MX2008005934A - Biodiesel fuel compositions having increased oxidative stability - Google Patents

Abstract

The present invention relates to biodiesel fuel compositions that have improved oxidation stability. More specifically, the biodiesel fuel compositions include at least one antioxidant that increases the oxidative stability of the fuel. The biodiesel fuel compositions may also include an antioxidant mixture, or an antioxidant mixture in combination with a polar and/or nonpolar solvent, that increases the oxidative stability of the fuel.

Description

COMPOSITIONS OF BIODIESEL FUEL THAT HAVE INCREASED OXIDATIVE STABILITY FIELD OF THE INVENTION The present invention relates to biodiesel fuel compositions having improved stability to oxidation. More specifically, biodiesel fuel compositions include at least one antioxidant that increases the oxidative stability of the fuel.

BACKGROUND OF THE INVENTION The use and production of biodiesel as an alternative to vehicle fuel, heating fuel and motor fuel has increased in recent years due to concerns regarding limited resources of petroleum-based fuels. Biodiesel is typically produced from transesterification, for example, vegetable oils, animal fats and cooking oils used. Biodiesel, since it has a higher content of unsaturated fatty acid esters, is easily oxidized in the presence of oxygen, UV light, heat, trace metals such as iron and copper, among others. The products made from this oxidation generate sediment formation and Ref.: 192445 rubber inside the fuel which generates corrosion and clogging in injection pumps and / or fuel pipes in engines, heaters and / or machines that use biodiesel as a fuel source. Thus, there is a need for a biodiesel fuel composition that has improved oxidation stability that reduces or eliminates sedimentation and gum formation within the fuel and as such reduces or eliminates corrosion and clogging in injection pumps and / or fuel lines in engines.

SUMMARY OF THE INVENTION One aspect of the present invention provides a fuel composition comprising a biodiesel from a different source of rapeseed oil, frying oil, sunflower oil and beef tallow and at least one antioxidant. The antioxidant is selected from the group consisting of n-propyl 3,4,5-trihydroxybenzoic acid ester, 1,2,3-tridoxybenzene, butylated hydroxyanisole, 2,6-diterbutyl-1-hydroxy-4-methylbenzene, a-tocopherol, α-tocopherol, α-tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthio butanoate, propyl gallate, dodecyl gallate, gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, palmityl citrate, chlorophyll, pyrogallol, naphthol, ascorbic acid, natural tocopherol, citric acid, sage extract, rosemary, eugenol and 6-ethoxy-l, 2-dihydro-2,2,4 - trimethylquinoline. Another aspect of the invention provides a fuel composition comprising a biodiesel and an antioxidant mixture. The mixture comprises at least two antioxidants which are selected from the group consisting of 2-terbutylhydroquinone, n-propyl ester of 3,4,5-trihydroxybenzoic acid, 1,2,3-trihydroxybenzene, butylated hydroxyanisole, 2,6-diterbutyl -l-hydroxy-4-methylbenzene, α-tocopherol acetate, α-tocopherol, β-tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthio butanoate, propyl gallate, dodecyl gallate, Gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, palmityl citrate, chlorophyll, pyrogallol, naphthol, ascorbic acid, natural tocopherol, citric acid, sage extract, rosemary, eugenol and 6-ethoxy-1 , 2-dihydro-2,2,4,4-trimethylquinoline. Yet another aspect of the invention provides a fuel composition comprising a first antioxidant having the formula (I), (I) wherein: R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen and an alkyl group having from 1 to about 6 carbons; and R5 is an alkoxy group having from 1 to about 12 carbons a second antioxidant does not have the formula (I), a polar solvent, a non-polar solvent in which the two solvents form a homogeneous liquid. A further aspect of the invention provides a method for increasing the oxidative stability of a fuel composition comprising contacting a biodiesel in an antioxidant mixture comprising at least two antioxidants. The two antioxidants are selected from the group consisting of 2-terbutylhydroquinone, 3, 4, 5-trihydroxybenzoic acid n-propyl ester, 1,2,3-trihydroxybenzene, butylated hydroxyanisole, 2,6-diterbutyl-l-hydroxy-4-methylbenzene, α-tocopherol acetate, α-tocopherol, ? -tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthio butanoate, propyl gallate, dodecyl gallate, gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, citrate palmityl, chlorophyll, pyrogallol, naphthol, ascorbic acid, natural tocopherol, citric acid, sage extract, rosemary, eugenol and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline. Other aspects and features of the invention will be evident in part and in part highlighted in what follows.

DETAILED DESCRIPTION OF THE INVENTION Advantageously, the present invention provides biodiesel fuel compositions that have improved stability to oxidation. The fuel compositions of the invention comprise a biodiesel and at least one antioxidant that increases the oxidative stability of the fuel. The combustible compositions of the present invention, as such, not only have improved oxidative stability but also have longer induction times, smaller amounts of insolubles and lower peroxide values.

I. Biodiesel The fuel composition of the invention includes a biodiesel. Generally speaking, a biodiesel suitable for use in the invention is typically an ester, such as a monoalkyl ester of long chain fatty acids derived from a lipid source. The lipid source can be found naturally such as a liquid derived from a plant or animal or it can be produced synthetically.

In one modality, biodiesel can be made from vegetable oil, spent cooking oil or animal fat. In one embodiment, biodiesel is produced from a vegetable oil. In another embodiment, biodiesel is produced from a vegetable oil that is selected from the group consisting of soybean oil, corn oil, rapeseed oil, coconut oil, peanut oil, palm oil, cottonseed oil, oil of sunflower, mustard seed oil, camelina oil, jojoba oil, safflower oil and hemp oil. Other vegetable oils can also be used if they depart from the scope of the invention. In an exemplary embodiment, biodiesel is produced from soybean oil. In another exemplary embodiment, biodiesel is produced from rapeseed oil. In another embodiment, biodiesel is produced from vegetable oil such as jatropha oil and algae oil. In a further embodiment, biodiesel is produced from spent cooking oil, such as used frying oil. In another additional embodiment, biodiesel is produced from animal fat that is selected from the group consisting of tallow, poultry fat and lard. In another additional embodiment, biodiesel can be produced from yellow fat. In yet another embodiment, biodiesel can be produced from fish oil such as menhaden oil, anchovy oil, and mackerel oil, other others. In a further embodiment, biodiesel can be produced from marine oil such as whale oil or shark oil. As will be appreciated by those skilled in the art, biodiesel can also be produced from a combination of lipids derived from different sources. For example, biodiesel can be produced from soybean oil and animal fat. A variety of methods generally known in the art can be used to make the biodiesel of the present invention from any lipid source known in the art and identified herein. In general, biodiesel is produced through the transesterification of vegetable oils, spent cooking oils or animal fats. The methods typically include base catalyzed transesterification of the oil or fat with an alcohol and direct acid catalyzed esterification of the oil or fat with methanol, conversion of the oil or fat to fatty acids and then to alkyl esters with an acid catalyst. In a base catalyzed transesterification process, an oil or a fat is reacted with an alcohol such as methanol or ethanol in the presence of a catalyst such as sodium hydroxide or potassium hydroxide to produce glycerin and methyl or ethyl esters. The glycerin is then separated from the biodiesel. Once the separation of glycerin and biodiesel has been completed, the alcohol is separated by distillation. Glycerin is usually neutralized with an acid and sent to store it as raw glycerin. Once separated from glycerin, biodiesel is generally purified by gently washing it with lukewarm water (the washing of methyl ester) to remove residual catalysts or soaps, it is dried and sent for storage. The present invention also contemplates combinations of biodiesel and petroleum-based biodiesel fuels. It will be appreciated by a person skilled in the art that the amount of biodiesel and petroleum diesel present in the fuel composition of the present invention can and will vary, depending on the proposed use of the fuel. For example, the fuel composition may comprise from about 10% to about 40% by weight of biodiesel and from about 60% to about 90% by weight of petroleum-based diesel. In another embodiment, the fuel composition may comprise from about 20% to about 30% by weight of biodiesel and from about 70% to about 80% by weight of petroleum-based diesel. In yet another embodiment, the fuel composition comprises about 20% by weight of biodiesel and about 80% by weight of petroleum-based diesel, which is known as B20.

II. Antioxidants The fuel composition of the invention also includes one or more antioxidants. Generally speaking, antioxidants suitable for use in the present invention inhibit the oxidation process and therefore increase the oxidative stability of the fuel composition and reduce the formation of insoluble substances. In particular, applicants have found that by contacting at least one antioxidant with a biodiesel to form a biodiesel fuel composition, the fuel has an increased oxidative stability. In addition, to increase the oxidative stability of the fuel, the antioxidant will further reduce the emissions of NOx, carbon monoxide and other fuels. Those skilled in the art will appreciate that different antioxidants can be used depending on the type of biodiesel to be stabilized. to. Individual Antioxidants In one embodiment, the antioxidant is selected from the group consisting of butylated hydroxyanisole (BHA); butylated hydroxytoluene; gallates such as octyl gallate, dodecyl gallate and n-propyl 3,4,5-trihydroxybenzoic acid ester (propyl gallate); 1,2,3-trihydroxybenzene (pyrogallol); Gallic acid; fatty acid esters including but not limited to methyl esters such as methyl linoleate, methyl oleate, methyl stearate and other esters such as ascorbic palmitate; disulfiram; tocopherols such as α-tocopherol, d-tocopherol acetate and α-tocopherol and α-tocopherol marketed under the name COPHEROL 1300MR by the company Henkel and tocopherol derivatives and precursors such as Coviox T-50 from the company Cognis; rosemary deodorized extract; propionate esters and thiopropionate esters such as isopropyl 2-hydroxy-4-methylthio butanoate, lauryl thiodipropionate or dilauryl thiodipropionate; β-lactoglobulin; ascorbic acid; amino acids such as phenylalanine, cysteine, tryptophan, methionine, glutamic acid, glutamine, arginine, leucine, tyrosine, lysine, serine, histidine, threonine, asparagine, glycine, aspartic acid, isoleucine, valine and alanine; 2, 2, 6, 6-tetramethylpiperidinooxi, also referred to as tannin; 2, 2, 6, 6-tetramethyl-4-hydroxypiperidino-l-oxyl also referred to as tanol; dimethyl-p-phenylaminophenoxysilane; di-p-anisylazoxides; p-hydroxydiphenylamine and carbonates, phthalates and adipates thereof; and diluted, a 1,4-dihydropyridine derivative. In another embodiment, the antioxidant may be selected from the group comprising lipid-soluble antioxidants including but not limited to ascorbyl palmitate, butylated hydroxytoluene, lecithin, α-tocopherol, phenyl-a-naphthylamine, hydroquinone, nordihydroguaiaretic acid and rosemary extract . In a further embodiment the antioxidant may be synthetic or natural antioxidants which are selected from the group comprising vitamin C and derivatives (ascorbic acid); vitamin E and derivatives (tocopherols, tocotrienols, acetate); sage extract; eugenol; rosemary; flavonoids and derivatives (which include catechins); phenolic acids and derivatives; 2-tert-butylhydroquinone (TBHQ); mixtures of TBHQ, glyceryl oleate, propylene glycol, vegetable oil and citric acid such as TENOX 20MR and TENOX 21MR by the Eastman Chemical Company; imidazolidinylurea, quaternary ammoniums, diazolidinylurea; Erythorbic acid; sodium erythorbate, lactic acid, calcium ascorbate, sodium ascorbate, potassium ascorbate, ascorbyl stearate, eritory acid; sodium eritorbine; butylhydroxinone; sodium, potassium, calcium or magnesium lactate; citric acid; sodium, monosodium, disoic or trisodium citrates; potassium citrate, monopotassium or tripotassium; stearyl citrate; Palmitoyl citrate; tartaric acid; sodium, monosodium or disodium tartrate; potassium tartrate, monopotassium or dipotassium tartrate; sodium and potassium tartrate; phosphoric acid; sodium, monosodium, disodium or trisodium phosphates; potassium, monopotassium, dipotassium and tripotassium phosphates; stannous chloride; chlorophyll; lecithin; nordihydroguaiaretic acid (NDGA); alcoholic esters of galatos; ascorbyl stearate; 2-tert-butyl-4-hydroxyanisole; 3-terbutyl-4-hydroxyanisole; 1-cysteine hydrochloride; guaiac gum; lecithin citrate; monoglyceride citrate; monoisopropyl citrate; Ethylenediaminetetraacetic acid; 2,6-diterbutyl-4-hydroxymethylphenol; 2-6-diterbutyl-4-methylphenol (BHT) and terbutyl-4-methylphenol (t-BHT); polyphosphates; trihydroxybutyrophenone; anoxomer and combinations thereof such as RENDOX ™ by Kemin Industries which contains a mixture of propylene glycol, monoglycerides and diglycerides, butylated hydroxyanisole and citric acid. Other synthetic antioxidants include antioxidants marketed under the names BIOCAPS GP, BIOCAPS A-70, BIOCAPS TL, BIOCAPS ER, BIOCAPS PA, AP, CONTROX VP, COPHEROL 1300, DADEX, VANLUBE 848, IONOL and BAYNOX. In yet another embodiment, the antioxidant may be water-soluble antioxidants that are selected from the group of ascorbic acid, sodium metabisulfite, sodium bisulfite, sodium thiosulfite, sodium formaldehyde sulfoxylate, isoascorbic acid, thioglycerol, thiosorbitol, thiourea, thioglycolic acid, hydrochloride. of cysteine, 1,4-diazobicyclo- (2, 2, 2) -octane, malic acid, fumaric acid and lycopene. In an exemplary embodiment, the antioxidant may be substituted 1,2-dihydroquinoline compounds. The substituted 1,2-dihydroquinoline compounds suitable for use in the invention generally correspond to formula (I): wherein: R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen and an alkyl group having from 1 to about 6 carbons; R5 is an alkoxy group having from 1 to about 12 carbons. In another embodiment, the substituted 1, 2-dihydroquinoline will have the formula (I) wherein: R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen and an alkyl group having from 1 to about 4 carbons; and R5 is an alkoxy group having from 1 to about 4 carbons. In a preferred embodiment, the substituted 1,2-dihydroquinoline will be 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline having the formula: 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, commonly known as ethoxyquin, is sold under the trade name SANTOQUINMR or AGRADOMR. The present invention also encompasses ethoxyquin salts and other compounds having formula (I). Ethoxyquin and other compounds having formula (I) are commercially available from Novus International, Inc. or can be made according to methods generally known in the art, for example as detailed in the US patent. No. 4,772,710, which is incorporated herein by reference in its entirety. b. Antioxidant Formulations In one embodiment, the antioxidant of the present invention is an antioxidant mixture comprising at least two antioxidants as described in part II (a). In another embodiment, the antioxidant mixture comprises a first antioxidant of a substituted 1,2-dihydroquinoline compound of formula (I) and a second antioxidant that does not have the formula (I). The second antioxidant may be any of the antioxidants described in part II (a) above other than the antioxidant of formula (I). In other embodiments, the antioxidant mixture may include at least three different antioxidants. In additional embodiments, the combination may include four or more antioxidants. Non-limiting examples of suitable antioxidant mixtures are set forth in Table A. A preferred composition comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (ethoxyquin) and 2-tert-butylhydroquinone. Other preferred compositions comprise 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline as well as one or more of the following: 2-tert-butylhydroquinone, 3,4-trihydroxybenzoic acid n-propyl ester, 1 2, 3-trihydroxybenzene, butylated hydroxyanisole, 2,6-diterbutyl-l-hydroxy-4-methylbenzene, α-tocopherol acetate, α-tocopherol, α-tocopherol, d-tocopherol, dilauryl thiodipropinate, 2-hydroxy-4 - isopropyl methylthiobutanoate, propyl gallate, dodecyl gallate, gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, palmityl citrate, chlorophyll, pyrogallol, a-naphthol, ascorbic acid, natural tocopherol, citric acid , extract of sage, rosemary and eugenol.

Table A. Formulations of antioxidant mixtures Other suitable combinations of antioxidants are detailed in the examples. c. Solvents The antioxidant composition may further comprise a polar solvent. Generally speaking, the polar solvent solubilizes water-soluble antioxidants. Suitable examples of polar solvents include, but are not limited to glycerol, isopropyl alcohol, ethyl alcohol, propylene glycol, erythritol, xylitol, sorbitol, maltitol, mannitol, water, polyol or combinations thereof. In one embodiment, the polar solvent is glycerol. In another embodiment, the polar solvent is propylene glycol. The concentration of the polar solvent will vary depending on the combination of antioxidants in the composition. In general, the volume percentage of the polar solvent can vary from about 5% to about 50%. The percentage by volume of glycerol can be about 5%, 10%, 15%, 20% or 25%. The volume percentage of propylene glycol can be about 5%, 10%, 15%, 20% or 25%. The antioxidant composition may further comprise a non-polar solvent. In general, the non-polar solvent solubilizes fat-soluble antioxidants and helps revert to the miscible antioxidant composition in an oil or a fat sample. In a preferred embodiment, the non-polar solvent is a biodiesel as described in part I above. Suitable examples of other non-polar solvents include, but are not limited to, vegetable oils, monoglycerides, diglycerides, triglycerides and combinations thereof. The vegetable oil can be corn oil, soybean oil, canola oil, cottonseed oil, palm oil, peanut oil, safflower oil and sunflower oil. The monoglycerides and diglycerides can be isolated and distilled from vegetable oils, or the monoglycerides and diglycerides can be synthesized chemically via an esterification reaction. In one embodiment, the non-polar solvent may be corn oil. In another embodiment, the non-polar solvent may comprise corn oil and monoglycerides. The concentration of the non-polar solvent will vary depending on the combination of antioxidants to the composition. In general, the volume percent of the non-polar solvent can vary from about 5% to about 50%. The volume percentage of monoglycerides can be 5%, 15%, 20% or 25%. The percentage by volume of corn oil can be 5%, 10%, 15%, 20% or 25%. In one embodiment, the percentage by volume of corn oil can be 15-25%. In another embodiment, the volume percentage of monoglycerides may be 15-20% and the volume percent corn oil may be about 5-10%.

III. Fuel Compositions The fuel compositions comprise biodiesel, one or more antioxidants and optionally a polar solvent, a non-polar solvent and / or a petroleum-based diesel. In one embodiment, the fuel composition of the invention comprises a biodiesel and at least one antioxidant the oxidative stability of the fuel composition is increased. In this embodiment, biodiesel can be any of the biodiesel described in part I in combination with any of the antioxidants described in part II. In an alternative embodiment, the fuel composition comprises any of the biodiesel as described in part I of the specification in addition to those produced from the undistilled or distilled forms of rapeseed oil, frying oil, sunflower oil and beef tallow and at least one antioxidant, is described in part II of the above specification. Examples of exemplary fuel compositions are presented in Table B below. Alternatively, each fuel composition detailed in Table B may also include 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.

TABLE B Raw material of Biodiesel antioxidants Soybean oil n-propyl ester of 3,4,5-trihydroxybenzoic acid Soybean oil 1,2,3-trihydroxybenzene Soybean oil Hydroxyanisole butylated Soybean oil terbuti1-4-methylphenol Soybean oil 2, 6-diterbutyl-l-hydroxy-4-methylbenzene Soybean oil 6-ethoxy-l, 2-dihydro-2,2, 4- trimethylquinoline Acetic acid a-tocopherol acetate Soybean oil a-tocopherol Soybean oil? -tocopherol Soybean oil d-tocopherol Soybean oil thiodipropionate of dilauril Soybean oil 2-hydroxy-4-methylpropiobutanoate isopropyl oil Soybean gallate dodecyl Soybean oil gallic acid Soybean oil octyl gallate Soybean oil Ascorbyl palmitate Soybean oil lecithin Soybean oil stearyl citrate Raw material of Biodiesel antioxidants Soybean oil Palmitoyl citrate Soybean oil Chlorophyll Soybean oil Propyl gallate Soybean oil Pyrogallol Soybean oil with naphthol Soybean oil Ascorbic acid Soybean oil Natural tocopherols Soybean oil Citric acid Soybean oil Sage extract soybean Rosemary Soybean eugenol Corn oil N-propyl ester of 3,4,5-trihydroxybenzoic acid Corn oil 1, 2, 3-trihydroxybenzene Hydrogenated corn oil butylated oxyanisole Corn oil terbutil-4-methylphenol Corn oil 2,6-diterbutyl-l-hydroxy-4-methylbenzene Corn oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline Corn oil a-tocopherol acetate Corn oil a-tocopherol Corn oil? -tocopherol Raw material of Biodiesel antioxidants Corn oil d- tocopherol Corn oil dilauryl thiodipropionate Corn oil 2-hydroxy-4-methylthio butanoate isopropyl corn oil Dodecyl gallate Corn oil gálico acid Corn oil octyl gallate Corn oil Ascorbyl palmitate Corn oil lecithin or oil corn stearyl citrate Corn oil Corn palm citrate Corn oil chlorophyll Corn oil Corn galley oil Corn oil pyrogallol Corn oil a-naphthol Corn oil ascorbic acid Corn oil natural tocopherols Corn oil citric acid Corn oil extract salvia Corn oil Rosemary Corn oil eugenol Coconut oil n-propyl ester of 3,4,5-trihydroxybenzoic acid Coconut oil 1,2,3-trihydroxybenzene no Coconut oil Butylated hydroxyanisole Coconut oil terbutyl-4-methylphenol Coconut oil 2,6-diterbuty1-1-hydroxy-4-methylbenzene Coconut oil 6-ethoxy-l, 2-dihydro-2, 2, 4- trimeti Iquinoline Coconut oil a-tocopherol acetate coconut oil a-tocopherol Coconut oil? -tocopherol Coconut oil d-tocopherol Coconut oil thiodipropionate of dilauryl Coconut oil 2-hydroxy-4-methylpropiobutanoate isopropyl Coconut oil dodecyl gallate Coconut oil Gallic acid Coconut oil octyl gallate Coconut oil Ascorbyl palmitate Coconut oil lecithin Coconut oil stearyl citrate Coconut oil palmitoyl citrate Coconut oil chlorophyll Coconut oil propyl gallate Coconut oil pyrogallol Raw material of Biodiesel antioxidants Peanut oil Dodecyl gallate Peanut oil Gallic acid Peanut oil Octyl gallate Peanut oil Ascorbyl palmitate Peanut oil Lecithin Peanut oil Stearyl citrate Peanut oil Palmitoyl citrate Peanut oil Chlorophyll oil propylene gallate peanut oil Pyrogallol peanut oil Naphthol oil Peanut oil ascorbic acid Peanut oil natural tocopherols Peanut oil citric acid Peanut oil Sage extract Peanut oil Rosemary Peanut oil eugenol Palm oil n-propyl ester acid 3,4,5- trihydroxybenzoic Palm oil 1,2,3-trihydroxybenzene Palm oil Butylated hydroxyanisole Palm oil terbutil-4-methylphenol Raw material of Biodiesel antioxidants Palm oil 2,6-diterbuty1-1-hydroxy-4 - methybenzene Palm oil 6-ethoxy-l, 2-dihydro-2, 2, 4-trimeti-quinoline Oil palm a-tocopherol acetate Palm oil a-tocopherol Palm oil? -tocopherol Palm oil d-tocopherol Palm oil thiodipropionate of dilauryl palm oil 2-hydroxy-4-methylthiobutanoate of isopropyl palm oil dodecyl gallate palm oil gallic acid palm oil octyl gallate palm oil ascorbyl palmitate palm oil lecithin palm oil stearyl citrate oil palm palmitoyl citrate Palm oil chlorophyll Palm oil palm propyl gallate Palm oil pyrogallol Palm oil to naphthol Palm oil ascorbic acid Raw material of Biodiesel Antioxidants Camelin oil 6-ethoxy-l, 2-dihydro-2, 2,4-trimeti-quinoline Acetate of camelina Acetate of a-tocopherol Aceite of camelina a-tocopherol Oil of camelina? -tocopherol Oil of camelina d- tocopherol Cameline oil Dilauryl thiodipropionate Cameline oil Isopropyl 2-hydroxy-4-methylthiobutanoate oil Dodecyl camelina gallate oil Cameline acid Gallic acid Camelline octyl gallate oil Cameline oil Ascorbyl palmitate Camelin lecithin oil Camelin citrate oil Stearil Oil Camelin Oil Palmite Citrate Cameline Oil Chlorophyll Cameline Oil Propyl Gallate Cameline Oil Pyrogallol Camelina Oil to Naphthol Camelina Oil Ascorbic Acid Cameline Oil Tocopherols Natural Raw material of Biodiesel Antioxidants Hemp oil A-tocopherol acetate Hemp oil a-tocopherol Hemp oil? -tocopherol Hemp oil d-tocopherol Hemp oil Dilauryl thiodipropionate Hemp oil 2-hydroxy-4-methylthiobutanoate isopropyl oil of hemp, dodecyl gallate, hemp oil, gallic acid, hemp oil, octyl gallate, hemp oil, hemp oil, ascorbyl palmitate, hemp oil, lecithin, hemp oil, stearyl citrate, hemp oil, palmitoyl citrate, hemp oil, chlorophyll, hemp oil, propyl gallate, oil, 'hemp pyrogallol Hemp oil naphthol Hemp oil ascorbic acid Hemp oil natural tocopherols Hemp oil citric acid Hemp oil Hemp extract Raw material of Biodiesel antioxidants Hemp oil Rosemary Hemp oil eugenol Marine oil n-propylester acid 3 , 4,5- trihydroxybenz oico Marine oil 1,2,3-trihydroxybenzene Marine oil Butylated hydroxyanisole Marine oil terbutil-4-methylphenol Marine oil 2,6-diterbutyl-l-hydroxy-4-methylbenzene Marine oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline Marine oil a-tocopherol acetate Marine oil a-tocopherol Marine oil? -tocopherol Marine oil d-tocopherol Marine oil dilastyl thiodipropionate Marine oil 2- isopropyl hydroxy-4-methylthiobutanoate Marine oil dodecyl gallate Marine oil gallic acid Marine oil octyl gallate Marine oil ascorbyl palmitate Marine oil lecithin Materi = i Antioxidants biodiesel premium 6-ethoxy-l, 2-dihydro-2, 2, 4-corral trimeti Iquinoline bird fat A-tocopherol acetate bird fat A-tocopherol poultry bird fat Bird fat of? -tocopherol corral D-tocopherol poultry bird fat Dilauryl thiodipropionate poultry bird fat Poultry dodecyl gallate 2-hydroxy-4-methylthiobutanoate bird fat Potato dodecyl gallate bird fat Poultry gallic acid bird fat Fat of birds of octyl gallate corral Fat of ascorbyl palmitate birds Raw material of Antioxidants biodiesel Fat of birds of lecithin corral Fat of birds of stearyl citrate corral Fat of birds of citrate of palmitoyl corral Fat of birds of chlorophyll corral Fat Fat of birds of gallant of propilo corral Fat of birds of pirogalol corral Fat of birds of a naftol corral Fat of birds of ascorbic acid corral Fat of birds of natural tocopherols corral Fat of birds of acid c poultry farm Poultry silage extract fat Raw material of Biodiesel antioxidants Poultry rosemary fat Pigeon eugenol bird oil Safflower n-propyl ester oil 3,4,5-trihydroxybenzoic acid Safflower oil 1,2,3 -trihydroxybenzene Safflower oil Butylated hydroxyanisole Safflower oil terbuti1-4-methylphenol Safflower oil 2, 6-diterbutyl-l-hydroxy-4-methylbenzene Safflower oil 6-ethoxy-l, 2-dihydro-2, 2, 4- trimeti Iquinoline Safflower oil a-tocopherol acetate a-tocopherol oil Safflower oil? -tocopherol Safflower oil d-tocopherol Safflower oil thiodipropionate Dilauril Safflower oil 2-hydroxy-4-methylpropiobutanoate isopropyl oil Safflower oil Dodecyl gallate Safflower oil Gallic acid Acetic safflower Oil of octyl gallate Raw material of Biodiesel antioxidants J atropha oil a-tocopherol acetate Jatropha a-tocopherol oil Jatropha? -tocopherol oil Jatropha d-tocopherol oil Dashuryl jatropha thiodipropionate oil Jatropha 2-hydroxy-4-methylthiobutanoate isopropyl oil Jatropha gallate dodecyl oil Jatropha oil gallic acid Jatropha oil octyl gallate Jatropha palmitate oil Ascorbyl oil Jatropha lecithin oil Jatropha oil stearyl citrate Jatropha oil palm citrate citrate Jatropha chlorophyll oil Jatropha gallate propyl oil Oil from jatropha pirogalol Jatropha to naphthol oil Jatropha acid ascorbic acid oil Natural jatropha tocopherols oil Jatropha acid citric acid Jatropha oil sage extract Raw material of Biodiesel antioxidants Seaweed oil stearil citrate Seaweed oil Palmitate citrate Algae oil chlorophyll Seaweed oil propyl gallate Seaweed oil pyrogallol Seaweed oil with naphthol Seaweed oil ascorbic acid Seaweed oil natural tocopherols Acid seaweed oil citrus Algae oil sage extract Algae oil Rosemary Seaweed oil eugenol In a preferred embodiment, the fuel composition comprises a biodiesel produced from soybean oil and 6-ethoxy-1,2-dihydro-2,2-trimethylquinoline. In another preferred embodiment, the fuel composition comprises a biodiesel produced from soybean oil and 2-tert-butylhydroquinone. In yet another embodiment, the fuel composition comprises a biodiesel produced from yellow fat (80% vegetable oil and 20% tallow that is not edible) and 6-ethoxy-1,2-dihydro-2, 2, 4- trimethylquinoline. In a further embodiment, the fuel composition comprises a biodiesel produced from fish oil and 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. Those skilled in the art will appreciate that the concentration of antioxidants added to biodiesel will vary depending on the source of biodiesel. In one embodiment the fuel composition comprises a biodiesel produced from soybean oil and from about 20 ppm to about 2000 ppm of 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and from about 50 ppm to about 500 ppm of 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. The present invention also relates to a fuel composition comprising a biodiesel and an antioxidant mixture comprising at least two antioxidants and optionally a polar solvent, a non-polar solvent and / or a petroleum-based diesel. In one embodiment, the fuel composition comprises any of the biodiesel as described in part I and an antioxidant mixture comprising at least two antioxidants as described in part II of the above specification. In another embodiment, the fuel composition comprises a first antioxidant having formula (I), a second antioxidant having no formula (I), a polar solvent, and a non-polar solvent as described in part II of the above specification , where the two solvents form a homogeneous liquid. Preferably, the non-polar solvent is a biodiesel as described in part I of the above specification. Of course, those skilled in the art will appreciate that mixtures of antioxidant will vary considerably depending on the type of biodiesel to be stabilized. Exemplary fuel compositions are presented in Table C below.

Yellow grease 2-tert-butylhydroquinone and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline Yellow fat butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy-4-methylbenzene Yellow fat butylated hydroxyanisole and 2, 6 diterbutyl-l-hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline Yellow fat 2-tert-butylhydroquinone and citric acid Yellow fat butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy 4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone Yellow fat 2-terbutylhydroquinone and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and oil of corn Yellow fat, butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and vegetable oil Yellow fat 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil Yellow fat 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline, propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol Yellow fat 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline, butylated hydroxyanisole oil and 2,6-diterbutyl-l-peanut hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl- l-peanut hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2, -trimethylquinoline 2-tert-butylhydroquinone oil and peanut citric acid Butylated hydroxyanisole oil and 2, 6-diterbutyl-l-peanut hydroxyanisole 4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-terbutylhydroquinone 2-tert-butylhydroquinone oil and 6-ethoxy-1,2-peanut dihydro-2,2,4-trimethylquinoline and corn oil Butylated hydroxyanisole oil and 2,6-diterbutyl-l-peanut hydroxy-4-methylbenzene and vegetable oil Oil of 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline peanut and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-l, 2-dihydro-2 oil , 2,4-trimethylquinoline, propyl gallate peanut, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-Ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline oil, dodecyl gallate peanut, naphthol, corn tocopherols, butylated hydroxyanisole palm oil and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and vegetable oil Palm oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil Palm oil 6-ethoxy-1, 2-dihydro- 2,2, 4-trimethylquinoline, propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol Palm oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline, dodecyl gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol Palm oil 6-ethoxy-l, 2-dihydro-2 , 2,4-trimethylquinoline, 2,6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil Palm oil 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline , mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2-tert-butylhydroquinone, lecithin and corn oil 2-tert.-butyl hydroquinone oil and 6-ethoxy-1, 2-fish dihydro-2,2,4-trimethylquinoline Butylated hydroxyanisole oil and 2, 6-diterbutyl-l-fish hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl-l-fish hydroxy-4-methylbenzene and 6-ethoxy-l, 2- dihydro-2,2, - trimethylquinoline 2-tert.-butyl hydroquinone oil and citric acid fish Butylated hydroxyanisole oil and 2,6-diterbutyl-l-fish hydroxy-4-methylbenzene and 6-ethoxy-l, 2- dihydro- 2, 2, 4-trimethylquinoline and 2-terbutylhydroquinone 2-tert-butylhydroquinone oil and 6-ethoxy-1,2-fish dihydro-2,2,4-trimethylquinoline and corn oil Butylated hydroxyanisole oil and 2,6-diterbutyl- l-fish hydroxy-4-methylbenzene and vegetable oil 6-ethoxy-l, 2-dihyd or-2, 2, 4-trimethylquinoline fish oil and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-1,2-dihydroxycarbonyl ether 2,2, 4-trimethylquinoline, fish propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline fish, dodecyl gallate fish, naphthol, propylene glycol tocopherols 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline butter 2 , 6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline, mixed natural tocopherols, ascorbyl palmitate, gallate propyl, 2- tert-butylhydroquinone, lecithin and corn oil 2-tert.-butylhydroquinone oil and 6-ethoxy-l, 2-cotton dihydro-2, 2,4-trimethylquinoline Butylated hydroxyanisole oil and 2,6-diterbutyl-l-cotton hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl-l-cotton hydroxy-4- methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline 2-tert-butylhydroquinone oil and cotton citric acid Butylated hydroxyanisole oil and 2,6-diterbutyl-l-cotton hydroxy-4-methylbenzene and 6- ethoxy-l, 2- dihydro-2, 2,4-trimethylquinoline and 2-terbutylhydroquinone 2-tert-butylhydroquinone oil and 6-ethoxy-1,2-cotton dihydro-2,2,4-trimethylquinoline and corn oil Hydroxyanisole oil butylated and 2, 6-diterbutyl-l-cotton hydroxy-4-methylbenzene and vegetable oil Oil of 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline cotton and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-l, 2-dihydro-2 oil , 2, 4-trimethylquinoline, cotton propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline, cotton dodecyl gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol 6-ethoxy-1,2-dihydro-2 oil 2, 4-trimethylquinoline, cotton 2, 6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil 6-Ethoxy-1,2-dihydro-2,2, -trimethylquinoline oil, cotton mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2-tert-butylhydroquinone, lecithin and corn oil 2-tert-butyl hydroquinone oil and 6-ethoxy-1, 2-sunflower dihydro-2,2,4-trimethylquinoline Butylated hydroxyanisole oil and 2, 6-diterbutyl-l-sunflower hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl-l-sunflower hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2, 2, 4- trimethylquinoline 2-tert.-alkylhydroquinone oil and sunflower citric acid Butylated hydroxyanisole oil and 2,6-diterbutyl-l-sunflower hydroxy-4-methylbenzene and 6-ethoxy-2- dihydro-2, 2,4-trimethylquinoline and 2-terbutylhydroquinone 2-tert-butylhydroquinone oil and 6-ethoxy-1,2-sunflower dihydro-2,2,4-trimethylquinoline and corn oil Butylated hydroxyanisole oil and 2, 6 diterbutil-l-sunflower hydroxy-4-methylbenzene and vegetable oil Oil of 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline sunflower and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-1,2-dihydro-2 oil , 2, 4-trimethylquinoline, sunflower propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-ethoxy-l, 2-dihydro-2,2, 4-trimethylquinoline, sunflower gallate dodecyl, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol oil 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline, sunflower 2, 6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline oil sunflower mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2- tert-butylhydroquinone, lecithin and corn oil 2-tert.-butyl hydroquinone oil and 6-ethoxy-1,2-camelina dihydro-2,2,4-trimethylquinoline Butylated hydroxyanisole oil and 2, 6-diterbutyl-l-camelina hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl-l-camelina hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4 -trimethylquinoline 2-tert.butylhydroquinone oil and citric acid camelina Butylated hydroxyanisole oil and 2,6-diterbutyl-l-camelina hydroxy-4-methylbenzene and 6-ethoxy-l , 2-dihydro-2, 2,4-trimethylquinoline and 2-tert-butylhydroquinone 2-tert-butylhydroquinone oil and 6-ethoxy-1,2-camelina dihydro-2,2,4-trimethylquinoline and corn oil Butylated hydroxyanisole oil and , 6-diterbutyl-l-camelina hydroxy-4-methylbenzene and vegetable oil Oil of 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline camelina and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-l, 2-dihydro-2 oil , 2-trimethylquinoline, propyl camelina gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-ethoxy-l, 2-dihydro-2,2, 4-trimethylquinoline oil, dodecyl camelina gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol 6-ethoxy-1, 2-dihydro-2 oil, 2, 4-trimethylquinoline, camelina 2, 6-diterbutyl-4-methylphenol, pyrogallol, 2-terbutylhydroquinone, stearyl citrate and corn oil 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline oil camelina mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2- tert-butylhydroquinone, lecithin and corn oil Jojoba oil 2-tert-butylhydroquinone and 6-ethoxy-l, 2-dihydro-2, 2, 4-trimethylquinoline Jojoba oil butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy-4-methylbenzene Oil of jojoba butylated hydroxyanisole and 2, 6-diterbutyl-l-hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline Jojoba oil 2-terbutylhydroquinone and citric acid Butylated hydroxyanisole jojoba oil and 2, 6-diterbutyl-l-hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-terbutylhydroquinone Jojoba oil 2-terbutylhydroquinone and 6-ethoxy-2 - dihydro-2,2,4-trimethylquinoline and corn oil Jojoba oil butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and vegetable oil Jojoba oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil Jojoba oil 6-ethoxy-1,2-dihydroxy 2, 2, 4 -trimeti-quinoline, propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol Jojoba oil 6-ethoxy-l, 2-dihydro-2,2, -trimethylquinoline, dodecyl gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol Jojoba oil 6-ethoxy-l, 2-dihydro-2, 2, 4-trimethylquinoline, 2,6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil Jojoba oil 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2- tert-butylhydroquinone, lecithin and corn oil Hemp oil 2-tert-butylhydroquinone and 6-ethoxy-2-dihydro-2,2,4-trimethylquinoline Hempylated hydroxyanisole hemp oil and 2, 6-diterbutyl-l-hydroxy-4-methylbenzene Butylated hydroxyanisole hemp oil and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and 6-ethoxy-l, 2- dihydro-2, 2, 4 - trimethylquinoline Hemp oil 2-tert-butylhydroquinone and citric acid Hemp oil hydroxyanisole butylated and 2,6-diterbutyl-l-hydroxy-4-methylbenzene oy 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-terbutylhydroquinone Hemp oil 2-tert-butylhydroquinone and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and corn oil Butylated hydroxyanisole hemp oil and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and vegetable oil Hemp oil 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil Hemp oil 6-ethoxy-1,2-dihydroxycarbonate 2, 2-trimethylquinoline, propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol Hemp oil 6-ethoxy-l, 2-dihydro-2,2, -trimethylquinoline, dodecyl gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol Hemp oil 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline, 2,6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil Hemp oil 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2-tert-butylhydroquinone, lecithin and corn oil Oil for 2-tert-butylhydroquinone and 6-ethoxy-l, 2-frying dihydro-2,2,4-trimethylquinoline Oil for butylated hydroxyanisole and 2, 6-diterbutil-l-frying hydroxy-4-methylbenzene Oil for butylated hydroxyanisole and 2, 6-diterbutyl-l-frying hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2, 2, 4- Trimethylquinoline Oil for 2-tert-butylhydroquinone and citric acid frying Oil for butylated hydroxyanisole and 2, 6-diterbutyl-l-fry hydroxy-4-methylbenzene and 6-etox il, 2- dihydro-2, 2, -trimethylquinoline and 2-tert-butylhydroquinone Oil for 2-tert-butylhydroquinone and 6-ethoxy-1, 2-frying dihydro-2,2,4-trimethylquinoline and corn oil Oil for butylated hydroxyanisole and , 6-diterbutil-l-frying hydroxy-4-methylbenzene and vegetable oil Oil for 6-ethoxy-l, 2-dihydro-2, 2, 4-trimetiIquinoline frying and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil Oil for 6-ethoxy-l, 2-dihydro-2 , 2,4-trimethylquinoline, fry propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol Oil for 6-ethoxy-l, 2-dihydro-2, 2, 4-trimethylquinoline, fry dodecyl gallate, naphthol, tocopherols Bird fat of butylated hydroxyanisole and 2,6-diterbutyl-l-corral hydroxy-4-methylbenzene Bird fat of butylated hydroxyanisole and 2, 6-diterbutyl-1-corral hydroxy-4-methylbenzene and 6-ethoxy-1, 2-dihydro-2,2,4-trimethylquinoline Bird fat of 2-terbutylhydroquinone and citric acid corral Bird fat of butylated hydroxyanisole and 2,6-diterbutyl-1-corral hydroxy-4-methylbenzene and 6-ethoxy-2, 2-dihydro-2,2,4-trimethylquinoline and 2-terbutylhydroquinone 2-terbutylhydroquinone bird fat and 6-ethoxy-1, 2-corral dihydro-2,2,4-trimethylquinoline and corn oil Bird fat of butylated hydroxyanisole and 2,6-diterbutyl-1-corral hydroxy-4-methylbenzene and vegetable oil Bird fat of 6-ethoxy-l, 2-dihydro-2,2, 4-trimethylquinoline corral and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-2, bird fat -dihydro-2,2,4-trimethylquinoline, corral propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol Bird fat of 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline, corral dodecyl gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol Bird fat 6-ethoxy-l, 2- dihydro-2,2,4-trimethylquinoline, 2,6-diterbutyl-4-methylphenol barnyard, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil 6-ethoxy-1,2-dihydro-2 bird fat 2,4-trimethylquinoline, corral mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2- tert-butylhydroquinone, lecithin and corn oil 2-tert.-butylhydroquinone and 6-ethoxy-1, 2-safflower-2,2,4 -trimethylquinoline Butylated hydroxyanisole oil and 2,6-diterbutyl-l-safflower hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl-l-safflower hydroxy-4-methylbenzene and 6-ethoxy-2-dihydro -2, 2, 4-trimethylquinoline 2-tert-butylhydroquinone oil and citric acid safflower Butylated hydroxyanisole oil and 2,6-diterbutyl-l-safflower hydroxy-4-methyl benzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone 2-tert-butylhydroquinone oil and 6-ethoxy-1,2-safflower dihydro-2,2,4-trimethylquinoline and oil corn Butylated hydroxyanisole oil and 2,6-diterbutyl-l-safflower hydroxy-4-methylbenzene and vegetable oil Oil of 6-ethoxy-l, 2-dihydro-2, 2,4-trimethylquinoline safflower and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-ethoxy-1,2-dihydro-2 oil , 2, 4-trimethylquinoline, propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-ethoxy-l, 2-dihydro-2,2, 4-trimethylquinoline oil, dodecyl gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol 6-ethoxy-l, 2-dihydro-2 oil, 2,4-trimethylquinoline, safflower 2,6-diterbutyl-4-methylphenol, pyrogallol, 2- tert-butylhydroquinone, stearyl citrate and corn oil 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline oil safflower mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2- tert-butylhydroquinone, lecithin and corn oil 2-tert.-butyl hydroquinone oil and 6-ethoxy-1,2-Jatropha dihydro-2,2,4-trimethylquinoline Butylated hydroxyanisole oil and 2, 6-diterbutyl-1-Jatropha hydroxy-4-methylbenzene Butylated hydroxyanisole oil and 2,6-diterbutyl-1-Jatropha hydroxy-4-methylbenzene and 6-ethoxy-1, 2-dihydro-2, 2, 4 -trimethylquinoline 2-tert-butyl hydroquinone oil and citric acid Jatropha Butylated hydroxyanisole oil and 2,6-diterbutyl-1-Jatropha hydroxy-4-methylbenzene and 6-ethoxy-l, 2- dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone 2-tert.-butylhydroquinone and 6-ethoxy-2-, Jatropha-dihydro-2,2,4-trimethylquinoline and corn oil Oil of butylated hydroxyanisole and 2,6-diterbutyl-l- Jatropha hydroxy-4-methylbenzene and vegetable oil 6-Ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline oil Jatropha and 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline oil, Jatropha propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate, butylated hydroxyanisole and propylene glycol 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline oil, dodecyl jatropha gallate, naphthol, natural tocopherols, ascorbyl palmitate and propylene glycol 6-ethoxy-l, 2-dihydro-2 oil, 2, 4-trimethylquinoline, Jatropha 2, 6-diterbutyl-4-methylphenol, pyrogallol, 2-terbutylhydroquinone, stearyl citrate and corn oil 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline oil Jatropha mixed natural tocopherols, ascorbyl palmitate, propyl gallate, 2- tert-butylhydroquinone, lecithin and corn oil 2-tert-butyl hydroquinone and 6-ethoxy-2-, dihydro-2,2,4-trimethylquinoline algae oil Butylated hydroxyanisole algae and 2,6-diterbutyl- l- hydroxy-4-methylbenzene Butylated hydroxyanisole algae oil and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline 2-terbutylhydroquinone seaweed oil and citric acid Butylated hydroxyanisole seaweed oil and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline and 2-terbutylhydroquinone 2-terbutyl hydroquinone seaweed oil and 6-ethoxy-2- In a preferred embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising 2-terbutylhydroquinone (TBHQ), 6-ethoxy-1, 2-dihydro -2, 2, 4-trimethylquinoline (EQ) and vegetable oil. In another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising butylated hydroxyanisole.

(BHA), 2,6-di-tert-butyl-l-hydroxy-4-methylbenzene (BHT) and vegetable oil. The antioxidant mixture is sold under the trade name PETGUARD ™ and PETGUARD 4 ™ (PG4) and commercially available from Novus International Inc. In yet another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising 2-tert-butylhydroquinone (TBHQ), citric acid and vegetable oil. The antioxidant mixture is sold under the trademark FEEDGUARDMR and can be purchased commercially from Novus International Inc. In still another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising 2-terbutylhydroquinone and 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and corn oil. The antioxidant mixture is sold under the trade name SANTOQUIN Qm and commercially available from Novus International Inc. In a further embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising 6-ethoxy-1. , 2-dihydro-2,2,4-trimethylquinoline, 2-tert-butylhydroquinone, 1,2-propanediol, citric acid and corn oil. The antioxidant mixture is sold under the tradename AGRADO RMR and commercially available from Novus International Inc. In yet another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising butylated hydroxyanisole, 2, 6-di-tert-butyl-1-hydroxy-4-methylbenzene, 6-ethoxy-1,2-dihydro-2, 2,4-trimethylquinoline, 2-tert-butylhydroquinone. In one embodiment, the fuel composition comprises a biodiesel produced from yellow fat and an antioxidant mixture comprising 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, 2-terbutylhydroquinone, 1,2-propanediol, citric acid and corn oil. In one embodiment, the fuel composition comprises a biodiesel produced from fish oil and an antioxidant mixture comprising 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, 2-terbutylhydroquinone, 1,2-propanediol, acid citrus and corn oil. In one embodiment, the fuel composition comprises a first antioxidant having formula (I), preferably 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a second antioxidant having no formula (I), a solvent polar and a non-polar solvent, preferably a biodiesel produced from soybean oil. In another embodiment, the fuel composition comprises a biodiesel produced from soybean oil, a first antioxidant, preferably 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a second antioxidant, preferably a mixture of gallate of propyl, dilauryl thiodipropionate, ascorbyl palmitate and butylated hydroxyanisole, and a polar solvent, preferably propylene glycol. In still another embodiment, the fuel composition comprises a biodiesel produced from soybean oil, a first antioxidant, preferably 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a second antioxidant, preferably a mixture of dodecyl, α-naphthol, natural tocopherol and ascorbyl palmitate and a polar solvent, preferably propylene glycol. In a further embodiment, the fuel composition comprises a biodiesel produced from soybean oil, a first antioxidant, preferably 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a second antioxidant, preferably a mixture of 2- 6-di-tert-butyl-4-methylphenol, pyrogallol, 2-tert-butylhydroquinone and stearyl citrate and a second non-polar solvent, preferably corn oil. In another embodiment, the fuel composition comprises a biodiesel produced from soybean oil, a first antioxidant, preferably 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, a second antioxidant preferably a mixture of mixed tocopherols natural, ascorbyl palmitate, propyl gallate, 2-tert-butylhydroquinone and lecithin, and a second non-polar solvent, preferably corn oil. In still another embodiment, the fuel composition comprises a biodiesel produced from soybean oil, a first antioxidant, preferably 6-ethoxy-1,2-dihydro-2,2, -trimethylquinoline, a second antioxidant, preferably a mixture of acid citric acid, 2-tert-butylhydroquinone and 1,2-propanediol, and a second non-polar solvent, preferably corn oil. Those skilled in the art will appreciate that the concentration of antioxidants added to the biodiesel will vary depending on the source of the biodiesel. In one embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising from about 20 ppm to about 500 ppm of 6-ethoxy-1,2-dihydro-2,2-trimethylquinoline, from about 20 ppm to about 500 ppm of a mixture of butylated hydroxyanisole and 2,6-di-tert-butyl-1-hydroxy-4-methylbenzene and from about 10 to about 60 ppm of 2-tert-butylhydroquinone. In another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising approximately 400 ppm of 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, approximately 20 ppm of a mixture of butylated hydroxyanisole and 2,6-di-tert-butyl-l-hydroxy-4-methylbenzene, and about 50 ppm of 2-tert-butylhydroquinone. In another embodiment, the fuel composition comprises a biodiesel produced from soybean oil and an antioxidant mixture comprising approximately 40 ppm of 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, approximately 40 ppm of a mixture of butylated hydroxyanisole and 2,6-di-tert-butyl-l-hydroxy-4-methylbenzene, and about 50 ppm of 2-tert-butylhydroquinone. In addition, the concentration of antioxidants will also vary according to the oxidative stability desired for the fuel. There are several methods generally known in the art for measuring the oxidative stability of a fuel including the Rancimat method, the oxidative stability index (OSI) method, the active oxygen method (AOM), the standard test method for stability of oxidation of distillate fuel oil (ASTMD-2274), both of which are detailed in the examples. These methods can be used by a person skilled in the art to formulate combinations of antioxidants having an adequate concentration of each ingredient so that the combination of antioxidants imparts the desired oxidative stability for the fuel of the invention. For example, all oils and fats have a resistance to oxidation, which depends on the degree of saturation, of natural or added oxidants, pro-oxidants or before abuse. Oxidation is slow until this resistance is overcome, at which point the oxidation accelerates and becomes very fast. The length of time before this rapid acceleration of oxidation is the measure of oxidation resistance and is commonly referred to as the induction period. The OSI method measures this period of induction. Another method used in the art to measure the induction period is a Rancimat method. The fuel compositions of the present invention, as shown in example 2, typically have an induction time of more than 6 hours. The AOM method measures the time (in hours) required for a sample of grease or oil to reach a predetermined value under the specific conditions of the test. The duration of this period of time is supposed to be an index of resistance to rancidity. The fuel compositions of the present invention, as shown in example 1, generally have a peroxide value from about 4 meq / kg of fat to about 400 meq / kg of fat after 20 hours under the AOM method.

The ASTM method (D-2274) measures the insoluble fractions of fuels under specified oxidizing conditions at 95 ° C. In particular, the method calculates the total insoluble mass (mg / 100 ml) as the sum of filterable insolubles and adherent insolubles. The calculations are described further in the examples. In one example, a fuel composition comprising a biodiesel produced from yellow fat and 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline has a total insolubles mass of 0.9 mg / ml, as shown in Example 3. In one embodiment, a fuel composition of the invention comprises a biodiesel and a petroleum-based diesel wherein the fuel composition has improved oxidative stability. In another embodiment, the fuel composition comprises any of the composition of Table A and a petroleum-based diesel fuel wherein the fuel composition has improved oxidative stability. In yet another embodiment, the fuel composition comprises any of the compositions of Table C and petroleum-based diesel fuel. In one embodiment, the method of increasing the oxidative stability of a fuel composition comprises contacting a biodiesel with an antioxidant mixture that increases the oxidative stability of the fuel. It is generally known that the addition of biodiesel to diesel fuel increases the emissions of nitrogen oxide (N0X). Wyatt, et al., Fuel Properties and Nitrogen Oxide Emussion Levees of Biodiesel Produced from Animal Fats, Journal of the American Oil Chemists' Society, Vol. 82, No. 8, page 585-591 (2005). The addition of antioxidants to the biodiesel fuel of the invention or a fuel comprising a biodiesel and petroleum-based diesel of the The invention, however, has decreased NOx emissions from fuels compared to a B20 fuel without the addition of at least one antioxidant or an oil-based diesel fuel. In one embodiment, a fuel composition of the invention comprises a source of ] _5 different biodiesel from shell oil, frying oil, sunflower oil and beef tallow and at least one antioxidant selected from the group consisting of 1, 2, 3-trihydroxybenzene, α-tocopherol acetate,? tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthiobutanoate, dodecyl gallate, gallic acid, octyl gallate, lecithin, stearyl citrate, palmityl citrate, chlorophyll and 6-ethoxy-1, 2-dihydro-2,2,4-trimethylquinoline wherein the fuel composition has a lower NOx emission compared to a fuel B20 without the addition of at least one antioxidant. In another embodiment, a fuel composition of the invention comprises a biodiesel source different from rapeseed oil, frying oil, sunflower oil and beef tallow and at least one antioxidant that is selected from the group consisting of 1, 2, 3 -trihydroxybenzene, a-tocopherol acetate, α-tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthiobutanoate, dodecyl gallate, gallic acid, octyl gallate, lecithin, stearyl citrate, citrate palmityl, chlorophyll and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline wherein the fuel composition has a lower NOx emission than petroleum-based diesel fuel. In one embodiment, a fuel composition of the invention comprises any of the compositions of Table 2 and a petroleum-based diesel wherein the fuel composition has a NOx emission lower than a B20 fuel without the addition of at least one antioxidant In another embodiment, the fuel composition comprises any of the compositions of Table 2 and petroleum-based diesel where the fuel composition has a lower NOx emission than petroleum-based diesel fuel. In a further embodiment, the fuel composition has a N0X emission reduction of at least about 1% compared to the B20 fuel without the addition of at least one antioxidant. In a further embodiment, the fuel composition has a N0X emission reduction of at least about 2%, 4%, 6%, 8%, 10% compared to fuel B20 of the addition of at least one antioxidant. In one embodiment, the method for reducing N0X emissions of a fuel composition comprises contacting a biodiesel with an antioxidant mixture that decreases NOx emissions from the fuel. The It will be appreciated by those skilled in the art that the properties of the biodiesel fuel compositions of the invention may also vary considerably depending on the combination of fuel and antioxidant used. The physical and chemical properties that are usually measured for 2_5 a biodiesel composition include kinematic viscosity at 40 ° C, acid value, density, cold filter plug and sulphated ash. The ASTM standard for the kinematic viscosity of a 100% biodiesel composition at 40 ° C (D-445) is between 1.9 and 6.0 mm2 / sec. The compositions biodiesel fuel of the invention have a kinematic viscosity at 40 ° C of less than about 5.0 mm2 / sec, less than about 4.5 mm2 / sec and less than about 4.0 mm2 / sec. The ASTM standard for the acid value of a 100% biodiesel composition (D-664) is 0.8 mg of KOH / g. The biodiesel fuel compositions of the invention have an acid value of less than about 0.75 mg of KOH / g, less than about 0.6 mg of KOH / g, less than about 0.5 mg of KOH / g, less than about 0.45 mg of KOH / g, less than about 0.3 mg KOH / g, less than about 0.2 mg KOH / g, and less than about 0.1 mg KOH / g. The biodiesel fuel compositions of the invention have a density of 20 ° C lower than 0.884 g / cm3, lower than approximately 0.88 g / cm3, lower than approximately 0.87 g / cm3, lower than -00 approximately 0.865 g / cm3. The biodiesel compositions of the invention are a cold filter seal (CFPP) of at least -1 ° C, at least -2 ° C, at least -5 ° C, at least -10 ° C. The ASTM standard for the maximum percent by mass of sulphated ash of a composition 100% biodiesel (D-874) is 0.002% by mass. The biodiesel compositions of the invention have a percentage of sulphated ash of less than about 0.002% by mass, less than about 0.001% by mass. IV. Additional Agents 20 The biodiesel fuel compositions of the invention may contain additional agents that increase one or more fuel characteristics. Those skilled in the art will appreciate that the selection of the particular agent will vary considerably depending on the type of fuel used. In particular, these additives can be particularly beneficial when the fuel composition comprises a biodiesel and a petroleum-based diesel. For example, suitable additives may include, but are not limited to, cetane improvers and / or ignition accelerators, corrosion inhibitors and / or metal deactivators, cold flow improvers and the like as described in the following. Preferred organic nitrates are substituted or unsubstituted alkyl or cycloalkyl nitrates that "LQ have up to about 10 carbon atoms, preferably from 2 to 10 carbon atoms, The alkyl group can be linear or branched, The specific examples of nitrate compounds suitable for use in the preferred embodiments include, but are not limited to the following : methyl nitrate, ethyl nitrate, n-propyl nitrate, isopropyl nitrate, allyl nitrate, n-butyl nitrate, isobutyl nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate, nitrate of isoamyl, 2-amyl nitrate, 3-amyl nitrate, ter-amyl nitrate, nitrate n-hexyl, 2-ethylhexyl nitrate, n-heptyl nitrate, sec-ethyl nitrate, n-octyl nitrate, sec-octyl nitrate, n-nonyl nitrate, n-decyl nitrate, nitrate n-dodecyl, cyclopentyl nitrate, cyclohexyl nitrate, methylcyclohexyl nitrate, isopropylcyclohexyl nitrate And esters of aliphatic alcohols substituted with alkoxy such as 2-methoxypropyl 2-nitrate, 1-ethoxypropyl 2-nitrate, 1-isopropoxybutyl nitrate, 1-ethoxybutyl nitrate and the like. Preferred alkyl nitrates are ethyl nitrate, propyl nitrate, amyl nitrates and hexyl nitrates. Other preferred alkyl nitrates are mixtures of primary amyl nitrate or primary oxyl nitrate. By the primary term it may be indicated that the nitrate functional group is attached to a carbon atom that is bonded to two hydrogen atoms. Examples of primary hexyl nitrates include n-hexyl nitrate, 2-ethylhexyl nitrate, 4-methyl-n-pentyl nitrate, and the like. The preparation of the nitrate esters can be carried out by any of the commonly used methods, such as, for example, esterification of the appropriate alcohol or reaction of a suitable alkyl halide with silver nitrate. Another suitable additive for use in the improvement of cetane and / or reduction of emissions of particulate material is diterbutyl peroxide. Conventional ignition accelerators such as hydrogen peroxide, benzoyl peroxide, diterbutyl peroxide and the like can also be used. In addition certain inorganic and organic chlorides and bromides such as, for example, aluminum chloride, chloride or ethyl bromide may find use in the preferred embodiments as primers when used in combination with other ignition accelerators. The low temperature operability of diesel fuel is commonly characterized by the point of turbidity and the point of cold seal (CFPP) or the test of low-temperature filtration capacity (LTFT). Thermal stabilizers can also be added to the biodiesel composition. In one embodiment, the composition may also comprise jojoba oil as an additional component. It is a liquid that has antioxidant characteristics and is able to withstand very high temperatures without losing its antioxidant capabilities. Jojoba oil is a mixture of liquid wax ester that is extracted from ground or crushed seeds of shrubs native to Arizona, California and northern Mexico. The source of the jojoba oil is the shrub Simmondsia chinensis, commonly known as the jojoba plant. It is a perennial woody shrub with thick leaves, similar to blue-green leather and a dark brown fruit similar to walnut. Jojoba oil can be extracted from the fruit by conventional pressing or by solvent extraction methods. The oil is a light and golden color. Jojoba oil is composed almost entirely of wax esters of monounsaturated straight-chain acids and alcohols with high molecular weights (C16-C26). Jojoba oil is typically defined as a liquid wax ester with the generic formula RCOOR ", wherein RCOOH represents oleic acid (C18), eicosanoic acid (C20) and / or erucic acid (C22) and wherein -R" OH represents eicosenyl alcohol (C20), docosenyl alcohol (C22) and / or portions of tetrasenyl alcohol. Pure esters or mixed esters having the formula RCOOR "wherein R is an Alk (en) yl group of 20 to 22 carbon atoms and wherein R" is an alk (en) yl group of 20 to 22 carbon atoms they can be suitable substitutes, in part or in full for jojoba oil. Acids and alcohols include monounsaturated straight-chain alkenyl groups, which are the most preferred. Other oils that are known for their thermal stability include peanut oil, cottonseed oil, rapeseed oil (cañola), macadamia oil, avocado oil, palm oil, palm kernel oil, castor oil, all the rest vegetable and nut oils, all animal oils including mammalian oils (eg, whale oils) and fish oils and combinations thereof. In a modality, the oil may be alkoxylated, for example methoxylated or ethoxylated. Alkoxylation is preferably carried out in medium chain oils such as castor oil, macadamia nut oil, cottonseed oil and the like. The alkoxylation can provide benefits in that it can allow the coupling of oil / water mixtures in a fuel, which results in a potential reduction in nitrogen oxides and / or emissions of particulate material upon combustion of the fuel. Other suitable thermal stabilizers known in the art include liquid mixtures of alkylphenols including 2-tert-butylphenol, 2,6-diterbutylphenol, 2-tert-butyl-4-n-butylphenol, 2,4,6-triterbutylphenol and 2,6-diterbutyl-4. -n-butylphenol which are suitable for use as stabilizers for middle distillate fuels (U.S. Patent Nos. 5,076,814 and 5,024,775 to Hanlon, et al). Other commercially available phenolic and hindered antioxidants that also show an effect of thermal stability include 2,6-diterbutyl-4-methylphenol; 2,6-diterbutylphenol; 2,2'-methylenebis (6-tert-butylbutyl-4-methoxyphenol); N- octadecyl 3- (3, 5-diterbutyl-4-hydroxyphenyl) propionate, 1,1,3-tris (3-tert-butyl-6-methyl-4-hydroxyphenyl) -butane, tetrakis [3- (3, 5 pentaerythrityl -diterbutil-4-hydroxyphenyl) propionate; D-n-octadecyl (3, 5-diterbutyl-4-hydroxybenzyl) phosphonate; 2,4,6-tris (3,5-diterbutyl-4-hydroxybenzyl) mesitylene; and tris (3,5-diterbutyl-4-hydroxybenzyl) isocyanurate (U.S. Patent Nos. 4,007,157, 3,920,661). Other suitable thermal stabilizers include: pentaerythritol esters derived from pentaerythritol, (3-alkyl-4-hydroxyphenyl) alkanoic acids and alkylthioalkanoic acids or lower alkyl esters of the acids which are useful as stabilizers of organic material normally susceptible to oxidative deterioration and / or thermal (U.S. Patent Nos. 4,806,675 and 4,734,519 to Dunski et al.); hindered phenyl phosphites (U.S. Patent No. 4,207,229 to Spivack); hydrocarbyl-alkylene alkylene phosphites (U.S. Patent No. 3,524,909); Hydroxybenzylthioalkylene phosphites (U.S. Patent No. 3,655,833) and the like. Some compounds suitable for use are capable of functioning as antioxidants and as thermal stabilizers. Therefore, in certain embodiments it may be preferable to prepare formulations containing as an additional component a hydrophobic vegetable oil extract in combination with a single compound that provides thermal stability and antioxidant effect, instead of two different compounds, one that provides thermal stability and the other with antioxidant activity. Examples of compounds known in the art that provide a certain degree of oxidation resistance and thermal stability include diphenylamines, dynathylamines and phenylnaphthylamines, whether substituted or unsubstituted, for example N, N'-diphenylphenylenediamine, p-octyldiphenylamine, P, P ~ dioctyldiphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, N- (p-dodecyl) phenyl-2-naphthylamine, di-1-naphthylamine and di-2-naphthylamine; phenothiazines such as N-alkylphenothiazines; imino (bisbenzyl); and hindered phenols such as 6- (tert-butyl) phenol, 2,6-di (tert-butyl) phenol, 4-methyl-2,6-di (tert-butyl) phenol, 4,4'-methylenebis (-2,6-di ( terbutilus) phenol and the like Certain lubricant fluid base concentrates having high thermal stability are known in the art and as such may be beneficial in some embodiments of the invention The base concentrates may be capable of imparting thermal stability to the formulations of preferred embodiments and as such may be replaced in part or in whole by jojoba oil Suitable base concentrates include polyalphaolefins, dibasic acid esters, polyol esters, alkylated aromatic substances, polyalkylene glycols and phosphate esters. the fuel composition of the invention a polyalphaolefin diversity Polyalphaolefins are hydrocarbon polymers that do not contain sulfur, phosphorus or metals Polyalphaolefins have good stability thermally but are typically used together with a suitable antioxidant. The dibasic acid esters also show good thermal stability but are usually also used in combination with additives for hydrolysis and oxidation resistance. Various polyol esters can be used in the fuel composition of the invention. Polyol esters include molecules that contain two or more alcohol moieties such as trimethopropane, neopentyl glycol, and pentaerythritol esters. The synthetic polyol esters are the reaction product of a fatty acid derived from animal or vegetable sources and a synthetic polyol. Polyol esters have excellent thermal stability and can resist oxidation hydrolysis better than other base concentrates. Triglycerides that are found naturally or vegetable oils that are in the same chemical family as polyol esters. However, polyol esters tend to be more resistant in the oxidation of oils. The oxidation instabilities associated with vegetable oils is generally due to a high content of linoleic and linolenic fatty acids. In addition, the degree of unsaturation (ie, double bonds) in the fatty acids in vegetable oils is related to oxidation sensitivity, with a higher number of double bonds resulting in a more sensitive material susceptible to rapid oxidation. Various trimethylolpropane esters are suitable for use in the fuel compositions of the invention. The trimethylolpropane esters may include mono-, di- and triesters. The neopentyl glycol esters can include mono and diesters. The pentaerythritol esters include mono, di, tri and tetraesters. The dipentaerythritol esters can include up to six ester portions. Preferred esters are typically those of long chain monobasic fatty acids. Preferred are C20 esters or higher acids, for example gondoic acid, eicosadienoic acid, eicosatrienoic acid, eicosatetraenoic acid, eicosapentanoic acid, arachidonic acid, arachidonic acid, behenic acid, erucic acid, docosapentanoic acid, docosahexanoic acid or lignicérico acid. However, in some embodiments, C18 esters or minor acids may be preferred, for example butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristoleic acid, myristic acid, pentadecanoic acid, palmitic acid, palmytoleic acid, hexadecadienoic acid. , hexadecatienoic acid, hexadecatetraenoic acid, margaric acid, margroleic acid, stearic acid, linoleic acid, octadecatetraenoic acid, vaccenic acid or linolenic acid. In some embodiments it may be preferred to esterify the pentaerythritol as a mixture of different acids. In some embodiments an alkylated aromatic substance may be used in the fuel compositions of the invention. The alkylated aromatic substances are formed by the reaction of olefins or alkyl halides with aromatic compounds such as benzene. The thermal stability is similar to those of the polyalphaolefins and the additives are typically used to provide oxidative stability. The polyalkylene glycols are alkylene oxide polymers which exhibit good thermal stability but which are typically administered in combination with adhesives to provide resistance to oxidation. The phosphate esters are synthesized from phosphorus oxychloride and alcohols or phenols and also show good thermal stability. In some embodiments it may be preferred to prepare formulations containing jojoba oil in combination with other vegetable oils. For example, it has been reported that cress oil from the crude meadow resists oxidative destruction almost 18 times longer than most common vegetable oil, specifically soybean oil. The meadow cress oil can be added in small amounts to other oils such as triolein oil, jojoba oil and castor oil to improve its oxidative stability. The watercress oil stability of the crude meadow can not be attributed to common antioxidants. One possible explanation for the oxidative stability of meadow cress oil may be its unusual composition of fatty acid. The main fatty acid of meadow cress oil is 5-eicosanoic acid, which is found to be almost 5 times more stable to oxidation than the more common fatty acid, oleic acid and 16 times more stable than other monounsaturated fatty acids. . See "Oxidative Stability Index of Vegetable Oils in Binary Mixtures with Meadowfoam Oil," Terry, et al., United States Department of Agriculture, Sgricultural Research Service, 1997. Any of numerous types of suitable detergent additives may be included in fuel compositions diesel of various modalities. These detergents include succinimide detergents / dispersants, long chain aliphatic polyamines and long chain Mannich bases. The use of long-chain, fuel-soluble aliphatic polyamines as cleaning induction additives in distilled fuels is described, for example, in the US patent. number 3,438,757. The use of fuel-soluble Mannich base additives formed from a long-chain alkylphenol, formaldehyde (or a formaldehyde precursor thereof), and a polyamine to control the formation of deposits in the induction system in combustion engines internal is described, for example, in the US patent number 4,231,759. Detergent additives, for example, are effective in reducing deposits in the carburetor and fuel injector tanks. Diesel fuel compositions of various embodiments may advantageously contain one or more anti-wear agents. Preferred antiwear agents include long chain primary amines that incorporate an alkyl or alkenyl radical having 8 to 50 carbon atoms. The amine to be used may be an amine alone or may consist of mixtures of the amines. Examples of long chain primary amines which can be used in the preferred embodiments are 2-ethylhexylamine, n-octylamine, n-decylamine, dodecylamine, oleylamine, linolyl amine, stearylamine, eicosylamine, triacontylamine, pentacontylamine and the like. A particularly effective amine is oleylamine which can be obtained from Akzo Nobel Surface Chemistry LLC of Chicago, III, under the name ARMEENMR O or ARMEENMR OD. Other suitable amines which are generally mixtures of aliphatic amines include ARMEEN ™ T and ARMEEN ™ TD, the distilled form of ARMEEN ™ T which contains the mixture of 0-2% tetradecylamine, 24% to 30% hexadecylamine, 25% to 28% of octadecylamine and 45% to 46% octadecenylamine. ARMEENMR T and ARMEENMR TD are derived from tallow fatty acids. Lauryl amine is also suitable, as is ARMEENMR 12D, which can be obtained from the supplier indicated above. This product is about 0-2% decylamine, 90% to 95% dodecylamine, 0-3% tetradecylamine and 0-1% octadecenylamine. Amines of the types indicated as useful are well known in the art and can be prepared from fatty acids by converting the acid or mixture of acids to their ammonium soap, converting the soap to the corresponding amide by means of heat, converting additionally the amide to the corresponding nitrile and hydrogenate the nitrile to produce the amine. In addition to the various amines described, the mixture of the amines derived from soy fatty acids are also within the class of amines described above and is suitable for suitable use with this invention. It is noted that all of the amines described in the above are useful as linear aliphatic primary amines. Those amines having 16 to 18 carbon atoms per molecule and which are saturated or unsaturated are those that are particularly preferred. Other preferred antiwear agents include dimerized unsaturated fatty acids, preferably dimers of a comparatively long chain fatty acid, for example one containing from 8 to 30 carbon atoms and can be pure or substantially pure dimers. Alternatively and preferably, commercially sold material known as "dimeric acid" can be used. The latter material is prepared by dimerizing unsaturated fatty acid and consists of a mixture of monomer, dimer and acid trimer. A particularly preferred dimer acid is the dimer of linoleic acid. The fuel composition can include a variety of demulsifiers. Demulsifiers are molecules that help in the separation of oil from water usually at very low concentrations. They avoid the formation of a mixture of water and oil. A wide variety of demulsifiers are available for use in fuel formulations of various modalities including, for example, organic sulfonates, polyoxyalkylene glycols, oxyalkylated phenolic resins and similar materials. Particularly preferred are mixtures of alkylaryl sulfonates, polyoxyalkylene glycols and oxyalkylated alkyl phenolic resins such as those commercially designed from Baker Petrolite Corporation of Sugar Land, Tex. as T0LADMR. Other known de-emulsifiers can also be used. A variety of corrosion inhibitors are available for use in fuel formulations of various modalities. Dimeric and trimeric acids such as those produced from tall oil fatty acids, oleic acid, linoleic acid or the like can be used. Products of this type are currently available from various commercial sources such as, for example, dimeric and trimeric acids sold under the trademark EMPOLMR by Cognis Corporation of Cincinnati, Ohio. Other useful types of corrosion inhibitors are alkylene succinic acid and alkenyl succinic anhydride corrosion inhibitors such as, for example, tetrapropenylsuccinic acid, tetrapropenylsuccinic anhydride, tetradecenylsuccinic acid, tetradecenylsuccinic anhydride, hexadecenylsuccinic acid, hexadecenylsuccinic anhydride and the like. Semi-esters of alkenyl succinic acids having 8 to 24 carbon atoms in the alkenyl group with alcohols such as polyglycols are also useful. If desired, the fuel compositions may contain a conventional type of metal deactivator of the type having the ability to complex with heavy metals such as copper and the like. Typically, the metal deactivators used are the gasoline soluble forms of N, N '-disalicylidene-1,2-alkanediamines or N, N' -disalicylidene-1,2-cycloalkanediamines or combinations thereof. Examples include N, N'-disalicylidene-1,2-ethanediamine, N, N '-disalicidene-1,2-propanediamine, N, N' -disalicylidene-1,2-cyclohexanediamine and N, N "-disalicylidene- 1-methyldipropylenetriamine. The various additives that can be included in the diesel compositions of this invention are used in conventional amounts. The amounts used in this particular case are sufficient to provide the desired functional property to the diesel composition and the amounts are well known to those skilled in the art.

DEFINITIONS To facilitate understanding of the invention, numerous abbreviation terms are used herein and are defined as follows: The term "AGRADO1" refers to a form of ethoxyquin. The term "AGRADO" 3 'R "refers to a form of ethoxyquin and TBHQ The term" acid number "refers to the milligrams of KOH needed in the test to neutralize all the acid constituents present in a 1 gram sample of the combustible product This property is often used to indicate the degree of contamination or oxidation of fuel The term "AOM" indicates the active oxygen method The method measures the time required (in hours) for a sample of fat or oil to obtain a predetermined value under specific test conditions The term "B20" refers to a combustible composition having approximately 20% by weight of biodiesel and approximately 80% by weight of petroleum-based diesel. "refers to the temperature at which the small solid crystals are visually observed for the first time in cooled fuel.This is the most conservative measurement of the cold flow dades. The term "cold filter plugging point (CFPP) (or LTFT)" refers to the temperature at which the fuel will cause the fuel filter to clog due to fuel components which have begun to crystallize or gel. . The term "FEEFUARD 20MR" refers to an antioxidant mixture of TBHQ, citric acid and vegetable oil. The term "induction time" indicates a measure of the resistance to oxidation. The term "kinematic viscosity at 40 ° C" refers to the measurement of a fuel resistance to flow under gravity at a specific temperature, in this case 40 ° C. The term "oxidative stability" refers to the ability to slow the oxidation of a fuel. The term "OSI" indicates the oil stability index. The method measures the induction time of a fuel. The term "PETGUARDMR" refers to an antioxidant mixture of BHA, BHT and vegetable oil. The term "PERGUARD 4MR" refers to an antioxidant mixture of BHA, BHT and vegetable oil. The term "PV" indicates the value of the peroxide. The term "PPM" indicates parts per million.

The term "SANTOQUINMR" refers to a form of ethoxyquin. The term "SANTOQUIN QMR" refers to a form of ethoxyquin and TBHQ. The term "TENOX 21MR" refers to an antioxidant mixture of TBHQ, glyceryl oleate, propylene glycol, vegetable oil and citric acid. The term "yellow fat" as used herein, refers to restaurant waste grease and low grade grease from extraction plants; Yellow fat is a mixture of vegetable oils and animal fats. EXAMPLES The following examples illustrate various embodiments of the invention. Example 1: Efficacy of various antioxidants to stabilize biodiesel The stability of biodiesel alone or in the presence of various antioxidants is tested using two methods approved by American Oil Chemists Society, that is, the active oxygen method (AOM) (AOCS official method Cd 12). -57) and the Oxidation Stability Index (OSI) method (AOCS official method Cd 12b-92) which is the equivalent to the Rancimat method. The biodiesel consists of soybean oil, yellow fat and shad oil. Unless completely liquefied, each sample melts at a temperature no higher than 10 ° C above its melting point. Antioxidants include SANTOQUINMR, SANTOQUIN QMR, AGRADOMR, AGRADO RMR, PETGUARDMR and PETGUARD 4MR. The concentrations of the tested antioxidants are presented in Table 1. All conditions are tested in duplicate. AOM measures the concentrations of peroxides or oxidation products in a liquid sample after exposure to air and heat. For this, 20 ml of sample (+ antioxidants) are added to the reaction tubes. The aeration pipe assembly is inserted into the reaction tube and adjusted so that the end of the air supply pipe is 5 cm below the surface of the sample. The tube and the sample are placed in a vessel of vigorous boiling water for 5 minutes. The tube is then separated from the water, it is dried by rubbing and it is transferred immediately to the constant temperature heater that is maintained at 97.8 + 0.2 ° C. The aeration pipe is connected to the capillary in the manifold and air is bubbled into the sample to ensure oxidation. After 20 hours, a sample is analyzed to determine the peroxide content. The lower the peroxide or AOM value (expressed in meq / kg of lipid), the more stable is the lipid sample. For lipids derived from animals, an AOM value of 20 mlq / kg or greater indicates rancidity.

During the OSI method, a stream of air is passed through the lipid sample and the effluent air from the lipid sample is bubbled through a test vessel containing deionized water, whose conductivity is closely monitored. As the oil is oxidized, volatile organic acids are generated and trapped in the water, which increases their conductivity. To perform OSI, the conductivity tubes are filled with 50 ml of deionized water and the probes are joined. The conductivity of the water in the tubes is verified so that it is constant with an opening of 25 μS / cm or less. 20 ml of sample (liquefied) (+ antioxidant) are placed directly on the bottom of the reaction tube. The analyzes are carried out with biodiesel soya oil or yellow fat and are carried out at 110 ° C and the analyzes are carried out with fish oil (shad) and are carried out at 80 ° C. The air manifold pipe is connected to the conductivity measuring tube and the aeration pipe is adjusted so that it is 5 mm from the bottom of both the reaction and conductivity pipes. The air flow is adjusted to 2.5 + 0.2 ml / sec. A computer is used to monitor the conductivity of each instrument probe and a water conductivity plot is generated versus time obtained from the reader. The OSI value is defined as the induction period in hours and mathematically represents the inflection point (second derivative) of the graph that reflects the maximum change in the oxidation rate. The higher the OSI value, the more stable the oil. The norm of E.U.A. for stabilization it is a value of 6 (hr) or higher. The AOM and OSI values for the different antioxidants are presented in Table 1. These tests show that SANTOQUINMR Q, AGRADO R * and TBHQ are effective in reducing the oxidation of soybean oil and that AGRADO R "11 is effective in reducing oxidation. of yellow fat or shad oil.

Table 1. Efficacy of various antioxidants to stabilize biodiesel Example 2: Efficacy of antioxidant mixtures to stabilize soybean biodiesel The ability of various antioxidants or combinations of antioxidants to stabilize biodiesel comprising soybean oil using the AOM and OSI methods is compared, essentially as described in example 1. Antioxidants include Etoxiquin (EQ), FeedGuard 20 (FG20), PETGUARD 4m (PG4), TBHQ and BHT. Each of the antioxidants or combinations of antioxidants is used in a concentration of 500 ppm. Table 2 presents the various conditions as well as the AOM and OSI values. TBHQ is the best antioxidant to avoid the oxidation of soybean oil, as analyzed by both methods.

Table 2. Antioxidant efficacy to avoid oxidation Example 3: Capacity of the antioxidant mixtures to stabilize soybean biodiesel The efficacy of various formulations of ethoxyquin (EQ) PETGUARD 4MR (PGE) and TBHQ was compared to stabilize a biodiesel constituted of soybean oil, using the AOM and OSI methods, as is detailed in example 1. Table 3 shows the concentration of each component of the formulations and the AOM and OSI values. This experiment shows that any formulation comprising TBHQ at 50 ppm has an excellent antioxidant activity.

Table 3. Efficacy of antioxidant formulations Example 4: Efficacy of antioxidant combinations (# 1) to stabilize biodiesel Additional combinations of antioxidants are compared to determine their efficacy to inhibit oxidation of a biodiesel comprising soybean oil. The biodiesel stability alone or in the presence of an antioxidant formulation can be used from the AOM and OSI methods, as detailed in example 1. The tested antioxidants (AOX) are ethoxyquin (EQ), BHT, pyrogallol (PY), TBHQ and stearyl citrate (SC). The non-polar solvent is corn oil (CO). The concentration of each oxidant in the formulations is presented in Table 4. The application rate of each formulation is 2000 ppm. Table 4 also presents the AOM and OSI values. It is found that formulations comprising 500 ppm of ethoxyquin (25%) and 200 ppm of pyrogallol (10%) are particularly effective in stabilizing biodiesel (shaded in table 4) Table 4. Efficacy of various antioxidant formulations Example 5: Efficacy of antioxidant combinations (# 2) to stabilize biodiesel Additional combinations of antioxidants are compared to determine their efficacy in inhibiting biodiesel oxidation of soybean oil.

The stability of the biodiesel alone or in the presence of an antioxidant formulation is tested using the AOM and OSI methods, as detailed in example 1. The antioxidants tested are propyl gallate (PG), ethoxyquin (EQ), dilauryl thiodipropionate (DD ), ascorbyl palmitate (AP) and BHA. The polar solvent is propylene glycol (PGL). Table 5 shows the concentration of each antioxidant in the formulations. The application rate of each formulation is 2000 ppm. As shown in Table 5, formulations comprising 300 ppm of propyl gallate (15%) and 500 ppm of ethoxyquin (25%) are effective in preventing the oxidation of biodiesel.

Table 5 Efficacy of various antioxidant formulations Example 6: Efficacy of antioxidant combinations (# 3) to stabilize biodiesel Additional combinations of antioxidants are compared to determine their efficacy to inhibit biodiesel oxidation of soybean oil. The stability of the biodiesel alone or in the presence of an antioxidant formulation is tested using the AOM and OSI methods, as detailed in example 1. The tested antioxidants are docecyl gallate (DG), ethoxyquin (EQ), ocnaphthol (AN), Natural tocopherols (NT) and ascorbic acid (AA). The polar solvent is propylene glycol (PGL). The concentration of each antioxidant in the formulations is presented in Table 5. The application rate of each formulation is 2000 ppm. As shown in Table 6, formulations comprising 300 ppm of docecyl gallate (15%) and 500 ppm of ethoxyquin (25%) prevent the oxidation of biodiesel.

Table 6. Efficacy of various antioxidant formulations Example 7: Efficacy of various antioxidant combinations applied at different rates to stabilize biodiesel The efficacy of different concentrations of various antioxidant combinations is compared to avoid oxidation of biodiesel using the AOM and OSI methods, as described in example 1. The antioxidants tested are ethoxyquin (EQ), natural mixed natural tocopherols (NMT), ascorbyl palmitate (AP), propyl gallate (PG), TBHQ and lecithin (LE). The non-polar solvent is corn oil. Table 7 shows the concentration of each antioxidant in the formulations. Each formulation is applied at either 200 ppm or 500 ppm. As shown in Table 7, the formulation comprising EQ, NMT, AP, PG and TBHQ at 500 ppm is the most effective for stabilizing biodiesel.

Table 7. Efficacy of different application rates of various antioxidant combinations Example 8: Efficacy of antioxidant combinations to reduce soluble substances in biodiesel The standard test method for oxidation stability of distillate fuel oil (ASTM D2274, accelerated method) is also used to classify the effectiveness of different combinations of antioxidants. This method measures filterable insolubles, insoluble adherents and total insolubles after an accelerated oxidative process. For this method 400 ml of fuel is filtered through a membrane filter free of cellulose ester surfactant having a nominal pore size of 0.8 μm. A clean oxygen supply tube is placed in each clean oxidation cell and 350 ml of filtered fuel is added to the test cell. The test cell is placed in a heating bath at 95 ° C and oxygen is bubbled through the test sample at a rate of 3 l / h for 16 hours. The test sample is allowed to cool to room temperature and for a period not exceeding 4 hours. Then the sample is filtered through two filters simultaneously (Whatman GF / F filters). After all the fuel has been extracted through the filters, three washes of 50 ml of isooctane are used to rinse the oxidation cell and the supply tube of - | _0 oxygen. All rinses are passed through the filter assembly. Additionally, the edge of the filter medium and the adjacent parts of the filter assembly wash with another 50 ml of isooctane. The filtrate is discarded. The two filters are dried at 80 ° C for 30 minutes and then cool for 30 minutes. Both filters are weighed. The upper filter is considered to be the sample filter, while the lower filter is considered the white filter. The mass (A) of filterable insolubles is calculated in milligrams per 100 ml. The mass of the white Wi-Fi filter (lower part) subtracts from the weight of the filter sample W2 (top) and divides by 3.5 to reduce the result to a base of 100 ml (A = (W2-W?) /3.5). After the oxidation cell and the oxygen supply tube are rinsed (see above), the insoluble adherent fractions of the surface of these pieces are dissolved using three rinses of 75 ml of the trisolvent (equal parts of toluene, acetone and methanol). If needed, a quarter rinse of 75 ml of trisolvent is used. The trisolvent rinses are collected in previously tared beakers and evaporated. Two sets of weights are recorded - the tare weight and weight after evaporation for the sample beaker and then a tare and the weight after evaporation for a blank beaker containing only an equivalent volume of trisolvent. The mass of adherent insolubles (B) in milligrams per 100 ml is also calculated. The tare weight of the white (W3) and sample (W4) beaker is subtracted from the final mass (after evaporation) of the white beakers (5) and sample (W6). The difference between the blank and the sample is then calculated and divided by 3.5 to reduce the result to a base of 100 mi (B = ((W5-W4) - (W5-W3)) /3.5). The total insoluble mass (C) in milligrams per 100 ml is calculated as the sum of the filterable insolubles (A) and the adherent insolubles (B) such that C = A + B. A fuel composition comprising a biodiesel produced by yellow fat in the absence or presence of 2000 ppm of SANTOQUINMR using the above method. It was found that the total insoluble mass decreases from 5.5 mg / 100 ml to 0.9 mg / 10 ml in the presence of the antioxidant. Antioxidant combinations are tested and filterable insolubles, adherent insolubles and total insolubles are determined. The following antioxidant combinations are tested: 1-6, 1-8, 1-14 and 1-16 of Example 4 (see Table 4); 2-4 and 2-12 of example 5 (see table 5); and 3-12 of Example 6 (see Table 6). Each combination is tested at 500 ppm, 1000 ppm and 2000 ppm. The controls include biodiesel and biodiesel containing 1000 ppm of TBHQ and 1000 ppm of TENOX-21 (TNX21). The results are presented in Table 8. The totality of the antioxidant combinations, with the exception of the lowest concentration of the 3-12 combination, reduces the amount of insolubles in the biodiesel.

Table 8. Reduction of insolubles by antioxidant combinations It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (63)

CLAIMS Having described the invention as above, the contents of the following claims are claimed as property:

1. A combustible composition, characterized in that it comprises: a. a biodiesel; and b. an antioxidant mixture, the mixture comprises at least two antioxidants which are selected from the group of 2-terbutylhydroquinone, n-propyl ester of 3,4,5-trihydroxybenzoic acid, 1,2,3-trihydroxybenzene, butylated hydroxyanisole, 2,6 -diterbutil-l-hydroxy-4-methylbenzene, a-tocopherol acetate, α-tocopherol, α-tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthio butanoate, propyl gallate, gallate dodecyl, gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, palmityl citrate, chlorophyll, pyrogallol, naphthol, ascorbic acid, natural tocopherol, citric acid, sage extract, rosemary, eugenol, natural antioxidant and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline.

2. The fuel composition according to claim 1, characterized in that the biodiesel is produced from a source that is selected from the group consisting of soybean oil, yellow fat, corn oil, rapeseed oil, coconut oil, peanut, palm oil, fish oil, marine oil, cottonseed oil, mustard seed oil, camelina oil, jojoba oil, hemp oil, tallow, poultry fat, lard, safflower oil, oil of jatropha, algae oil and sunflower oil.

3. The fuel composition according to claim 1, characterized in that the biodiesel is produced from rapeseed oil.

4. The fuel composition according to claim 1, characterized in that the biodiesel is produced from algae oil.

5. The fuel composition according to claim 1, characterized in that the biodiesel is produced from soybean oil.

The fuel composition according to claim 5, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and 2-tert-butylhydroquinone.

The fuel composition according to claim 5, characterized in that the antioxidant mixture comprises butylated hydroxyanisole, 2,6-diterbutyl-l-hydroxy-4-methylbenzene, 6-ethoxy-6-ethoxy-1,2-dihydro-2. , 2,4-trimethylquinone or 2-tert-butylhydroquinone.

8. The fuel composition according to claim 7, characterized in that the antioxidant mixture comprises from about 20 ppm to about 500 ppm of a mixture of butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy-4-methylbenzene, from about 20 ppm to about 500 ppm of 6-ethoxy-1,2-dihydro-2,2-trimethylquinoline and from about 10 to about 60 ppm of 2-tert-butylhydroquinone.

9. The fuel composition according to claim 5, further characterized in that it comprises a non-polar solvent.

10. The fuel composition according to claim 9, characterized in that the antioxidant mixture comprises butylated hydroxyanisole and 2,6-diterbutyl-l-hydroxy-4-methylbenzene and the non-polar solvent is vegetable oil.

11. The fuel composition according to claim 1, characterized in that it also comprises a polar solvent.

12. The fuel composition according to claim 1, characterized in that it also comprises a petroleum-based diesel fuel.

The fuel composition according to claim 12, characterized in that it comprises from about 20% to about 30% by weight of the fuel composition according to claim 4 and from about 70% to about 80% by weight of diesel based fuel in oil.

The fuel composition according to claim 1, further characterized in that it comprises an additive which is selected from the group consisting of cetane improvers, ignition accelerators, metal deactivators, corrosion inhibitors, thermal stabilizers, detergents, antiwear agents and demulsifiers.

15. The combustible composition, characterized in that it comprises: a. a biodiesel; b. a first antioxidant having the formula (I): wherein: R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen and an alkyl group having from 1 to about 6 carbons; and R5 is an alkoxy group having from 1 to about 12 carbons; c. a second antioxidant that does not have the formula (I); d. a polar solvent; and e. a non-polar solvent in which the two solvents form a homogeneous liquid.

16. The fuel composition according to claim 15, characterized in that the second antioxidant is selected from the group consisting of 2-tert-butylhydroquinone, n-propyl ester of 3,4,5-trihydroxybenzoic acid, 1,2,3-trihydroxybenzene, butylated hydroxyanisole, 2,6-diterbutyl-l-hydroxy-4-methylbenzene, α-tocopherol acetate, α-tocopherol, α-tocopherol, d-tocopherol, dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthio butanoate, propyl gallate, dodecyl gallate, gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, palyl citrate, chlorophyll, pyrogallol, naphthol, ascorbic acid, natural tocopherol, citric acid, sage extract, rosemary, eugenol, natural antioxidant and combinations thereof.

The fuel composition according to claim 15, characterized in that the polar solvent is selected from the group consisting of glycerol, propylene glycol, propylene glycol, polyol, a sugar alcohol and combinations thereof.

18. The fuel composition according to claim 15, characterized in that the non-polar solvent is selected from the group consisting of vegetable oil, monoglycerides, diglycerides, triglycerides and combinations thereof.

19. The fuel composition according to claim 15, characterized in that the biodiesel is produced from a source that is selected from the group consisting of soybean oil, yellow fat, corn oil, rapeseed oil, coconut oil, peanut oil, palm oil, fish oil, marine oil, cottonseed oil, mustard seed oil, camelina oil, jojoba oil, hemp oil, tallow, poultry fat, lard, safflower oil , jatropha oil, algae oil and sunflower oil.

20. The fuel composition according to claim 15, characterized in that the biodiesel is produced from rapeseed oil.

21. The fuel composition according to claim 15, characterized in that the biodiesel is produced from algae oil.

22. The fuel composition according to claim 15, characterized in that the biodiesel is produced from soybean oil.

23. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a natural antioxidant.

24. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a mixture of propyl gallate, dilauryl thiodipropionate , ascorbyl palmitate and butylated hydroxyanisole and the polar solvent is propylene glycol.

25. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a mixture of dodecyl gallate, α-naphthol , natural tocopherol and ascorbyl palmitate and the polar solvent is propylene glycol.

26. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a mixture of 2,6-diterbutyl-4. -methylphenol, pyrogallol, 2-terbutylhydroquinone and stearyl citrate and the non-polar solvent is corn oil.

27. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a mixture of natural mixed tocopherols, ascorbyl palmitate, propyl gallate, 2-tert-butylhydroquinone and lecithin and the non-polar solvent is corn oil.

28. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is citric acid and the non-polar solvent is oil. corn.

29. The fuel composition according to claim 28, characterized in that the second antioxidant further comprises 2-terbutylhydroquinone and 1,2-propanediol.

30. The fuel composition according to claim 22, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is 2-terbutylhydroquinone and the second non-polar solvent is corn oil.

The fuel composition according to claim 15, characterized in that it further comprises an additive which is selected from the group comprising cetane improvers, ignition accelerators, metal deactivators, corrosion inhibitors, thermal stabilizers, detergents, anti-wear agents and demulsifiers.

32. A method for increasing the oxidative stability of a fuel composition, characterized in that it comprises contacting a biodiesel with an antioxidant mixture comprising at least antioxidants that are selected from the group consisting of 2-tert-butylhydroquinone, n-propyl ester of the acid 3,4,5-trihydroxybenzoic acid, 1,2,3-trihydroxybenzene, butylated hydroxyanisole, 2,6-diterbutyl-l-hydroxy-4-methylbenzene, α-tocopherol acetate, α-tocopherol, α-tocopherol, d-tocopherol , dilauryl thiodipropionate, isopropyl 2-hydroxy-4-methylthio butanoate, propyl gallate, dodecyl gallate, gallic acid, octyl gallate, ascorbyl palmitate, lecithin, stearyl citrate, palmityl citrate, chlorophyll, pyrogallol, a naphthol, ascorbic acid, natural tocopherol, citric acid, sage extract, rosemary, eugenol, natural antioxidant and 6-ethoxy-l, 2-dihydro-2,2,4-trimethylquinoline.

The method according to claim 32, characterized in that the biodiesel is produced from a source that is selected from the group consisting of soybean oil, yellow fat, corn oil, rapeseed oil, coconut oil, oil peanuts, palm oil, fish oil, marine oil, cottonseed oil, mustard seed oil, camelina oil, jojoba oil, hemp oil, tallow, poultry fat, lard, safflower oil, jatropha oil, algae oil and sunflower oil.

34. The method according to claim 32, characterized in that the biodiesel is produced from rapeseed oil.

35. The method according to claim 32, characterized in that the biodiesel is produced from algae oil.

36. The method according to claim 32, characterized in that the biodiesel is produced from soybean oil.

37. The method according to claim 36, characterized in that it also comprises a polar solvent.

38. The method according to claim 37, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, propyl gallate, dilauryl thiodipropionate, ascorbyl palmitate and butylated hydroxyanisole and the polar solvent is propylene glycol.

39. The method according to claim 37, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, dodecyl gallate, naphthol, natural tocopherol and ascorbyl palmitate and the polar solvent is propylene glycol.

40. The method according to claim 36, characterized in that it also comprises a non-polar solvent.

41. The method according to claim 40, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, 2,6-diterbutyl-4-methylphenol, pyrogallol, 2-tert-butylhydroquinone. and stearyl citrate and the non-polar solvent is corn oil.

42. The method according to claim 40, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, natural mixed tocopherols, ascorbyl palmitate, propyl gallate, 2-tert-butylhydroquinone. and lecithin and the non-polar solvent is corn oil.

43. The method according to claim 40, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and citric acid and the non-polar solvent is corn oil.

44. The method according to claim 43, characterized in that the antioxidant mixture further comprises 2-terbutylhydroquinone and 1,2-propanediol.

45. The method according to claim 40, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, 2-terbutylhydroquinone and the non-polar solvent is corn oil.

46. The method according to claim 32, characterized in that it also comprises contacting an additive with biodiesel and the antioxidant mixture.

47. The method according to claim 46, characterized in that the additive is selected from the group comprising cetane improvers, ignition accelerators, metal deactivators, corrosion inhibitors, thermal stabilizers, detergents, anti-wear agents and demulsifiers.

48. The method according to claim 32, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and a second antioxidant and the fuel composition has less than 2.8 mg / 100 ml. of filterable insoluble materials.

49. The method according to claim 32, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and the second antioxidant and the fuel composition has less than 4.3 mg / 100 ml. of insoluble adherents.

50. The method according to claim 32, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and a second antioxidant and the fuel composition has less than 6.8 mg / 100 ml. of total insoluble substances.

51. The method according to claim 32, characterized in that the fuel has a kinematic viscosity at 40 ° C from about 4.00 mm2 / sec to about 5.0 mm2 / sec.

52. The method according to claim 32, characterized in that the fuel has an acid value from about 0.1 mg KOH / g to about 0.75 mg KOH / g.

53. The method according to claim 32, characterized in that the fuel has a density at 20 ° C from about 0.865 g / cm3 to about 0.884 g / cm3.

54. The method according to claim 32, characterized in that the fuel has a cold filter seal point (CFPP) from about -1 ° C to about -10 ° C.

55. The method according to claim 32, characterized in that the fuel has a percentage of sulphated ash in mass from about 0.001 mass% to about 0.002 mass%.

56. The fuel composition according to claim 1, characterized in that the antioxidant mixture comprises 2-terbutylhydroquinone and 1,2,3-trihydroxybenzene.

57. The fuel composition according to claim 1, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, propyl gallate and butylated hydroxyanisole.

58. The fuel composition according to claim 1, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, propyl gallate, citric acid and 2-tert-butylhydroquinone.

59. The fuel composition according to claim 15, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a mixture of butylated hydroxyanisole and 1, 2, 3-trihydroxybenzene and the polar solvent is propylene glycol.

60. The fuel composition according to claim 15, characterized in that the first antioxidant is 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, the second antioxidant is a mixture of propyl gallate, citric acid and 2-tert-butylhydroquinone and the polar solvent is propylene glycol.

61. The fuel composition according to claim 37, characterized in that the antioxidant mixture comprises 2-terbutylhydroquinone and 1,2,3-trihydroxybenzene.; and the polar solvent is propylene glycol.

62. The method according to claim 37, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, propyl gallate and butylated hydroxyanisole; and the polar solvent is propylene glycol.

63. The method according to claim 37, characterized in that the antioxidant mixture comprises 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, propyl gallate, citric acid and 2-tert-butylhydroquinone; and the polar solvent is propylene glycol.