Three-branch betaine demulsifier as well as preparation method and application thereof
By grafting maleic anhydride onto betaine and performing hydrophobic modification, a three-branched betaine demulsifier is prepared, which solves the problems of poor permeability and poor dehydration effect in the existing technology and achieves high-efficiency, low-volume demulsification and strong salt resistance.
Patent Information
- Application Number
- CN202410330570.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-22
- Publication Date
- 2025-09-23
AI Technical Summary
Existing chemical demulsifiers have poor permeability and poor dehydration effect when treating crude oil emulsions rich in colloids and asphaltene. In addition, the synthesis conditions are dangerous, the demulsification speed is slow, and the cost is high.
A three-branched betaine demulsifier was prepared by grafting maleic anhydride onto betaine and performing hydrophobic modification. The hydrophilic center and multi-branched hydrophobic chain structure were combined to improve its permeability and interfacial activity at the oil-water interface.
It achieves efficient demulsification, which can be achieved at low dosage. It has good salt resistance and temperature adaptability. The demulsification efficiency is above 92%, and it is still effective at low concentrations, making it suitable for high-salt environments.
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Figure CN120682127A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oilfield chemistry, and in particular to a three-branched betaine demulsifier, a preparation method thereof and an application thereof. Background Art
[0002] The oil industry generates large quantities of crude oil emulsions during production. Water in these emulsions can cause pipeline corrosion and increased transportation costs. Therefore, the handling of crude oil emulsions has become a global challenge, and oil-water separation is an essential process prior to transportation and processing. Demulsification methods for crude oil emulsions can generally be categorized as physical, biological, and chemical. Chemical demulsification is widely used due to its rapidity, efficiency, and low cost.
[0003] Chemical demulsifiers are generally amphiphilic, possessing both hydrophilic and hydrophobic ends. They can promote the demulsification of crude oil emulsions by altering the properties of the interfacial membrane. Currently, the main raw materials for commonly used commercial demulsifiers are ethylene oxide and propylene oxide, which present problems such as dangerous and complex synthesis conditions and low demulsification capabilities. Furthermore, current technologies still suffer from poor permeability and dehydration effects for crude oils rich in colloids and asphaltene. Due to the high viscosity, low oil-water density, and excessively high active components of crude oils rich in colloids and asphaltene, the diffusion rate of the demulsifier and the rate of water droplet aggregation are slow, resulting in large demulsifier dosages, slow demulsification speeds, and poor demulsification effects. Summary of the Invention
[0004] In order to solve the problems existing in the background technology, the present invention provides a three-branched betaine demulsifier and a preparation method and application thereof. The demulsifier has high demulsification performance, strong adaptability and a simple preparation method.
[0005] The technical solution of the present invention to solve the above technical problems is as follows:
[0006] In a first aspect, the present invention provides a three-branched betaine demulsifier, which is prepared by grafting maleic anhydride onto betaine and performing hydrophobic modification, and has the general structural formula:
[0007]
[0008] In a second aspect, the present invention provides a method for preparing the above-mentioned three-branched betaine demulsifier, comprising the following steps:
[0009] S1. Preparation of betaine;
[0010] S2. Preparation of maleic anhydride-modified betaine by grafting betaine with maleic anhydride;
[0011] S3. Performing hydrophobic modification on the maleic anhydride-modified betaine to obtain the three-branched betaine demulsifier.
[0012] According to the above scheme, step S1 is specifically as follows: triethanolamine and sultone are added to solvent I, and reacted at 50-100° C. for 5-15 hours to obtain the betaine. The structure of the betaine is:
[0013]
[0014] According to the above scheme, the molar ratio of triethanolamine to sultone is 1:(1-2), the sultone is one or more of 1,3-propane sultone, 1,4-butane sultone, and 1,3-propene sultone, and the solvent I is one or more of tetrahydrofuran, dioxane, acetone, ethyl acetate, N,N-dimethylformamide, and xylene.
[0015] According to the above scheme, step S2 is specifically as follows: adding maleic anhydride to the above betaine, reacting at 50-100° C. for 5-15 hours to obtain maleic anhydride-modified betaine, the structure of which is:
[0016]
[0017] According to the above scheme, the molar ratio of maleic anhydride to triethanolamine is (3-5):1.
[0018] According to the above scheme, step S3 specifically comprises: adding alkyl mercaptan to the maleic anhydride-modified betaine, then adding an organic base catalyst, and reacting at 50-100° C. for 5-15 hours to obtain a three-branched betaine demulsifier. The structure of the three-branched betaine demulsifier is:
[0019] Where R is -(CH2) n CH3, n=11~21.
[0020] According to the above scheme, the molar ratio of the alkyl mercaptan to maleic anhydride is (1-2):1, and the amount of the organic base catalyst added is 1%-5% of the alkyl mercaptan.
[0021] According to the above scheme, the alkyl mercaptan is one or more of dodecanethiol, tetradecanethiol, hexadecanethiol, octadecanethiol, eicosinethiol, and docosinethiol, and the organic base catalyst is one or more of trimethylamine, triethylamine, and pyridine.
[0022] In a third aspect, the present invention provides use of the above-mentioned three-branched betaine demulsifier in demulsifying crude oil emulsions.
[0023] According to the above scheme, the specific application steps are: dissolving the three-branched betaine demulsifier in solvent II to obtain a solution, and then mixing the solution with the crude oil emulsion at a set temperature and standing for 0.5h-2h.
[0024] According to the above scheme, the solvent II is one or more of water, alcohol, and xylene, the mass fraction of the solution is 0.1wt%-0.6wt%, and the volume ratio of the solution to the crude oil emulsion is 1:(10-20).
[0025] The beneficial effects of the present invention are:
[0026] The three-branched betaine demulsifier provided by the present invention has a betaine structure, a hydrophilic center and a three-branched hydrophobic long chain. It organically combines the characteristics of the betaine structure and the multi-branched demulsifier structure, so that it has good amphiphilicity and interfacial activity. The multi-branched hydrophobic chain structure enables it to have good dispersibility in a continuous oil phase, can be quickly adsorbed at the oil-water interface and interact with interfacial active substances, penetrate into the interfacial film to reduce the oil-water interfacial tension, weaken the stability of the interfacial film, or directly destroy the interfacial film to induce demulsification, and has the characteristics of low dosage and high efficiency.
[0027] The three-branched betaine demulsifier of the present invention has a demulsification efficiency of over 92% for crude oil emulsions within 1 hour at a concentration of 250 mg / L. Even at a concentration as low as 50 mg / L, the demulsification efficiency for crude oil emulsions is still as high as 77.9%, showing the characteristics of low dosage and high efficiency. The demulsification efficiency can reach 95.6% within 1 hour at 60°C, the demulsification temperature is low, and the demulsification efficiency is good at a high salt concentration of 50,000 mg / L, showing high salt resistance. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 The present invention is a flow chart of the preparation process of the three-branched betaine demulsifier. DETAILED DESCRIPTION
[0029] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0030] In the first aspect, the demulsifier is prepared by grafting maleic anhydride onto betaine and performing hydrophobic modification, and its general structural formula is:
[0031] Where R is -(CH2) n CH3, n=11~21.
[0032] In the second aspect, the present invention provides a method for preparing the above-mentioned three-branched betaine demulsifier, and the preparation process flow chart thereof is as follows: Figure 1 As shown, the following steps are included:
[0033] S1. Preparation of betaine;
[0034] S2. Preparation of maleic anhydride-modified betaine by grafting betaine with maleic anhydride;
[0035] S3. Performing hydrophobic modification on the maleic anhydride-modified betaine to obtain the three-branched betaine demulsifier.
[0036] In some specific embodiments, step S1 is specifically: adding triethanolamine and sultone to solvent I, and reacting at 50-100° C. for 5-15 hours to obtain the betaine, and the structure of the betaine is:
[0037]
[0038] In some specific embodiments, the molar ratio of triethanolamine to sultone is 1:(1-2), the sultone is one or more of 1,3-propane sultone, 1,4-butane sultone, and 1,3-propene sultone, and the solvent I is one or more of tetrahydrofuran, dioxane, acetone, ethyl acetate, N,N-dimethylformamide, and xylene.
[0039] In some specific embodiments, step S2 is specifically: adding maleic anhydride to the above betaine, reacting at 50-100° C. for 5-15 hours to obtain maleic anhydride-modified betaine, wherein the structure of the maleic anhydride-modified betaine is:
[0040]
[0041] In some specific embodiments, the molar ratio of maleic anhydride to triethanolamine is (3-5):1.
[0042] In some specific embodiments, step S3 is specifically: adding alkyl mercaptan to the maleic anhydride modified betaine, then adding an organic base catalyst, and reacting at 50-100° C. for 5-15 hours to obtain a three-branched betaine demulsifier, wherein the structure of the three-branched betaine demulsifier is:
[0043] Where R is -(CH2) n CH3, n=11~22.
[0044] In some specific embodiments, the molar ratio of the alkyl mercaptan to maleic anhydride is (1-2):1, and the amount of the organic base catalyst added is 1%-5% of the alkyl mercaptan.
[0045] In some specific embodiments, the alkyl mercaptan is one or more of dodecanethiol, tetradecanethiol, hexadecanethiol, octadecanethiol, eicosinethiol, and docosinethiol, and the organic base catalyst is one or more of trimethylamine, triethylamine, and pyridine.
[0046] In a third aspect, the present invention provides use of the above-mentioned three-branched betaine demulsifier in demulsifying crude oil emulsions.
[0047] In some specific embodiments, the specific application steps are: dissolving the three-branched betaine demulsifier in solvent II to obtain a solution, and then mixing the solution with the crude oil emulsion at a set temperature and standing for 0.5h-2h.
[0048] In some specific embodiments, the solvent II is one or more of water, alcohol, and xylene, the mass fraction of the solution is 0.1 wt%-0.6 wt%, and the volume ratio of the solution to the crude oil emulsion is 1:(10-20).
[0049] The following are specific examples.
[0050] Example 1
[0051] This embodiment provides a three-branched betaine demulsifier, which is obtained by the following steps:
[0052] 1 mol of triethanolamine and 1 mol of 1,3-propane sultone were added to dioxane and reacted at 100°C for 10 hours to obtain betaine. Then, 3 mol of maleic anhydride was added to the betaine and reacted at 100°C for 10 hours to obtain maleic anhydride-modified betaine. Finally, 3 mol of hexadecanethiol was added to the maleic anhydride-modified betaine, mixed thoroughly, and then 0.01 mol of trimethylamine was added and reacted at 100°C for 10 hours to obtain a three-branched betaine demulsifier.
[0053] Example 2
[0054] This embodiment provides a three-branched betaine demulsifier, which is obtained by the following steps:
[0055] 1 mol of triethanolamine and 1.5 mol of 1,4-propane sultone were added to dioxane and reacted at 100°C for 8 hours to obtain betaine. Then, 4 mol of maleic anhydride was added to the betaine and reacted at 100°C for 8 hours to obtain maleic anhydride-modified betaine. Finally, 3 mol of dodecanethiol was added to the maleic anhydride-modified betaine, mixed thoroughly, and then 0.01 mol of trimethylamine was added. The mixture was reacted at 100°C for 8 hours to obtain a three-branched betaine demulsifier.
[0056] Example 3
[0057] This embodiment provides a three-branched betaine demulsifier, which is obtained by the following steps:
[0058] 1 mol of triethanolamine and 1 mol of 1,3-propane sultone were added to dioxane and reacted at 80°C for 8 hours to obtain betaine. Then, 3 mol of maleic anhydride was added to the betaine and reacted at 80°C for 8 hours to obtain maleic anhydride-modified betaine. Finally, 3.5 mol of eicosethiol was added to the maleic anhydride-modified betaine, mixed thoroughly, and then 0.01 mol of trimethylamine was added and reacted at 80°C for 8 hours to obtain a three-branched betaine demulsifier.
[0059] Test Example 1
[0060] The three-branched betaine demulsifier prepared in Examples 1 to 3 was used to characterize the demulsification performance of the three-branched betaine demulsifier in crude oil emulsion.
[0061] 150 parts by weight of crude oil was added to 350 parts by weight of deionized water, stirred and mixed, heated to 60° C., and then stirred at a speed of 11,000 r / min for 20 minutes. This process was repeated three times until a stable water-in-oil emulsion was obtained.
[0062] The three-branched betaine demulsifier prepared in Examples 1 to 3 was added to a xylene / ethanol mixed solution (75:25) to prepare a solution with a mass fraction of 0.5%, namely, experimental groups 1-3.
[0063] 1 part by volume of the above three-branched betaine demulsifier solution was added to 20 parts by volume of crude oil emulsion and then fully shaken to mix evenly. The mixture was then transferred to a 60°C water bath and allowed to stand for 1 hour. The dehydration rate was measured, and the results are shown in Table 1.
[0064] Table 1 Demulsification results of experimental groups 1-3
[0065]
[0066] It can be seen from Table 1 that the three-branched betaine demulsifiers prepared in Examples 1-3 all have very good demulsification performance, and the demulsification efficiency can reach more than 92%.
[0067] Test Example 2
[0068] The three-branched betaine demulsifier prepared in Example 1 was used to characterize the demulsification performance of the three-branched betaine demulsifier at different concentrations in crude oil emulsion.
[0069] 150 parts by weight of crude oil was added to 350 parts by weight of deionized water, stirred and mixed, heated to 60° C., and then stirred at a speed of 11,000 r / min for 20 minutes. This process was repeated three times until a stable water-in-oil emulsion was obtained.
[0070] Different weight portions of the three-branched betaine demulsifier prepared in Example 1 were added to a xylene / ethanol mixed solution (75:25) to prepare three-branched betaine demulsifiers with mass fractions of 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, and 0.1%, respectively. The obtained samples were recorded as experimental groups 4-9; the blank group was 0%, and the sample was recorded as experimental group 10.
[0071] 1 part by volume of the above experimental groups 4-10 was added to 20 parts by volume of crude oil emulsion and then thoroughly shaken to mix. The mixture was then transferred to a 60°C water bath and allowed to stand for 1 hour. The dehydration rate was measured. The results are shown in Table 2.
[0072] Table 2 Demulsification results of experimental groups 4-10
[0073]
[0074] As can be seen from Table 2, the three-branched betaine demulsifier provided by the present invention has good demulsification performance. A demulsification efficiency of 91.0% can be achieved with a concentration of 150 mg / L of the three-branched betaine demulsifier. When the concentration is 200 mg / L, the demulsification efficiency reaches 93.1%. When the concentration is 250 mg / L, the demulsification efficiency is 95.6%. When the concentration is as low as 50 mg / L, the demulsification efficiency of the crude oil emulsion is still as high as 77.9%.
[0075] Test Example 3
[0076] Based on the three-branched betaine demulsifier prepared in Example 1, experimental groups 11-14 were established in sequence to characterize the demulsification performance of the three-branched betaine demulsifier at different temperatures.
[0077] 150 parts by weight of crude oil was added to 350 parts by weight of deionized water, stirred and mixed, heated to 60° C., and then stirred at a speed of 11,000 r / min for 20 minutes. This process was repeated three times until a stable water-in-oil emulsion was obtained.
[0078] The three-branched betaine demulsifier prepared in Example 1 was added to a xylene / ethanol mixed solution (75:25) to prepare a solution with a mass fraction of 0.5%.
[0079] 1 part by volume of the above three-branched betaine demulsifier was added to 20 parts by volume of crude oil emulsion and then fully shaken to mix. The mixture was then transferred to water baths set at different temperatures and allowed to stand for 1 hour. The dehydration rates were measured, and the results are shown in Table 3.
[0080] Table 3 Demulsification results of experimental groups 11-14
[0081]
[0082] It can be seen from Table 3 that the three-branched betaine demulsifier provided by the present invention can achieve a demulsification efficiency of 95.6% at 60° C. for 1 hour, and the demulsification temperature is low.
[0083] Test Example 4
[0084] Based on the three-branched betaine demulsifier prepared in Example 1, experimental groups 15-19 were established in sequence to characterize the demulsification performance of the three-branched betaine demulsifier at different pH values.
[0085] 150 parts by weight of crude oil was added to 350 parts by weight of deionized water and stirred. The pH was adjusted with hydrochloric acid and sodium hydroxide, heated to 60°C, and then stirred at a speed of 11,000 r / min for 20 minutes. This process was repeated three times until a stable water-in-oil emulsion was obtained.
[0086] The three-branched betaine demulsifier prepared in Example 1 was added to a xylene / ethanol mixed solution (75:25) to prepare a solution with a mass fraction of 0.5%.
[0087] 1 part by volume of the above three-branched betaine demulsifier was added to 20 parts by volume of crude oil emulsion and then fully shaken to mix. The mixture was then transferred to a 60°C water bath and allowed to stand for 1 hour. The dehydration rate was measured, and the results are shown in Table 4.
[0088] Table 4 Demulsification results of experimental groups 15-19
[0089]
[0090] As shown in Table 4, the three-branched betaine demulsifier provided by the present invention has a high demulsification efficiency in both strong acid and strong base environments.
[0091] Test Example 5
[0092] Based on the three-branched betaine demulsifier prepared in Example 1, experimental groups 20-25 were sequentially established to characterize the demulsification performance of the three-branched betaine demulsifier at different salinities.
[0093] 150 parts by weight of crude oil was added to 350 parts by weight of deionized water and stirred. The salinity was adjusted with sodium chloride, heated to 60°C, and then stirred at a speed of 11,000 r / min for 20 minutes. This process was repeated three times until a stable water-in-oil emulsion was obtained.
[0094] The three-branched betaine demulsifier prepared in Example 1 was added to a xylene / ethanol mixed solution (75:25) to prepare a solution with a mass fraction of 0.5%.
[0095] 1 part by volume of the above three-branched betaine demulsifier was added to 20 parts by volume of crude oil emulsion and then fully shaken to mix. The mixture was then transferred to a 60°C water bath and allowed to stand for 1 hour. The dehydration rate was measured, and the results are shown in Table 5.
[0096] Table 5 Demulsification results of experimental group 20-25
[0097]
[0098]
[0099] It can be seen from Table 5 that the three-branched betaine demulsifier provided by the present invention can have a stable demulsification efficiency under a high salinity condition of 50,000 mg / L, indicating that the demulsifier has high salt resistance.
[0100] Therefore, the three-branch betaine demulsifier provided by the present invention has the characteristics of low dosage, high efficiency, acid, alkali and salt resistance.
[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A three-branched betaine demulsifier, characterized in that: The demulsifier is prepared by grafting maleic anhydride onto betaine and performing hydrophobic modification, and its general structural formula is: Where R is -(CH2) n CH3, n=11~21.
2. The method for preparing the three-branched betaine demulsifier according to claim 1, wherein The steps include: S1. Preparation of betaine; S2. Preparation of maleic anhydride-modified betaine by grafting betaine with maleic anhydride; S3. Performing hydrophobic modification on the maleic anhydride-modified betaine to obtain the three-branched betaine demulsifier.
3. The preparation method of the three-branched betaine demulsifier according to claim 2, characterized in that, Step S1 specifically comprises: adding triethanolamine and sultone into solvent I, and reacting at 50-100° C. for 5-15 hours to obtain the betaine.
4. The preparation method of the three-branched betaine demulsifier according to claim 3, characterized in that: The molar ratio of triethanolamine to sultone is 1:(1-2), the sultone is one or more of 1,3-propane sultone, 1,4-butane sultone, and 1,3-propene sultone, and the solvent I is one or more of tetrahydrofuran, dioxane, acetone, ethyl acetate, N,N-dimethylformamide, and xylene.
5. The preparation method of the three-branched betaine demulsifier according to claim 2, characterized in that, Step S2 specifically comprises: adding maleic anhydride to the above betaine, reacting at 50-100° C. for 5-15 hours to obtain maleic anhydride-modified betaine.
6. The method for preparing the three-branched betaine demulsifier according to claim 5, wherein: The molar ratio of maleic anhydride to triethanolamine is (3-5):
1.
7. The method for preparing the three-branched betaine demulsifier according to claim 2, wherein: Step S3 specifically comprises: adding alkyl mercaptan to the maleic anhydride-modified betaine, then adding an organic base catalyst, and reacting at 50-100° C. for 5-15 hours to obtain a three-branched betaine demulsifier.
8. The method for preparing the three-branched betaine demulsifier according to claim 7, wherein: The molar ratio of the alkyl mercaptan to maleic anhydride is (1-2):1, and the amount of the organic base catalyst added is 1%-5% of the alkyl mercaptan.
9. The method for preparing the three-branched betaine demulsifier according to claim 8, wherein: The alkyl mercaptan is one or more of dodecanethiol, tetradecanethiol, hexadecanethiol, octadecanethiol, eicosinethiol, and docosinethiol, and the organic base catalyst is one or more of trimethylamine, triethylamine, and pyridine.
10. Use of the three-branched betaine demulsifier according to claim 1 in demulsification of crude oil emulsion.