A ternary diesel pour point depressant and its preparation and application

Abstract

The present invention relates to the technical field of diesel pour point depressants, and in particular to a ternary diesel pour point depressant and its preparation and application. The present invention first mixes methacrylic acid, tetradecanol and toluene, then adds a polymerization inhibitor and a catalyst, mixes again and performs a pre-reaction, continues to heat up for esterification, and performs post-processing to obtain tetradecyl methacrylate; then mixes 3-benzoylethyl acrylate, acrylamide, tetradecyl methacrylate and toluene, adds a polymerization initiator, performs a polymerization reaction, and performs post-processing to obtain a ternary diesel pour point depressant: tetradecyl methacrylate-3-benzoylethyl acrylate-acrylamide copolymer. In the ternary diesel pour point depressant of the present invention, a long alkyl chain reacts eutectically with wax crystals in diesel, thereby improving the solubility of the pour point depressant in diesel.

Description

Technical Field

[0001] The invention relates to the technical field of diesel pour point depressants, and in particular to a ternary diesel pour point depressant and the preparation and application thereof. Background Art

[0002] Diesel is a light petroleum product, containing a mixture of various complex hydrocarbons such as aliphatic hydrocarbons, isoparaffins, aromatic hydrocarbons and non-hydrocarbon compounds. In the era of development of both emerging energy and traditional energy, diesel as an important traditional energy still has a wide range of application value. It is not only used in the military industry, but also widely used in industries related to national economy and people's livelihood such as industrial and agricultural production and transportation. However, in some cold areas and winter low temperature seasons in some regions, the normal alkanes in diesel will precipitate in the form of wax crystals, and continue to grow to form planar crystals, and then cross-linked together to form large wax crystals with a three-dimensional network structure, causing the diesel to lose its low-temperature fluidity and become solid, thereby blocking the copper wire filter of the diesel engine, causing the normal operation of the diesel engine to shut down, affecting the normal operation of the work, and causing serious economic losses to industrial and agricultural transportation and production. In order to enable diesel to be used normally under low temperature conditions, certain methods need to be adopted to improve the low-temperature performance of diesel. At present, there are blending methods, adding diesel pour point depressant, and improving the production process. Adding diesel pour point depressant is the most economical, efficient and simple method, which is favored by users at home and abroad. Since its development, the types of diesel pour point depressants mainly include: methacrylates, methacrylate-maleic anhydride, ethylene-vinyl acetate (EVA), poly-α-olefins and fumarate copolymers.

[0003] After adding diesel pour point depressant, under low temperature conditions, when wax crystals are just formed, the pour point depressant can precipitate together with the wax crystals or adsorb on the surface of the wax crystals, preventing the wax crystals from sticking to each other, changing the growth direction and speed of the wax crystals, and hindering the formation of large wax crystals and three-dimensional network structures, thereby improving the flow properties of diesel under low temperature conditions. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a ternary diesel pour point depressant and its preparation and application. Compared with the prior art, the pour point depressant effect of the ternary diesel pour point depressant of the present invention is greatly improved.

[0005] With regard to the current research status of diesel pour point depressants, the present invention introduces a PMA (polymethacrylate polymer) type diesel pour point depressant, which has simple synthesis, readily available raw materials, and a low addition amount, and can effectively reduce the pour point and cold filter point of diesel, and further reduce the viscosity of diesel at low temperatures.

[0006] The long alkyl chain of the PMA diesel pour point depressant in the present invention can improve the solubility and dispersibility of the polymer in diesel, and can form a eutectic with normal alkanes in diesel under low temperature conditions. The wax crystal can further adsorb polar pour point depressant molecules to disperse them in diesel, thereby improving the dispersibility and solubility of the polymer in diesel. Benzoyl and ester groups, as polar groups of 3-benzoyl ethyl acrylate, can change the growth habit and growth direction of wax crystals through intermolecular forces, thereby effectively preventing wax crystals from agglomerating, further increasing the solubility and dispersibility of pour point depressant molecules in diesel, and in order to achieve a more ideal effect, a free radical polymerization method is adopted and the ratio between monomers is changed to synthesize the polymer pour point depressant.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] The first object of the present invention is to provide a method for preparing a ternary diesel pour point depressant, comprising the following steps:

[0009] (1) methacrylic acid, tetradecanol and toluene are mixed, then a polymerization inhibitor and a catalyst are added, mixed again and then pre-reacted, the temperature is continued to be raised for esterification reaction, and post-processed to obtain tetradecanol methacrylate;

[0010] (2) 3-benzoyl ethyl acrylate, acrylamide, tetradecyl methacrylate prepared in step (1) and toluene are mixed, a polymerization initiator is added, a polymerization reaction is carried out, and post-treatment is performed to obtain a ternary diesel pour point depressant: tetradecyl methacrylate-3-benzoyl ethyl acrylate-acrylamide copolymer.

[0011] In the present invention, the reaction equation of the ternary diesel pour point depressant is shown in formula (I):

[0012]

[0013] In one embodiment of the present invention, the molar ratio of methacrylic acid to tetradecanol is 1.2 mol:2 mol;

[0014] The ratio of toluene to the total mass of methacrylic acid and tetradecanol is 1.2:1-1.5:1; the amount of the inhibitor is 0.50%-0.75% of the total mass of methacrylic acid and tetradecanol; and the amount of the catalyst is 1%-1.6% of the total mass of methacrylic acid and tetradecanol.

[0015] In one embodiment of the present invention, the amount of the polymerization inhibitor is 0.6% of the total mass of methacrylic acid and tetradecanol, and the amount of the catalyst is 1.2% of the total mass of methacrylic acid and tetradecanol.

[0016] In one embodiment of the present invention, the polymerization inhibitor is selected from one of hydroquinone and p-hydroxyanisole, and the catalyst is selected from one of p-toluenesulfonic acid and benzenesulfonic acid.

[0017] In one embodiment of the present invention, in step (1), during the pre-reaction, the temperature is 90° C. and the time is 2 h; during the esterification reaction, the temperature is 100-130° C. and the time is 5-7 h.

[0018] In one embodiment of the present invention, in step (1), the post-treatment is to wash the product with a NaOH solution to a weak alkaline state after the esterification reaction is completed, and then wash it with deionized water to a neutral state, and then rotary evaporate the obtained organic phase on a rotary evaporator, and move the evaporated product to a vacuum drying oven for drying.

[0019] In one embodiment of the present invention, in step (2), the molar ratio of ethyl 3-benzoylacrylate, acrylamide and tetradecyl methacrylate is 1 mol: 1 mol: 1-15 mol;

[0020] The ratio of toluene to the total mass of tetradecyl methacrylate and 3-benzoylethyl acrylate-acrylamide is 6:1-8:1;

[0021] The amount of the polymerization initiator used is 0.8%-2% of the total mass of tetradecyl methacrylate and 3-benzoylethyl acrylate-acrylamide.

[0022] In one embodiment of the present invention, the polymerization initiator is selected from one of benzoyl peroxide and dibenzoyl peroxide.

[0023] In one embodiment of the present invention, in step (2), it is necessary to evacuate and pass nitrogen before the polymerization reaction. During the polymerization reaction, the temperature is 120-130° C. and the time is 7-9 h.

[0024] The post-treatment is to perform rotary evaporation on the solution after the reaction to remove the toluene solvent, then wash with anhydrous ethanol to rotary evaporate the product, and then perform vacuum drying.

[0025] In one embodiment of the present invention, during the vacuum drying process, the temperature is 40° C. and the time is 12 h.

[0026] The second object of the present invention is to provide a ternary pour point depressant prepared by the method.

[0027] The third object of the present invention is to use a ternary pour point depressant in reducing the freezing point and cold filter point of diesel, and the ternary diesel pour point depressant is added to the diesel at 0.025%-0.25% of the total mass of the diesel.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The long alkyl chain of the ternary diesel pour point depressant of the present invention undergoes a eutectic reaction with wax crystals in diesel, thereby improving the solubility of the pour point depressant in diesel.

[0030] (2) The ternary diesel pour point depressant of the present invention comprises acrylamide containing a carbon-carbon double bond and an amide group, and having the chemical properties of a double bond; the benzoyl group and the ester group in 3-benzoyl ethyl acrylate have certain polarity; the carbonyl group in the benzoyl group affects and changes the electron cloud density of the benzene ring, making it have an electric charge, and the dispersibility and solubility of the polymer in diesel can be enhanced through the repulsive effect between the charges; wherein the benzoyl group and the ester group change the crystallization habit of wax crystals in diesel, and effectively inhibit the formation of large wax crystals and three-dimensional network structures.

[0031] (3) The preparation method of the ternary diesel pour point depressant of the present invention has the advantages of simple preparation process, small addition amount and stable performance.

[0032] (4) The ternary diesel pour point depressant of the present invention can further enhance the pour point depressant effect on diesel, and effectively enhance the cold flow properties of diesel. When the ternary diesel pour point depressant of the present invention is added to commercially available -10# diesel, the condensation point and cold filter point of the commercially available -10# diesel can be reduced by 13°C and 9°C, respectively, so that the diesel has better fluidity at a lower temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 1H NMR diagram of tetradecyl methacrylate-3-benzoylethyl acrylate-acrylamide polymer;

[0034] Figure 2 This is the infrared spectrum of tetradecyl methacrylate-3-benzoylethyl acrylate-acrylamide polymer. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] In the following examples, all raw materials used are commercially available products purchased from Shanghai Titan Technology Co., Ltd.; unless otherwise specified, all reagents used are commercially available reagents, and all detection means and methods used are conventional detection means and methods in the art.

[0037] Example 1

[0038] This embodiment provides a ternary diesel pour point depressant and a preparation method thereof.

[0039] A ternary diesel pour point depressant, the preparation method is as follows:

[0040] (1) Weigh 21.44 g of tetradecanol and 10.33 g of methacrylic acid (molar ratio of 1:1.2) respectively and add them into a dry and clean three-necked flask. Move the three-necked flask containing the reactants to an oil bath for heating and stirring. Then add hydroquinone and p-toluenesulfonic acid (the amount of hydroquinone and p-toluenesulfonic acid added is 0.6% and 1.2% of the total mass of tetradecanol and methacrylic acid, respectively) into the three-necked flask. Use 45 ml of toluene as solvent, raise the temperature to 80°C and pre-react for 2 hours. After the preliminary reaction, the temperature was raised to 110°C, and the esterification reaction was continued for 6 hours; after the reaction was completed, the mixture was cooled to room temperature, poured into a 250ml separatory funnel, washed with 5% NaOH solution until weakly alkaline, and then washed with deionized water until neutral, and then the bottom aqueous phase was removed, and the upper organic phase was poured into a 100ml rotary evaporator, and the solvent was removed by reduced pressure distillation in a rotary evaporator at 75°C, and then dried in a vacuum drying oven at 40°C for 12 hours to obtain tetradecyl methacrylate;

[0041] (2) 2.82 g of tetradecyl methacrylate prepared in step (1), 2.04 g of ethyl 3-benzoylacrylate, and 0.71 g of acrylamide were added to a three-necked flask (wherein the molar ratio of tetradecyl methacrylate: ethyl 3-benzoylacrylate: acrylamide was 1:1:1), and then 40 ml of toluene was added to the three-necked flask as a solvent. A constant pressure separatory funnel, a reflux tube, and a nitrogen gas guide tube were installed and fixed on the three-necked flask, and the three-necked flask was evacuated and nitrogen was passed through for three times. When the reaction temperature reached 125° C., 1 0ml of toluene solution containing 0.0486g of benzoyl peroxide was slowly added dropwise to a three-necked flask, and the polymerization reaction was carried out for 9 hours; after the reaction, the three-necked flask was cooled to room temperature, and the mixed solution after the reaction was distilled under reduced pressure on a rotary evaporator at 75°C for 0.5 hour, and the product after rotary evaporation was washed with excess anhydrous ethanol until the ethanol solution was clear, and the washed product was placed in a vacuum drying oven at 40°C and dried for 12 hours to obtain the target product, tetradecyl methacrylate-3-benzoyl ethyl acrylate-acrylamide copolymer pour point depressant (its nuclear magnetic hydrogen spectrum is shown as Figure 1 As shown, the infrared spectrum is Figure 2 shown).

[0042] Example 2

[0043] This embodiment provides a ternary diesel pour point depressant and a preparation method thereof.

[0044] Compared with Example 1, except that 4.24 g of tetradecyl methacrylate, 1.02 g of ethyl 3-benzoyl acrylate, and 0.36 g of acrylamide (wherein the molar ratio of tetradecyl methacrylate:ethyl 3-benzoyl acrylate:acrylamide is 3:1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0526 g, everything else is the same.

[0045] Example 3

[0046] This embodiment provides a ternary diesel pour point depressant and a preparation method thereof.

[0047] Compared with Example 1, except that 5.65 g of tetradecyl methacrylate, 0.68 g of ethyl 3-benzoyl acrylate, and 0.24 g of acrylamide (wherein the molar ratio of tetradecyl methacrylate:ethyl 3-benzoyl acrylate:acrylamide is 6:1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0633 g, everything else is the same.

[0048] Example 4

[0049] This embodiment provides a ternary diesel pour point depressant and a preparation method thereof.

[0050] Compared with Example 1, except that 8.47 g of tetradecyl methacrylate, 0.51 g of ethyl 3-benzoyl acrylate, and 0.18 g of acrylamide (wherein the molar ratio of tetradecyl methacrylate:ethyl 3-benzoyl acrylate:acrylamide is 9:1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0687 g, everything else is the same.

[0051] Example 5

[0052] This embodiment provides a ternary diesel pour point depressant and a preparation method thereof.

[0053] Compared with Example 1, except that 6.78 g of tetradecyl methacrylate, 0.41 g of ethyl 3-benzoyl acrylate, and 0.14 g of acrylamide (wherein the molar ratio of tetradecyl methacrylate:ethyl 3-benzoyl acrylate:acrylamide is 12:1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0719 g, everything else is the same.

[0054] Example 6

[0055] This embodiment provides a ternary diesel pour point depressant and a preparation method thereof.

[0056] Compared with Example 1, except that 7.06 g of tetradecyl methacrylate, 0.34 g of ethyl 3-benzoyl acrylate, and 0.12 g of acrylamide (wherein the molar ratio of tetradecyl methacrylate:ethyl 3-benzoyl acrylate:acrylamide is 15:1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0740 g, everything else is the same.

[0057] Example 7

[0058] The ternary diesel pour point depressants prepared in the above Examples 1-6 are numbered 1, 2, 3, 4, 5, and 6, and added to the commercially available -10# diesel at an addition amount of 0.025%-0.25%. The diesel pour point is measured according to GB / T510-1991, and the diesel filter point is measured according to SH / T0248-2006. The test results of the pour point and filter point of -10# diesel after adding the ternary diesel pour point depressants obtained in Examples 1-6 are shown in the table.

[0059] Table 1 Effect of the ternary diesel pour point depressants obtained in Examples 1-6 on the condensation point and cold filter point of commercially available -10# diesel

[0060]

[0061]

[0062] △SP represents the reduction value of the pour point of -10# diesel after adding the ternary polymer pour point depressant. △CFPP represents the reduction value of the cold filter point of -10# diesel after adding the ternary polymer pour point depressant. It can be seen from Table 1 that the ternary diesel pour point depressant has a significant effect on reducing the pour point and filter point of -10# diesel, with the highest condensation point reduced by 13℃ and the cold filter point reduced by 9℃.

[0063] Comparative Example 1

[0064] Compared with Example 4, except that 8.47 g of tetradecyl methacrylate and 0.51 g of 3-benzoyl ethyl acrylate (wherein the molar ratio of tetradecyl methacrylate to 3-benzoyl ethyl acrylate is 9:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0687 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 7°C and 4°C, respectively.

[0065] By comparing this comparative example with Example 4, it can be seen that the ternary diesel pour point depressant polymerized from tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide improves the pour point depressant effect by improving the solubility and dispersibility of the pour point depressant in diesel and inhibiting the formation of large wax crystals and network structures, thereby effectively improving the low-temperature fluidity of diesel.

[0066] Comparative Example 2

[0067] Compared with Example 4, except that 8.47 g of tetradecyl methacrylate and 0.18 g of acrylamide (wherein the molar ratio of tetradecyl methacrylate to acrylamide is 15:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0687 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 5°C and 3°C, respectively.

[0068] By comparing this comparative example with Example 4, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0069] Comparative Example 3

[0070] Compared with Example 4, except that 0.51 g of 3-benzoyl ethyl acrylate and 0.18 g of acrylamide (wherein the molar ratio of 3-benzoyl ethyl acrylate to acrylamide is 1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0687 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 2°C and 2°C respectively.

[0071] By comparing this comparative example with Example 4, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0072] Comparative Example 4

[0073] Compared with Example 1, except that 2.82 g of tetradecyl methacrylate and 2.04 g of 3-benzoyl ethyl acrylate (wherein the molar ratio of 3-benzoyl ethyl acrylate to acrylamide is 1:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0486 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 3°C and 2°C respectively.

[0074] By comparing this comparative example with Example 1, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0075] Comparative Example 5

[0076] Compared with Example 2, except that 4.24 g of tetradecyl methacrylate and 1.02 g of 3-benzoyl ethyl acrylate (wherein the molar ratio of tetradecyl methacrylate to 3-benzoyl ethyl acrylate is 3:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0526 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 4°C and 2°C respectively.

[0077] By comparing this comparative example with Example 2, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0078] Comparative Example 6

[0079] Compared with Example 3, except that 5.65 g of tetradecyl methacrylate and 0.68 g of 3-benzoyl ethyl acrylate (wherein the molar ratio of tetradecyl methacrylate to 3-benzoyl ethyl acrylate is 6:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0633 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 4°C and 3°C respectively.

[0080] By comparing this comparative example with Example 3, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0081] Comparative Example 7

[0082] Compared with Example 5, except that 6.78 g of tetradecyl methacrylate and 0.41 g of 3-benzoyl ethyl acrylate (wherein the molar ratio of tetradecyl methacrylate to 3-benzoyl ethyl acrylate is 12:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0719 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 5°C and 4°C, respectively.

[0083] By comparing this comparative example with Example 5, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0084] Comparative Example 8

[0085] Compared with Example 6, except that 7.06 g of tetradecyl methacrylate and 0.34 g of 3-benzoyl ethyl acrylate (wherein the molar ratio of tetradecyl methacrylate to 3-benzoyl ethyl acrylate is 15:1) are added in step (2), and the mass of the initiator benzoyl peroxide dissolved in toluene is 0.0740 g, the rest is the same. The prepared polymer is directly added to commercially available 0# diesel in an amount of 0.25%, mixed and stirred at a temperature of 40°C, and ultrasonically dispersed for 25 minutes to completely dissolve. After testing, compared with commercially available 0# diesel, its condensation point and cold filter point are reduced by 4°C and 3°C, respectively.

[0086] By comparing this comparative example with Example 6, it can be seen that the ternary diesel pour point depressant prepared by polymerization of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide has a better pour point depressing effect on diesel.

[0087] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the explanation of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing a ternary diesel pour point depressant, characterized in that: The following steps are involved: (1) Methacrylic acid, tetradecanol and toluene are mixed, then an inhibitor and a catalyst are added, mixed again for pre-reaction, the temperature is continued to be raised for esterification reaction, and post-treatment is performed to obtain tetradecanol methacrylate; (2) mixing 3-benzoyl ethyl acrylate, acrylamide, tetradecyl methacrylate prepared in step (1) and toluene, adding a polymerization initiator, carrying out polymerization reaction, and post-treating to obtain a ternary diesel pour point depressant: tetradecyl methacrylate-3-benzoyl ethyl acrylate-acrylamide copolymer; Wherein, in step (2), the molar ratio of 3-benzoyl ethyl acrylate, acrylamide and tetradecyl methacrylate is 1 mol:1 mol:1-15 mol.

2. The method for preparing a ternary diesel pour point depressant according to claim 1, characterized in that: The molar ratio of methacrylic acid to tetradecanol is 1.2 mol:2 mol; The ratio of toluene to the total mass of methacrylic acid and tetradecanol is 1.2:1-1.5:1; the amount of the inhibitor is 0.50%-0.75% of the total mass of methacrylic acid and tetradecanol; and the amount of the catalyst is 1%-1.6% of the total mass of methacrylic acid and tetradecanol.

3. The method for preparing a ternary diesel pour point depressant according to claim 2, characterized in that: The polymerization inhibitor is selected from one of hydroquinone and p-hydroxyanisole, and the catalyst is selected from one of p-toluenesulfonic acid and benzenesulfonic acid.

4. The method for preparing a ternary diesel pour point depressant according to claim 1, characterized in that: In step (1), during the pre-reaction process, the temperature is 90°C and the time is 2 hours; during the esterification reaction process, the temperature is 100-130°C and the time is 5-7 hours.

5. The method for preparing a ternary diesel pour point depressant according to claim 1, characterized in that: In step (1), the post-treatment is to wash the product with NaOH solution to a weak alkaline state after the esterification reaction is completed, and then wash it with deionized water to a neutral state, and then evaporate the obtained organic phase on a rotary evaporator, and then move the evaporated product to a vacuum drying oven for drying.

6. The method for preparing a ternary diesel pour point depressant according to claim 1, characterized in that: In step (2), the ratio of toluene to the total mass of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide is 6:1-8:1; The amount of the polymerization initiator used is 0.8%-2% of the total mass of tetradecyl methacrylate, 3-benzoylethyl acrylate and acrylamide.

7. The method for preparing a ternary diesel pour point depressant according to claim 6, characterized in that: The polymerization initiator is selected from benzoyl peroxide or dibenzoyl peroxide.

8. The method for preparing a ternary diesel pour point depressant according to claim 1, characterized in that: In step (2), it is necessary to evacuate and pass nitrogen before the polymerization reaction. During the polymerization reaction, the temperature is 120-130°C and the time is 7-9h; The post-treatment is to perform rotary evaporation on the solution after the reaction to remove the toluene solvent, then wash the product with anhydrous ethanol to perform rotary evaporation, and then perform vacuum drying.

9. A ternary diesel pour point depressant prepared by the method according to any one of claims 1 to 8.

10. Application of a ternary diesel pour point depressant in reducing diesel condensation point and cold filter point, characterized in that: The ternary diesel pour point depressant according to claim 9 is added to diesel at 0.025%-0.25% of the total mass of diesel.

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