An aviation fuel composition is disclosed, containing 50-95 vol-% of petroleum-derived jet fuel component, and 5-50 vol-% of renewable middle distillate component. The fuel composition has a viscosity of 12 mm2/s or below at −40° C., 10 mm2/s or below at −30° C., and 8 mm2/s or below at −20° C., as measured in accordance with an EN ISO 3104 (1996) standard. A method for producing the aviation fuel composition is also disclosed. The method containing mixing the petroleum derived jet fuel component and the renewable middle distillate component to obtain the aviation fuel composition, such that the petroleum-derived jet fuel component and the renewable middle distillate component are mixed together in an amount containing 5-50 vol-% of renewable middle distillate component and about 50-95 vol-% of petroleum-derived jet fuel component.

The use of at least one wax anti-settling additive, optionally in combination with one or more further additives, to reduce the filter blocking tendency of a fuel composition having a tendency to block filters, wherein the fuel composition comprises a renewable diesel component and a biodiesel component.

The use of at least one wax anti-settling additive, optionally in combination with one or more further additives, to reduce the filter blocking tendency of a fuel composition having a tendency to block filters, wherein the fuel composition comprises a renewable diesel component and a biodiesel component.

Friction modifier and compositions containing the friction modifier as a fuel additive are provided. Methods for improving fuel efficiency using these compositions are also provided.

A method of improving the emulsification performance of nonionic alkoxylated surfactants, for example when used as fuel additives. The method involves a) providing a composition comprising at least one nonionic alkoxylated surfactant; and b) prior to the addition of said composition to an aircraft fuel, thermally cycling said composition by (i) chilling the composition from a first temperature to a second temperature that causes metal ions and/or associated ions contained therein to precipitate as ionic salts; (ii) filtering the chilled composition to remove the precipitated ionic salts; and (iii) heating the filtered composition to the first temperature.

A method of improving the emulsification performance of nonionic alkoxylated surfactants, for example when used as fuel additives. The method involves a) providing a composition comprising at least one nonionic alkoxylated surfactant; and b) prior to the addition of said composition to an aircraft fuel, thermally cycling said composition by (i) chilling the composition from a first temperature to a second temperature that causes metal ions and/or associated ions contained therein to precipitate as ionic salts; (ii) filtering the chilled composition to remove the precipitated ionic salts; and (iii) heating the filtered composition to the first temperature.

A method of improving the low temperature properties of a middle distillate fuel composition comprising: (a) a nitrogen-containing dispersant; and (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives; (y) middle distillate flow improvers and mixtures thereof; the method comprising adding to the fuel an additive (c) which is a copolymer comprising units of formula (A): and units of formula (B): wherein R is an alkyl group and each of R.sup.1 and R.sup.2 is an alkyl group.

##STR00001##

A method of improving the low temperature properties of a middle distillate fuel composition comprising: (a) a nitrogen-containing dispersant; and (b) one or more low temperature property enhancers which are not fumarate vinyl ester copolymers and which are selected from (x) wax antisettling additives; (y) middle distillate flow improvers and mixtures thereof; the method comprising adding to the fuel an additive (c) which is a copolymer comprising units of formula (A): and units of formula (B): wherein R is an alkyl group and each of R.sup.1 and R.sup.2 is an alkyl group.

##STR00001##

The invention relates to specific copolymers obtainable by co-polymerizing at least the following monomers: at least one bicyclic (meth)acrylate ester at least one lower-alkyl (meth)acrylate optionally, and preferably, at least one aromatic vinyl monomer; and optionally other ethylenically unsaturated monomers, whereby the copolymer has a weight averaged molecular weight of from 100,000 to 10,000,000 D, determined using GPC-MALS techniques for a solution in THF at 40° C., as well as to the way to synthesize such copolymers and the use of such polymers to modify the rheology of a liquid in which they are soluble.

The invention relates to specific copolymers obtainable by co-polymerizing at least the following monomers: at least one bicyclic (meth)acrylate ester at least one lower-alkyl (meth)acrylate optionally, and preferably, at least one aromatic vinyl monomer; and optionally other ethylenically unsaturated monomers, whereby the copolymer has a weight averaged molecular weight of from 100,000 to 10,000,000 D, determined using GPC-MALS techniques for a solution in THF at 40° C., as well as to the way to synthesize such copolymers and the use of such polymers to modify the rheology of a liquid in which they are soluble.