A diesel fuel composition including (a) a quaternary ammonium salt additive; and (b) one or more nitrogen-free detergents; wherein the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; wherein each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

A diesel fuel composition including (a) a quaternary ammonium salt additive; and (b) one or more nitrogen-free detergents; wherein the quaternary ammonium salt additive includes the quaternised reaction product of a hydrocarbyl substituted succinic acid derived acylating agent and a compound able to react with said acylating agent and which includes a tertiary amine group; wherein each molecule of the hydrocarbyl substituted succinic acid derived acylating agent includes on average at least 1.2 succinic acid moieties.

The present invention generally relates to oil compositions, primarily to fuel oil and petroleum compositions produced there from susceptible to wax formation at low temperatures, to polymeric imides for use with such fuel oil compositions, and to methods for their manufacture.

A multipurpose chemical additives (MPC) is disclosed to mitigate fouling in hydrocarbon refinery processes, such as in a heat exchanger. A method for reducing fouling of a hydrocarbon is also disclosed that includes (i) providing a crude hydrocarbon for a refining process; and (ii) adding an additive to the crude hydrocarbon.

The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150 C. (T.sub.150) is 1.6 to 2.9 mPa.Math.s, and a ratio of a kinematic viscosity at 40 C. (V.sub.40) [mm.sup.2/s] to the HTHS viscosity at 150 C. (T.sub.150) [mPa.Math.s] (V.sub.40/T.sub.150) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

Inhibiting gas hydrate formation while transporting hydrocarbon fluids may include providing a kinetic gas hydrate inhibitor, adding the kinetic gas hydrate inhibitor to a fluid capable of producing gas hydrates, and transporting the fluid that comprises the kinetic gas hydrate inhibitor. Generally a kinetic gas hydrate inhibitor may include a heterocyclic compound comprising nitrogen, e.g., poly(vinyl pyrrolidone).

A method for treating an emulsion of a hydrocarbon is disclosed. The method includes providing an emulsion of a crude hydrocarbon, and adding an additive to the emulsion to obtain a treated hydrocarbon.

Concentrates containing specific functionalised diblock copolymers serve as effective additives for improving the cold flow behaviour of fuels and oils, the copolymers being derived from a terminally-unsaturated intermediate polymer obtained via a metallocene process involving hydrogen.

Described herein are associative polymers capable of controlling a physical and/or chemical property of non-polar compositions that can be used when the non-polar composition is in a flow, and related compositions, methods and systems. Associative polymers herein described have a non-polar backbone with a longest span having a molecular weight that remains substantially unchanged under the flow conditions and functional groups presented at ends of the non-polar backbone, with a number of the functional groups presented at the ends of the non-polar backbone formed by associative functional groups capable of undergoing an associative interaction with another associative functional group with an association constant (k) such that the strength of each associative interaction is less than the strength of a covalent bond between atoms and in particular less than the strength of a covalent bond between backbone atoms.

This invention relates to a lubricating oil composition and production thereof. The lubricating oil composition comprises a Mannich base represented by the following formula (III) (wherein A and R.sub.2 are as defined in the specification) and a lubricant base oil. The lubricating oil composition according to this invention exhibits excellent cleansing and dispersing performance and excellent anticorrosion performance. ##STR00001##