Stabilizer for fuel oil containing ethylene tar and preparation process of stabilizer

Abstract

The invention discloses a stabilizer for fuel oil containing ethylene tar and a preparation process of the stabilizer, and belongs to the technical field of energy and chemical industry. The stabilizer is composed of 8-20% of a composite antioxidant, 20-25% of a nano-scale dispersant, 5-8% of a metal deactivator, 10-15% of a viscosity modifier and 20-50% of a solvent, the composite antioxidant is compounded by alkylated diphenylamine and D-tocopherol according to a ratio of 3: 1, the nano-scale dispersant is prepared by loading polyisobutylene succinimide on a silane coupling agent modified nano-silica carrier, and the viscosity modifier is a silane coupling agent modified nano-silica carrier. The metal passivator is selected from six specific benzotriazole derivatives. According to the preparation method, the synergistic interaction of the components is realized through the processes of nano-carrier surface modification, dispersing agent in-situ loading, antioxidant system compounding, high-pressure homogenization treatment and the like. Through innovative formula design and process optimization, the problems of storage deterioration, metal catalytic deterioration and viscosity regulation of ethylene tar fuel oil are solved, and the method has important industrial application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy and chemical engineering, and particularly relates to a stabilizer for fuel oil containing ethylene tar and a preparation process thereof. Background Art

[0002] In today's energy field, fuel oil containing ethylene tar, as an important energy substance, has been widely used in industrial production and daily life. However, this fuel oil faces many problems during storage and use, which urgently need to be solved.

[0003] First of all, fuel oil containing ethylene tar is prone to oxidation reaction during storage, resulting in a decline in its quality. The oxidation reaction will generate harmful substances such as peroxides, aldehydes, and ketones. These substances will not only reduce the calorific value of the fuel oil but also may produce carbon deposits during the combustion process, affecting the combustion efficiency and the service life of the equipment. Therefore, an effective antioxidant is needed to inhibit the oxidation reaction and maintain the stability of the fuel oil.

[0004] Secondly, solid particles in the fuel oil are prone to aggregation and sedimentation, affecting the fluidity and uniformity of the fuel oil. This phenomenon will lead to problems such as uneven injection and incomplete combustion during the transportation and combustion of the fuel oil, reducing the combustion efficiency and increasing pollutant emissions. To improve the dispersion stability of the fuel oil, a highly efficient nanoscale dispersant is needed, which can uniformly disperse the solid particles in the fuel oil and prevent them from re-aggregating.

[0005] In addition, metal ions contained in the fuel oil are prone to react with other components in the fuel oil, accelerating the deterioration of the fuel oil. Metal ions may also form metal oxides during the combustion process, resulting in corrosion and wear of the combustion equipment. Therefore, a metal deactivator is needed to deactivate metal ions and prevent them from having a negative impact on the stability of the fuel oil.

[0006] In practical applications, the viscosity of the fuel oil is also a key factor. Fuel oil with too high viscosity will cause problems such as difficult transportation and incomplete combustion, while too low viscosity will affect the lubrication performance and combustion stability of the fuel oil. Therefore, a viscosity modifier is needed to adjust the viscosity of the fuel oil so that it maintains an appropriate viscosity range during storage and use.

[0007] To sum up, there is currently a lack of a stabilizer in the market that can simultaneously solve the problems of fuel oil containing ethylene tar in terms of antioxidant, dispersion stability, metal passivation, and viscosity adjustment. Based on this market demand, the present invention provides a stabilizer for fuel oil containing ethylene tar and a preparation method thereof to overcome the deficiencies in the prior art, improve the comprehensive performance of the fuel oil, and meet the high-quality development needs of the energy field. Summary of the Invention

[0008] The present invention aims to provide a stabilizer for fuel oil containing vinyl tar, which has advantages in aspects such as antioxidant, dispersion stability, metal passivation and viscosity adjustment.

[0009] The present invention provides a stabilizer for fuel oil containing vinyl tar. The mass ratio of the stabilizer for fuel oil containing vinyl tar is as follows: compound antioxidant 8 - 20%, nano - level dispersant 20 - 25%, metal passivator 5 - 8%, viscosity improver 10 - 15%, and solvent 20 - 50%.

[0010] Furthermore, the compound antioxidant includes alkylated diphenylamine and D - tocopherol mixed in a mass ratio of 3:1.

[0011] Furthermore, the nano - level dispersant is polyisobutylene succinimide and nano - silica carrier.

[0012] Furthermore, the viscosity improver is propylene glycol methyl ether acetate.

[0013] Furthermore, the solvent is hydrogenated palm oil.

[0014] Furthermore, the metal passivator is a benzotriazole derivative;

[0015] Furthermore, the benzotriazole derivative is selected from: metal passivator - 1 to metal passivator - 6;

[0016] Furthermore, the structures of the metal passivator - 1 to metal passivator - 6 are as follows:

[0017]

[0018] Furthermore, the Chinese names of the metal passivator - 1 to metal passivator - 6 are:

[0019] The Chinese name of the metal passivator - 1 is: 1 - (5 - (4 - (6 - (benzyloxy) - 2 - phenyl - 1,2,3,4 - tetrahydronaphthalen - 1 - yl)phenoxy)pentyl) - 1H - benzotriazole;

[0020] The Chinese name of the metal passivator - 2 is: (S) - 8 - ((5 - (1H - benzotriazol - 1 - yl)pentyl)oxy) - 7 - methoxy - 10 - (2 - (trimethylsilyl)ethoxy)methyl) - 1,11 - dihydro - 5H - benzo[e]pyrrolo[1,2 - a][1,4]diazepine - 2,5,11(3H,10H) - trione;

[0021] The Chinese name of the metal deactivator-3 is: (4-(5-(1H-benzo[d][1,2,3]triazol-1-yl)pentyl)oxy)-5-methoxy-2-nitrophenyl)(2-(bis(ethylthio)methyl)pyrrolidin-1-yl)methanone;

[0022] The Chinese name of the metal deactivator-4 is: 3-(4-(1H-benzo[d][1,2,3]triazol-1-yl)butyl)-4-acetyl-5-((R)-1-((tert-butyldiphenylsilyl)oxy)propyl)-5-methyl-oxazolidin-2-one;

[0023] The Chinese name of the metal deactivator-5 is: Allyl (S)-8-(3-(1H-benzo[d][1,2,3]triazol-1-yl)propoxy)-7-methoxy-2-(4-methoxyphenyl)-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-10(5H)-carboxylate;

[0024] The Chinese name of the metal deactivator-6 is: Methyl 4-(((2-(5-(1H-benzo[d][1,2,3]triazol-1-yl)pentyl)oxy)phenethyl)(5-ethoxy-5-oxopentyl)amino)methyl)benzoate.

[0025] Furthermore, the synthesis steps of the benzotriazole derivative are as follows: Add benzotriazole to the first solvent, stir, add the raw materials, add triphenylphosphine and stir, displace the gas by introducing nitrogen, add palladium carbon, raise the temperature to 80-90 °C, and react for 12 h.

[0026] Furthermore, the first solvent is toluene.

[0027] Furthermore, the structure of the raw materials is:

[0028]

[0029] Furthermore, the Chinese names of raw material-1 to raw material-6 are:

[0030] The Chinese name of the raw material-1 is: 6-(benzyloxy)-1-(4-(5-bromopentyl)oxy)phenyl)-2-phenyl-1,2,3,4-tetrahydronaphthalene;

[0031] The Chinese name of the raw material-2 is: (S)-8-((5-bromopentyl)oxy)-7-methoxy-10-((2-(trimethylsilyl)ethoxy)methyl)-1,11-dihydro-5H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-2,5,11(3H,10H)-trione;

[0032] The Chinese name of the raw material - 3 is: (2-(bis(ethylthio)methyl)pyrrolidin-1-yl)(4-((5-bromopentyl)oxy)-5-methoxy-2-nitrophenyl)methanone;

[0033] The Chinese name of the raw material - 4 is: 4-ethylene-3-(4-source methyl)-5-((R)-1-((tert-butyldiphenylsilyl)oxy)propyl)-5-methyloxazolidin-2-one;

[0034] The Chinese name of the raw material - 5 is: (S)-8-(3-bromopropoxy)-7-methoxy-2-(4-methoxyphenyl)-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-10(5H)-carboxylic acid allyl ester;

[0035] The Chinese name of the raw material - 6 is: methyl 4-(((2-((5-bromopentyl)oxy)phenethyl)(5-ethoxy-5-oxopentyl)amino)methyl)benzoate.

[0036] Furthermore, a preparation method of a stabilizer for fuel oil containing vinyl tar comprises the following steps:

[0037] S1. Ultrasonically disperse nano-silica (10 - 20 nm) in absolute ethanol, add silane coupling agent KH-550, and react at 60 °C for 2 hours to form the nano-silica carrier;

[0038] S2. Mix the polyisobutylene succinimide and the nano-silica carrier according to a mass ratio of 1:2, disperse in a high-speed shear machine (8000 rpm) for 1 hour, and dry under reduced pressure at 60 °C to obtain a supported dispersant;

[0039] S3. Dissolve the alkylated diphenylamine and the D-α-tocopherol in the hydrogenated palm oil according to a ratio of 3:1, add 0.5% citric acid as a pH stabilizer, and stir at 50 °C until transparent;

[0040] S4. Add the dispersant of S2 and the metal deactivator to the hydrogenated palm oil, and premix at 60 °C for 30 minutes;

[0041] S5. Add the antioxidant composite system, heat up to 70 °C and continuously stir for 1 hour;

[0042] S6. Finally, add ethylene glycol methyl ether acetate, and process with a high-pressure homogenizer (50 MPa) for 3 times to obtain a stabilizer for fuel oil containing vinyl tar.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] 1. By compounding dialkyl diphenylamine and D-tocopherol in a ratio of 3:1, the activity bottleneck of a single antioxidant is broken through, and the oxidation induction period is increased to 420 hours, which is 110% longer than that of the traditional BHT system, significantly inhibiting the formation of oxidation gum in ethylene tar fuel oil.

[0045] 2. Innovation in the structure of nano-dispersant: Using nano-silica modified by silane coupling agent as the carrier, in-situ loading of polyisobutylene succinimide to form a dual-stabilization mechanism of steric hindrance and electrostatic repulsion, making the particle D50 in the fuel oil ≤ 200 nm, without precipitation after standing for 30 days, overcoming the problem of particle aggregation caused by the lack of carrier in conventional dispersants.

[0046] 3. Outstanding targeted metal passivation performance: The passivator based on benzotriazole derivatives forms a chelation barrier with metal ions, optimizing the copper strip corrosion grade to 1a level, with a passivation efficiency ≥ 98.5%, and reducing the corrosion risk by 80% compared with nitrite-based passivators.

[0047] 4. Optimization of low-temperature viscosity regulation: Through a compound solvent system of hydrogenated vegetable oil and propylene glycol methyl ether acetate, in cooperation with a viscosity improver, the viscosity of the fuel oil is maintained at 150 cP at -20 °C, and the fluidity is better than 180 cP of mineral oil-based solvents, solving the problem of viscosity during storage and transportation in alpine environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is the structure of the metal passivator described in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0049] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0050] Example 1-1

[0051] Synthesis of metal passivator-1.

[0052] Add 1 eq of benzotriazole to toluene, stir, add 1 eq of raw material-1 (6-(benzyloxy)-1-(4-(5-bromopentyl)oxy)phenyl)-2-phenyl-1,2,3,4-tetrahydronaphthalene), add 1.5 eq of triphenylphosphine and stir, displace the gas by introducing nitrogen, add 0.01 eq of palladium carbon, heat up to 85 °C, react for 12 h, spin dry the solvent, and purify through a silica gel purification column to obtain metal passivator-1.

[0053] MS(MS + 1) shows: 594.

[0054] Example 1-2

[0055] Synthesis of metal deactivator-2: Referring to the synthesis steps of metal deactivator-1 in Example 1-1, the raw materials were replaced with Raw Material-2 ((S)-8-((5-bromopentyl)oxy)-7-methoxy-10-((2-(trimethylsilyl)ethoxy)methyl)-1,11-dihydro-5H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-2,5,11(3H,10H)-trione), and the remaining operations were the same as those in Example 1-1.

[0056] MS(MS + 1) showed: 594.

[0057] Example 1-3

[0058] Synthesis of metal deactivator-3: Referring to the synthesis steps of metal deactivator-1 in Example 1-1, the raw materials were replaced with Raw Material-3 ((2-(bis(ethylthio)methyl)pyrrolidin-1-yl)(4-((5-bromopentyl)oxy)-5-methoxy-2-nitrophenyl)methanone), and the remaining operations were the same as those in Example 1-1;

[0059] MS(MS + 1) showed: 588.

[0060] Example 1-4

[0061] Synthesis of metal deactivator-4: Referring to the synthesis steps of metal deactivator-1 in Example 1-1, the raw materials were replaced with Raw Material-4 (4-ethylene-3-(4-source methyl)-5-((R)-1-((tert-butyldiphenylsilyl)oxy)propyl)-5-methyloxazolidin-2-one), and the remaining operations were the same as those in Example 1-1;

[0062] MS(MS + 1) showed: 612.

[0063] Example 1-5

[0064] Synthesis of metal deactivator-5: Referring to the synthesis steps of metal deactivator-1 in Example 1-1, the raw materials were replaced with Raw Material-5 ((S)-8-(3-bromopropoxy)-7-methoxy-2-(4-methoxyphenyl)-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-10(5H)-carboxylic acid allyl ester), and the remaining operations were the same as those in Example 1-1;

[0065] MS(MS + 1) showed: 596.

[0066] Example 1-6

[0067] Synthesis of metal deactivator - 6: Refer to the synthesis steps of metal deactivator - 1 in Example 1 - 1, replace the raw materials with Raw Material - 6 (methyl 4 - ((((2 - ((5 - bromopentyl)oxy)phenethyl)(5 - ethoxy - 5 - oxopentyl)amino)methyl)benzoate), and the remaining operations are the same as in Example 1 - 1;

[0068] MS (MS + 1) shows: 601.

[0069] Example 1: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0070] Preparation of nano - silica carrier: Take 10 g of nano - silica (15 nm) and disperse it in 200 mL of anhydrous ethanol, ultrasonically treat for 30 minutes, add 2 g of silane coupling agent KH - 550, stir and react at 60 °C for 2 hours, and obtain the modified carrier by centrifugation and drying.

[0071] Preparation of supported dispersant: Mix 5 g of polyisobutylene succinimide with 10 g of modified carrier, disperse in a high - speed shearer at 8000 rpm for 1 hour, and dry under reduced pressure at 60 °C.

[0072] Preparation of antioxidant system: Dissolve 9 g of alkylated diphenylamine and 3 g of D - tocopherol in 30 g of hydrogenated palm oil, add 0.15 g of citric acid, and stir at 50 °C until transparent.

[0073] Premixed dispersion system: Add the dispersant from Step 2 and 6 g of metal deactivator - 1 (prepared in Example 1 - 1) to 20 g of hydrogenated palm oil, and premix at 60 °C for 30 minutes.

[0074] Final mixing treatment: Add the antioxidant system to the premixed system, heat up to 70 °C and stir for 1 hour, finally add 12 g of propylene glycol methyl ether acetate, and perform high - pressure homogenization treatment at 50 MPa for 3 times to obtain Stabilizer A.

[0075] Formulation composition: Composite antioxidant 12%, nano - dispersant 20% (including carrier), metal deactivator 6%, viscosity improver 12%, solvent 45%.

[0076] Example 2: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0077] Refer to the preparation method of Example 1, adjust the formulation ratio to: Composite antioxidant 10%, nano - dispersant 25% (including carrier), metal deactivator 7%, viscosity improver 15%, solvent 40%, and the rest is the same as in Example 1.

[0078] Example 3: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0079] Referring to the preparation method of Example 1, replace the metal deactivator-1 with metal deactivator-4 (prepared in Example 1-4), and the rest is the same as Example 1.

[0080] Example 4: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0081] Referring to the preparation method of Example 1, adjust the formulation ratio to: the viscosity modifier is increased to 18%, and the rest is the same as Example 1.

[0082] Example 5: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0083] Referring to the preparation method of Example 1, adjust the particle size of the nano-silica carrier in the formulation to 5 nm and the dispersant loading ratio to 1:1.5, and the rest is the same as Example 1.

[0084] Comparative Example 1: Nano-dispersant-free system

[0085] Referring to the preparation method of Example 1, omit the nano-silica carrier and directly use polyisobutylene succinimide, and the rest is the same as Example 1.

[0086] Comparative Example 2: Replacement with traditional antioxidants

[0087] Referring to the preparation method of Example 1, replace the compound antioxidant with BHT (dibutylhydroxytoluene), and the rest is the same as Example 1.

[0088] Comparative Example 3: Non-benzotriazole-based deactivator

[0089] Referring to the preparation method of Example 1, replace the metal deactivator with sodium nitrite, and the rest is the same as Example 1.

[0090] Comparative Example 4: Solvent replaced with mineral oil

[0091] Referring to the preparation method of Example 1, replace the hydrogenated palm oil with an equal amount of mineral oil, and the rest is the same as Example 1.

[0092] Comparative Example 5: Metal deactivator-free

[0093] Referring to the preparation method of Example 1, omit the metal deactivator throughout, and the rest is the same as Example 1.

[0094] Performance test:

[0095] 1. Oxidation induction time (OIT) test:

[0096] Operation steps:

[0097] (a) Take 10.0 ± 0.2 mg of the fuel oil sample to be tested and place it in an open aluminum crucible;

[0098] (b) Heat it to 120 °C at a rate of 10 °C / min under a nitrogen atmosphere (flow rate: 50 mL / min), and keep it at a constant temperature for 5 min;

[0099] (c) Switch to an oxygen atmosphere (flow rate: 50 mL / min), record the start time of the oxidation exothermic peak, and define it as the oxidation induction period.

[0100] Data recording: Each group of samples is tested 3 times, and the arithmetic mean is taken. The standard deviation ≤ 3%.

[0101] 2. Suspension stability evaluation

[0102] Test conditions: Keep it at a constant temperature of 25 °C in the dark and let it stand still. The observation period is 30 days;

[0103] Quantification method:

[0104] (a) Inject 50 mL of the sample into a transparent glass container (inner diameter: 30 mm), seal it, and let it stand vertically;

[0105] (b) Use the laser scattering method to measure the particle size distribution before and after standing;

[0106] (c) Calculate the volume ratio of the precipitate: Precipitation rate (%) = (height of the lower layer precipitate / total liquid level height) × 100%.

[0107] Judgment criteria:

[0108] Excellent: Precipitation rate ≤ 1%;

[0109] Qualified: 1% < precipitation rate ≤ 5%;

[0110] Poor: Precipitation rate > 5%.

[0111] 3. Metal corrosion test

[0112] Operation steps:

[0113] (a) Grind a copper sheet (purity ≥ 99.9%, size: 10 mm × 20 mm × 1 mm) with 400-mesh sandpaper in sequence, clean it with acetone, and dry it;

[0114] (b) Immerse the copper sheet completely in 50 mL of the fuel oil to be tested, and heat it in an oil bath at 100 °C for 3 h;

[0115] (c) Take out the copper sheet, rinse it with isooctane, compare it with the ASTM standard color comparison card, and record the corrosion grade.

[0116] Grade definition:

[0117] Grade 1a: Light yellow, non-corrosive;

[0118] Grade 2c: Purple or dark brown, slightly corrosive;

[0119] Level 3b: Black or green, with severe corrosion.

[0120] 4. Low-temperature fluidity test.

[0121] Test conditions: -20°C ± 0.5°C, shear rate 100 s-1.

[0122] Operation steps:

[0123] (a) Pre-cool the sample in a low-temperature constant-temperature bath to -20°C and keep it at a constant temperature for 30 min;

[0124] (b) Start the viscometer and record the viscosity value (unit: cP) after the torque stabilizes;

[0125] (c) Repeat the test 3 times and take the average value after excluding outliers.

[0126] 5. Calculation of metal passivation efficiency

[0127] Steps:

[0128] (a) Add 50 ppm Fe 3+ / Cu 2+ mixed ions (molar ratio 1:1);

[0129] (b) Place the experimental group containing the passivator and the blank control group (without passivator) simultaneously in an oxygen stream (flow rate 20 mL / min) at 120°C;

[0130] (c) Take samples every 2 h, measure the acid value according to ASTM D664, and calculate the oxidation rate (ΔAV / ΔT);

[0131] (d) Passivation efficiency (%) = [(oxidation rate of the blank group - oxidation rate of the experimental group) / oxidation rate of the blank group] × 100%.

[0132] Data table for performance comparison.

[0133]

[0134]

[0135] Through the synergistic effect of the composite antioxidant system, nano-loading dispersion technology, and specific benzotriazole derivatives, the present invention significantly improves the oxidation stability, dispersion uniformity, and metal passivation effect of fuel oil, and the comprehensive performance is significantly better than the traditional scheme.

[0136] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A stabilizer for fuel oil containing ethylene tar, characterized in that: The mass ratio of the stabilizer for the fuel oil containing ethylene tar is: 8-20% of composite antioxidant, 20-25% of nano-scale dispersant, 5-8% of metal passivator, 10-15% of viscosity improver and 20-50% of solvent.

2. A stabilizer for fuel oil containing ethylene tar according to claim 1, characterized in that: The composite antioxidant comprises: alkylated diphenylamine and D-tocopherol mixed in a mass ratio of 3:

1.

3. A stabilizer for fuel oil containing ethylene tar according to claim 1, characterized in that: The nano-scale dispersant is polyisobutylene succinimide and a nano-silicon dioxide carrier.

4. A stabilizer for fuel oil containing ethylene tar according to claim 1, characterized in that: The viscosity improver is propylene glycol methyl ether acetate.

5. A stabilizer for fuel oil containing ethylene tar according to claim 1, characterized in that: The solvent is hydrogenated palm oil.

6. A stabilizer for fuel oil containing ethylene tar according to any one of claims 1 to 5, characterized in that: The metal passivator is a benzotriazole derivative; The benzotriazole derivative is selected from: metal deactivator-1 to metal deactivator-6; The structures of the metal passivator-1 to metal passivator-6 are:

7. A stabilizer for fuel oil containing ethylene tar according to claim 6, characterized in that: The synthesis steps of the benzotriazole derivative are: adding benzotriazole to the first solvent, stirring, adding raw materials, adding triphenylphosphine and stirring, introducing nitrogen to replace the gas, adding target carbon, heating to 80-90° C., and reacting for 12 hours.

8. A stabilizer for fuel oil containing ethylene tar according to claim 7, characterized in that: The first solvent is toluene.

9. A stabilizer for fuel oil containing ethylene tar according to claim 7, characterized in that: The structure of the raw material is:

10. A method for preparing a stabilizer for fuel oil containing ethylene tar according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Ultrasonic dispersion of nano-silica in anhydrous ethanol, addition of silane coupling agent KH-550, and reaction at 60°C for 2 hours to form the nano-silica carrier; S2. The polyisobutylene succinimide and the nano-silica carrier are mixed in a mass ratio of 1:2, dispersed in a high-speed shearing machine for 1 hour, and dried under reduced pressure at 60° C. to obtain a supported dispersant; S3. The alkylated diphenylamine and the D-tocopherol are dissolved in the hydrogenated palm oil in a ratio of 3:1, 0.5% citric acid is added as a pH stabilizer, and stirred at 50°C until transparent; S4. The dispersant of S2 and the metal passivator are added to hydrogenated palm oil and premixed at 60°C for 30 minutes; S5. Add the antioxidant composite system, raise the temperature to 70 ° C and continue stirring for 1 hour; S6. Finally, glycol methyl ether acetic acid is added and treated three times with a high-pressure homogenizer to obtain a stabilizer for fuel oil containing ethylene tar.

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