CN104371772B - A kind of compositions of additives and Dresel fuel compositions and the method improving oxidation stability of biodiesel - Google Patents

Abstract

The invention provides a kind of compositions of additives and the Dresel fuel compositions containing this compositions of additives and the method using this compositions of additives to improve oxidation stability of biodiesel.Described compositions of additives contains component a and component b, and described component a is the product of amino polyacid and organic amine；Described component b is phenol type antioxidant.The Dresel fuel compositions that the present invention provides has preferable oxidation stability.

Description

A kind of additive composition and diesel oil composition and improving biodiesel oxidation stability Methods

technical field

The invention relates to an additive composition, a diesel composition containing the additive composition and a method for improving the oxidation stability of biodiesel by using the additive composition.

Background technique

With the acceleration of dieselization of vehicles worldwide, the demand for diesel will increase. The depletion of petroleum resources and the improvement of people's awareness of environmental protection have greatly promoted the development of diesel alternative fuels in countries around the world. Biodiesel It has been valued by various countries for its superior environmental protection performance and renewability.

Biodiesel (BD100), also known as fatty acid methyl ester (Fatty Acid Methyl Ester), is derived from oil crops such as soybeans and rapeseeds, oil-bearing forest fruits such as oil palm and pistachio, engineering microalgae and other oil-bearing aquatic plants, and animal fats, Waste cooking oil and other raw materials are obtained through transesterification with alcohols (methanol, ethanol). It is a clean biofuel. Biodiesel has the three major advantages of being renewable, clean and safe, and is of great strategic significance to the adjustment of my country's agricultural structure, energy security and comprehensive management of the ecological environment. But our country is a net importer of oil at present, and the oil reserves are very limited. Importing a large amount of oil poses a threat to our energy security; therefore, the research and production of biodiesel has important practical significance to our country.

However, due to raw materials and processing techniques, some biodiesel has poor oxidation stability, which causes great difficulties in the use and storage of biodiesel. Biodiesel with poor oxidation stability is prone to produce the following aging products: 1) insoluble polymers (colloids and sludge), which will cause engine filter blockage and injection pump coking, and lead to increased smoke exhaust and difficulty in starting; 2) soluble polymers 3) aging acids, which can cause corrosion of metal parts in the engine; 4) peroxides, which can cause aged rubber parts to become brittle and cause Fuel leaks, etc.

European biodiesel standard EN14214:2003, Australian biodiesel standard (Draft2003), New Zealand biodiesel standard NZS7500:2005, Brazilian biodiesel standard ANP255 (2003), Indian biodiesel standard IS15607:2005, South African biodiesel standard SANS1935:2004 and my country The national standard GB/T20828-2007 of biodiesel (BD100) for diesel fuel blending stipulates that the oxidation stability of biodiesel is not less than 6 hours at 110°C, and the measurement method is EN14112:2003.

CN1742072A discloses a method for improving the storage stability of biodiesel. The method comprises dissolving a liquid stock solution containing 15-60% by weight of 2,4-di-tert-butylhydroxytoluene (BHT) dissolved in biodiesel Add it into the biodiesel to be stabilized until the concentration of 2,4-di-tert-butylhydroxytoluene reaches 0.005-2% by weight based on the total solution of biodiesel.

CN1847368A discloses a method for improving the oxidation stability of biodiesel, which method comprises bisphenol type antioxidants such as 4,4'-methylene bis[2,6-di-tert-butylphenol], 2,2 `-Methylenebis[6-tert-butyl-4-methylphenol] was added to the biodiesel to be stabilized in an amount of 10-20000ppm (w/w).

CN1847369A discloses a method for improving the oxidation stability of biodiesel, which includes adding a primary antioxidant with a melting point of less than or equal to 40°C to the biodiesel to be stabilized in an amount of 10-20000ppm (w/w), wherein The primary antioxidant contains alkylphenols.

US2007/113467A1 discloses a fuel composition with improved oxidation stability comprising biodiesel and at least one antioxidant selected from the group consisting of propyl gallate, 1,2,3- One of trihydroxybenzene, 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, lauryl thiodipropionate, tocopherol, and quinoline derivatives.

US2009/0094887A1 discloses a Mannich base and a hindered phenol antioxidant formed by the reaction of an alkylphenol represented by the following formula (I), an aldehyde represented by the formula (II) and a polyamine represented by the formula (III) Composite as the application of biodiesel antioxidant,

In formula (I), R ₄ and R ₅ are the same or different, each independently being an alkyl group, aryl group, alkaryl group or aralkyl group with 1-20 carbon atoms, and x is 0 or 1; formula (II ), R ₈ is hydrogen or an alkyl group with 1-8 carbon atoms; in formula (III), Z is a positive integer, R ₆ and R ₇ are the same or different, each independently hydrogen and 1 carbon atom -20 alkyl, aryl, alkaryl or aralkyl, y is 0 or 1. Among them, the polyamine represented by formula (III) is particularly preferably ethylenediamine, and the phenolic antioxidants are preferably 2,6-di-tert-butyl-p-methylphenol (BHT) and 2,6-di-tert-butylphenol (DTBP ).

The above method of using traditional antioxidants to improve the oxidation stability of biodiesel has certain effects, but the effect is not obvious or requires a large amount of antioxidants to obtain obvious improvement effects.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the method for improving the oxidation stability of biodiesel in the above-mentioned prior art that the effect is not obvious or that a large amount of antioxidant is required to obtain an obvious improvement effect, and to provide a The invention provides an additive composition which can obviously improve the oxidation stability of diesel oil composition, a diesel composition containing the same and a method for improving the oxidation stability of biodiesel.

The present invention provides an additive composition, characterized in that the additive composition contains component a and component b, the component a is the condensation reaction product of amino polyacid and organic amine; the component b It is a phenolic antioxidant.

The present invention also provides a diesel oil composition, which contains base diesel oil and an additive, and the base diesel oil contains biodiesel, wherein the additive is the above-mentioned additive composition provided by the present invention.

The present invention also provides a method for improving the oxidation stability of biodiesel. The method includes adding an additive to the base diesel containing biodiesel, wherein the additive is the above-mentioned additive composition provided by the present invention.

By using the additive composition provided by the present invention, whether pure biodiesel is used as the base diesel oil or a blended fuel containing biodiesel is used as the base diesel oil, excellent oxidation stability can be obtained at a relatively small amount. Component a and Surprisingly, there is a synergistic effect between components b, and the antioxidant effect is much better than that of using antioxidants alone. Component a can be regarded as an auxiliary antioxidant, which can unexpectedly greatly enhance the effect of the antioxidant. Therefore, when achieving the same oxidation stability requirements, the amount of component b in the biodiesel composition can be greatly reduced, especially when component b is particularly expensive or component b has certain toxicity or corrosiveness, the reduction Its dosage is of great significance.

detailed description

According to the additive composition provided by the present invention, the weight ratio of component b to component a may be 0.01-100:1, preferably 0.1-10:1, more preferably 0.2-5:1.

Component a

The component a is a condensation reaction product of amino polyacid and organic amine.

The "amino polyacid" refers to a polycarboxylic acid containing amino groups in its molecule, preferably the number of amino groups is 1-5, more preferably 1-3. The amino groups are preferably all tertiary amino groups. The number of carboxylic acid groups (-COOH) in the amino polycarboxylic acid may be 2-6, more preferably 2-5. The carboxylic acid group is more preferably one or more of formate, acetate, propionate and butyrate, particularly preferably acetate and/or propionate. The total number of carbon atoms in the amino polyacid is preferably 2-20, more preferably 4-14. Specific examples of the aminopolycarboxylic acid include, but are not limited to, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetrapropionic acid (EDTP), 1,2-propylenediaminetetra One of acetic acid, 1,3-propylenediaminetetraacetic acid (PDTA), diethylenetriaminepentaacetic acid (DTPA), 1,6-hexanediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid or Various.

The organic amine can be various organic amines capable of condensation reaction with the carboxyl group in the amino polyacid to form an amide structure, for example, it can have the structure shown in formula (1)

In formula (1), R ₁ and R ₂ are independently H, a group represented by formula (2), formula (3) or (4), and R ₁ and R ₂ are not H at the same time.

In formula (2), x is 2 or 3, y is an integer from 0 to 5, R ₃ is a C ₁ -C ₃₀ hydrocarbon group; preferably y is an integer from 1 to 4, R ₃ is a C ₆ -C ₂₄ hydrocarbon group .

In formula (3), x1 is 2 or 3, y1 is an integer from 0 to 5, R ₄ is a C ₁ -C ₃₀ hydrocarbon group; preferably y1 is an integer from 1 to 4, R ₄ is a C ₆ -C ₂₄ hydrocarbon group .

In formula (4), y2 is an integer from 0 to 5, and R ₅ is a C ₁ -C ₂₆ hydrocarbon group.

For formula (2), it is further preferred that y is an integer from 1 to 3, and R ₃ is a C ₈ -C ₂₂ hydrocarbon group. The hydrocarbon group may be a saturated alkyl group, an alkenyl group with a double bond or an aryl group with a benzene ring. The alkyl group can be a straight-chain normal alkyl group or an iso-alkyl group with a side chain. Examples of the alkyl group include n-octyl, n-nonyl, n-decyl, n-undecyl, n-decyl Dialkyl, n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, n-behenyl; isobutyl, tert-butyl, isopentyl, neopentyl , isohexyl, isoheptyl, isooctyl (2-ethylhexyl), isononyl, isodecyl, isododecyl, isotetradecyl, isohexadecyl, isoctadecyl group and isoeicosyl group. Examples of alkenyl include 9-octadecenyl. Examples of aryl groups having a benzene ring include benzyl (benzyl), phenethyl and phenylpropyl.

When y is equal to 1, the formula (2) is -CH ₂ CH ₂ NHR ₃ or -CH ₂ CH ₂ CH ₂ NHR ₃ , preferably a -CH ₂ CH ₂ CH ₂ NHR ₃ group, and the definition of R ₃ is the same as above. For example, the group of formula (2) can be,

-CH ₂ CH ₂ CH ₂ NHC ₁₀ H ₂₁ (3-(n-decylamino)propyl),

-CH ₂ CH ₂ CH ₂ NHC ₁₂ H ₂₅ (3-(n-dodecylamino)propyl),

-CH ₂ CH ₂ CH ₂ NHC ₁₄ H ₂₉ (3-(n-tetradecylamino)propyl),

-CH ₂ CH ₂ CH ₂ NHC ₁₆ H ₃₃ (3-(n-hexadecylamino)propyl),

-CH ₂ CH ₂ CH ₂ NHC ₁₈ H ₃₇ (3-(n-octadecylamino)propyl) and

_{-CH2CH2CH2NHC18H35 (} 3- _{( oleylamino} ) _propyl ).

According to the present invention, for formula (3), preferably y1 is an integer of 1-5. It is further preferred that x1 is 2, y1 is an integer of _1-4 , and R4 is the same as the definition of _R3 above. For example, the group of formula (3) can be:

-CH ₂ CH ₂ NHCOC ₁₁ H ₂₃ ,

-CH ₂ CH ₂ NHCOC ₁₃ H ₂₇ ,

-CH ₂ CH ₂ NHCOC ₁₅ H ₃₁ ,

-CH ₂ CH ₂ NHCOC ₁₇ H ₃₅ ,

-CH ₂ CH ₂ NHCOC ₁₇ H ₃₃ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₁ H ₂₃ ,

_{-CH2CH2NHCH2CH2NHCOC13H27 , _ _ _ _}

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₅ H ₃₁ ,

_{-CH2CH2NHCH2CH2NHCOC17H35 , _ _ _ _}

_{-CH2CH2NHCH2CH2NHCOC17H33 , _ _ _ _}

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₁ H ₂₃ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₃ H ₂₇ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₅ H ₃₁ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₇ H ₃₅ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₇ H ₃₃ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₁ H ₂₃ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₃ H ₂₇ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₅ H ₃₁ ,

-CH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCH ₂ CH ₂ NHCOC ₁₇ H ₃₅ and

_{-CH2CH2NHCH2CH2NHCH2CH2NHCH2CH2NHCOC17H33 . _ _ _ _ _ _ _ _}

According to the composition provided by the present invention, for formula (4), preferably y2 is an integer of 0-2. R ₅ is as defined above for R ₃ . For example, the group of formula (4) can be:

According to the invention it is preferred that the organic amine contains at least two NH groups or at least one NH and at least one C=C. The NH group can be a primary amino group NH ₂ or a secondary amino group. Further preferably, the organic amine is one or more of NH ₂ (CH ₂ ) _m NHR', NH ₂ R'' and NH ₂ (CH ₂ ) _n NH ₂ in the amides formed with R'''COOH wherein, m and n are each 1-4, preferably 2 or 3; each of R', R'' and R''' is a hydrocarbon group with 5-25 carbon atoms, and the hydrocarbon group is further It preferably contains at least one C═C, and it is more preferred that R', R'' and R''' are each cocoyl or 9-octadecenyl.

In the present invention, it is particularly preferred that the organic amine is N-cocoyl ethylenediamine, N-cocoyl-1,3-propylenediamine, N-oleyl ethylenediamine, N-oleyl-1, 3-propylenediamine, 9-octadecylamine, the amide formed by the reaction of cocoic acid and diethylenetriamine in a molar ratio of 1:0.5-1, and the molar ratio of cocoic acid and triethylenetetramine in a molar ratio of 1:0.3- One of the amide formed by the reaction, the amide formed by the reaction of oleic acid and diethylenetriamine in a molar ratio of 1:0.5-1, the amide formed by the reaction of oleic acid and triethylenetetramine in a molar ratio of 1:0.3-1 or Various.

The condensation reaction of the amino polyacid and the organic amine generally follows that the molar ratio of the number of carboxyl groups in the amino polyacid to the organic amine is 1:0.2-5, preferably 1:0.6-1.5. The reaction temperature is generally 80-300°C, more preferably within the range of 120-250°C, most preferably within the range of 180-220°C. The reaction time is based on the sufficient progress of the reaction, the extent of the reaction can be determined according to the water content, and the preferred reaction time is 5-30 hours. The reaction medium can be an aromatic solvent such as xylene, ethylbenzene, aromatic diluent oil (distillation range 159-185°C), mineral oil (boiling point above 120°C), decahydronaphthalene, or a mixture thereof. The amount of solvent used is generally 30-150% by weight of the total weight of the reaction materials. The reaction can also be performed without a solvent. The reaction system can be protected with nitrogen, or the system can be carried out under the condition of reflux and water separation. The reaction can be carried out without a catalyst, or under the action of an acidic or basic catalyst, such as sulfuric acid, phosphoric acid, p-toluenesulfonic acid, acidic ion exchange resin, heteropolyacid, solid superacid, acidic clay, acidic molecular sieve, etc. Active catalysts such as NaOH, KOH, Ca(OH) ₂ , Mg(OH) ₂ , sodium methoxide, potassium methoxide, organic amines, etc. At the end of the reaction, the solvent can also be distilled off, and then a diluent with a solvent content of 20-50% by weight can be prepared with a heavy aromatic hydrocarbon solvent for use. In the present invention, the addition amount in the additive composition and diesel oil is uniformly calculated as dry dosage (that is, the addition amount without solvent).

The amide formed by NH ₂ (CH ₂ ) _n NH ₂ and R'''COOH can be obtained in various ways, for example, it can be obtained commercially, or it can be obtained by condensation reaction according to the existing method. For the specific operation of the condensation reaction, please refer to The above-mentioned condensation reaction between amino polyacid and organic amine can also be carried out with reference to known methods, and the present invention will not repeat them here.

Component b

Component b is a phenolic antioxidant, which refers to substances that contain phenolic hydroxyl groups in their molecules and can be used as antioxidants.

The phenolic antioxidant can be monophenol, bisphenol or polyphenol, or a mixture of them in any proportion.

Among them, the monophenol is a substituted phenol with a benzene ring/and a hydroxyl group on the benzene ring, and at least one of the substituents is a tert-butyl group, and other substituents can be hydrocarbon groups or substituents containing heteroatoms, wherein the hydrocarbon group Selected from C ₁ -C ₁₀ alkyl groups, such as methyl, ethyl, allyl, n-butyl, sec-butyl, nonyl, etc., and the substituents containing heteroatoms are selected from oxygen-containing substituents such as methoxy , methoxy-substituted methyl, hydroxymethyl, nitrogen-containing substituents such as α-dimethylaminomethyl. For example, it can be a monophenol of the following structure: o-tert-butylphenol, p-tert-butylphenol, 2-tert-butyl-4-methylphenol, 6-tert-butyl-2-methylphenol, 6-tert-butyl -3-methylphenol; 4-tert-butyl-2,6-dimethylphenol, 6-tert-butyl-2,4-dimethylphenol; 2,4-di-tert-butylphenol, 2,5 -Di-tert-butylphenol, 2,6-di-tert-butylphenol; 2,5-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-methylphenol (BHT, anti Oxygen T501), 4,6-di-tert-butyl-2-methylphenol; 2,4,6-tri-tert-butylphenol, 2-allyl-4-methyl-6-tert-butylphenol, 2-sec-butyl-4-tert-butylphenol, 4-sec-butyl-2,6-di-tert-butylphenol, 4-nonyl-2,6-di-tert-butylphenol, 2,6-di-tert-butylphenol Butyl-4-ethylphenol (antioxidant DBEP), 2,6-di-tert-butyl-4-n-butylphenol (antioxidant 678); tert-butylhydroxyanisole (BHA), 2,6 -Di-tert-butyl-α-methoxy-p-cresol (BHT-MO), 4-hydroxymethyl-2,6-di-tert-butylphenol (antioxidant 754), 2,6-di-tert-butyl -α-Dimethylamino-p-cresol (Antioxidant 703), various 3,5-di-tert-butyl-4-hydroxyphenylpropionates and 3,5-di-tert-butyl-4-hydroxy Phenylpropionamide, etc.

Wherein the monophenol antioxidant preferably has at least one tert-butyl hindered monophenol at the ortho position of the phenolic hydroxyl group, such as:

2-tert-butyl-4-methylphenol, 6-tert-butyl-2,4-dimethylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol Phenol (BHT, antioxidant T501), 2,4,6-tri-tert-butylphenol, 4-sec-butyl-2,6-di-tert-butylphenol, 4-nonyl-2,6-di-tert-butyl phenylphenol, 2,6-di-tert-butyl-4-ethylphenol (antioxidant DBEP), tert-butylhydroxyanisole (BHA), 2,6-di-tert-butyl-α-methoxy-p- Cresol (BHT-MO), 4-hydroxymethyl-2,6-di-tert-butylphenol (antioxidant 754), 2,6-di-tert-butyl-α-dimethylamino-p-cresol (antioxidant Oxygen agent 703) in one or more.

Bisphenols refer to phenolic antioxidants that are connected by two monophenols through sulfur or carbon atoms, such as:

(1) Bisphenol linked by carbon atoms

4,4'-Isopropylidene bisphenol (bisphenol A);

2,2'-bis-(3-methyl-4-hydroxyphenyl)propane (bisphenol C);

4,4’-dihydroxybiphenyl (antioxidant DOD);

4,4'-dihydroxy-3,3',5,5'-tetra-tert-butylbiphenyl (antioxidant 712);

2,2'-methylene-bis-(4-methyl-6-tert-butylphenol) (antioxidant bisphenol 2246);

4,4'-methylene-bis-(2-methyl-6-tert-butylphenol) (antioxidant methylene 736);

2,2'-methylene-bis-(4-ethyl-6-tert-butylphenol) (antioxidant 425);

2,2'-methylene-bis-(4-methyl-6-cyclohexylphenol) (antioxidant ZKF);

2,2'-methylene-bis[4-methyl-6-(α-methylcyclohexyl)phenol] (antioxidant WSP);

2,2'-methylene-bis-(6-α-methylbenzyl-p-cresol);

4,4'-methylene-bis-(2,6-di-tert-butylphenol) (antioxidant T511);

4,4'-methylene-bis-(2-tert-butylphenol) (antioxidant 702);

2,2'-Ethylene-bis-(4-methyl-6-tert-butylphenol);

4,4'-Ethylene-bis-(2-methyl-6-tert-butylphenol);

4,4'-Ethylene-bis-(2,6-di-tert-butylphenol);

4,4'-butylene-bis-(6-tert-butyl-m-cresol) (antioxidant BBM, antioxidant TCA);

4,4'-isobutylene-bis-(2,6-di-tert-butylphenol), etc.

(2) Bisphenols connected by sulfur atoms

4,4'-Thiobis-(3-methyl-6-tert-butylphenol) (Antioxidant 300 or AO-1);

2,2'-Thiobis-(4-methyl-6-tert-butylphenol) (antioxidant 2246-S);

4,4'-thiobis-(2-methyl-6-tert-butylphenol) (antioxidant 736);

4,4'-thiobis-(5-methyl-2-tert-butylphenol);

4,4'-thiobis-(2,6-di-tert-butylphenol) (Nocrac300);

2,2'-thiobis-(4-octylphenol), etc.

(3) Bisphenols connected by carbon atoms but containing heteroatoms

N,N'-hexamethylenebis-(3,5-di-tert-butyl-4-hydroxyphenylpropanamide) (Antioxidant 1098);

Hexylene glycol bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 259);

Bis-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl propionyl) hydrazine (antioxidant BPP);

Bis-(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide (antioxidant methylene 4426-S);

2,2'-Sulfoethylene glycol bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Antioxidant 1035);

Triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate (antioxidant 245), etc.

Bisphenol antioxidants are preferably bisphenols that have at least one tert-butyl group in the ortho-position of the phenolic hydroxyl group through a monophenol linked by methylene, for example:

2,2'-Methylene-bis-(4-methyl-6-tert-butylphenol) (Antioxidant 2246);

4,4'-methylene-bis-(2-methyl-6-tert-butylphenol) (antioxidant methylene 736);

4,4'-methylene-bis-(2,6-di-tert-butylphenol) (antioxidant T511);

4,4'-methylene-bis-(2-tert-butylphenol) (antioxidant 702);

Bisphenol antioxidants are also preferably bisphenols that have at least one tert-butyl group in the ortho-position of the phenolic hydroxyl group through sulfur-linked bisphenols, such as:

4,4'-Thiobis-(3-methyl-6-tert-butylphenol) (Antioxidant 300 or AO-1);

2,2'-Thiobis-(4-methyl-6-tert-butylphenol) (antioxidant 2246-S);

4,4'-thiobis-(2-methyl-6-tert-butylphenol) (antioxidant 736);

4,4'-thiobis-(2,6-di-tert-butylphenol) (Nocrac300);

The bisphenol-type antioxidant is also preferably a bisphenol connected by a monophenol with at least one tert-butyl group in the ortho position of the phenolic hydroxyl group through sulfur and two methylene groups, for example:

Bis(3-tert-butyl-4-hydroxybenzyl)sulfide;

Bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide (antioxidant methylene 4426-S);

Bis(2-methyl-5-tert-butyl-4-hydroxybenzyl)sulfide;

Bis(3-methyl-5-tert-butyl-4-hydroxybenzyl)sulfide;

Bis(3-tert-butyl-4-hydroxy-α-methylbenzyl)sulfide;

Bis(3,5-di-tert-butyl-4-hydroxy-α-methylbenzyl)sulfide;

Bis(3-tert-butyl-5-methyl-4-hydroxy-α-methylbenzyl)sulfide;

Bis(3-tert-butyl-2-hydroxybenzyl)sulfide;

Bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)sulfide;

Bis(3-tert-butyl-2-hydroxy-α-methylbenzyl)sulfide;

One or more of bis(3-tert-butyl-5-methyl-2-hydroxy-α-methylbenzyl) sulfide.

In particular, bis-(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide (antioxidant methylene 4426-S) and the like are preferable.

The polyphenol antioxidant refers to a phenolic antioxidant containing multiple phenolic hydroxyl groups in the molecule. Multiple phenolic hydroxyl groups can be located on the same benzene ring or on different benzene rings. It can mean that the molecule consists of at least three Monophenolic macromolecular antioxidant. Preference is given to polyphenols consisting of monophenolic groups having at least one tert-butyl group ortho to the phenolic hydroxyl group, especially preferred are hindered polyphenols having two tert-butyl groups ortho to the phenolic hydroxyl group, for example:

1,3,5-Trimethyl-2,4,6-tri-(4'-hydroxy-3',5'-di-tert-butyl)benzene (antioxidant 330);

Tris[2-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanate (Antioxidant 3125);

Tetrakis(3,5-di-tert-butyl-4-hydroxyphenylpropionate) pentaerythritol ester (antioxidant 1010);

1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H) (antioxidant 3114);

1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane (antioxidant CA);

1,3,5-tris(2,6-dimethyl-4-tert-butyl-3-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H) (antioxidant 1790 );

Bis[3,3-bis-(3'-tert-butyl-4'-hydroxybenzyl)butanoic acid]ethylene glycol ester, etc.

The phenolic antioxidant as component b can also be phenol with two or three hydroxyl groups in the benzene ring, such as hydroquinone, tert-butyl hydroquinone, di-tert-butyl hydroquinone Pyrogallic acid and gallic acid monoesters or diesters such as methyl gallate, ethyl gallate, propyl gallate, butyl gallate, amyl gallate, hexyl gallate, heptyl gallate, Octyl gallate, nonyl gallate, decyl gallate, lauryl gallate, tetradecyl gallate, cetyl gallate, octadecyl gallate, octadecyl gallate, etc., preferably tert-butyl Hydroquinone and Propyl Gallate.

The above-mentioned phenolic antioxidants are preferably bisphenolic antioxidants with at least one tert-butyl group in the ortho position of the phenolic hydroxyl group, especially bisphenolic antioxidants and polyphenolic antioxidants linked by methylene and/or sulfur Medium gallate.

Surprisingly, the inventors found that after the component a is compounded with the above-mentioned component b, there is an obvious synergistic effect, and the improvement effect on the oxidation stability of the fuel containing biodiesel is greatly enhanced.

According to the needs of use, the diesel oil composition provided by the present invention can also contain other additives, such as polymer amine type ashless dispersant, flow improver, cetane number improver, antistatic agent, preservative, rust inhibitor, demulsifier one or more of these.

The polymer amine type ashless dispersant includes alkenyl succinimide and/or alkenyl succinic acid amide, Mannich base type ashless dispersant, polyetheramine type ashless dispersant and polyolefin amine type ashless One or more of powders. The alkenyl succinimide and/or succinic acid amide ashless dispersant, for example, the reaction product of polyalkenyl succinic anhydride and/or succinic acid and amine with a number average molecular weight of 500-3000, such as a domestic product The grades are T151A (monosuccinimide), T151B (monosuccinimide), T152 (bisuccinimide), T154 (bisuccinimide), T155 (polysuccinimide) amine) and/or T161 (polysuccinimide), etc. Imported additives such as OLOA-1200, LZ894, Infineum C9238, 9237, Hitec644, etc. Mannich base type ashless dispersant, such as the condensation product of polyolefin-based phenol with formaldehyde and amine at a number average molecular weight of 500-3000; said polyetheramine type ashless dispersant, such as C8-C30 alkylphenol and ethylene oxide Or the product of condensation with amine after addition of propylene oxide or the product of condensation with amine after addition of C8-C30 alcohol with ethylene oxide or propylene oxide; the polyolefin amine type ashless dispersant such as chlorinated Polyolefin-based amines formed by reacting polyolefins with amines. The flow improver is preferably a (meth)acrylate-containing polymer. The cetane number improver can be a nitrate ester or a peroxide, such as one or more of isooctyl nitrate and di-tert-butyl peroxide.

The preparation of the additive composition provided by the invention is simple, and it only needs to mix the components constituting the additive composition uniformly.

The additive composition provided by the present invention is preferably used in an amount of 50-10000 ppm by weight relative to the base diesel, more preferably 50-5000 ppm by weight, further preferably 100-3000 ppm by weight, especially preferably 200-2000 ppm by weight. Especially, when the base diesel is pure biodiesel, the additive is preferably used in an amount of 600-2000 ppm by weight, more preferably 700-1500 ppm by weight. When the base diesel is a blend of biodiesel and petroleum diesel, the additive is preferably used in an amount of 100-1000 ppm by weight, more preferably 200-500 ppm by weight.

According to the diesel oil composition provided by the present invention, the diesel oil composition contains base diesel oil and an additive, and the base diesel oil contains biodiesel, wherein the additive is the above-mentioned additive composition provided by the present invention.

In the present invention, the base diesel oil can be all biodiesel, or partly biodiesel, and also contain other diesel oils, and the other diesel oils are petroleum diesel, Fischer-Tropsch synthetic diesel oil, hydrocracking biodiesel, oxygenated diesel oil One or more of the blends. Preferably, the volume ratio of biodiesel to other diesel is 1:2-99.

The preparation of the diesel composition provided by the invention is simple, and only needs to mix the components of the diesel composition uniformly. The additive components can be directly mixed with the base diesel oil, or the various additive components can be uniformly mixed first to obtain the additive composition, and then the obtained additive composition can be mixed with the base diesel oil. For the convenience of operation, when mixing various additive components evenly, it can be carried out in the presence of a solvent. The solvent here can be a polar solvent such as N,N-dimethylformamide (DMF), 1,4-dioxahexa One or more of ring, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), pyrrolidone and methylpyrrolidone. It can also be hydrocarbons, especially aromatics such as benzene, toluene, xylene, aromatics diluent oil and their mixtures, and biodiesel.

In the present invention, the biodiesel refers to fatty acid lower alcohol esters generated by transesterification (alcoholysis) reaction of fats and low carbon alcohols (such as C ₁ -C ₅ fatty alcohols), generally fatty acid methyl esters, i.e. The transesterification product of oil and methanol.

The transesterification process can be any known or unknown process for obtaining biodiesel through transesterification of oils and low-carbon alcohols, such as acid catalysis, alkali catalysis, enzyme catalysis, supercritical method, etc. Wait. For details, reference can be made to documents such as CN1473907A, DE3444893, CN1472280A, CN1142993C, CN1111591C, and CN1594504A.

The fat has a general meaning known in the art, which is a general term for oil and fat, and its main component is fatty acid triglyceride. Generally, what is liquid at room temperature is called oil, and what is solid or semi-solid at room temperature is called fat (referred to as fat). The oils include vegetable oils and animal oils. In addition, oils from microorganisms, algae, etc. can even be waste oils, such as used oils such as catering waste oil, waste oil, swill oil, acidified oil from oil factories, etc. or spoiled grease. Described vegetable oil can be herbaceous vegetable oil also can be woody vegetable oil, as peanut oil, corn oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, safflower oil, linseed oil, coconut oil, oak tree oil, almond oil, walnut oil, castor oil, sesame oil, olive oil, tall oil (Tall Oil), sunflower oil, jatropha oil, tung oil, sorbetia oil, pistachio oil, oils of halo plants such as sea mallow, oil sand bean and other plants . The animal oil may be lard, chicken oil, duck oil, goose oil, suet oil, horse oil, tallow, whale oil, shark oil, etc.

In the biodiesel composition of the present invention, the base diesel oil may also contain other diesel oils, and the other diesel oils are one of petroleum diesel, Fischer-Tropsch synthetic diesel oil, hydrocracking biodiesel, and oxygenated diesel blends or more, the volume ratio of biodiesel to other diesel is preferably 1:2-99.

Among them, petroleum diesel refers to crude oil (petroleum) with a distillation range of 160-380°C after being treated by various refining processes in refineries, such as atmospheric and vacuum, catalytic cracking, catalytic reforming, coking, hydrofining, and hydrocracking. The fractions between them are blended to meet the national standard GB252 for ordinary diesel or the national standard GB/T19147 for automotive diesel fuel for compression ignition internal combustion engines.

Fischer-Tropsch synthetic diesel mainly refers to GTL diesel (Gas To Liquid) or CTL diesel (Coal To Liquid) produced by the Fischer-Tropsch (F-T) synthesis method using natural gas or coal as raw material, and it can also be plant fiber by the Fischer-Tropsch synthesis method And the production of BTL diesel (Biomass To Liquid). Fischer-Tropsch synthetic diesel basically does not contain sulfur and aromatics, and is a very clean fuel, but its lubricity is extremely poor. After blending with biodiesel, the lubricity is greatly improved, but the oxidation stability of the blended oil may deteriorate , so blended fuels containing biodiesel also need to add antioxidants.

Hydrocracking biodiesel, also known as second-generation biodiesel, refers to C ₈ -C ₂₄ alkanes, especially C ₁₂ -C ₂₀ normal alkanes, produced by hydrogenation and cracking reactions of animal and vegetable oils As the reaction product of the main component, this hydrocracking biodiesel has a high cetane number and extremely low sulfur and aromatic content. As a diesel engine fuel or a blending component, it can greatly reduce the emission of diesel engine pollutants.

Oxygenated diesel blending components refer to oxygenated compounds or mixtures of oxygenated compounds that can be blended with various diesel fuels to meet certain specification requirements, usually alcohols and ethers or their mixtures, alcohols such as C ₁ -C ₁₈ Fatty alcohols, preferably C ₁ -C ₁₂ monohydric fatty alcohols, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecyl alcohol, lauryl alcohol and its various isomers. Ethers can be dimethyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, C ₆ -C ₁₄ fatty alcohol polyoxyethylene ether, C ₆ -C ₁₄ fatty alcohol polyoxypropylene ether, C ₆ -C ₁₄ Alkylphenol polyoxyethylene ethers, C ₆ -C ₁₄ alkylphenol polyoxypropylene ethers, polyoxymethylene dimethyl ethers (Polyoxymethylene Dimethyl Ethers, CH ₃ O(CH ₂ O) _x CH ₃ , x=1 -8) etc. and mixtures thereof.

In the present invention, when the base diesel oil is a blended fuel containing biodiesel, the diesel oil composition can be obtained by directly mixing the additive, biodiesel and other diesel oils, or can first mix the additive with biodiesel Mixed, and then blended with other diesel obtained. The various components of the additive can be directly mixed with the base diesel, or the various components of the additive can be pre-mixed to obtain the additive mixture and then mixed with the base diesel. The mixing order of the various components of the additive and biodiesel and other diesel is not particularly limited, and may be mixed in various orders. The mixing conditions can be carried out under various conditions that do not adversely affect the diesel composition, for example, mixing can be at ambient temperature.

The method for improving the oxidation stability of biodiesel provided by the present invention comprises adding an additive to the base diesel containing biodiesel, and the additive is the above-mentioned additive composition provided by the present invention.

Preferably, the additive is added in an amount of 50-10000 ppm by weight (mg/kg), more preferably 50-5000 ppm by weight, further preferably 100-3000 ppm by weight, and especially preferably 200-2000 ppm by weight relative to the base diesel oil . Especially, when the base diesel is pure biodiesel, the additive is preferably used in an amount of 600-2000 ppm by weight, more preferably 700-1500 ppm by weight. When the base diesel is a blend of biodiesel and petroleum diesel, the additive is preferably used in an amount of 100-1000 ppm by weight, more preferably 200-500 ppm by weight.

The base diesel oil and the additive composition have been described above, and the present invention will not repeat them here.

The following examples will further illustrate the present invention.

Preparations 1-5 are used to illustrate the synthesis of component a.

Preparation Example 1

In a three-necked bottle, add 116.2 g of N-cocoyl-1,3-propylenediamine and 35.0 g of ethylenediaminetetraacetic acid (EDTA), wherein N-cocoyl-1,3-propylenediamine The molar ratio to ethylenediaminetetraacetic acid is 4:1, that is, the molar ratio of amine to carboxyl in amino polyacid is 1:1. Heat and stir to 190°C, pass through nitrogen to react for 20h, and collect the generated water with a collector, then lower the temperature to 120°C, use a vacuum pump to depressurize for 2h to remove a small amount of water generated by the reaction, a total of 13.6g of watery matter was collected, and obtained The reaction product was 125.2 g.

Preparation example 2

In a three-neck flask, add 129.8g of N-oleyl-1,3-propylenediamine and 38.2g of nitrilotriacetic acid (NTA), wherein N-oleyl-1,3-propylenediamine and nitrilo The molar ratio of triacetic acid is 2:1, that is, the molar ratio of amine to carboxyl in amino polyacid is 1:1.5. Heat and stir to 170°C, pass through nitrogen to react for 18h, and collect the generated water with a collector, then lower the temperature to 110°C, use a vacuum pump to depressurize for 2h to remove a small amount of water generated by the reaction, and a total of 6.6g of watery matter is collected to obtain The reaction product was 149.4 g.

Preparation example 3

In the three-necked flask, add 133.8g oleylamine and 38.3g 1,3-propylenediaminetetraacetic acid (PDTA), wherein the molar ratio of oleylamine to 1,3-propylenediaminetetraacetic acid is 4:1, that is, amine and The carboxyl molar ratio in the amino polyacid is 1:1. Heat and stir to 200°C, pass through nitrogen to react for 25h, and collect the generated water with a collector, then lower the temperature to 120°C, use a vacuum pump to depressurize for 2h to remove a small amount of water generated by the reaction, and collect a total of 10.1g of water-like substance to obtain The reaction product was 149.4 g.

Preparation Example 4

In the three-necked flask, add 186.2g of amide formed by the reaction of oleic acid and triethylenetetramine and 35.0g of ethylenediaminetetraacetic acid (EDTA), wherein the amide formed by the reaction of oleic acid with triethylenetetramine and ethylenediaminetetramine The molar ratio of the organic amine to the carboxyl group in the amino polyacid is 0.75:1. Heat and stir to 200°C, pass through nitrogen to react for 20h, and collect the generated water with a collector, then lower the temperature to 120°C, use a vacuum pump to depressurize for 2h to remove a small amount of water generated by the reaction, and a total of 12.8g of watery matter is collected to obtain The reaction product was 162.2 g.

Wherein, the amide formed by the reaction of oleic acid and triethylenetetramine is prepared according to the following steps:

In a 500ml three-neck flask, add 0.5mol oleic acid and 0.3mol triethylenetetramine, heat and stir to 130°C, and blow water with nitrogen to react for 5 hours. The product after water removal is analyzed by infrared, and it is found that there are characteristic peaks of amide groups in the reaction product. The reaction product is directly used as the amide formed by the reaction of oleic acid and triethylenetetramine to prepare the condensation product of amino polyacid and organic amine in the present invention.

Preparation Example 5

In the three-neck flask, add octadecylamine and 1,3-propylenediaminetetraacetic acid (PDTA), wherein the molar ratio of octadecylamine to 1,3-propylenediaminetetraacetic acid is 4:1, that is, amine The molar ratio of carboxyl to amino polyacid is 1:1. Heat and stir to 200°C, pass nitrogen gas to react for 25 hours, and collect the generated water with a collector, then lower the temperature to 120°C, and use a vacuum pump to depressurize for 2 hours to remove a small amount of water generated by the reaction to obtain 150.1 g of the reaction product.

Examples 1-7 and Comparative Examples 1-10 illustrate the compositions of the additive compositions.

Additive compositions were prepared according to the weight ratios shown in Table 1.

Table 1

Example Component a Component b Component a: Component b Example 1 Preparation Example 1 Antioxidant 2246 1:3 Comparative example 1 Preparation Example 1 - - Comparative example 2 - Antioxidant 2246 - Example 2 Preparation example 2 Propyl gallate 2:1 Comparative example 3 Preparation example 2 - - Comparative example 4 - Propyl gallate - Example 3 Preparation example 3 Antioxidant Methylene 4426-S 1:1 Comparative example 5 Preparation example 3 - - Comparative example 6 - Antioxidant Methylene 4426-S - Example 4 Preparation example 2 TBHQ 1:2 Comparative example 7 - TBHQ - Example 5 Preparation Example 1 Antioxidant T501 1:3 Comparative example 8 - Antioxidant T501 - Example 6 Preparation Example 4 Antioxidant T501 1:0.2 Comparative example 9 Preparation Example 4 - Example 7 Preparation Example 5 Antioxidant T501 1:5 Comparative example 10 Preparation Example 5 - -

Performance Testing

In the following tests, the waste oil biodiesel used was provided by Guangdong Sanshui Zhenghe Bioenergy Co., Ltd., the acidified oil biodiesel used was the biodiesel product provided by Jiangsu Hengshunda Bioenergy Co., Ltd., and the petroleum diesel was produced by Sinopec Yanshan Branch It meets the Beijing local standard DB11/239-2007 diesel. The added amount is uniformly calculated as dry dose (that is, the added amount without solvent).

(1) Oxidation stability test of biodiesel composition with pure biodiesel as base diesel

Use EN14112:2003 method (Racimat method) to measure the induction period at 110°C to evaluate the oxidation stability of biodiesel. The instrument used is Metrohm's 743 oil oxidation stability tester. Among them, the longer the induction period, the higher the oxidation stability of diesel oil. The better the oxidation resistance of the composition, on the contrary the shorter the induction period, the worse the oxidation resistance of the diesel oil composition. The test results are shown in Table 2 and Table 3.

Table 2

table 3

As can be seen from the data in Table 2 and Table 3, the condensation reaction product of amino polyacid and polyamine provided by the present invention is used as component a and phenolic antioxidant (component b) after compounding to biodiesel oxidation stability There is a very good improvement effect, and the unexpected synergistic effect of the two appears, and the effect is much better than that used alone. The antioxidant effect of bisphenol or polyphenol antioxidant compounded as component b is better than that of monophenolic antioxidant compounded as component b (T501) with component a (Example 5).

(2) Test the stability of the blended diesel composition using a mixture of biodiesel and petroleum diesel as the base diesel, and the biodiesel used is acidified oil biodiesel.

Use SH/T0175 method to measure the oxidation stability total insoluble matter of petroleum diesel oil and blended diesel oil respectively, and the test results are shown in Table 4.

Table 4

From the results in Table 4, it can be seen that after adding biodiesel, the oxidation stability of the blended fuel containing biodiesel is poor, and the total insoluble matter increases. The invention provides the condensation reaction product of amino polyacid and polyamine as component a and compounded with phenolic antioxidant, which has a good effect on improving the oxidation stability of biodiesel blended fuel, which is obviously better than using phenolic antioxidant alone. Oxygen effect.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

Claims (15)

1. an additive composition, it is characterized in that, this additive composition contains component a and component b, and described component a is the reaction product of aminopolyacid and organic amine; Described component b is bisphenol type Antioxidant or gallate antioxidant; the organic amine contains at least two NH groups; the weight ratio of component b to component a is 0.01-10:1. 2. The additive composition according to claim 1, wherein, the number of amino groups in the amino polyacid is 1-5, the number of carboxylic acid groups is 2-6, and the amino groups are all tertiary Amino. 3. The additive composition according to claim 1 or 2, wherein, the total number of carbon atoms of the amino polyacid is 4-14, and the carboxylic acid group is among formate, acetate, propionate and butyrate One or more of NH ₂ (CH ₂ ) _m NHR' and one or more of NH ₂ (CH ₂ ) _n NH ₂ and one of the amides formed with R"'COOH or more, wherein m and n are each 1-4, and R' and R"' are each a hydrocarbon group with 5-25 carbon atoms. 4. The additive composition according to claim 2, wherein, the number of amino groups in the amino polyacid is 1-3, the number of carboxylic acid groups is 2-5, and the carboxylic acid groups are acetic acid groups and / or propionyl, R' and R"' are each cocoyl or 9-octadecenyl. 5. The additive composition according to claim 2, wherein, the number of amino groups in the amino polyacid is 1-3, the number of carboxylic acid groups is 2-5, and the carboxylic acid groups are acetic acid groups and / or propionyl, R' and R"' are each cocoyl or 9-octadecenyl. 6. The additive composition according to claim 1, wherein the amino polyacid is iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, ethylenediaminetetrapropionic acid, 1,2-propanedi One or more of amine tetraacetic acid, 1,3-propanediamine tetraacetic acid, diethylene triamine pentaacetic acid, 1,6-hexanediamine tetraacetic acid, 1,2-cyclohexanediamine tetraacetic acid; The organic amines are N-cocoyl ethylenediamine, N-cocoyl-1,3-propylenediamine, N-oleylethylenediamine, N-oleyl-1,3-propylenediamine Amine, 9-octadecylamine, amides formed by the reaction of cocoic acid and diethylenetriamine in a molar ratio of 1:0.5-1, amides formed by the reaction of cocoic acid and triethylenetetramine in a molar ratio of 1:0.3-1 One or more of the amides formed by the reaction of oleic acid and diethylenetriamine at a molar ratio of 1:0.5-1, and the amides formed by the reaction of oleic acid and triethylenetetramine at a molar ratio of 1:0.3-1. 7. according to the additive composition described in any one in claim 2,4-6, wherein, the mol ratio of the described amino polyacid and organic amine of the carboxyl in the amino polyacid is 1:0.6-1.5, The temperature of the condensation reaction is 80-300° C., and the time of the condensation reaction is 5-30 hours. 8. The additive composition according to claim 3, wherein, the mol ratio of the amino polyacid and the organic amine in terms of the carboxyl group in the amino polyacid is 1:0.6-1.5, and the temperature of condensation reaction is 80-300 °C, the condensation reaction time is 5-30 hours. 9. The additive composition according to claim 1, wherein the component b is 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol), 4,4' -Methylene-bis-(2-methyl-6-tert-butylphenol), 4,4'-methylene-bis-(2,6-di-tert-butylphenol), 4,4'- Methyl-bis-(2-tert-butylphenol), 4,4'-thiobis-(3-methyl-6-tert-butylphenol), 2,2'-thiobis-(4-methyl base-6-tert-butylphenol), 4,4'-thiobis-(2-methyl-6-tert-butylphenol), 4,4'-thiobis-(2,6-di-tert-butyl phenylphenol), bis-(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, methyl gallate, ethyl gallate, propyl gallate, butyl gallate, amyl gallate, Hexyl gallate, Heptyl gallate, Octyl gallate, Nonyl gallate, Decyl gallate, Lauryl gallate, Myristyl gallate, Cetyl gallate, Octadeyl gallate, Gallic acid One or more of octadecenyl esters. 10. A diesel oil composition, the diesel oil composition contains base diesel oil and additives, the base diesel oil contains biodiesel, characterized in that the additive is the additive composition according to any one of claims 1-9. 11. The diesel composition according to claim 10, wherein the content of the additive is 50-10000 ppm by weight relative to the base diesel. 12. The diesel composition according to claim 10 or 11, wherein the base diesel oil also contains other diesel oils, and the other diesel oils are one of petroleum diesel, Fischer-Tropsch synthetic diesel oil, and oxygenated diesel blends or several, the volume ratio of the biodiesel to other diesel is 1:2-99. 13. A method for improving the oxidation stability of biodiesel, the method comprising, adding additives in the base diesel containing biodiesel, characterized in that, the additives are the additive combinations described in any one of claims 1-9 thing. 14. The method according to claim 13, wherein the additive is added in an amount of 50-10000 ppm by weight relative to the base diesel oil. 15. The method according to claim 13 or 14, wherein the base diesel oil also contains other diesel oils, and the other diesel oils are one or more of petroleum diesel oil, Fischer-Tropsch synthetic diesel oil, and oxygenated diesel oil blends. species, the volume ratio of biodiesel to other diesel is 1:2-99.