulent flow of liquid hydrocarbons with polymer non-solving solvents. The prepared product is a commodity form of the reagent with a high polymer content of at least 75 wt % used to reduce the hydrodynamic drag of the flow of liquid hydrocarbons in pipelines. The product prepared according to the described method is injected into the flow of hydrocarbon fluid transported through the pipeline using the injection apparatus that mechanically moves the product using a screw auger or screw feeder.

The present invention provides a spark ignition fuel mixture, comprising: a) diethyl ether with a content from 33.3 to 50 vol % of the mixture; b) ethanol with a content of at least 27 vol % of the mixture; and c) water with a content of at least 6 vol % of the mixture and not exceeding the ethanol content; wherein the mixture remains in a form of homogeneous liquid at −40° C. The present invention also provides a method of making or handling the spark ignition fuel mixture.

Embodiments of the invention provide a method of inhibiting precipitation of biodiesel fuel components. The method includes providing a biodiesel fuel composition; providing a copolymer comprising at least first and second polymer units, said first polymer units derived from a carboxylic acid anhydride and said second polymer units derived from an olefin; and blending said copolymer with the biodiesel fuel to form a treated fuel composition. Alternatively, instead of the copolymer, a dialkylene glycol additive can be provided. Embodiments of the invention provide a method of reducing the cold soak filter blocking tendency of a biodiesel fuel composition.