A method for reducing the propensity of a fuel to form an emulsion comprises combining an additive having a chemical structure comprising a 6-membered aromatic ring sharing two adjacent aromatic carbon atoms with a 6- or 7-membered saturated heterocyclic ring, the 6- or 7-membered saturated heterocyclic ring comprising a nitrogen atom directly bonded to one of the shared carbon atoms to form a secondary amine and an atom selected from oxygen or nitrogen directly bonded to the other shared carbon atom, the remaining atoms in the 6- or 7-membered heterocyclic ring being carbon with the fuel. Thus, the additive may be used as a demulsifier in a fuel.

A method for preparing a fuel composition which comprises a base fuel, an oxygenate and an octane-boosting additive comprises: blending an additised oxygenate with a base fuel, wherein the additised oxygenate comprises an oxygenate and an octane-boosting additive. The method enables suitable amounts of octane-boosting additives to be incorporated into a fuel composition, whilst enabling fuels having a range of properties to be prepared.

A fuel composition for a spark-ignition internal combustion engine comprises a non-metallic octane-boosting additive. The non-metallic octane-boosting additive is an additive which, when used at a treat rate of 0.67 % by weight, increases the research octane number of a fuel by at least 1.8 whilst maintaining the T.sub.90 and/or the vapour pressure.

A method for improving the ferrous corrosion-preventing characteristics of a fuel comprises combining an additive having a chemical structure comprising a 6-membered aromatic ring sharing two adjacent aromatic carbon atoms with a 6- or 7-membered saturated heterocyclic ring, the 6- or 7-membered saturated heterocyclic ring comprising a nitrogen atom directly bonded to one of the shared carbon atoms to form a secondary amine and an atom selected from oxygen or nitrogen directly bonded to the other shared carbon atom, the remaining atoms in the 6- or 7-membered heterocyclic ring being carbon with the fuel. The additive may also be used for preventing ferrous corrosion in a system which comprises a fuel, such as a fuel system in a vehicle.

The present disclosure concerns embodiments of a catalyst system, such as a mixed catalyst composition, that can be used to make biofuel. In some embodiments, the mixed catalyst composition can comprise an inorganic catalyst and an organic catalyst, such as a cyclic organic catalyst. In particular disclosed embodiments, a mixed catalyst composition comprising, consisting essentially of, or consisting of an inorganic catalyst and an organic catalyst can be used to enhance the production of biofuel, such as biodiesel, by reducing the amount of time needed to make the biofuel as compared to that needed for the inorganic catalyst or the organic catalyst independently. Also disclosed herein are combinations and kits comprising, consisting essentially of, or consisting of embodiments of a mixed catalyst composition.

A synergistic mixture comprising from 1 to 99.9% by weight of compounds having structural elements (I) ##STR00001##
in which the free valencies on the oxygen atom and on the nitrogen atom may be combined to form a five-, six- or seven-membered ring and the benzene ring may also bear substituents at one or more of the free positions, and from 0.1 to 99% by weight of sulfur-containing organic compounds with antioxidant action. This synergistic mixture is suitable as a stabilizer for stabilizing inanimate organic material, especially mineral oil products and fuels, against the action of light, oxygen and heat.

A synergistic mixture comprising from 1 to 99.9% by weight of compounds having structural elements (I) ##STR00001##
in which the free valencies on the oxygen atom and on the nitrogen atom may be combined to form a five-, six- or seven-membered ring and the benzene ring may also bear substituents at one or more of the free positions, and from 0.1 to 99% by weight of sulfur-containing organic compounds with antioxidant action. This synergistic mixture is suitable as a stabilizer for stabilizing inanimate organic material, especially mineral oil products and fuels, against the action of light, oxygen and heat.

The present invention is related to a process for obtaining organic ammonium salts (OAS) and their derivatives, supramolecular surfactants (SS), which simultaneously present the properties of traceability and detergents dispersant of organic scales. Organic ammonium salts (OAS) and their derivatives supramolecular surfactants (SS) have applications as differentiators, markers, or tracers in fuels derived from hydrocarbons; and also to disperse organic scales or inhibit the gums precipitation both in injectors and intake valves of automotive vehicle engines. Organic ammonium salts (OAS) are obtained through an acid-base reaction between a molecule from the azo family and an amine. Once the OAS is obtained, it reacts with an organic compound (OC) so that through non-covalent interactions, a self-assembly process occurs that gives rise to the SS. Said process is based on green chemistry, that is, in the absence of solvents. These OAS and SS are quantified through the analytical techniques of ultraviolet-visible (UV-VIS) and high-performance liquid chromatography (HPLC) through a calibration curve. Additionally, its performance as a gum-dispersing agent in a single-cylinder engine is evaluated.

The present invention is related to a process for obtaining organic ammonium salts (OAS) and their derivatives, supramolecular surfactants (SS), which simultaneously present the properties of traceability and detergents dispersant of organic scales. Organic ammonium salts (OAS) and their derivatives supramolecular surfactants (SS) have applications as differentiators, markers, or tracers in fuels derived from hydrocarbons; and also to disperse organic scales or inhibit the gums precipitation both in injectors and intake valves of automotive vehicle engines. Organic ammonium salts (OAS) are obtained through an acid-base reaction between a molecule from the azo family and an amine. Once the OAS is obtained, it reacts with an organic compound (OC) so that through non-covalent interactions, a self-assembly process occurs that gives rise to the SS. Said process is based on green chemistry, that is, in the absence of solvents. These OAS and SS are quantified through the analytical techniques of ultraviolet-visible (UV-VIS) and high-performance liquid chromatography (HPLC) through a calibration curve. Additionally, its performance as a gum-dispersing agent in a single-cylinder engine is evaluated.