Gemini block polyether low temperature demulsifier containing aromatic core and its preparation method and application

Abstract

The application relates to a gemini type block polyether low-temperature demulsifier with an aromatic core and a preparation method and application thereof, wherein the demulsifier is obtained by anion ring-opening polymerization of ethylene oxide and butylene oxide and has the following structure shown in formula I. The demulsifier is a gemini type block polyether demulsifier with an aromatic core, has excellent surface interfacial activity, small demulsification addition amount, high demulsification rate, low oil content in a water phase after demulsification, can realize rapid oil-water separation of high-viscosity low-water-content mixed oil emulsion (W / O type) under low-temperature conditions, can play a good viscosity reduction effect, and has the advantages of low cost, safe process and simple synthesis. Formula I.

Description

Technical Field

[0001] This invention relates to a twin-block polyether low-temperature demulsifier containing an aromatic core, its preparation method and application, belonging to the field of crude oil demulsifier technology. Background Technology

[0002] With the gradual depletion of conventional crude oil and the continued growth in energy demand from industrial development, the exploitation of unconventional crude oil will play a crucial role in the coming decade. Heavy oil, as an important component of unconventional crude oil, has the potential to become a major source of crude oil energy if effectively extracted and utilized. However, the high density and viscosity of heavy oil present significant challenges to its extraction, transportation, and refining processes. In recent years, the method of mixing and transporting high-viscosity heavy oil with thin oil has been widely applied in major heavy oil production blocks in China and has proven to be a reliable and economical process. Although the viscosity of the mixed oil emulsion formed after blending is significantly reduced, it still exhibits characteristics such as low water content and complex composition of gums and asphaltenes, thus facing difficulties in demulsification during its development and application.

[0003] Chemical demulsification is widely used in heavy oil demulsification due to its high dehydration rate, simple operation, and low cost. However, common demulsifiers such as ionic liquid demulsifiers, block polyether demulsifiers, and nanoparticle demulsifiers generally suffer from problems such as large dosage, long demulsification time, and high temperature. The high demulsification temperature not only leads to significant energy consumption but also adds new difficulties to the subsequent processing of the separated aqueous phase. In recent years, research on low-temperature demulsification has gradually attracted attention, as this method can effectively reduce energy consumption during the demulsification process. Low-temperature demulsifiers typically refer to demulsifiers that can maintain a good dehydration rate below 50°C. This requires not only excellent interfacial activity but also strong migration ability in the oil phase, which places higher demands on the structure of the demulsifier. Common linear, dendritic, branched, and hyperbranched demulsifiers often fail to meet both of these conditions simultaneously.

[0004] 1,2-Epoxybutane (EPR) is a representative epoxide compound, exhibiting high ring-opening reactivity similar to ethylene oxide and propylene oxide. Theoretically, poly(epoxybutane) (PBO) blocks are more hydrophobic than PPO blocks, and the ethyl group in the PBO block may loosen the oil-water interface film during demulsification, thus facilitating demulsification. However, research on the application of PBO-block-containing polyethers in demulsification is still relatively limited. Gemini surfactants are compounds containing two hydrophobic chains, two hydrophilic groups, and one bridging group. Compared to ordinary surfactants, they exhibit extremely high interfacial activity, demonstrating potential for low-temperature demulsification.

[0005] How to introduce epoxide into gemini-block polyethers and use it to prepare mixed oil emulsion demulsifiers to obtain high-performance low-temperature demulsifiers remains a challenge. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a low-temperature demulsifier containing an aromatic core gemini block polyether, its preparation method, and its application.

[0007] The demulsifier of the present invention is a gemini block polyether demulsifier containing an aromatic core. It has excellent surface activity, requires a small amount of demulsifier, has a high demulsification rate, and produces water with low oil content. It can achieve rapid oil-water separation of low-water-content mixed oil emulsions (W / O type) under low-temperature conditions, and can also achieve good viscosity reduction. Furthermore, the preparation method has the advantages of low cost, safe process, and simple synthesis.

[0008] To achieve the aforementioned objective, the present invention employs the following technical solution:

[0009] This invention provides a gemini-type block polyether low-temperature demulsifier containing an aromatic core, wherein the demulsifier is obtained by anionic ring-opening polymerization of ethylene oxide and ethylene butane, and has the structure shown in Formula I:

[0010]

[0011] Formula I,

[0012] In Equation I, n = 20 - 30.

[0013] The present invention also provides a method for preparing the above-mentioned gemini block polyether low-temperature demulsifier containing an aromatic core, comprising the following steps:

[0014] (1) The initiator p-hydroxyphenylethanol reacts with ethylene oxide in the presence of catalyst a to prepare ethylene oxide block intermediate;

[0015] (2) The ethylene oxide block intermediate reacts with ethylene oxide butane in the presence of catalyst b to obtain a low-temperature demulsifier of a gemini block polyether containing an aromatic core.

[0016] According to a preferred embodiment of the present invention, in step (1), the catalyst a is selected from alkali metal alkoxides, alkali metal hydroxides, amines, alkaline earth metal oxides, phosphazene organic base compounds or coordination bimetallic compounds.

[0017] More preferably, in step (1), the catalyst a is a phosphazene organic base compound.

[0018] Most preferably, in step (1), the catalyst a is 2,2,4,4,6,6-hexa(tetramethylguanidino)-1,3,5,2λ 5,4λ 5 ,6λ 5 - Cyclotriphosphazene HTGCP.

[0019] According to a preferred embodiment of the present invention, in step (1), the mass of catalyst a is 0.1%-1.5% of the mass of ethylene oxide.

[0020] Most preferably, in step (1), the mass of catalyst a is 0.3% of the mass of ethylene oxide.

[0021] According to a preferred embodiment of the present invention, in step (1), the mass ratio of the initiator p-hydroxyphenylethanol to ethylene oxide is 1:(10-20).

[0022] More preferably, in step (1), the mass ratio of the initiator p-hydroxyphenylethanol to ethylene oxide is 1:(10-16).

[0023] According to a preferred embodiment of the present invention, in step (1), the reaction is carried out for 4-12 h under conditions of pressure of 0.1-0.5 MPa and temperature of 100-130°C.

[0024] More preferably, in step (1), the reaction is carried out for 6 h at a pressure of 0.3 MPa and a temperature of 110 °C.

[0025] According to a preferred embodiment of the present invention, in step (2), the catalyst b is a phosphazene organic base compound.

[0026] More preferably, in step (2), the catalyst b is 2,2,4,4,6,6-hexa(tetramethylguanidino)-1,3,5,2λ 5 ,4λ 5 ,6λ 5 - Cyclotriphosphazene HTGCP.

[0027] According to a preferred embodiment of the present invention, in step (2), the mass of catalyst b is 0.1%-2.5% of the mass of epoxide.

[0028] More preferably, in step (2), the mass of catalyst b is 0.3% of the mass of epoxide butane.

[0029] According to a preferred embodiment of the present invention, in step (2), the mass ratio of ethylene oxide block intermediate to ethylene oxide butane is 1:(1-5).

[0030] More preferably, in step (2), the mass ratio of ethylene oxide block intermediate to ethylene oxide butane is 1:(1-2).

[0031] According to a preferred embodiment of the present invention, in step (2), the reaction is carried out for 4-10 h under conditions of pressure of 0.1-1.0 MPa and temperature of 140-170°C.

[0032] More preferably, in step (2), the reaction is carried out for 6 h at a pressure of 0.3 MPa and a temperature of 150 °C.

[0033] The synthetic route for the above-mentioned gemini block polyether low-temperature demulsifier containing an aromatic core is shown in the following formula:

[0034]

[0035] This invention provides the application of the above-mentioned gemini block polyether low-temperature demulsifier containing an aromatic core for low-temperature demulsification of high-viscosity mixed oil emulsions.

[0036] According to a preferred embodiment of the present invention, the specific demulsification method is as follows: a low-temperature demulsifier containing an aromatic core of gemini block polyether is added to a mixed oil emulsion, shaken to mix evenly, and then allowed to stand at 25-45°C to separate into layers to complete the demulsification. The amount of the low-temperature demulsifier containing an aromatic core of gemini block polyether is 50-100 ppm.

[0037] Technical features and advantages of the present invention:

[0038] 1. The low-temperature demulsifier containing an aromatic core of the present invention has strong interfacial activity, requires a small amount of demulsifier, has a high demulsification rate, low oil content in the dewatered water, and has a good viscosity reduction effect. It has excellent demulsification effect and solves the problems of difficult demulsification of mixed oil, large amount of demulsifier, high energy consumption and poor demulsification effect in the crude oil extraction process.

[0039] 2. The aromatic core-containing gemini block polyether low-temperature demulsifier of the present invention can achieve complete dehydration within 10 minutes for a mixed oil emulsion with a water content of 10.7% and an apparent viscosity of 40,771 mPa·s at 40°C when the amount of demulsifier added is 75 ppm.

[0040] 3. The preparation method of the present invention uses p-hydroxyphenylethanol, ethylene oxide and ethylene oxide as main raw materials to prepare a low-temperature demulsifier containing an aromatic core through anionic ring-opening polymerization. The preparation method has the advantages of low cost, safe process and simple synthesis. Attached Figure Description

[0041] Figure 1 HEB-1, the product obtained in Example 1 1 H-NMR spectrum.

[0042] Figure 2The images show demulsification photographs of HEB-1 obtained in Example 1 and the products obtained in Comparative Examples 1-4. Detailed Implementation

[0043] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0044] Example 1

[0045] The preparation method of a low-temperature demulsifier containing an aromatic core, consisting of gemini-block polyethers, comprises the following steps:

[0046] 1) Add 13.8 g of p-hydroxyphenylethanol and 0.53 g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1 MPa. Turn on the mechanical stirrer and adjust the speed to 50 rpm. Raise the temperature to 105℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3 MPa. Maintain the reaction temperature at 110℃. Introduce 176 g of ethylene oxide and react for 4 h until the pressure drops to -0.1 MPa. Lower the temperature to 50℃ and discharge the product to obtain 189.8 g of ethylene oxide block intermediate HE#1.

[0047] 2) Add 94.9g of ethylene oxide block intermediate HE#1 and 0.43g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1MPa. Turn on the mechanical stirrer and adjust the speed to 50rpm. Raise the temperature to 145℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3MPa and the reaction temperature at 130℃. Introduce 144g of ethylene oxide and react for 6 hours until the pressure drops to -0.1MPa. Lower the temperature to 50℃ and discharge the product to obtain 238.9g of HEB-1, a low-temperature demulsifier containing an aromatic core of gemini block polyether.

[0048] HEB-1, a low-temperature demulsifier containing an aromatic core, is a gemini-block polyether. 1 See the H-NMR spectrum. Figure 1 In the figure, the signal peaks at 3.25-3.71 ppm correspond to the methylene and methine proton peaks on the main chain of the block polyether, and the signal peaks at 1.40-1.66 ppm and 0.87-0.99 ppm correspond to the methylene proton peak and methyl proton peak in the PBO block, respectively. This indicates that the present invention has successfully synthesized a low-temperature demulsifier containing an aromatic core of a gemini block polyether.

[0049] Example 2

[0050] The preparation method of a low-temperature demulsifier containing an aromatic core, consisting of gemini-block polyethers, comprises the following steps:

[0051] 1) Add 13.8 g of p-hydroxyphenylethanol and 0.66 g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1 MPa. Turn on the mechanical stirrer and adjust the speed to 50 rpm. Raise the temperature to 105℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3 MPa. Maintain the reaction temperature at 110℃. Introduce 220 g of ethylene oxide and react for 4 h until the pressure drops to -0.1 MPa. Lower the temperature to 50℃ and discharge the product to obtain 233.8 g of ethylene oxide block intermediate HE#2.

[0052] 2) Add 116.9g of ethylene oxide block intermediate HE2# and 0.43g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1MPa. Turn on the mechanical stirrer and adjust the speed to 50rpm. Raise the temperature to 145℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3MPa and keep the reaction temperature at 130℃. Introduce 144g of ethylene oxide and react for 6 hours until the pressure drops to -0.1MPa. Lower the temperature to 50℃ and discharge the product to obtain HEB-2, a low-temperature demulsifier containing an aromatic core of gemini block polyether.

[0053] Example 3

[0054] The preparation method of a low-temperature demulsifier containing an aromatic core, consisting of gemini-block polyethers, comprises the following steps:

[0055] 1) Add 13.8 g of p-hydroxyphenylethanol and 0.53 g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1 MPa. Turn on the mechanical stirrer and adjust the speed to 50 rpm. Raise the temperature to 105℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3 MPa. Maintain the reaction temperature at 110℃. Introduce 264 g of ethylene oxide and react for 4 h until the pressure drops to -0.1 MPa. Lower the temperature to 50℃ and discharge the product to obtain 277.8 g of ethylene oxide block intermediate HE3#.

[0056] 2) Add 138.9g of ethylene oxide block intermediate HE3# and 0.43g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1MPa. Turn on the mechanical stirrer and adjust the speed to 50rpm. Raise the temperature to 145℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3MPa and keep the reaction temperature at 130℃. Then introduce 142.3g of ethylene oxide and react for 6 hours until the pressure drops to -0.1MPa. Lower the temperature to 50℃ and discharge the product to obtain HEB-3, a low-temperature demulsifier containing an aromatic core of gemini block polyether.

[0057] Comparative Example 1

[0058] The preparation method of the low-temperature demulsifier containing an aromatic core of the gemini block polyether described in Example 1 differs from that in:

[0059] Step 1), replace the catalyst HTGCP with the catalyst KOH.

[0060] Step 2) Replace the catalyst HTGCP with the catalyst KOH, and proceed as in Example 1 to obtain a total of 238.9 g of demulsifier HEBK.

[0061] Comparative Example 2

[0062] The preparation method of the low-temperature demulsifier containing an aromatic core of the gemini block polyether described in Example 1 differs from that in:

[0063] Step 1), replace 13.8 g of p-hydroxyphenylethanol with 14.6 g of 1,8-octanediol.

[0064] Other steps were carried out as in Example 1, yielding demulsifier OEB2 39.3 g.

[0065] Comparative Example 3

[0066] The preparation method of the low-temperature demulsifier containing an aromatic core of the gemini block polyether described in Example 1 differs from that in:

[0067] Step 1), replace 13.8 g of p-hydroxyphenylethanol with 12.2 g of p-ethylphenol.

[0068] Other procedures were carried out as in Example 1, yielding demulsifier EEB238.1 g.

[0069] Comparative Example 4

[0070] A method for preparing a low-temperature demulsifier, comprising the following steps:

[0071] 1) Add 13.8 g of p-hydroxyphenylethanol and 0.86 g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1 MPa. Turn on the mechanical stirrer and adjust the speed to 50 rpm. Raise the temperature to 145 ℃. Slowly introduce epoxide butane to maintain the pressure at 0.3 MPa. Maintain the reaction temperature at 130 ℃. Introduce 288 g of epoxide butane and react for 8 h until the pressure drops to -0.1 MPa. Lower the temperature to 50 ℃ and discharge the product to obtain 301.8 g of epoxide butane block intermediate HB.

[0072] 2) Add 0.9 g of epoxide butane block intermediate HB15 and 0.26 g of catalyst HTGCP to a high-pressure reactor. Connect the high-pressure reactor to a vacuum pump and evacuate to -0.1 MPa. Turn on the mechanical stirrer and adjust the speed to 50 rpm. Raise the temperature to 105℃. Slowly introduce ethylene oxide to maintain the pressure at 0.3 MPa and keep the reaction temperature at 110℃. Introduce 88 g of ethylene oxide and react for 6 h until the pressure drops to -0.1 MPa. Lower the temperature to 50℃ and discharge the product to obtain low-temperature demulsifier HBE238.9 g.

[0073] Performance testing:

[0074] 1. The demulsification performance of the demulsifiers in Examples 1-3 and Comparative Examples 1-4 was determined according to SY / T 5218-2000 (Test Method for Performance of Crude Oil Demulsifiers). The demulsifier dosage was 100 ppm. The demulsification target was a mixed oil emulsion with a water content of 10.7% and an apparent viscosity of 40,771 mPa·s at 40℃. The test results are shown in Table 1 below.

[0075] Table 1. Dehydration rate of different demulsifiers at different time intervals

[0076]

[0077] As can be seen from Table 1, the demulsifiers of Examples 1-3 can achieve a dehydration rate of 100% in 10 minutes, and the dehydration rate is high, achieving complete dehydration of the mixed oil emulsion at low temperature in 10 minutes. Comparative Example 1, using KOH as a catalyst, resulted in more chain transfer reactions during the anionic ring-opening polymerization process, leading to a low dehydration rate of HEBK, less than 100% within 10 minutes. Comparative Example 2, using 1,8-octanediol as an initiator, altered the bridging group, eliminating the aromatic core structure in the low-temperature demulsifier. The resulting demulsifier OEB weakened the interaction between natural interfacial active substances such as gums and asphaltenes in the mixed oil emulsion, thus lowering the dehydration rate compared to the examples, less than 100% within 10 minutes. Comparative Example 3, using p-ethylphenol as an initiator, yielded a linear demulsifier EEB. Comparative Example 4, first ring-opening polymerization with butane oxide and then with ethylene oxide, yielded a demulsifier HBE with a Bola structure. Neither Comparative Example 3 nor Comparative Example 4 possessed the excellent interfacial activity of the twin structure, resulting in a significantly reduced dehydration rate, with almost no dehydration ability within 10 minutes.

[0078] Based on the comparative analysis, it can be seen that in the synthesis process of Examples 1-3 of the present invention, HTGCP is used as a catalyst and p-hydroxyphenylethanol is used as an initiator. The demulsifier is first anionicly ring-opened with ethylene oxide and then ring-opened with ethylene oxide. The resulting demulsifier has strong interfacial activity, requires a small amount of demulsifier, has a high demulsification rate, and has a low oil content in the aqueous phase.

[0079] 2. The amount of demulsifier added in Example 1 was changed to 50 ppm, 75 ppm, 100 ppm and 125 ppm respectively. The demulsification performance was determined according to SY / T 5218-2000 (Test Method for Performance of Crude Oil Demulsifier). The demulsification object was a mixed oil emulsion with a water content of 10.7% and an apparent viscosity of 40,771 mPa·s at 40℃. The test results are shown in Table 2 below.

[0080] Table 2. Demulsifying effect of different concentrations of HEB-1

[0081]

[0082] 1 The demulsification time is when the dehydration rate reaches 85%.

[0083] Table 2 shows that when the amount of demulsifier added is below 100 ppm, both the dehydration rate and viscosity reduction rate increase with increasing concentration, while the demulsification time shortens. However, when the concentration exceeds 100 ppm, the dehydration rate decreases to 95.3%, and the demulsification time extends to 6.90 min. This is because excessively high concentrations of HEB have a certain emulsifying effect, thus inhibiting the demulsification process. Considering factors such as economic cost, demulsification time, oil content in the extracted aqueous phase, and viscosity reduction rate, the optimal demulsification concentration of HEB is 75 ppm.

[0084] Further analysis of the data in the table, combined with the examples and comparative examples, shows that the Gemini block polyether low-temperature demulsifier HEB containing an aromatic core obtained by the present invention has the best dehydration rate, low water content in the dehydrated aqueous phase, short demulsification time, and good viscosity reduction effect.

[0085] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any substitutions, modifications, combinations, changes, simplifications, etc., made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A gemini-block polyether low-temperature demulsifier containing an aromatic core, said demulsifier being obtained by anionic ring-opening polymerization of ethylene oxide and butylene oxide, having the structure shown in Formula I: ， Formula I, In Equation I, n = 20 - 30.

2. The preparation method of the low-temperature demulsifier containing an aromatic core of the gemini block polyether according to claim 1, comprising the following steps: (1) The initiator p-hydroxyphenylethanol reacts with ethylene oxide in the presence of catalyst a to prepare ethylene oxide block intermediate; (2) The ethylene oxide block intermediate reacts with ethylene oxide butane in the presence of catalyst b to obtain a low-temperature demulsifier containing an aromatic core of a gemini block polyether.

3. The preparation method according to claim 2, characterized in that, In step (1), the catalyst a is selected from alkali metal alkoxides, alkali metal hydroxides, amines, alkaline earth metal oxides, phosphazene organic base compounds or coordination bimetallic compounds.

4. The preparation method according to claim 2, characterized in that, The catalyst a is 2,2,4,4,6,6-hexa(tetramethylguanidinyl)-1,3,5,2λ 5 ,4λ 5 ,6λ 5 - Cyclotriphosphazene HTGCP.

5. The preparation method according to claim 2, characterized in that, In step (1), the mass of catalyst a is 0.1%-1.5% of the mass of ethylene oxide, the mass ratio of the initiator p-hydroxyphenylethanol to ethylene oxide is 1:(10-20), and the reaction is carried out for 4-12 h at a pressure of 0.1-0.5 MPa and a temperature of 100-130°C.

6. The preparation method according to claim 2, characterized in that, In step (2), the catalyst b is a phosphazene organic base compound.

7. The preparation method according to claim 2, characterized in that, In step (2), the catalyst b is 2,2,4,4,6,6-hexa(tetramethylguanidino)-1,3,5,2λ 5 ,4λ 5 ,6λ 5 - Cyclotriphosphazene HTGCP, catalyst b has a mass of 0.1%-2.5% of the mass of epoxide butane.

8. The preparation method according to claim 2, characterized in that, In step (2), the mass ratio of ethylene oxide block intermediate to ethylene oxide butane is 1:(1-5), and the reaction is carried out at a pressure of 0.1-1.0 MPa and a temperature of 140-170°C for 4-10 h.

9. The application of the aromatic core-containing gemini block polyether low-temperature demulsifier of claim 1 for low-temperature demulsification of mixed oil emulsions.

10. The application according to claim 9, characterized in that, The specific demulsification method is as follows: Add the low-temperature demulsifier containing the aromatic core of the gemini block polyether to the high-viscosity mixed oil emulsion, shake to mix evenly, and then let it stand at 25-45℃ to complete the demulsification by layering. The amount of the low-temperature demulsifier containing the aromatic core of the gemini block polyether is 50-100 ppm.

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