Pour point depressant as well as preparation method and application thereof

Abstract

The invention provides a pour point depressant as well as a preparation method and application thereof. The pour point depressant comprises a polymer with a structure as shown in a formula I. The preparation method of the pour point depressant comprises the following steps: (1) mixing alpha-olefin, maleic anhydride, an initiator and a solvent, and polymerizing to obtain a reaction system containing an intermediate product; and (2) adding long-chain fatty alcohol and / or long-chain fatty amine, monohydroxyl-terminated silicone oil and a catalyst into the reaction system obtained in the step (1), and reacting to obtain the pour point depressant. According to the present invention, the structure of the polymer represented by the formula I is designed to obtain the polymer represented by the formula I with excellent performance, and the pour point depressant prepared from the polymer represented by the formula I has a low condensation point.

Description

Technical Field

[0001] The present invention belongs to the technical field of crude oil pour point depressant materials, and particularly relates to a pour point depressant, a preparation method thereof, and an application thereof. Background Art

[0002] High pour point and high viscosity crude oil generally refers to crude oil with a high freezing point and relatively high viscosity. Such crude oil generally contains a relatively large amount of long-chain normal paraffin wax, and the average molecular weight of such long-chain normal paraffin wax is relatively large. During the cooling process of crude oil, the large-molecule long-chain normal paraffin wax is prone to slowly crystallize and precipitate, forming a flaky structure and further forming a three-dimensional laminated structure, causing the crude oil to slowly solidify, significantly increasing the viscosity of the crude oil, and thereby reducing the fluidity of the crude oil.

[0003] During the process of transporting crude oil through pipelines, the long-chain normal paraffin wax precipitated at low temperatures in the crude oil is prone to deposit on the inner wall of the pipeline, reducing the fluidity of the pipeline, and even blocking the pipeline, seriously affecting the pipeline transportation efficiency, increasing the power cost, and possibly bringing potential safety hazards to the pipeline transportation. Currently, it is known that adding a pour point depressant to crude oil can improve the low-temperature fluidity of crude oil and enhance the pipeline transportation effect of high pour point and high viscosity crude oil. The mechanism is generally considered to be that through the interaction between the pour point depressant and the long-chain normal paraffin wax in the crude oil, the formation of the three-dimensional laminated structure of the long-chain normal paraffin wax in the crude oil can be reduced, thereby reducing the pour point and viscosity of the crude oil, enhancing the low-temperature fluidity of the crude oil, and ensuring the transportation of crude oil under low-temperature conditions.

[0004] Crude oil has a strong selectivity for pour point depressants, which is mainly determined by the composition and physical and chemical properties of the crude oil, which also leads to a wide variety of corresponding pour point depressants. The known types of pour point depressants mainly include ethylene-vinyl acetate copolymers, self-polymers of higher fatty alcohol acrylates or higher fatty alcohol methacrylates, copolymers of higher fatty alcohol acrylates and maleic anhydride, copolymers of higher fatty alcohol acrylates and styrene, copolymers of olefins and unsaturated dicarboxylic acid esters, copolymers of olefins and unsaturated diamides, and various multi-component copolymers composed of the above polymer monomers. At the same time, pour point depressants prepared by compounding multiple polymers also have good pour point depression effects. These pour point depressants have achieved effective pour point depression purposes for their respective suitable types of crude oil.

[0005] The general preparation method of known copolymer pour point depressants of olefins and unsaturated dicarboxylic acid esters or unsaturated diamides is as follows: First, dissolve olefins and maleic anhydride in an aliphatic or aromatic solvent, add an initiator for copolymerization reaction, and then carry out an esterification or amidation reaction with alcohols or amines in the presence of a catalyst to obtain the product. The olefins are generally α-olefins with 12 or more carbon atoms, and the alcohols or amines are long-chain fatty alcohols and long-chain fatty amines with 12 or more carbon atoms. To meet the requirements of transportation and on-site use, the above polymer solution is further diluted to a suitable concentration with an aliphatic or aromatic solvent.

[0006] The main reason for solvent dilution is the solidification phenomenon of the pour point depressant itself, which reduces the convenience of on-site use. Generally, it is desired to ensure that the pour point depressant is in a liquid state at the ambient temperature of use, so as to facilitate the quick and uniform addition of the pour point depressant to the crude oil. Solvent dilution can lower the freezing point of the pour point depressant itself, and pour point depressant products with different concentrations can be prepared according to the requirements of the use temperature. However, solvent dilution increases the transportation cost and the cost of the solvent material. Especially in some places with relatively low temperatures or remote locations, the concentration of the pour point depressant should be increased as much as possible under the condition of meeting the on-site use temperature to achieve the optimal economic transportation and on-site use convenience.

[0007] Therefore, how to provide a new type of pour point depressant with a lower freezing point has become an urgent technical problem to be solved at present. Summary of the Invention

[0008] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a pour point depressant and its preparation method and application. In the present invention, by designing the structure of the polymer shown in Formula I, and further designing an organosilicon structural group (i.e., R3) with a specific content in the polymer shown in Formula I, a polymer shown in Formula I with excellent performance is obtained. The pour point depressant prepared from the polymer shown in Formula I has a lower freezing point.

[0009] To achieve this purpose, the present invention adopts the following technical solutions:

[0010] In the first aspect, the present invention provides a pour point depressant, which comprises a polymer having the structure shown in Formula I as follows:

[0011]

[0012] Among them, n represents an integer between 10 and 100, m represents an integer between 10 and 100, p represents an integer between 1 and 20, and n:m:p is (0.3 - 0.6):(0.2 - 0.7):(0.01 - 0.14);

[0013] R1 represents an alkyl group containing 6 - 38 carbon atoms;

[0014] R2 represents H(CH2) x NH- or H(CH2) y O-, and x and y each independently represent an integer between 12 and 40;

[0015] R3 represents a group having the structure shown in Formula II as follows:

[0016]

[0017] Among them, z represents an integer between 1 and 50, and * represents the connection site.

[0018] In the present invention, by designing the structure of the polymer shown in Formula I and further introducing a silicone structural group (i.e., R3) with a specific content in the polymer shown in Formula I, a polymer shown in Formula I with excellent properties is obtained. The pour point depressant prepared from the polymer shown in Formula I has a lower pour point.

[0019] In the present invention, by controlling the numerical ratio of n, m, and p in the polymer shown in Formula I within a specific range, the content of R3 in the polymer shown in Formula I is controlled within a specific range, improving the properties of the polymer shown in Formula I, and thus a pour point depressant with a lower pour point is prepared.

[0020] In the present invention, the pour point depressant prepared from the polymer shown in Formula I, compared with the pour point depressant provided by the prior art, can maintain the same pour point depressing effect at the same concentration, but the pour point depressant provided by the present invention has a lower pour point; at the same ambient temperature of use, the pour point depressant provided by the present invention has a higher concentration, which can effectively reduce the solvent consumption and thus reduce the overall usage amount of the pour point depressant.

[0021] In the present invention, n represents an integer between 1 and 50 (such as 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100, etc.).

[0022] m represents an integer between 1 and 50 (such as 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100, etc.). n can represent 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100, etc.

[0023] p represents an integer between 1 and 50 (such as 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, or 20, etc.).

[0024] The ratio of n:m:p is (0.3 - 0.6):(0.2 - 0.7):(0.01 - 0.14), where 0.3 - 0.6 can be 0.3, 0.4, 0.5, or 0.6, etc.; 0.2 - 0.7 can be 0.2, 0.3, 0.4, 0.5, 0.6, or 0.7, etc.; 0.01 - 0.14 can be 0.01, 0.02, 0.05, 0.08, 0.1, 0.12, or 0.14, etc.

[0025] R1 represents an alkyl group containing 6 - 38 (such as 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, or 36, etc.) carbon atoms.

[0026] x and y each independently represent an integer between 12 and 40 (for example, it can be 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38 or 40, etc.).

[0027] z represents an integer before 1 to 50 (for example, it can be 1, 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50, etc.).

[0028] In the present invention, for the convenience of calculation, the ratio of n, m, and p can be represented by the molar ratio of α-olefin, long-chain fatty alcohol and / or long-chain fatty amine, and mono-hydroxy terminated silicone oil, that is, n:m:p = the amount of substance of α-olefin: the amount of substance of long-chain fatty alcohol and / or long-chain fatty amine: the amount of substance of mono-hydroxy terminated silicone oil.

[0029] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the purpose and beneficial effects of the present invention can be better achieved and realized.

[0030] As a preferred technical solution of the present invention, the weight-average molecular weight of the polymer shown in Formula I is 3000 to 30000 Daltons, for example, it can be 3000 Daltons, 6000 Daltons, 9000 Daltons, 12000 Daltons, 15000 Daltons, 18000 Daltons, 21000 Daltons, 24000 Daltons, 27000 Daltons or 30000 Daltons, etc.

[0031] In the present invention, by controlling the weight-average molecular weight of the polymer shown in Formula I within a specific range, a pour point depressant with excellent performance can be prepared. If the weight-average molecular weight of the polymer shown in Formula I is too small or too large, it will have an adverse effect on the pour point depressing effect.

[0032] Preferably, the weight-average molecular weight of the group shown in Formula II is 300 to 3000 Daltons, for example, it can be 300 Daltons, 500 Daltons, 700 Daltons, 1000 Daltons, 1200 Daltons, 1500 Daltons, 1800 Daltons, 2000 Daltons, 2300 Daltons, 2600 Daltons, 2800 Daltons or 3000 Daltons, etc.

[0033] In the present invention, by controlling the weight-average molecular weight of the group shown in Formula II within a specific range, on the premise that the pour point depressing effect of the pour point depressant of the polymer shown in Formula I does not decrease, the pour point of the pour point depressant itself can be effectively reduced. If the weight-average molecular weight of the group shown in Formula II is too small, the improvement of the pour point of the pour point depressant of the polymer shown in Formula I is not obvious; if the weight-average molecular weight of the group shown in Formula II is too large, it will have an impact on the pour point depressing effect of the pour point depressant of the polymer shown in Formula I.

[0034] Preferably, based on the molar percentage content of R2 and R3 being 100 mol%, the molar percentage content of R3 is 3 to 31 mol%, for example, it can be 3 mol%, 6 mol%, 8 mol%, 10 mol%, 12 mol%, 15 mol%, 18 mol%, 20 mol%, 22 mol%, 25 mol%, 27 mol%, 29 mol% or 31 mol% etc.

[0035] In the present invention, by controlling the molar percentage content of R3 within a specific range, the performance of the polymer shown in formula I can be further optimized.

[0036] In the present invention, for the convenience of calculation, the amount of long-chain fatty alcohol and / or long-chain fatty amine used to form the R2 group is taken as the content of the R2 group in the polymer of formula I, and the amount of mono-hydroxy terminated silicone oil used to form the R3 group is taken as the content of the R3 group in the polymer of formula I. Therefore, based on the molar percentage content of R2 and R3 being 100 mol%, the calculation method for the molar percentage content of R3 is: molar percentage content of R3 = amount of substance of mono-hydroxy terminated silicone oil ÷ amount of substance of long-chain fatty alcohol and / or long-chain fatty amine × 100%.

[0037] As a preferred technical solution of the present invention, the raw materials for preparing the polymer shown in formula I include the following components:

[0038] α-olefin, maleic anhydride, long-chain fatty alcohol and / or long-chain fatty amine, mono-hydroxy terminated silicone oil.

[0039] In the present invention, the raw materials for preparing the polymer shown in formula I include the following components: α-olefin, maleic anhydride, long-chain fatty alcohol, mono-hydroxy terminated silicone oil; or, α-olefin, maleic anhydride, long-chain fatty amine, mono-hydroxy terminated silicone oil; or, α-olefin, maleic anhydride, long-chain fatty alcohol, long-chain fatty amine, mono-hydroxy terminated silicone oil.

[0040] It should be noted that in the present invention, a single α-olefin can be used as the raw material to prepare the polymer shown in formula I, or multiple α-olefins can be used together as the raw material to prepare the polymer shown in formula I; similarly, a single long-chain fatty alcohol can be used as the raw material to prepare the polymer shown in formula I, or multiple long-chain fatty alcohols can be used together as the raw material to prepare the polymer shown in formula I, a single long-chain fatty amine can be used as the raw material to prepare the polymer shown in formula I, or multiple long-chain fatty amines can be used together as the raw material to prepare the polymer shown in formula I.

[0041] Preferably, the molar ratio of the α-olefin, maleic anhydride, long-chain fatty alcohol and / or long-chain fatty amine, and mono-hydroxy-terminated silicone oil is (0.3 - 0.6):(0.4 - 0.7):(0.2 - 0.7):(0.01 - 0.14), where 0.3 - 0.6 can be 0.3, 0.4, 0.5 or 0.6, etc.; 0.4 - 0.7 refers to the total amount of long-chain fatty alcohol and / or long-chain fatty amine, which can be 0.4, 0.5, 0.6 or 0.7, etc.; 0.2 - 0.7 can be 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7, etc.; 0.01 - 0.14 can be 0.01, 0.02, 0.05, 0.08, 0.1, 0.12 or 0.14, etc.

[0042] In the present invention, by controlling the amounts of each raw material within a specific range, a polymer of Formula I with a specific structure can be prepared, and then a pour point depressant with excellent performance can be prepared. Further, in the present invention, by controlling the amount of mono-hydroxy-terminated silicone oil within a specific range, the content of silicon-containing groups in the polymer of Formula I can be controlled within a specific range, thereby further improving the performance of the pour point depressant.

[0043] As a preferred technical solution of the present invention, the α-olefin is selected from styrene, straight-chain α-olefins containing 8 - 40 (such as 8, 10, 12, 15, 18, 20, 22, 25, 27, 30, 33, 36 or 40, etc.) carbon atoms or branched-chain α-olefins containing 8 - 40 (such as 8, 10, 12, 15, 18, 20, 22, 25, 27, 30, 33, 36 or 40, etc.) carbon atoms, preferably straight-chain α-olefins containing 18 - 32 (such as 18, 20, 22, 24, 26, 28, 30 or 32, etc.) carbon atoms or branched-chain α-olefins containing 18 - 32 (such as 18, 20, 22, 24, 26, 28, 30 or 32, etc.) carbon atoms.

[0044] Preferably, based on the molar percentage of the α-olefin being 100 mol%, the molar percentage of the branched-chain α-olefin containing 8 - 40 carbon atoms is ≤20 mol%, such as 0 mol%, 2 mol%, 4 mol%, 6 mol%, 8 mol%, 10 mol%, 12 mol%, 14 mol%, 16 mol%, 18 mol% or 20 mol%, etc.

[0045] In the present invention, controlling the amount of the branched-chain α-olefin containing 8 - 40 carbon atoms within a specific range can achieve a better pour point depressing effect; if the amount of the branched-chain α-olefin containing 8 - 40 carbon atoms used in the preparation of the polymer of Formula I is too large, the pour point depressing effect will be poor.

[0046] Preferably, the long-chain fatty alcohol has 12 to 40 carbon atoms (for example, it can be 12, 16, 18, 20, 22, 25, 27, 30, 32, 36, or 40, etc.), and more preferably 16 to 32.

[0047] Preferably, the long-chain fatty amine has 12 to 40 carbon atoms (for example, it can be 12, 16, 18, 20, 22, 25, 27, 30, 32, 36, or 40, etc.), and more preferably 16 to 32.

[0048] Preferably, the weight-average molecular weight of the mono-hydroxy terminated silicone oil is 300 to 3000 Daltons, for example, it can be 300 Daltons, 500 Daltons, 700 Daltons, 1000 Daltons, 1200 Daltons, 1500 Daltons, 1800 Daltons, 2000 Daltons, 2300 Daltons, 2600 Daltons, 2800 Daltons, or 3000 Daltons, etc.

[0049] As a preferred technical solution of the present invention, the raw materials for preparing the pour point depressant shown in Formula I further include an initiator.

[0050] Preferably, the initiator includes di-tert-butyl peroxide.

[0051] In the present invention, there is no special limitation on the dosage of the initiator, and the commonly used ranges in the art are applicable. Exemplarily, including but not limited to: based on the total mass percentage of all reaction monomers being 100%, the mass percentage of the catalyst is 0.5% to 8% (for example, it can be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 8%, etc.).

[0052] Preferably, the raw materials for preparing the pour point depressant shown in Formula I further include a catalyst.

[0053] Preferably, the catalyst is selected from any one or a combination of at least two of sulfuric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, tetra-isobutyl titanate, or zinc chloride.

[0054] In the present invention, there is no special limitation on the dosage of the catalyst, and the commonly used ranges in the art are applicable. Exemplarily, including but not limited to: based on the total mass percentage of all reaction monomers being 100%, the mass percentage of the catalyst is 0.05% to 3%, for example, it can be 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, etc.

[0055] Preferably, the raw materials for preparing the pour point depressant shown in Formula I further include a solvent.

[0056] Preferably, the solvent is selected from high-boiling aliphatic solvents and / or aromatic solvents, and more preferably a mixed aromatic solvent with the number of carbon atoms ≥8.

[0057] In the present invention, the boiling point of the high-boiling aliphatic solvent is 130-220 °C (for example, it can be 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, 210 °C or 220 °C, etc.), and the aromatic hydrocarbon solvent is selected from any one or a combination of at least two of xylene, trimethylbenzene, tetramethylbenzene or mixed aromatic hydrocarbon solvent oil.

[0058] As a preferred technical solution of the present invention, based on the mass percentage content of the pour point depressant being 100%, the mass percentage content of the polymer shown in Formula I is 25-65% (for example, it can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% or 65%, etc.).

[0059] In a second aspect, the present invention provides a preparation method of the pour point depressant as described in the first aspect, and the preparation method includes the following steps:

[0060] (1) Mix α-olefin, maleic anhydride, initiator and solvent, and carry out polymerization to obtain a reaction system containing intermediate products;

[0061] (2) Add long-chain fatty alcohol and / or long-chain fatty amine, monohydroxy-terminated silicone oil and catalyst to the reaction system obtained in step (1), and carry out a reaction to obtain the pour point depressant.

[0062] In the present invention, through the reaction of α-olefin and maleic anhydride in step (1), the main chain structure of the polymer is obtained. Then, through the intermediate product and long-chain fatty alcohol and / or long-chain fatty amine in step (2), the R2 group is grafted onto the main chain structure of the polymer. Through the reaction of the intermediate product and monohydroxy-terminated silicone oil, the R3 group is grafted onto the main chain structure of the polymer to obtain the polymer shown in Formula I with a specific structural formula.

[0063] As a preferred technical solution of the present invention, the temperature of the mixing in step (1) is 70-85 °C (for example, it can be 70 °C, 72 °C, 74 °C, 76 °C, 78 °C, 80 °C, 81 °C, 83 °C, 84 °C or 85 °C, etc.).

[0064] Preferably, the temperature of the polymerization reaction in step (1) is 130-160 °C (for example, it can be 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 155 °C or 160 °C, etc.), and the time is 6-10 h (for example, it can be 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h or 10 h, etc.).

[0065] Preferably, the polymerization reaction in step (1) is carried out in an atmosphere of protective gas, and the protective gas includes nitrogen and / or inert gas.

[0066] In the present invention, the inert gas includes argon.

[0067] Preferably, the temperature of the reaction in step (2) is 30 - 220 °C (for example, it can be 30 °C, 40 °C, 60 °C, 80 °C, 100 °C, 120 °C, 140 °C, 160 °C, 180 °C, 200 °C or 220 °C, etc.), and more preferably 30 - 180 °C.

[0068] Preferably, the reaction time in step (2) is 0.5 - 16 h, for example, it can be 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h or 16 h, etc.

[0069] As a preferred technical solution of the present invention, the preparation method specifically includes the following steps:

[0070] (1) At 70 - 85 °C, mix an α-olefin, maleic anhydride and a solvent, after heating to 130 - 160 °C, add an initiator thereto, and carry out polymerization for 6 - 10 h in an inert gas atmosphere to obtain a reaction system containing an intermediate product;

[0071] (2) Add a long-chain fatty alcohol and / or a long-chain fatty amine, a mono-hydroxy terminated silicone oil, and a catalyst to the reaction system obtained in step (1), and carry out a reaction at 30 - 220 °C for 0.5 - 16 h to obtain the pour point depressant.

[0072] The pour point depressant provided by the present invention includes a polymer shown in Formula I and a solvent. Based on the mass percentage of the pour point depressant being 100%, the mass percentage of the polymer shown in Formula I is 25 - 65%.

[0073] It should be noted that in the mixing process of step (1), it can be to first mix maleic anhydride and the solvent to dissolve maleic anhydride, and then add the α-olefin to the reaction system for reaction.

[0074] The reaction process of step (2) can be to add the long-chain fatty alcohol and / or the long-chain fatty amine, the mono-hydroxy terminated silicone oil, and the catalyst together to react with the intermediate product obtained in step (1); or it can be to add the mono-hydroxy terminated silicone oil and the catalyst to the reaction system of step (1) to first react the mono-hydroxy terminated silicone oil with the intermediate product, and then add the long-chain fatty alcohol and / or the long-chain fatty amine to continue the reaction, and the long-chain fatty alcohol and / or the long-chain fatty amine react with the intermediate product again.

[0075] Third aspect, the present invention provides an application of the pour point depressant as described in the first aspect in crude oil transportation. The mass content of the pour point depressant in crude oil is 100 - 6000 ppm, for example, it can be 100 ppm, 500 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm, 3000 ppm, 3500 ppm, 4000 ppm, 4500 ppm, 5000 ppm, 5500 ppm or 6000 ppm, etc.

[0076] In the present invention, the pour point depressant prepared from the polymer shown in Formula I, compared with the pour point depressant provided by the prior art, can maintain the same pour point depressing effect at the same concentration, but the pour point depressant provided by the present invention has a lower pour point; at the same ambient temperature of use, the pour point depressant provided by the present invention has a higher concentration, which can effectively reduce the solvent dosage, thereby reducing the overall usage amount of the pour point depressant, and effectively reducing the solvent dosage of the pour point depressant and the transportation cost in remote areas.

[0077] Compared with the prior art, the present invention has the following beneficial effects:

[0078] (1) In the present invention, by designing the structure of the polymer shown in Formula I and further controlling the dosage ratio of each preparation raw material within a specific range, a polymer shown in Formula I with excellent performance is obtained. The pour point depressant prepared from the polymer shown in Formula I has a lower pour point.

[0079] (2) Compared with the pour point depressant provided by the prior art, on the premise of maintaining the same pour point depressing effect at the same concentration, the pour point depressant provided by the present invention has a lower pour point; at the same ambient temperature of use, the pour point depressant provided by the present invention has a higher concentration, which can effectively reduce the solvent dosage, thereby reducing the overall usage amount of the pour point depressant. Detailed Embodiments

[0080] To facilitate the understanding of the present invention, the following examples are listed. Those skilled in the art should understand that the examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0081] The sources of some components in the examples and comparative examples are as follows:

[0082] Mono-hydroxy terminated silicone oil 1: The weight average molecular weight is 250 daltons, purchased from Anhui Mingyi Silicon Industry Co., Ltd.;

[0083] Mono-hydroxy terminated silicone oil 2: The weight average molecular weight is 300 daltons, purchased from Anhui Mingyi Silicon Industry Co., Ltd.;

[0084] Mono-hydroxy terminated silicone oil 3: The weight average molecular weight is 530 daltons, purchased from Anhui Mingyi Silicon Industry Co., Ltd.;

[0085] Mono-hydroxy terminated silicone oil 4: The weight-average molecular weight is 1300 Daltons, purchased from Anhui Mingyi Silicon Industry Co., Ltd.;

[0086] Mono-hydroxy terminated silicone oil 5: The weight-average molecular weight is 3000 Daltons, purchased from Anhui Mingyi Silicon Industry Co., Ltd.;

[0087] Mono-hydroxy terminated silicone oil 6: The weight-average molecular weight is 3500 Daltons, purchased from Anhui Mingyi Silicon Industry Co., Ltd.

[0088] Example 1

[0089] This example provides a pour point depressant 1 and its preparation method. The preparation method is as follows:

[0090] (1) Mix maleic anhydride (1 mol) with mesitylene (100 g), heat up to 80 °C to dissolve maleic anhydride, add C20-C24 α-olefins (a total of 1 mol, including 0.25 mol of C20 α-olefin, 0.45 mol of C22 α-olefin, and 0.3 mol of C24 α-olefin) thereto, heat up to 145 °C, and under a nitrogen atmosphere, add di-tert-butyl peroxide (0.01 mol) thereto within 6 h, and then continue the polymerization reaction for 2 h;

[0091] (2) Heat the reaction system in step (1) to 170 °C, add mono-hydroxy terminated silicone oil 4 (0.05 mol, with a weight-average molecular weight of 1300 Daltons) and p-toluenesulfonic acid (with a mass percentage of p-toluenesulfonic acid being 2% based on the total mass percentage of all reaction monomers being 100%) thereto, react at 170 °C for 2 hours, cool down to 160 °C, and add a mixture of molten octadecanol (0.45 mol), eicosanol (0.1 mol), and docosanol (0.4 mol) to the above reactants, and react at 160 °C for 8 hours to obtain the pour point depressant 1.

[0092] Example 2

[0093] This example provides a pour point depressant 2 and its preparation method. The difference from Example 1 is only that:

[0094] In step (2), the amount of substance of mono-hydroxy terminated silicone oil is adjusted to 0.1 mol, and the amount of substance of octadecanol is adjusted to 0.4 mol;

[0095] Other conditions are the same as those in Example 1.

[0096] Example 3

[0097] This example provides a pour point depressant 3 and its preparation method. The difference from Example 1 is only that:

[0098] In step (2), replace the monohydroxy-terminated silicone oil 4 with a weight-average molecular weight of 1300 Daltons with monohydroxy-terminated silicone oil 3 with a weight-average molecular weight of 530 Daltons;

[0099] Other conditions are the same as those in Example 1.

[0100] Example 4

[0101] This example provides a pour point depressant 4 and a preparation method thereof. The preparation method is as follows:

[0102] (1) Mix maleic anhydride (0.6 mol) and mesitylene (100 g), heat up to 80 °C to dissolve maleic anhydride, add straight-chain α-olefin with C20 (0.2 mol), straight-chain α-olefin with C24 (0.1 mol), and straight-chain α-olefin with C30 (0.1 mol) thereto, heat up to 150 °C, and add di-tert-butyl peroxide (0.006 mol) thereto within 6 h under a nitrogen atmosphere, and continue the polymerization reaction for 6 h;

[0103] (2) Heat up the reaction system obtained in step (1) to 170 °C, add monohydroxy-terminated silicone oil 4 (0.08 mol, with a weight-average molecular weight of 1300 Daltons) and p-toluenesulfonic acid (with a mass percentage content of p-toluenesulfonic acid being 2% based on the total mass percentage of all reaction monomers being 100%) thereto, react at 170 °C for 2 h, cool down to 160 °C, and add a mixture containing octadecyl alcohol (0.2 mol), eicosyl alcohol (0.2 mol), and docosyl alcohol (0.2 mol) in a molten state to the above reactants, and react at 160 °C for 8 h to obtain the pour point depressant 4.

[0104] Example 5

[0105] This example provides a pour point depressant 5 and a preparation method thereof. The preparation method is as follows:

[0106] (1) Mix maleic anhydride (0.4 mol) with mesitylene (100 g), heat up to 85 °C to dissolve maleic anhydride, add straight-chain α-olefin with C25 (0.1 mol) and straight-chain α-olefin with C24 (0.2 mol) thereto, heat up to 160 °C, and add di-tert-butyl peroxide (0.006 mol) thereto within 6 h under a nitrogen atmosphere, and continue the polymerization reaction for 2 h;

[0107] (2) Heat the reaction system obtained in step (1) to 180 °C, and add monohydroxy-terminated silicone oil 4 (0.05 mol, weight average molecular weight of 1300 daltons), p-toluenesulfonic acid (with a mass percentage of 2% based on the total mass percentage of all reaction monomers being 100%), and a molten mixture containing cetyl alcohol (0.1 mol), eicosanol (0.05 mol), and docosanol (0.05 mol). React at 180 °C for 6 h to obtain the pour point depressant 5.

[0108] Example 6

[0109] This example provides a pour point depressant 6 and its preparation method. The preparation method is as follows:

[0110] (1) Mix maleic anhydride (0.7 mol) and mesitylene (100 g), heat to 80 °C to dissolve maleic anhydride, add a straight-chain α-olefin with C20 (0.3 mol), a branched-chain α-olefin with C24 (0.1 mol, purchased from Shell), and a straight-chain α-olefin with C30 (0.2 mol). After heating to 130 °C, add di-tert-butyl peroxide (0.006 mol) thereto within 6 h under a nitrogen atmosphere, and continue the polymerization reaction for 10 h;

[0111] (2) Heat the reaction system obtained in step (1) to 170 °C, add monohydroxy-terminated silicone oil 4 (0.14 mol, weight average molecular weight of 1300 daltons), p-toluenesulfonic acid (with a mass percentage of 2% based on the total mass percentage of all reaction monomers being 100%), react at 170 °C for 2 h, cool to 150 °C, and add a molten mixture containing stearyl alcohol (0.3 mol), tetracosanol (0.2 mol), and dotriacontanol (0.2 mol) to the above reactants. React at 150 °C for 12 h to obtain the pour point depressant 6.

[0112] Example 7

[0113] This example provides a pour point depressant 7 and its preparation method. The preparation method is as follows:

[0114] (1) At 75 °C, mix maleic anhydride (0.4 mol) and mesitylene (100 g), heat to 80 °C to dissolve maleic anhydride, add a straight-chain α-olefin with C22 (0.2 mol), a straight-chain α-olefin with C24 (0.2 mol), and a straight-chain α-olefin with C18 (0.2 mol). After heating to 140 °C, add di-tert-butyl peroxide (0.006 mol) thereto within 6 h under a nitrogen atmosphere, and continue the polymerization reaction for 4 h;

[0115] (2) Heat the reaction system obtained in step (1) to 170 °C, add mono-hydroxy terminated silicone oil 4 (0.1 mol, weight-average molecular weight of 1300 daltons) and p-toluenesulfonic acid (with a mass percentage of 2% based on the total mass percentage of all reaction monomers being 100%), react at 170 °C for 2 hours, cool down to 165 °C, and add a molten mixture containing octadecylamine (0.4 mol), docosylamine (0.1 mol), and tetracosylamine (0.1 mol) to the above reactants, and react at 165 °C for 9 h to obtain the pour point depressant 7.

[0116] Example 8

[0117] This example provides a pour point depressant 8 and its preparation method, and the preparation method is as follows:

[0118] (1) At 85 °C, mix maleic anhydride (0.7 mol) and mesitylene (100 g), heat up to 80 °C to dissolve maleic anhydride, add a C20 linear α-olefin (0.3 mol) thereto, after heating up to 150 °C, in a nitrogen atmosphere, add di-tert-butyl peroxide (0.006 mol) thereto within 6 h, and continue the polymerization reaction for 7 h;

[0119] (2) Heat the reaction system obtained in step (1) to 170 °C, add mono-hydroxy terminated silicone oil 4 (0.08 mol, weight-average molecular weight of 1300 daltons) and p-toluenesulfonic acid (with a mass percentage of 2% based on the total mass percentage of all reaction monomers being 100%), react at 170 °C for 2 hours, cool down to 160 °C, and add a molten mixture containing dodecanol (0.1 mol), eicosanol (0.0.2 mol), and tetracontanol (0.1 mol) to the above reactants, and react at 160 °C for 10 h to obtain the pour point depressant 8.

[0120] Example 9

[0121] This example provides a pour point depressant 9 and its preparation method, and the difference from Example 4 is only that:

[0122] In step (2), adjust the amount of substance of the mono-hydroxy terminated silicone oil to 0.01 mol;

[0123] Other conditions are the same as those in Example 4.

[0124] Example 10

[0125] This example provides a pour point depressant 10 and its preparation method, and the difference from Example 4 is only that:

[0126] In step (2), adjust the amount of the mono-hydroxy terminated silicone oil to 0.14 mol;

[0127] Other conditions are the same as those in Example 4.

[0128] Example 11

[0129] This example provides a pour point depressant 11 and its preparation method. The difference from Example 4 is only that:

[0130] In step (2), adjust the amount of the mono-hydroxy terminated silicone oil to 0.005 mol;

[0131] Other conditions are the same as those in Example 4.

[0132] Example 12

[0133] This example provides a pour point depressant 12 and its preparation method. The difference from Example 4 is only that:

[0134] In step (2), adjust the amount of the mono-hydroxy terminated silicone oil to 0.2 mol;

[0135] Other conditions are the same as those in Example 4.

[0136] Example 13

[0137] This example provides a pour point depressant 13 and its preparation method. The difference from Example 4 is only that:

[0138] In step (2), replace the mono-hydroxy terminated silicone oil 4 with a weight average molecular weight of 1300 Da with the mono-hydroxy terminated silicone oil 2 with a weight average molecular weight of 300 Da;

[0139] Other conditions are the same as those in Example 4.

[0140] Example 14

[0141] This example provides a pour point depressant 14 and its preparation method. The difference from Example 4 is only that:

[0142] In step (2), replace the mono-hydroxy terminated silicone oil 4 with a weight average molecular weight of 1300 Da with the mono-hydroxy terminated silicone oil 5 with a weight average molecular weight of 3000 Da;

[0143] Other conditions are the same as those in Example 4.

[0144] Example 15

[0145] This example provides a pour point depressant 15 and its preparation method. The difference from Example 4 is only that:

[0146] In step (2), replace the monohydroxy-terminated silicone oil 4 with a weight-average molecular weight of 1300 daltons with a monohydroxy-terminated silicone oil 1 with a weight-average molecular weight of 250 daltons;

[0147] Other conditions are the same as those in Example 4.

[0148] Example 16

[0149] This example provides a pour point depressant 16 and a preparation method thereof. The difference from Example 4 is only that:

[0150] In step (2), replace the monohydroxy-terminated silicone oil 4 with a weight-average molecular weight of 1300 daltons with a monohydroxy-terminated silicone oil 6 with a weight-average molecular weight of 3500 daltons;

[0151] Other conditions are the same as those in Example 4.

[0152] Example 17

[0153] This example provides a pour point depressant 17 and a preparation method thereof. The difference from Example 6 is only that:

[0154] In step (1), replace 0.1 mol of branched-chain α-olefin of C24 with 0.1 mol of straight-chain α-olefin of C24, and replace 0.2 mol of straight-chain α-olefin of C30 with 0.2 mol of branched-chain α-olefin of C30 (purchased from Shell);

[0155] Other conditions are the same as those in Example 6.

[0156] Comparative Example 1

[0157] This comparative example provides a pour point depressant A and a preparation method thereof. The preparation method is as follows:

[0158] (1) Mix maleic anhydride (1 mol) and mesitylene (100 g), heat up to 80 °C to dissolve maleic anhydride, add α-olefin of C20-C24 (1 mol, including 0.25 mol of α-olefin of C20, 0.45 mol of α-olefin of C22, and 0.3 mol of α-olefin of C24) thereto, heat up to 145 °C, and add di-tert-butyl peroxide (0.01 mol) thereto within 6 h under a nitrogen atmosphere, and continue to react for 2 h;

[0159] (2) Heat up the reaction system obtained in step (1) to 170 °C, add stearyl alcohol (0.45 mol), eicosanol (0.1 mol), docosanol (0.4 mol) and p-toluenesulfonic acid (the mass percentage of p-toluenesulfonic acid is 2% based on the total mass percentage of all reaction monomers being 100%), and react at 160 °C for 10 h to obtain the pour point depressant A.

[0160] Using mesitylene, dilute the pour point depressants provided in the above examples and comparative examples to form pour point depressants with solute concentrations of 25%, 30%, 40%, 50% and 65% (where the solute is all other components except mesitylene), and test their performance:

[0161] (1) Determination of the pour point depressing effect of the pour point depressant on crude oil: The highly viscous crude oil with high pour point was used as the experimental oil, and the pour point of this experimental oil was measured to be 32 °C. In order to determine the effect of the pour point depressant on reducing the pour point of the above experimental oil, 1500 ppm of the pour point depressant based on the weight of the experimental oil was added to the above experimental oil respectively to obtain experimental samples, and the pour points of the experimental samples were detected according to the standard of GB / T510-1983;

[0162] Among them, the pour point reduction range of the experimental oil is (32 - the pour point of the experimental sample) °C.

[0163] (2) Pour point of the pour point depressant itself: It was detected according to the method of GB / T510-1983.

[0164] The test results are shown in Table 1 below:

[0165] Table 1

[0166]

[0167]

[0168] In the present invention, by designing the structure of the polymer shown in Formula I, and further controlling the dosage ratio of each preparation raw material within a specific range, thereby controlling the content of the organosilicon group in the polymer shown in Formula I within a specific range, a polymer shown in Formula I with excellent performance is obtained. Thus, the pour point depressant prepared from the polymer shown in Formula I has a relatively low pour point and can reduce the pour point of crude oil.

[0169] It can be seen from the content of Table 1 that the pour point of the pour point depressant with a concentration of 25% is 3 - 5 °C. When its dosage is 1500 ppm, it can reduce the pour point of crude oil by 0 - 3 °C; the pour point of the pour point depressant with a concentration of 30% is 4 - 8 °C. When its dosage is 1500 ppm, it can reduce the pour point of crude oil by 1 - 4 °C; the pour point of the pour point depressant with a concentration of 40% is 8 - 13 °C. When its dosage is 1500 ppm, it can reduce the pour point of crude oil by 5 - 9 °C; the pour point of the pour point depressant with a concentration of 50% is 11 - 18 °C. When its dosage is 1500 ppm, it can reduce the pour point of crude oil by 7 - 14 °C; the pour point of the pour point depressant with a concentration of 65% is 16 - 23 °C. When its dosage is 1500 ppm, it can reduce the pour point of crude oil by 11 - 18 °C.

[0170] Compared with Examples 1-10, if the amount of the mono-hydroxy terminated silicone oil is too small (Example 11), in the polymer shown by Formula I prepared, based on the molar percentage content of R2 and R3 being 100 mol%, the molar percentage content of R3 is too low, and the performance of the prepared pour point depressant is poor; if the amount of the mono-hydroxy terminated silicone oil is too large (Example 12), in the polymer shown by Formula I prepared, based on the molar percentage content of R2 and R3 being 100 mol%, the molar percentage content of R3 is too high, and the performance of the prepared pour point depressant is also poor.

[0171] Compared with Examples 1-10 and Examples 13-14, if the weight average molecular weight of the mono-hydroxy terminated silicone oil is relatively low (Example 15), or if the weight average molecular weight of the mono-hydroxy terminated silicone oil is relatively high (Example 16), the performance of the prepared pour point depressant is poor.

[0172] Compared with Examples 1-10 and Examples 13-14, if the molar percentage content of the branched chain α-olefin in the α-olefin is too high (Example 17), the performance of the prepared pour point depressant is slightly poor.

[0173] It can be seen from the content of Comparative Example 1 that if there is no mono-hydroxy terminated silicone oil in the raw materials for preparing the polymer shown by Formula I, the performance of the prepared pour point depressant is poor.

[0174] In summary, the present invention designs the structure of the polymer shown by Formula I, and further controls the content of the silicone group in the polymer shown by Formula I within a specific range by controlling the dosage ratio of each raw material for preparation within a specific range, thereby obtaining a polymer shown by Formula I with excellent performance. The pour point depressant prepared from the polymer shown by Formula I has a low pour point and can reduce the pour point of crude oil.

[0175] The applicant declares that the present invention uses the above examples to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A pour point depressant, characterized in that, The pour point depressant includes a polymer having the structure shown in the following formula I: Wherein, n represents an integer between 10 and 100, m represents an integer between 10 and 100, p represents an integer between 1 and 20, and n:m:p is (0.3 - 0.6):(0.2 - 0.7):(0.01 - 0.14); R1 represents an alkyl group containing 6 to 38 carbon atoms; R2 represents H(CH2) x NH- or H(CH2) y O-, where x and y each independently represent an integer between 12 and 40; R3 represents a group having the structure shown in the following formula II: Wherein, z represents an integer between 1 and 50, and * represents the connection site.

2. The pour point depressant according to claim 1, characterized in that, The weight average molecular weight of the polymer shown in the formula I is 3000 - 30000 Daltons; Preferably, the weight average molecular weight of the group shown in the formula II is 300 - 3000 Daltons; Preferably, based on the molar percentage content of R2 and R3 being 100 mol%, the molar percentage content of R3 is 3 - 31 mol%.

3. The pour point depressant according to claim 1 or 2, characterized in that, The preparation raw materials of the polymer shown in the formula I include the following components: α-olefin, maleic anhydride, long-chain fatty alcohol and / or long-chain fatty amine, mono-hydroxy terminated silicone oil; Preferably, the molar ratio of the α-olefin, maleic anhydride, long-chain fatty alcohol and / or long-chain fatty amine, mono-hydroxy terminated silicone oil is (0.3 - 0.6):(0.4 - 0.7):(0.2 - 0.7):(0.01 - 0.14).

4. The pour point depressant according to claim 3, characterized in that, The α-olefin is selected from styrene, a straight-chain α-olefin containing 8 to 40 carbon atoms or a branched-chain α-olefin containing 8 to 40 carbon atoms, preferably a straight-chain α-olefin containing 18 to 32 carbon atoms or a branched-chain α-olefin containing 18 to 32 carbon atoms; Preferably, based on the molar percentage content of the α-olefin being 100 mol%, the molar percentage content of the branched-chain α-olefin containing 8 to 40 carbon atoms is ≤20 mol%; Preferably, the number of carbon atoms of the long-chain fatty alcohol is 12 - 40, and more preferably 16 - 32; Preferably, the number of carbon atoms of the long-chain fatty amine is 12 - 40, and more preferably 16 - 32; Preferably, the weight average molecular weight of the mono-hydroxy terminated silicone oil is 300 - 3000 Daltons.

5. The pour point depressant according to claim 3 or 4, characterized in that The preparation raw materials of the pour point depressant shown in the formula I further include an initiator; Preferably, the initiator includes di-tert-butyl peroxide; Preferably, the preparation raw materials of the pour point depressant shown in the formula I further include a catalyst; Preferably, the catalyst is selected from any one or a combination of at least two of sulfuric acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, tetra-isobutyl titanate or zinc chloride; Preferably, the preparation raw materials of the pour point depressant shown in the formula I further include a solvent; Preferably, the solvent is selected from high-boiling aliphatic solvents and / or aromatic solvents.

6. The pour point depressant according to any one of claims 1-5, characterized in that, Based on the mass percentage content of the pour point depressant being 100%, the mass percentage content of the polymer shown in the formula I is 25 - 65%.

7. A preparation method of the pour point depressant according to any one of claims 1-6, characterized in that, The preparation method includes the following steps: (1) Mix the α-olefin, maleic anhydride, initiator and solvent, and carry out polymerization to obtain a reaction system containing an intermediate product; (2) Add long-chain fatty alcohol and / or long-chain fatty amine, mono-hydroxy terminated silicone oil, and catalyst to the reaction system obtained in step (1), and carry out a reaction to obtain the pour point depressant.

8. The preparation method according to claim 7, characterized in that, The temperature of the mixing in step (1) is 70 - 85°C; Preferably, the temperature of the polymerization reaction in step (1) is 130 - 160°C, and the time is 6 - 10 h; Preferably, the polymerization reaction in step (1) is carried out in an atmosphere of protective gas, and the protective gas includes nitrogen and / or inert gas; Preferably, the temperature of the reaction in step (2) is 30 - 220°C, more preferably 30 - 180°C; Preferably, the time of the reaction in step (2) is 0.5 - 16 h.

9. The preparation method according to claim 7 or 8, characterized in that, The preparation method specifically comprises the following steps: (1) At 70 - 85°C, mix an α-olefin, maleic anhydride and a solvent, after raising the temperature to 130 - 160°C, add an initiator thereto, and carry out polymerization for 6 - 10 h in an atmosphere of protective gas to obtain a reaction system containing an intermediate product; (2) Add a long-chain fatty alcohol and / or a long-chain fatty amine, a mono-hydroxy terminated silicone oil and a catalyst to the reaction system obtained in step (1), and carry out a reaction at 30 - 220°C for 0.5 - 16 h to obtain the pour point depressant.

10. Use of a pour point depressant as described in any one of claims 1-6 in crude oil transportation, characterized in that, The mass content of the pour point depressant in crude oil is 100 - 6000 ppm.

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