Improvements in fuels

Abstract

A fuel composition comprising a renewable diesel and one or more low temperature enhancing additives selected from the group consisting of: (a) a copolymer comprising units of formula (I) and units of formula (II): # imgabs0 wherein R is an alkyl group and R1 and R2 are each an alkyl or alkenyl group having 6 to 22 carbon atoms; (b) a reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine; and (c) a reaction product of a secondary amine and a copolymer of maleic anhydride and an alpha-olefin.

Description

[0001] The present invention relates to improvements in fuel compositions comprising renewable diesel, and in particular to improving the performance of fuel compositions comprising renewable diesel at low temperatures.

[0002] As fuel cools, crystals begin to form within the fuel. These can cause problems during storage, transportation and combustion of the fuel.

[0003] Three measurements are commonly used to evaluate the low temperature performance of diesel fuels. Standardized tests have been designed to measure the temperature at which the fuel becomes cloudy (cloud point - CP), the lowest temperature at which the fuel can flow (pour point - PP), and the lowest temperature at which the fuel flows through the filter (cold filter plugging point - CFPP); and the changes caused by additives (ΔCP, ΔPP, ΔCFPP). Standardized tests for measuring PP, and especially CP and CFPP, are one of the common working tools of those skilled in the art.

[0004] The standard test for measuring the pour point of diesel fuel is ASTM D5949.

[0005] The cloud point (CP) of a fuel is the temperature at which a cloud of wax crystals first appears in the liquid when cooled under the conditions specified in the test method as defined in ASTM D2500 or ASTM D5773.

[0006] At temperatures below the cloud point but above the pour point, wax crystals can reach a size and shape that can plug fuel lines, screens and filters, even if the fuel can physically flow. These problems are well known in the art and have many recognized test methods, such as the CFPP value (cold filter plugging point, determined according to DIN EN116 or ASTM D6371).

[0007] Because cloud point tests were considered too pessimistic, tests such as this were introduced to indicate low temperature operability.

[0008] Cold flow improvers (CFIs) and wax anti-settling additives (WASAs) have been developed to ameliorate the problem of wax precipitation below the cloud point in fuels, and their effects can be studied by the above test methods, comparing the results between un-additived fuels and fuels with additives.

[0009] Some of these additives may help keep so-called "waxes" in solution in the fuel; others may alter their crystal morphology or size so that filterability and pourability are maintained despite precipitation.

[0010] The present invention is particularly concerned with improving the low temperature properties of fuel compositions comprising renewable diesel.

[0011] In recent years, environmental pressures have led to an increasing use of greener alternatives to fossil fuels. It is now common to replace some or all of the diesel fuel obtained from petroleum sources with diesel fuel obtained from natural or renewable sources. However, the addition of a renewable diesel component can have a significant impact on the fuel's performance at low temperatures.

[0012] The chemistry of renewable diesel is very different from mineral diesel, which is derived from petroleum and contains a mixture of alkanes with a high degree of branching, as well as aromatic and olefinic compounds.

[0013] Renewable diesel is produced by hydrodeoxygenation of fats and oils and contains mainly straight-chain alkanes. Their chemical composition is different from that of mineral diesel.

[0014] Because renewable diesel has a different chemistry than mineral diesel, these fuels form different waxes and precipitates when cooled. For blended fuels, wax crystals formed in one component may not be as soluble in the other components of the fuel. This can lead to more issues, such as filterability of the fuel at low temperatures.

[0015] Additives that improve the low temperature properties of mineral diesel fuel do not necessarily improve the low temperature properties of a fuel composition comprising renewable diesel due to the different compositions of these fuels.

[0016] The inventors have discovered that certain additives are particularly effective for improving the low temperature performance of a fuel composition comprising renewable diesel. Specifically, the inventors have discovered that certain additives reduce the cloud point of the fuel composition.

[0017] According to a first aspect of the present invention, there is provided a fuel composition comprising renewable diesel and one or more low temperature enhancing additives selected from the following:

[0018] (a) A copolymer comprising units of formula (I) and units of formula (II):

[0019]

[0020] Where R is an alkyl group, and R 1 and R 2 Each is an alkyl or alkenyl group having 6 to 22 carbon atoms;

[0021] (b) the reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine; and

[0022] (c) The reaction product of a secondary amine with a copolymer of maleic anhydride and an alpha-olefin.

[0023] In some embodiments, the fuel composition comprises an additive (a).

[0024] Additive (a) can be prepared by copolymerizing vinyl ester monomers and fumaric acid monomers and then esterifying the acid residues.

[0025] Preferably, the additive (a) is prepared by copolymerizing vinyl ester monomers and dialkyl fumarate monomers.

[0026] Additive (a) is preferably a copolymer prepared by reacting a vinyl ester monomer of formula (III) with a dialkyl fumarate monomer of formula (IV):

[0027]

[0028] The monomers of formula (III) used to prepare the copolymer additive (a) may be the same, or the copolymer may be prepared from a mixture of two or more different monomers of formula (III).

[0029] R is an alkyl group, preferably an unsubstituted alkyl group.

[0030] Preferably, R is an alkyl group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms.

[0031] Preferably, R is an unsubstituted alkyl group having 1 to 4 carbon atoms.

[0032] Most preferably, R is methyl and the monomer of formula (III) is vinyl acetate.

[0033] The monomers of formula (IV) used to prepare the copolymer additive (a) may be the same, or the copolymer may be prepared from a mixture of two or more different monomers of formula (IV).

[0034] Preferably, all monomers of formula (IV) used to prepare additive (a) are identical.

[0035] R 1 and R 2 Each may be the same or different. Preferably, R 1 With R 2 same.

[0036] R 1 and R 2 Each is an alkyl or alkenyl group. Preferably, each is an alkyl group, preferably an unsubstituted alkyl group. 1 and R 2 It can be straight chain or branched. Preferably, R 1 and R 2 Each is a straight-chain alkyl group.

[0037] In some embodiments, R 1 and R 2Each is an alkyl group having 6 to 22 carbon atoms, preferably 8 to 18 carbon atoms.

[0038] Preferably, R 1 and R 2 Each is an alkyl group having 6 to 14 carbon atoms, preferably 8 to 14 carbon atoms, more preferably 10 to 14 carbon atoms, and most preferably 12 to 14 carbon atoms.

[0039] Additive (a) is a copolymer comprising formula (I) unit and formula (II) unit. In some embodiments, additive (a) may include other additional units that do not belong to formula (I) or formula (II). In such embodiments, copolymer is suitably prepared by vinyl ester monomer, fumaric acid derived monomer (preferably dialkyl fumarate) and one or more other monomeric units. In a preferred embodiment, one or more other monomeric units account for less than 20 mol %, preferably less than 10 mol %, more preferably less than 5 mol %, more preferably less than 1 mol % of all monomeric units for the preparation of additive (a).

[0040] In a preferred embodiment, additive (a) consists essentially of units of formula (I) and units of formula (II). This means that units of formula (I) and units of formula (II) together provide at least 80 mol%, preferably at least 90 mol%, more preferably at least 95 mol%, more preferably at least 99 mol%, for example at least 99.5 mol% or at least 99.9 mol% of all monomer-derived units present in the copolymer.

[0041] Suitable additives (a) contain 10 to 90 mol % of units of formula (I) and 90 to 10 mol % of units of formula (II); preferably 25 to 75 mol % of units of formula (I) and 25 to 75 mol % of units of formula (II); more preferably 40 to 60 mol % of units of formula (I) and 60 to 40 mol % of units of formula (II).

[0042] Preferably, additive (a) is a random copolymer.

[0043] Suitably, the copolymer additive (a) has a number average molecular weight of from 1,000 to 100,000, preferably from 2,000 to 50,000, more preferably from 5,000 to 25,000, for example from 6,000 to 20,000.

[0044] In some particularly preferred embodiments, the number average molecular weight of the copolymer additive (a) is from 4000 to 25000, preferably from 5000 to 20000, more preferably from 6000 to 15000. In some embodiments, the number average molecular weight of the copolymer additive (a) is from 8000 to 10000.

[0045] In a particularly preferred embodiment, additive (a) is a copolymer comprising units of formula (I) and units of formula (II):

[0046]

[0047]

[0048] Where R is an alkyl group, and R 1 and R 2 Each is an alkyl group having 10 to 14 carbon atoms, and preferably 12 to 14 carbon atoms, and the number average molecular weight of the copolymer is 4000 to 25000, preferably 5000 to 20000, more preferably 6000 to 15000. Most preferably, the copolymer comprises 40 to 60 mol % of units of formula (I) and 60 to 40 mol % of units of formula (II).

[0049] In some embodiments, the fuel composition comprises (b) the reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine.

[0050] The polycarboxylic acid with at least one tertiary amino group preferably has 2 to 20 carbon atoms, at least one tertiary amino group and 2 to 12 carboxylic acid groups. Each carboxylic acid group in the polycarboxylic acid preferably has 2 to 10 carbon atoms. The polycarboxylic acid groups may be identical or different. Preferably, each carboxylic acid group is an acetic acid group. The polycarboxylic acid preferably has 1 to 3 tertiary amino groups and 2 to 8 carboxylic acid groups. In a preferred embodiment, the polycarboxylic acid has 3 to 5, preferably 3 or 4 carboxylic acid groups and 1 to 3, preferably 1 or 2 tertiary amino groups.

[0051] In some preferred embodiments, the polycarboxylic acid has formula (V) or (VI):

[0052]

[0053] wherein A is a linear or branched C2-C6 alkylene or HOOC-BN(CH2CH2)2, and B is C1 to C 19 Alkylene.

[0054] Preferably, A has 2 to 4 carbon atoms, more preferably 2 or 3 carbon atoms, most preferably 2 carbon atoms.

[0055] Preferably, B has 1 to 10, more preferably 1 to 4 carbon atoms.

[0056] Preferred carboxylic acids for preparing additive (b) include nitrilotriacetic acid, ethylenediaminetetraacetic acid, and 1,2-propylenediaminetetraacetic acid.

[0057] To form additive (b), the polycarboxylic acid is reacted with a primary or secondary amine. Most preferably, the polycarboxylic acid is reacted with a secondary amine, preferably a secondary amine of formula HNR2, wherein each R is independently a linear or branched C 10 To C 30 Alkyl or alkenyl, preferably C 14 To C 24 Preferably, each R is an alkyl group. Preferably, each R is the same.

[0058] Secondary amines can react with polycarboxylic acids to form amides and / or ammonium salts. In a preferred embodiment, all amines react to form amides.

[0059] Preferred amines for reaction with the polycarboxylic acid include dioleylamine, dipalmitylamine, dicocoamine, distearylamine, dibehenylamine and hydrogenated and / or unhydrogenated ditallow amine. Ditallow amine is particularly preferred.

[0060] Preferably, the amine is reacted with the carboxylic acid in a ratio of 0.5 to 1.5, preferably 0.8 to 1.2 mol of amine per carboxylic acid group present in the carboxylic acid.

[0061] A particularly preferred additive component (b) is the reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated tallow fatty amine.

[0062] Other preferred compounds of this type include the N,N dialkylammonium salts of 2-N-,N' dialkylamide benzoates, such as the reaction product of 1 mole of phthalic anhydride with 2 moles of ditallow amine and the reaction product of 1 mole of alkenyl-spiro-dilactone with 2 moles of a dialkylamine, such as ditallow amine (hydrogenated or unhydrogenated).

[0063] In some embodiments, the fuel composition comprises (c) the reaction product of a secondary amine and a copolymer of an α,β-unsaturated dicarboxylic acid anhydride and an α-olefin.

[0064] Preferred compounds of this type are copolymers based on polyoxyalkylene ethers of α,β-unsaturated dicarboxylic acid anhydrides, α,β-unsaturated compounds and optionally lower unsaturated alcohols, including:

[0065] a) 20-80 mol % of divalent structural units (VII) and / or (VIII)

[0066]

[0067] Where R 1 and R 2 are independently hydrogen or methyl,

[0068] X and Y are the same or different groups and are selected from: and N-HR3 Group, where R 3 C6-C 40 -alkyl, C5-C 20 -cycloalkyl or C6-C 18 -aryl; N-(R 3 )2 group, wherein R 3 each being the same or different and as defined above; and OR 4 Group, where R 4 Hydrogen, formula H2N + (R 3 )2 or H3N + R 3 Cations, C6-C 40 -alkyl, C5-C 20 -cycloalkyl or C6-C 18 - aryl;

[0069] b) 19-80 mol % of divalent structural units (IX)

[0070]

[0071] Where R 5 is hydrogen or C1-C4-alkyl and R 6 C6-C 60 -alkyl or C6-C 18 - aryl; and

[0072] c) 0-30 mol% of divalent structural units (X):

[0073]

[0074] Where R 7 is hydrogen or methyl, R 8 is hydrogen or C1-C4-alkyl, Z is C1-C4-alkylene

[0075] m is a number between 1 and 100, R 9 C1-C 24 -alkyl, C5-C 20 -Cycloalkyl, C6-C 18 -Aryl or --C(O)--R 10 , where R 10 C1-C 40 -alkyl, C5-C 10 -cycloalkyl or C6-C 18 -Aryl.

[0076] It will be appreciated by those skilled in the art that the copolymer may contain small amounts of unopened anhydride or imide structural units derived from the α,β-unsaturated dicarboxylic acid anhydride structural units (VII) and / or (VIII).

[0077] Preferred copolymers do not contain the structural unit X. In a preferred embodiment, X is of the formula N-(R 3 )2, wherein R 3 C6-C 40 Alkyl, and Y is of the formula OR 4 A group in which R 4 Formula H2N + (R 3 )2 cation, where R 3 C6-C 40 alkyl.

[0078] Preferred additives (c) are derived from copolymers of maleic anhydride and α-olefins having 6 to 30 carbon atoms reacted with 2 equivalents of aliphatic amine.

[0079] A particularly preferred additive (c) is prepared by reacting a copolymer of maleic anhydride and a C18 alpha olefin with 2 equivalents of ditallow fatty amine.

[0080] In some embodiments, the fuel composition comprises component (a).

[0081] In some embodiments, the fuel composition comprises component (b).

[0082] In some embodiments, the fuel composition comprises component (c).

[0083] In some embodiments, the fuel composition comprises component (a) and component (b).

[0084] In some embodiments, the fuel composition comprises component (a) and component (c).

[0085] In some embodiments, the fuel composition comprises component (b) and component (c).

[0086] In some particularly preferred embodiments, the fuel composition comprises component (a), component (b) and component (c).

[0087] In some embodiments, the fuel composition comprises component (a), but does not comprise component (b) or component (c).

[0088] The fuel composition of the present invention comprises renewable diesel. It may comprise only renewable diesel and one or more additives, or it may comprise a mixture of renewable diesel and another diesel fuel.

[0089] Preferably, the fuel composition has a low sulfur content fuel, preferably a sulfur content of less than 200 ppm, preferably less than 100 ppm, preferably less than 50 ppm, preferably less than 20 ppm, preferably less than 15 ppm, preferably less than 10 ppm.

[0090] In some embodiments, the fuel compositions of the present invention comprise renewable diesel and one or more additional components selected from the group consisting of biodiesel, mineral diesel, and mixtures thereof.

[0091] In some embodiments, the diesel fuel comprises renewable diesel and biodiesel.

[0092] In some embodiments, the diesel fuel comprises renewable diesel and mineral diesel.

[0093] In some embodiments, the diesel fuel comprises mineral diesel, biodiesel, and renewable diesel.

[0094] The fuel composition comprises renewable diesel. In this specification, renewable diesel refers to a diesel fuel obtained by hydrodeoxygenation of fats and oils. Such fuels are commonly referred to as second generation biodiesel, and are derived from renewable resources such as vegetable oils and animal fats, and are typically processed in refineries, for example using hydroprocessing such as the H-Bio process developed by Petrobras. Second generation biodiesel is sold by ConocoPhillips under the name of Renewable Diesel and by Neste under the name of NExBTL.

[0095] Preferably, the renewable diesel present in the fuel composition of the present invention comprises less than 5 wt% aromatic compounds, preferably less than 1 wt%, suitably less than 0.1 wt%. Most preferably, the renewable diesel used in the present invention is substantially free of aromatic compounds.

[0096] The renewable diesel present in the fuel composition of the present invention may comprise greater than 4 wt%, preferably greater than 5 wt% C14 to C16 normal alkanes.

[0097] The renewable diesel present in the fuel composition of the present invention may comprise greater than 5 wt%, preferably greater than 7 wt%, more preferably greater than 10 wt% C14 to C18 normal alkanes.

[0098] The renewable diesel present in the fuel composition of the present invention may comprise less than 8 wt%, preferably less than 6 wt%, of C14 to C16 normal alkanes.

[0099] The renewable diesel present in the fuel composition of the present invention may comprise less than 20 wt%, preferably less than 18 wt%, more preferably less than 16 wt% C14 to C18 normal alkanes.

[0100] The renewable diesel present in the fuel composition of the present invention may comprise greater than 4 wt%, preferably greater than 5 wt%, C14 to C16 normal alkanes and less than 8 wt%, preferably less than 6 wt%, C14 to C16 normal alkanes.

[0101] The renewable diesel present in the fuel composition of the present invention may comprise greater than 5 wt%, preferably greater than 7 wt%, more preferably greater than 10 wt% C14 to C18 normal alkanes and less than 20 wt%, preferably less than 18 wt%, more preferably less than 16 wt% C14 to C18 normal alkanes.

[0102] The renewable diesel present in the fuel composition of the present invention may comprise 4 to 8 wt%, preferably 5 to 6 wt% C14 to C16 normal alkanes.

[0103] The renewable diesel present in the fuel composition of the present invention may comprise 5 to 20 wt%, preferably 7 to 18 wt%, more preferably 10 to 16 wt% C14 to C18 normal alkanes.

[0104] The renewable diesel present in the fuel composition of the present invention may comprise from 3 to 30 wt. % C6 to C24 normal alkanes (ie, normal paraffins).

[0105] In some embodiments, the fuel composition used in the present invention can include petroleum-based fuel oil, especially middle distillate fuel oil. The boiling point of such distillate fuel oil is generally 110° C. to 500° C., for example 150° C. to 400° C. Diesel fuel can include a mixture of atmospheric distillate or vacuum distillate, cracked gas oil or any proportion of straight run fraction (stream) and refinery fraction (e.g., thermal and / or catalytic cracking and hydrocracking fraction).

[0106] Fossil fuels herein refer to fuels derived entirely from mineral (ie, petroleum) sources.

[0107] In this specification, biodiesel refers to esters of fatty acids. Such fuels are generally referred to as first generation biodiesel. Biodiesel as defined herein contains esters of, for example, vegetable oils, animal fats and waste cooking fats. This form of biodiesel can be obtained by transesterification of oil with an alcohol (usually a monohydric alcohol) usually in the presence of a catalyst. Fatty acids used to produce the fuel can be derived from a variety of natural sources, including, but not limited to, vegetable oils, rapeseed oil, safflower oil, sunflower oil, nasturtium seed oil, canola oil, olive oil, sesame oil, soybean oil, corn oil, peanut oil, cottonseed oil, rice bran oil, babassu nut oil, castor oil, palm oil, rapeseed oil, canola oil, palm kernel oil, lupine oil, jatropha oil, coconut oil, linseed oil, evening primrose oil, jojoba oil, camelina oil, tallow, beef tallow, butter, chicken fat, lard, cream, shea butter, waste frying oil, oil blends, waste cooking oil, yellow trap grease, hydrogenated oils, derivatives of oils, fractions of oils, conjugated derivatives of oils, and any mixtures thereof.

[0108] The fuel composition may include non-renewable Fischer-Tropsch fuels, such as those described as GTL (gas-to-liquids) fuels, CTL (coal-to-liquids) fuels, and OTL (oil sands-to-liquids) fuels.

[0109] The diesel fuel composition may include one or more additional components, such as fuels known as third generation biodiesel. Third generation biodiesel utilizes gasification and Fischer-Tropsch technologies, including those known as BTL (biomass to liquid) fuels. Third generation biodiesel is not much different from some second generation biodiesels, but is designed to utilize whole plants (biomass), thereby expanding the feedstock base.

[0110] In some embodiments, the fuel composition may include a pyrolysis fuel oil, such as a plastic pyrolysis oil or a biomass (wood, vegetable oil, algae) pyrolysis oil.

[0111] The diesel fuel composition may contain a mixture of any or all of the above diesel fuels.

[0112] In some embodiments, the diesel fuel composition can be a mixed diesel fuel comprising mineral diesel and renewable diesel. In such mixtures, renewable diesel can be present in an amount of, for example, up to 0.5%, up to 1%, up to 2%, up to 3%, up to 4%, up to 5%, up to 10%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95% or up to 99% by volume.

[0113] In some embodiments, the fuel composition may comprise pure renewable diesel.

[0114] A fuel comprising 100% renewable diesel is denoted R100; a fuel comprising 90% mineral diesel and 10% renewable diesel (by volume) is referred to as R10; a fuel comprising 50% mineral diesel and 50% renewable diesel (by volume) is referred to as R50; and so on.

[0115] In some preferred embodiments, the fuel compositions of the present invention comprise renewable diesel and one or more additional components selected from the group consisting of biodiesel, mineral diesel, and mixtures thereof.

[0116] In some embodiments, the fuel composition comprises renewable diesel and at least 5% by volume biodiesel.

[0117] In some embodiments, the fuel composition comprises renewable diesel and at least 20% by volume biodiesel.

[0118] In some embodiments, the fuel composition comprises renewable diesel and at least 5% by volume mineral diesel.

[0119] In some embodiments, the fuel composition comprises renewable diesel and at least 20% by volume mineral diesel.

[0120] In some embodiments, the diesel fuel comprises renewable diesel and 1 to 30 vol%, preferably 1 to 20 vol%, more preferably 1 to 10 vol% of a fuel selected from biodiesel, mineral diesel, and mixtures thereof.

[0121] Suitably, the one or more cold temperature enhancing additives are present in the diesel fuel composition in an amount of at least 1 ppm, preferably at least 10 ppm, more preferably at least 30 ppm, suitably at least 50 ppm.

[0122] Suitably, the one or more low temperature enhancing additives are present in the fuel composition in an amount of less than 30000 ppm, preferably less than 10000 ppm, preferably less than 5000 ppm, preferably less than 3000 ppm, for example less than 2500 ppm.

[0123] Suitably, the one or more cold temperature enhancing additives are present in the fuel composition in an amount of from 1 to 20000 ppm, preferably from 10 to 10000 ppm, more preferably from 30 to 5000 ppm, for example from 50 to 2500 ppm, 70 to 1000 ppm or 100 to 750 ppm.

[0124] In this specification, any reference to ppm refers to parts per million by volume. Treat rate values ​​given in parts per million (ppm) represent the amount of active agent present in the composition and do not include any diluents, carriers or other materials that may be present.

[0125] Diesel fuel compositions of the present invention may comprise one or more additional additives, such as those common in diesel fuels. These include, for example, antioxidants, dispersants, detergents, metal deactivation compounds, wax anti-settling agents, cold flow improvers, cetane number improvers, demisters, stabilizers, demulsifiers, defoamers, corrosion inhibitors, lubricity improvers, dyes, markers, combustion improvers, metal deactivators, odor masking agents, drag reducers, and conductivity improvers. Examples of the respective appropriate amounts of these types of additives will be known to those skilled in the art.

[0126] In some preferred embodiments, the diesel fuel composition of the present invention comprises one or more additional detergents. Preferred are nitrogen-containing detergents. Suitable detergents will be known to those skilled in the art.

[0127] In some embodiments, the composition may include one or more additional low temperature enhancing additives. Those skilled in the art generally refer to such compounds as cold flow improvers. Additional cold flow improver additives suitable for use herein include ethylene vinyl acetate copolymers; terpolymers of ethylene, vinyl acetate, and a third monomer; polyalkyl methacrylates; alpha olefin maleic anhydride copolymers; ester or imide derivatives of alpha olefin maleic anhydride copolymers; and combinations thereof.

[0128] According to a second aspect of the present invention, there is provided a method for improving the low temperature performance of a fuel composition comprising renewable diesel, the method comprising mixing into the composition one or more low temperature enhancing additives selected from the following:

[0129] (a) A copolymer comprising units of formula (I) and units of formula (II):

[0130]

[0131] Wherein, R is an alkyl group, and R 1 and R 2 Each is an alkyl or alkenyl group having 6 to 22 carbon atoms;

[0132] (b) the reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine; and

[0133] (c) The reaction product of a secondary amine with a copolymer of maleic anhydride and an alpha-olefin.

[0134] According to a third aspect of the present invention, there is provided a use of one or more low temperature enhancing additives selected from the following for improving the low temperature performance of a fuel composition comprising renewable diesel:

[0135] (a) A copolymer comprising units of formula (I) and units of formula (II):

[0136]

[0137] Wherein, R is an alkyl group, and R 1 and R 2 Each is an alkyl group or alkenyl group having 6 to 22 carbon atoms.

[0138] (b) the reaction product of a polycarboxylic acid having at least one tertiary amino group and a primary or secondary amine; and

[0139] (c) The reaction product of a secondary amine with a copolymer of maleic anhydride and an alpha-olefin.

[0140] Preferred aspects of the second and third aspects of the present invention are as described in relation to the first aspect.

[0141] The method and use of the present invention improves the low temperature properties of a fuel composition comprising renewable diesel. Preferably, the method and use reduces the cloud point of a fuel composition comprising renewable diesel.

[0142] Preferably, the method and use reduces the cloud point of a fuel composition comprising renewable diesel by at least 0.5°C, preferably at least 1°C.

[0143] The invention will now be further described with reference to the following non-limiting examples.

[0144] Example 1

[0145] The following additives were added to renewable diesel fuel at the specified treat rates, and the cloud point and pour point of the resulting compositions were measured.

[0146] A—A copolymer of vinyl acetate and dialkyl fumarate, wherein the alkyl group has 14 carbon atoms, wherein the number average molecular weight of the copolymer is about 9,000.

[0147] B-Reaction of copolymer of maleic anhydride and C18 alpha-olefin with 2 equivalents of ditallow fatty amine

[0148] C- Reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated tallow fatty amine

[0149] D—a copolymer of vinyl acetate and a dialkyl fumarate, wherein the alkyl group has 12 to 14 carbon atoms, wherein the copolymer has a number average molecular weight of about 8,200.

[0150] E-copolymer of vinyl acetate and dialkyl fumarate, wherein the alkyl group has 16 carbon atoms, wherein the number average molecular weight of the copolymer is about 7000

[0151] F-A copolymer of vinyl acetate and a dialkyl fumarate, wherein the alkyl group has 16 to 18 carbon atoms, wherein the copolymer has a number average molecular weight of about 14,000.

[0152] The results are shown in Table 1:

[0153] Table 1

[0154]

[0155] Example 2

[0156] Additive D was added to a range of different renewable diesel fuels in the amounts detailed in Table 2, and the cloud point and pour point of the resulting compositions were measured.

[0157] Table 2

[0158]

[0159]

[0160] Example 3

[0161] Additive D was added to a range of renewable diesel fuels including conventional mineral diesel and renewable diesel in the amounts detailed in Table 3, and the cloud point and pour point of the resulting compositions were measured.

[0162] Table 3

[0163]

Claims

1. A fuel composition comprising renewable diesel and one or more low temperature enhancing additives selected from the group consisting of: (a) A copolymer comprising units of formula (I) and units of formula (II): in, R is an alkyl group, and R 1 and R 2 Each is an alkyl or alkenyl group having 6 to 22 carbon atoms; (b) reaction products of polycarboxylic acids having at least one tertiary amino group with primary or secondary amines; and (c) The reaction product of a secondary amine with a copolymer of maleic anhydride and an alpha-olefin.

2. A method of improving the low temperature performance of a fuel composition comprising renewable diesel, the method comprising mixing into the composition one or more low temperature enhancing additives selected from the group consisting of: (a) A copolymer comprising units of formula (I) and units of formula (II): in, R is an alkyl group, and R 1 and R 2 Each is an alkyl or alkenyl group having 6 to 22 carbon atoms; (b) reaction products of polycarboxylic acids having at least one tertiary amino group with primary or secondary amines; and (c) The reaction product of a secondary amine with a copolymer of maleic anhydride and an alpha-olefin.

3. Use of one or more low temperature enhancing additives selected from the following for improving the low temperature performance of a fuel composition comprising renewable diesel: (a) A copolymer comprising units of formula (I) and units of formula (II): in, R is an alkyl group, and R 1 and R 2 Each is an alkyl or alkenyl group having 6 to 22 carbon atoms; (b) reaction products of polycarboxylic acids having at least one tertiary amino group with primary or secondary amines; and (c) The reaction product of a secondary amine with a copolymer of maleic anhydride and an alpha-olefin.

4. A composition, method or use according to any one of the preceding claims, wherein R 1 and R 2 Each is an alkyl or alkenyl group having 8 to 14 carbon atoms.

5. The composition, method or use of any preceding claim, wherein the one or more low temperature enhancing additives comprises component (a).

6. The composition, method or use according to any one of the preceding claims, wherein the one or more low temperature enhancing additives comprises component (b).

7. The composition, method or use according to any one of the preceding claims, wherein the one or more low temperature enhancing additives comprises component (c).

8. The composition, method or use of any of the preceding claims, wherein the one or more low temperature enhancing additives comprise a copolymer comprising units of formula (I) and units of formula (II): Where R is an alkyl group, R 1 and R 2 Each is an alkyl group having 10 to 14 carbon atoms, preferably 12 to 14 carbon atoms, and the number average molecular weight of the copolymer is 4,000 to 25,000, preferably 5,000 to 20,000, more preferably 6,000 to 15,000.

9. The composition, method or use according to claim 8, wherein the copolymer comprises 40 to 60 mol% of units of formula (I) and 60 to 40 mol% of units of formula (II).

10. The composition, method or use of any preceding claim wherein the one or more low temperature enhancing additives comprises the reaction product of 1 mole of ethylenediaminetetraacetic acid and 4 moles of hydrogenated tallow fatty amine.

11. The composition, method or use of any of the preceding claims, wherein the one or more low temperature enhancing additives comprise the reaction product of a copolymer of maleic anhydride and a C18 alpha-olefin and 2 equivalents of ditallow fatty amine.

12. The composition, method or use of any preceding claim, wherein the fuel comprises a mixture of renewable diesel and another diesel fuel.

13. The composition, method or use of claim 12, wherein the additional diesel fuel is selected from biodiesel, mineral diesel and mixtures thereof.

14. A method or use according to any one of claims 2 to 13 which reduces the cloud point of the fuel composition by at least 1°C.

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