阅读说明：本技术 一种原油倾点降低剂 (Pour point depressant for crude oil ) 是由 邵北礼 李世洪 崔海滨 张云天 刘瑞 王楠 于 2020-12-21 设计创作，主要内容包括：一种原油倾点降低剂,包括改性乙烯-醋酸乙烯共聚物10份至40份,表面活性剂10份至40份和溶剂20份至80份；所述改性乙烯-醋酸乙烯共聚物含有衍生自醋酸乙烯单体的结构单元；至少部分所述结构单元含有接枝基团；所述接枝基团为马来酸酐；以所述改性乙烯-醋酸乙烯共聚物的重量为基准,所述改性乙烯-醋酸乙烯共聚物的接枝率为0.05wt.％至0.7wt.％；所述改性乙烯-醋酸乙烯共聚物的交联率为0-0.01％。本申请提供的原油倾点降低剂可以有效降低原油倾点,增强极性的改性EVA与具有长链烷基的表面活性剂和异构烷烃溶剂油并用,有很好的协同作用,在低温重复加热甚至低处理温度下,仍能保持良好的降凝效果。(A pour point depressant for crude oil is composed of modified ethylene-vinyl acetate copolymer (10-40 wt. portions), surfactant (10-40) and solvent (20-80); the modified ethylene-vinyl acetate copolymer contains structural units derived from vinyl acetate monomers; at least a portion of the structural units contain a grafting group; the grafting group is maleic anhydride; based on the weight of the modified ethylene-vinyl acetate copolymer, the grafting rate of the modified ethylene-vinyl acetate copolymer is 0.05 wt.% to 0.7 wt.%; the crosslinking rate of the modified ethylene-vinyl acetate copolymer is 0-0.01%. The crude oil pour point depressant provided by the application can effectively reduce the pour point of crude oil, and the modified EVA with enhanced polarity is used together with a surfactant with long-chain alkyl and isoparaffin solvent oil, so that a good synergistic effect is achieved, and a good pour point depression effect can be still kept at low-temperature repeated heating and even low treatment temperature.)

1. A pour point depressant for crude oil is composed of modified ethylene-vinyl acetate copolymer (10-40 wt. portions), surfactant (10-40) and solvent (20-80);

the modified ethylene-vinyl acetate copolymer contains structural units derived from vinyl acetate monomers; at least a portion of the structural units contain a grafting group; the grafting group is maleic anhydride;

based on the weight of the modified ethylene-vinyl acetate copolymer, the grafting rate of the modified ethylene-vinyl acetate copolymer is 0.05 wt.% to 0.7 wt.%; the crosslinking rate of the modified ethylene-vinyl acetate copolymer is 0-0.01%;

the solvent comprises isoparaffin mineral spirits.

2. The crude oil pour point depressant of claim 1 wherein the surfactant is selected from any one or more of alkyl polyoxyethylene ether, alkylphenol polyoxyethylene polyoxypropylene ether, alkyl polyoxyethylene polyoxypropylene ether;

optionally, the surfactant is selected from any one or more of octadecyl polyoxyethylene ether, octadecyl phenol polyoxyethylene polyoxypropylene ether, and octadecyl polyoxyethylene polyoxypropylene ether.

3. The crude oil pour point depressant of claim 1 wherein the solvent further comprises a mixed aromatic hydrocarbon;

alternatively, the isoparaffin mineral spirits are preferably isoparaffin mineral spirits;

optionally, the solvent is formed by mixing isoparaffin solvent oil and mixed aromatic hydrocarbon according to the weight ratio of 1: 1.

4. The crude oil pour point depressant according to any one of claims 1 to 3, wherein the modified ethylene-vinyl acetate copolymer is prepared by graft copolymerization of an ethylene-vinyl acetate copolymer with maleic anhydride under the initiation of an organic peroxide;

the maleic anhydride is used in an amount of 0.1 to 1 wt.% of the ethylene-vinyl acetate copolymer; the organic peroxide is used in an amount of 0.01 wt.% to 0.1 wt.% of the ethylene-vinyl acetate copolymer.

5. The crude oil pour point depressant of claim 4 wherein the ethylene vinyl acetate copolymer is selected from the group consisting of having a vinyl acetate content of 28% to 45% and a melt index of 20g/10min to 800g/10 min.

6. The crude oil pour point depressant of claim 5 wherein the ethylene vinyl acetate copolymer is selected from the group consisting of ethylene vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 20g/10min, ethylene vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 150g/10min, ethylene vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 800g/10min, ethylene vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 400g/10min, any one or more of an ethylene vinyl acetate copolymer having a vinyl acetate content of 33% and a melt index of 45g/10min and an ethylene vinyl acetate copolymer having a vinyl acetate content of 40% and a melt index of 60g/10 min;

preferably, the ethylene vinyl acetate copolymer is selected from either or both of an ethylene vinyl acetate copolymer having a vinyl acetate content of 33% and a melt index of 45g/10min and an ethylene vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 800g/10 min.

7. The crude oil pour point depressant of claim 4 wherein the organic peroxide is selected from any one or more of dicumyl peroxide, benzamide peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, and t-butyl peroxyacetate.

8. The crude oil pour point depressant of claim 4 wherein the modified ethylene vinyl acetate copolymer is prepared by a process comprising:

1) mixing and dissolving the organic peroxide and the maleic anhydride in an organic solvent to obtain a mixture;

2) uniformly mixing the mixture with the ethylene-vinyl acetate copolymer;

3) extruding by using an extruder, molding and drying to obtain the modified ethylene-vinyl acetate copolymer.

9. The high pour point depressant according to claim 8, wherein the organic solvent in step 1) is selected from any one or more of acetone, petroleum ether and ethyl acetate; the weight ratio of the sum of the organic peroxide and the maleic anhydride to the organic solvent is (1 to 2) to (1 to 3).

10. The pour point depressant for high pour point crude oil according to claim 8, wherein the extruder in step 3) is a parallel co-rotating twin screw extruder, the screw speed is 30r/min to 50r/min, the extruder temperature is 80 ℃ to 190 ℃, and the head temperature is 160 ℃ to 180 ℃.

Technical Field

The application relates to but is not limited to the technical field of petrochemical technology, in particular to but is not limited to a pour point depressant for crude oil.

Background

With the increasing production of high-coagulation and high-viscosity crude oil in the world, the energy-saving and safe gathering and transportation of the high-coagulation and high-viscosity crude oil is increasingly the hot point of the research of developed countries in the petroleum industry. At present, crude oil produced by several main oil fields (Sudan, Tande and Niger) developed in middle and non-regions of petroleum belongs to typical high-coagulation and high-viscosity crude oil. From the perspective of reducing energy consumption and production cost and improving pipeline operation safety, the synthetic polymer chemical modifier is added into crude oil, so that the solidifying point of the crude oil is reduced, the low-temperature fluidity of the crude oil is improved, the method is an effective way for improving the exploitation and transportation process of high-solidifying-point and high-viscosity crude oil, and is the simplest and most effective method for realizing normal-temperature and even low-temperature transportation of the crude oil.

China has always used the pour point as an important parameter for controlling the crude oil transportation temperature, and the pour point is generally adopted internationally. Pour point refers to the lowest temperature at which the oil can still flow. As the ambient temperature decreases, the flow of the oil becomes increasingly difficult and eventually even "loses" fluidity. The pour point test for crude oils is generally carried out by loading the oil sample into a pour point tube, heating it to 45 ℃ in a water bath at 48 ℃ and then placing it in a cold bath to initiate the temperature drop test, according to the pour point determination standards for crude oils (ASTM D5853, GB/T26985). The actual repeated heating temperature of the modified crude oil with the additive is 45 ℃, and the good pour point reducing effect can be ensured only when the repeated heating temperature reaches the treatment temperature (above 15 ℃ of the wax precipitation point) of the domestic pour point depressant at present, so that the pour point of the high pour point crude oil is not reduced.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the present application.

The application provides a crude oil pour point depressant capable of effectively reducing the pour point of crude oil.

A pour point depressant for crude oil is composed of modified ethylene-vinyl acetate copolymer (10-40 wt. portions), surfactant (10-40) and solvent (20-80); optionally, the crude oil pour point depressant consists of the above components.

The modified ethylene-vinyl acetate copolymer contains structural units derived from vinyl acetate monomers; at least a portion of the structural units contain a grafting group; the grafting group is maleic anhydride; the solvent comprises isoparaffin mineral spirits;

based on the weight of the modified ethylene-vinyl acetate copolymer, the grafting rate of the modified ethylene-vinyl acetate copolymer is 0.05 wt.% to 0.7 wt.%; the crosslinking rate of the modified ethylene-vinyl acetate copolymer is 0-0.01%.

In one embodiment disclosed herein, the surfactant is selected from any one or more of alkyl polyoxyethylene ether, alkylphenol polyoxyethylene polyoxypropylene ether, and alkyl polyoxyethylene polyoxypropylene ether;

in one embodiment disclosed herein, the surfactant is selected from any one or more of octadecyl polyoxyethylene ether, octadecyl phenol polyoxyethylene polyoxypropylene ether, and octadecyl polyoxyethylene polyoxypropylene ether.

In one embodiment disclosed herein, the solvent further comprises a mixed aromatic hydrocarbon;

in one embodiment disclosed herein, the isoparaffinic mineral spirits are preferably isoparaffinic mineral spirits;

in one embodiment disclosed herein, the solvent is a mixture of isoparaffin solvent oil and mixed aromatics at a weight ratio of 1: 1.

In one embodiment disclosed herein, the modified ethylene-vinyl acetate copolymer is prepared by graft copolymerization of an ethylene-vinyl acetate copolymer with maleic anhydride under the initiation of an organic peroxide;

in one embodiment disclosed herein, the maleic anhydride is used in an amount of 0.1 to 1 wt.% of the ethylene-vinyl acetate copolymer; the organic peroxide is used in an amount of 0.01 wt.% to 0.1 wt.% of the ethylene-vinyl acetate copolymer.

In one embodiment disclosed herein, the ethylene vinyl acetate copolymer is selected from the group consisting of having a vinyl acetate content of 28% to 45% and a melt index of 20g/10min to 800g/10 min.

In one embodiment disclosed herein, the ethylene-vinyl acetate copolymer is selected from any one or more of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 20g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 150g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 800g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 400g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 33% and a melt index of 45g/10min, and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 40% and a melt index of 60g/10 min;

in one embodiment disclosed herein, the ethylene vinyl acetate copolymer is selected from any one or both of an ethylene vinyl acetate copolymer having a vinyl acetate content of 33%, a melt index of 45g/10min and an ethylene vinyl acetate copolymer having a vinyl acetate content of 28%, and a melt index of 800g/10 min.

In one embodiment disclosed herein, the organic peroxide is selected from any one or more of dicumyl peroxide, benzamide peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, and t-butyl peroxyacetate.

In one embodiment disclosed herein, the method for preparing the modified ethylene vinyl acetate copolymer comprises:

1) mixing and dissolving the organic peroxide and the maleic anhydride in an organic solvent to obtain a mixture;

2) uniformly mixing the mixture with the ethylene-vinyl acetate copolymer;

3) extruding by using an extruder, molding and drying to obtain the modified ethylene-vinyl acetate copolymer.

In one embodiment disclosed herein, the organic solvent in step 1) is selected from any one or more of acetone, petroleum ether and ethyl acetate; the weight ratio of the sum of the organic peroxide and the maleic anhydride to the organic solvent is (1 to 2) to (1 to 3).

In one embodiment disclosed herein, the extruder in step 3) is a parallel co-rotating twin screw extruder, the screw speed is 30r/min to 50r/min, the extruder temperature is 80 ℃ to 190 ℃, and the head temperature is 160 ℃ to 180 ℃.

The application has the following characteristics:

the existing anhydride modified EVA in the market can not play a role in reducing the pour point by combining with wax crystals because the grafting rate and the crosslinking rate are higher and long-chain alkyl is shielded. Due to the fact that the grafting rate and the crosslinking rate are low, the acid anhydride modified EVA not only increases the polar group, but also keeps the long carbon chain to be capable of eutectic with wax crystals, and achieves the effects of changing the wax crystal structure and improving the low-temperature fluidity of crude oil.

The crude oil pour point depressant provided by the application can effectively reduce the pour point of crude oil, and the modified EVA with enhanced polarity is used together with a surfactant with long-chain alkyl and isoparaffin solvent oil, so that a good synergistic effect is achieved, and a good pour point depression effect can be still kept at low-temperature repeated heating and even low treatment temperature.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. Other advantages of the present application may be realized and attained by the invention in its aspects as described in the specification.

Drawings

The accompanying drawings are included to provide an understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the examples serve to explain the principles of the disclosure and not to limit the disclosure.

FIG. 1 is a process flow diagram according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application are described in detail below. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The embodiment of the application provides a crude oil pour point depressant which comprises 10 to 40 parts of modified ethylene-vinyl acetate copolymer, 10 to 40 parts of surfactant and 20 to 80 parts of solvent; optionally, the crude oil pour point depressant consists of the above components.

The modified ethylene-vinyl acetate copolymer contains structural units derived from vinyl acetate monomers; at least a portion of the structural units contain a grafting group; the grafting group is maleic anhydride; the solvent comprises isoparaffin mineral spirits;

based on the weight of the modified ethylene-vinyl acetate copolymer, the grafting rate of the modified ethylene-vinyl acetate copolymer is 0.05 wt.% to 0.7 wt.%; the crosslinking rate of the modified ethylene-vinyl acetate copolymer is 0-0.01%.

In the embodiment of the present application, the surfactant is selected from any one or more of alkyl polyoxyethylene ether, alkylphenol polyoxyethylene polyoxypropylene ether and alkyl polyoxyethylene polyoxypropylene ether;

in the embodiment of the present application, the surfactant is selected from any one or more of octadecyl polyoxyethylene ether, octadecyl phenol polyoxyethylene polyoxypropylene ether, and octadecyl polyoxyethylene polyoxypropylene ether.

In embodiments herein, the solvent further comprises a mixed aromatic hydrocarbon;

in the examples herein, the isoparaffinic mineral spirits are preferably isoparaffinic mineral spirits;

in the embodiment of the application, the solvent is formed by mixing isoparaffin solvent oil and mixed aromatic hydrocarbon according to the weight ratio of 1: 1.

In the embodiment of the application, the modified ethylene-vinyl acetate copolymer is prepared by graft copolymerization of ethylene-vinyl acetate copolymer and maleic anhydride under the initiation action of organic peroxide;

in the examples herein, the maleic anhydride is used in an amount of 0.1 to 1 wt.% of the ethylene-vinyl acetate copolymer; the organic peroxide is used in an amount of 0.01 wt.% to 0.1 wt.% of the ethylene-vinyl acetate copolymer.

In the examples herein, the ethylene vinyl acetate copolymer is selected from the group consisting of having a vinyl acetate content of 28% to 45% and a melt index of 20g/10min to 800g/10 min.

In the examples of the present application, the ethylene-vinyl acetate copolymer is selected from any one or more of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 20g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 150g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 800g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 400g/10min, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 33% and a melt index of 45g/10min, and an ethylene-vinyl acetate copolymer having a vinyl acetate content of 40% and a melt index of 60g/10 min;

in the examples herein, the ethylene vinyl acetate copolymer is selected from either or both of an ethylene vinyl acetate copolymer having a vinyl acetate content of 33% and a melt index of 45g/10min and an ethylene vinyl acetate copolymer having a vinyl acetate content of 28% and a melt index of 800g/10 min.

In the embodiments of the present application, the organic peroxide is selected from any one or more of dicumyl peroxide, benzamide peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, and t-butyl peroxyacetate.

In an embodiment of the present application, a method for preparing the modified ethylene-vinyl acetate copolymer comprises:

1) mixing and dissolving the organic peroxide and the maleic anhydride in an organic solvent to obtain a mixture;

2) uniformly mixing the mixture with the ethylene-vinyl acetate copolymer;

3) extruding by using an extruder, molding and drying to obtain the modified ethylene-vinyl acetate copolymer.

Alternatively, the preparation method consists of the above steps.

In the embodiments of the present application, the organic solvent in step 1) is selected from any one or more of acetone, petroleum ether and ethyl acetate; the weight ratio of the sum of the organic peroxide and the maleic anhydride to the organic solvent is (1 to 2) to (1 to 3).

In the embodiment of the application, the extruder in the step 3) is a parallel co-rotating twin-screw extruder, the screw rotating speed is 30r/min to 50r/min, the temperature of the extruder is 80 ℃ to 190 ℃, and the temperature of a machine head is 160 ℃ to 180 ℃.

Example 1

In this example, the ethylene-vinyl acetate copolymer is available from arkema, 28-800;

octadecyl phenol polyoxyethylene polyoxypropylene ether, available from Jiangsu Haian chemical plant, Inc., brand P184;

the isomeric hexadecane solvent oil is purchased from Kyoto Qi Asahi chemical Co., Ltd, No. IP 16;

the mixed aromatic hydrocarbon is purchased from Beijing Defu Dayu company and has the density of 0.85g/cm³To 0.91g/cm³The closed flash point is from 65 ℃ to 75 ℃.

100 weight portions of ethylene-vinyl acetate copolymer EVA (the vinyl acetate VA content is 28%, the melt index is 800g/10min) is added with 1 weight portion of Maleic Anhydride (MAH) and 0.1 weight portion of initiator dicumyl peroxide (DCP), and the modified ethylene-vinyl acetate copolymer, namely the modified EVA copolymer, is prepared by melt grafting. The preparation process comprises the following steps:

dissolving dicumyl peroxide (DCP) and Maleic Anhydride (MAH) in acetone (the weight ratio of dicumyl peroxide to maleic anhydride to acetone is 1: 1), then pouring the mixture into ethylene-vinyl acetate copolymer EVA, stirring the mixture in a high-speed mixer for 1min, extruding the mixture in an SHJ-72 type parallel co-rotating twin-screw extruder with the parameters of 80 ℃, 150 ℃, 180 ℃, 190 ℃ and 5 ℃ heating, wherein the temperatures are the heating zone temperature from a feed inlet to an extrusion head, the head temperature is 180 ℃ and the screw rotating speed is 45r/min, adopting water ring granulation, dehydrating the mixture by a water separator, drying (hot air drying, the hot air temperature is about 50 ℃ to 60 ℃), cooling the mixture by air cooling, weighing and packaging to obtain the modified ethylene-vinyl acetate copolymer, wherein the grafting rate of the modified ethylene-vinyl acetate copolymer is 0.6 wt.% based on the weight of the modified ethylene-vinyl acetate copolymer The crosslinking rate of the vinyl acetate copolymer is less than 0.01 percent.

In the total weight of 100 percent, 20 percent by weight of modified EVA copolymer, 30 percent by weight of octadecyl phenol polyoxyethylene polyoxypropylene ether, 25 percent by weight of isomeric hexadecane solvent oil and 25 percent by weight of mixed aromatic hydrocarbon are mixed according to the mass ratio to obtain the pour point depressant for crude oil.

The pour point depressant for crude oil obtained in example 1 can reduce Nigers Sokor mixed oil with the pour point of 27 ℃ to 12 ℃ and reduce the pour point by 15 ℃ under the conditions of adding 500mg/L of dosage and processing temperature of 65 ℃. The treatment temperature refers to the highest temperature reached by heating after the mixed crude oil is added with the pour point depressant so as to completely dissolve the wax crystals and the medicament, and the temperature reduction test is started from the treatment temperature.

Example 2

In this example, the ethylene-vinyl acetate copolymer was obtained from korean modern corporation, EVA810 brand;

octadecyl phenol polyoxyethylene polyoxypropylene ether was purchased from Jiangsu Haian chemical plant under the brand P184;

the isomeric hexadecane solvent oil is purchased from Kyoto Qi Asahi chemical Co., Ltd, No. IP 16;

the mixed aromatic hydrocarbon is the same as the mixed aromatic hydrocarbon in example 1;

100 weight portions of ethylene-vinyl acetate copolymer EVA (the vinyl acetate VA content is 33%, the melt index is 45g/10min) is added with 0.8 weight portion of Maleic Anhydride (MAH) and 0.06 weight portion of initiator dicumyl peroxide (DCP), and the modified ethylene-vinyl acetate copolymer, namely the modified EVA copolymer is prepared by melt grafting. The procedure was the same as in example 1. Based on the weight of the modified ethylene-vinyl acetate copolymer, the grafting rate of the modified ethylene-vinyl acetate copolymer was 0.6 wt.%; the crosslinking rate of the modified ethylene-vinyl acetate copolymer is less than 0.01 percent.

And mixing 30 wt.% of modified EVA copolymer, 30 wt.% of octadecyl polyoxyethylene ether, 20 wt.% of isomeric hexadecane solvent oil and 20 wt.% of mixed aromatic hydrocarbon according to the mass ratio to obtain the crude oil pour point depressant, wherein the total weight of the modified EVA copolymer is 100 percent.

The pour point depressant for crude oil obtained in example 2 can reduce Nigerl Adadi mixed oil with the pour point of 33 ℃ to 21 ℃ and reduce the pour point by 12 ℃ under the conditions of 1000mg/L of the addition dose and 65 ℃ of the processing temperature.

Comparative example 1 (without surfactant)

20 wt.% of the modified EVA copolymer prepared in example 1, 25 wt.% of iso-hexadecane and 60 wt.% of mixed aromatic hydrocarbon are compounded in a mass ratio in the total weight of 100% to obtain the crude oil pour point depressant. The pour point depressant for crude oil obtained in comparative example 1 can reduce Nigers Sokor mixed oil with the pour point of 27 ℃ to 18 ℃ and reduce the pour point by 9 ℃ under the conditions of adding 500mg/L of the pour point depressant and the treatment temperature of 65 ℃.

Comparative example 2

20 wt.% of the modified EVA copolymer prepared in example 1, 30 wt.% of octadecyl phenol polyoxyethylene polyoxypropylene ether and 50 wt.% of mixed aromatic hydrocarbon are mixed according to the mass ratio to obtain the pour point depressant for crude oil in the total weight of 100%. The pour point depressant for crude oil obtained in comparative example 2 can reduce Nigers Sokor mixed oil with the pour point of 27 ℃ to 18 ℃ and reduce the pour point by 9 ℃ under the conditions of adding 500mg/L of the pour point depressant and the treatment temperature of 65 ℃.

Comparative example 3 (not involving modification treatment)

20 wt.% of EVA copolymer (28-800, Acomata), 30 wt.% of octadecyl phenol polyoxyethylene polyoxypropylene ether, 25 wt.% of isomeric hexadecyl alkane and 25 wt.% of mixed aromatic hydrocarbon are mixed according to the mass ratio to obtain the pour point depressant for crude oil in the total weight of 100 percent. The pour point depressant for crude oil obtained in comparative example 3 can reduce Nigers Sokor mixed oil with the pour point of 27 ℃ to 24 ℃ and reduce the pour point by 3 ℃ under the conditions of adding 500mg/L of the pour point depressant and the treatment temperature of 65 ℃.

Comparative example 4 (No modification treatment and No surfactant)

20 wt.% of EVA copolymer (28-800 of Acoma company) and 80 wt.% of mixed aromatic hydrocarbon are compounded in the total weight of 100% by mass to obtain the pour point depressant for crude oil. The pour point depressant for crude oil obtained in comparative example 4 can reduce Nigers Sokor mixed oil with the pour point of 27 ℃ to the pour point of 27 ℃ and reduce the pour point by 0 ℃ under the conditions of adding 500mg/L of the pour point depressant and the treatment temperature of 65 ℃.

Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.