The present invention relates to a composition for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams, the composition comprising an oxazolidine compound and a synergistic additive.

The present invention relates to a composition for scavenging hydrogen sulphide and/or mercaptans in hydrocarbon streams, the composition comprising an oxazolidine compound and a synergistic additive.

Methods for preparing an octane-boosting fuel additive having the following formula: are provided. In a first aspect, the method may comprise carrying out the following reaction: (i), (ii) In a second aspect, the method may comprise: (1) preparing the fuel additive; and (2) purifying the product of step (1) by: (a) dissolving the fuel additive in a water-insoluble solvent to form a solution; (b) washing the solution with water; and (c) separating the fuel additive product from the water-insoluble solvent using distillation. Steps (i) and (1) of the methods are carried out in the presence of butylated hydroxytoluene. ##STR00001##

Methods for preparing an octane-boosting fuel additive having the following formula: are provided. In a first aspect, the method may comprise carrying out the following reaction: (i), (ii) In a second aspect, the method may comprise: (1) preparing the fuel additive; and (2) purifying the product of step (1) by: (a) dissolving the fuel additive in a water-insoluble solvent to form a solution; (b) washing the solution with water; and (c) separating the fuel additive product from the water-insoluble solvent using distillation. Steps (i) and (1) of the methods are carried out in the presence of butylated hydroxytoluene. ##STR00001##

This disclosure relates to anti-agglomerant low dosage hydrate inhibitors that can inhibit the formation of hydrate agglomerants and/or plugs. Thus, provided herein are carboxy alkyl ester compounds that can be used in hydrate inhibitor compositions and methods of inhibiting formation of hydrate agglomerants in a fluid comprising water, a gas, and optionally a liquid hydrocarbon. Also provided herein are methods of making the carboxy alkyl ester compound.

A method for improving the deposit control performance 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 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 controlling deposits in a system which comprises the fuel, such as in a spark-ignition internal combustion engine.

A method for improving the deposit control performance 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 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 controlling deposits in a system which comprises the fuel, such as in a spark-ignition internal combustion engine.

An optimised method for preparing a fuel additive f is provided. The method comprises carrying out the following reaction: (c, d, e) Starting material c may be prepared using an optimised method which comprises carrying out the following reaction: (a, b, c) ##STR00001##

An optimised method for preparing a fuel additive f is provided. The method comprises carrying out the following reaction: (c, d, e) Starting material c may be prepared using an optimised method which comprises carrying out the following reaction: (a, b, c) ##STR00001##

A method is provided for preparing a fuel additive having the formula: (1) The method comprises carrying out the following reactions: (i) addition of an alkylating agent b to starting material a: (a) to form an intermediate c; and (ii) ring closing intermediate c to form fuel additive e. ##STR00001##