Ionic compound, demulsifier and preparation method and application thereof

Abstract

The invention discloses an ionic compound, a demulsifier as well as a preparation method and application of the demulsifier. The preparation method of the ionic compound comprises the following steps: carrying out ring-opening reaction on glycerol triglycidyl ether and N, N-dibutyl ethanolamine to obtain a ring-opening product; and carrying out ionization reaction on the ring-opening product and halogenated hydrocarbon in a solvent A. The prepared ionic compound is used as a demulsifier for a crude oil emulsion, and has the characteristics of high demulsification efficiency, low demulsification temperature and high demulsification rate; in addition, the preparation method provided by the invention is simple in steps, low in raw material cost and suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of oil-water emulsion treatment, and in particular relates to an ionic compound, a demulsifier, and a preparation method and application thereof. Background Art

[0002] For most oil fields, water injection is an inevitable process. As a result, the production of crude oil emulsions with high water content is increasing. These emulsions cannot be simply regarded as a two-phase mixture of oil and water. Due to the presence of natural surfactants, this type of emulsion is very stable. The natural active substances in crude oil mainly include asphaltenes, resins, cyclohexane acids and solid particles (such as clay or wax). Among them, asphaltenes can be adsorbed on the oil-water interface to form a rigid interfacial film, which effectively wraps the water droplets and prevents their aggregation. Therefore, the stability of oil-water emulsions is a severe challenge in oil production, and this stability may cause many interferences to the operation of upstream separators (upper and lower separators) and the entire refining process. Therefore, the stability of oil-water emulsions poses a major challenge to the oil industry. Chemical demulsifiers are widely used because of their fast demulsification speed and high demulsification efficiency.

[0003] Chemical demulsification refers to the separation of oil and water in emulsions by adding various chemical agents and using chemical reactions. Chemical demulsifiers can replace natural emulsifiers adsorbed on the oil-water interface, reduce the viscoelasticity and strength of the oil-water interface film, promote droplet coalescence, and thus achieve oil-water separation. Commonly used chemical demulsifiers include polymer surfactants, nanoparticles and ionic liquids, such as ethylene oxide-propylene oxide (EO-PO) block copolymers, silicone polyethers, dendrimers, biodegradable polymer surfactants, and nanoparticle-based demulsifiers.

[0004] However, these demulsifiers have problems such as complex preparation process, high raw material cost, poor demulsification effect and potential pollution risk to the environment. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide an ionic compound, a demulsifier and a preparation method and application thereof, aiming to solve the problems of poor demulsification performance of demulsifiers, high cost of demulsifier raw materials, and potential environmental pollution in the prior art. The purpose of the present invention is achieved through the following technical solutions: An ionic compound with the following chemical formula: .

[0006] The ionic compound provided by the present invention is connected to halogenated hydrocarbons through the ring opening of glycerol triglycidyl ether to form a three-branched structure. This ionic compound has the characteristics of hydrophilic center and hydrophobic edge, and its hydrophobic part is composed of external carbon chains, which gives it hydrophobicity. At the same time, due to the presence of three long carbon chains, it has better dispersibility in the oil phase, and can interact more effectively with natural surfactants, thereby destroying the interfacial film, promoting the coalescence of water droplets, and realizing oil-water separation. In addition, the present invention is connected to halogenated hydrocarbons through the ring opening reaction of glycerol triglycidyl ether to prepare ionic compounds, and the synthesis step is simple and convenient. The ionic compound demulsifier prepared by the present invention can achieve rapid demulsification at a lower temperature, and can effectively reduce the tension of the oil-water interface.

[0007] The preparation method of the ionic compound comprises the following steps: subjecting glycerol triglycidyl ether and N,N-dibutylethanolamine to a ring-opening reaction to obtain a ring-opening product; subjecting the ring-opening product and a halogenated hydrocarbon to an ionization reaction in a solvent A to obtain an ionic compound.

[0008] Preferably, the molar ratio of glycerol triglycidyl ether to N,N-dibutylethanolamine is 1:3.

[0009] Preferably, the molar ratio of glycerol triglycidyl ether to halogenated hydrocarbon is 1:3.

[0010] Preferably, glycerol triglycidyl ether is purchased from MacLean Reagent Company, with epoxy equivalent: 143-154 g / equivalent, viscosity: 100-300 mPa·s, CAS number: G887780.

[0011] Preferably, the temperature of the ring-opening reaction is 110-130°C, and the time is 8-10 hours. Specifically, the temperature of the ring-opening reaction is 120°C, 122°C, 124°C, 126°C, 128°C, 130°C, or any value between 110-130°C; the time of the ring-opening reaction is 8h, 9h, 10h, or any value between 8-10h.

[0012] Preferably, the temperature of the ionization reaction is 60-70°C, and the time is 12-14h. Specifically, the temperature of the ionization reaction is 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, or any value between 60-70°C; the time of the ionization reaction is 12h, 13h, 14h, or any value between 12-14h.

[0013] The above reaction temperature is required to ensure that the reaction proceeds smoothly. Too low a reaction temperature will lead to incomplete reaction, and too high a reaction temperature will evaporate the solvent. The reaction time can be appropriately extended within a suitable range. Within the above range, the effect on the reaction is small.

[0014] Preferably, the halogenated hydrocarbon is at least one of dodecane bromide, hexadecane bromide, hexadecane chloride and octadecane bromide.

[0015] Preferably, solvent A is at least one of ethanol and xylene.

[0016] A demulsifier includes an ionic compound.

[0017] The application of the above demulsifier in demulsifying crude oil emulsion.

[0018] The application of the demulsifier in demulsifying crude oil emulsion comprises the following steps: firstly, dissolving the ionic compound in solvent B to obtain a solution, and then mixing the solution with the crude oil emulsion for demulsification. After demulsification, the demulsifier of the present invention has a clear oil-water interface, a low water content in the oil phase, a low required demulsification temperature, and a low demulsification cost.

[0019] Preferably, the mass percentage of the ionic compound in the solution is 0.2-1 wt %.

[0020] Preferably, solvent B is at least one of water, ethanol and xylene.

[0021] Preferably, the volume ratio of the solution to the crude oil emulsion is 1:(10-20).

[0022] Preferably, the demulsification temperature is 50-70°C and the time is 0.5-3 hours. More preferably, the demulsification time is 2-3 hours.

[0023] The preparation method of the ionic compound provided by the present invention has the advantages of simple synthesis steps, low required demulsification temperature and high demulsification efficiency. The use of the demulsifier is of great significance for the chemical demulsification problems of high demulsification cost, low demulsification efficiency and high required demulsification temperature of crude oil emulsion in the petroleum industry. Since it contains three long carbon chains, the demulsifier has better dispersibility in the oil phase and can generate stronger interaction force with natural surfactants, thereby changing the tension of the oil-water interface, promoting the aggregation of water droplets, and then achieving oil-water separation.

[0024] Compared with the prior art, the beneficial effects of the present invention include: The demulsifier provided by the present invention has high surface activity, good thermal stability, good dispersibility in the oil phase, is suitable for the treatment of petroleum crude oil emulsions, and has the characteristics of high demulsification efficiency, low demulsification temperature and fast demulsification rate; in addition, the preparation method provided by the present invention has simple steps and low raw material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the infrared spectrum of the ionic compound prepared in Example 1. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] Example 1 A method for preparing an ionic compound comprises the following steps: Glycerol triglycidyl ether (0.01 mol) and N,N-dibutylethanolamine (0.03 mol) were added to a three-necked flask and heated in an oil bath at 120° C. for 8 h to obtain a ring-opening product, the structural formula of which is shown in Formula I: (I), Then, the ring-opening product is cooled, and after the temperature is lowered to 65°C, 30 mL of ethanol is added, and then bromododecane (0.03 mol) is added, and the reaction is continued for 12 hours to obtain an ionized product. Finally, the ethanol is evaporated by vacuum distillation to obtain the final product, i.e., the ionic compound, whose structural formula is shown in Formula II: (II).

[0028] Figure 1 This is the infrared spectrum of the ionic compound prepared in Example 1, where 2925.53 cm -1 and 2854.18cm -1 The peaks at 1093.46 cm-1 correspond to the antisymmetric and symmetric stretching vibrations of -CH2-. -1 The peak at corresponds to the CN stretching vibration, which indicates the successful synthesis of the target product.

[0029] Example 2 Example 2 provides a method for preparing an ionic compound. Compared with Example 1, the only difference is that "octadecane bromide is used to replace dodecane bromide", and the other steps and conditions are the same as those in Example 1.

[0030] Example 3 Example 3 provides a method for preparing an ionic compound. Compared with Example 1, the only difference is that "the ring-opening product is cooled, the temperature is lowered to 100-110°C, and 30 mL of xylene is added", and the other steps and conditions are the same as those in Example 1.

[0031] Example 4 Example 4 provides a method for preparing an ionic compound. Compared with Example 1, the only difference is that "the time of the ring-opening reaction is increased from 8 hours to 12 hours", and the other steps and conditions are the same as those in Example 1.

[0032] Example 5 Example 5 provides a method for preparing an ionic compound. Compared with Example 1, the only difference is that "hexadecane chloride is used to replace dodecane bromide", and the other steps and conditions are the same as those in Example 1.

[0033] Test Section To avoid redundancy, the crude oil emulsions used in the following tests were prepared according to the following steps: 150 parts by weight of crude oil is added to 350 parts by weight of deionized water, stirred and mixed, heated to 60° C., and then stirred at a speed of 11000 r / min for 20 minutes. The stirring process is repeated one to three times until a stable oil-in-water emulsion, i.e., a crude oil emulsion, is obtained. To ensure the accuracy of the test, the crude oil emulsion that has been repeatedly stirred three times is tested in the present invention for more uniform mixing.

[0034] 1. The demulsification performance of the ionic compounds prepared in Examples 1 to 5 as demulsifiers in crude oil emulsion was compared and tested by using the commercial demulsifier PDB9429 as comparative example 1, RI-14A as comparative example 2, DI-18 as comparative example 3, and 1301 as comparative example 4. The specific steps are as follows: The ionic compounds prepared in Examples 1 to 5 were added to xylene / ethanol (75:25) to prepare solutions with a mass fraction of 1%, namely, experimental groups 1 to 5; the commercial demulsifier PDB9429 (purchased from BASF) was comparative example 1, RI-14A (purchased from BASF) was comparative example 2, DI-18 (purchased from BASF) was comparative example 3, and 1301 (purchased from BASF) was comparative example 4. The commercial demulsifiers in the comparative examples were added to xylene / ethanol (volume ratio of 75:25) to prepare solutions with a mass fraction of 1%, namely, comparative groups 1 to 4; The experimental groups 1-5 and the comparative groups 1-4 were added to the above crude oil emulsion at a volume ratio of 1:19, and then fully shaken and mixed, and then transferred to a 50°C water bath and allowed to stand for 2 hours. The dehydration rate was measured, and the results are shown in Table 1.

[0035] Table 1 Demulsification results of experimental groups 1 to 5 and comparative groups 1 to 4

[0036] Note: "Demulsifier (mg / L)" in the table refers to the concentration of demulsifier in crude oil emulsion.

[0037] As shown in Table 1, the demulsifiers prepared by Examples 1 to 5 all have very good demulsification performance, but due to the difference in preparation conditions, such as the changes in factors such as halogenated alkane types, solvent types and reaction time, there are differences in demulsification efficiency. For example, from the data of Example 1 and Example 2, appropriately shortening the length of the hydrophobic chain is conducive to improving the demulsification efficiency. In addition, the conditions of Example 3 and Example 4 are changed, so the resulting demulsification efficiency is also different. Compared with the commercial demulsifier in the comparison group, the demulsifier provided by the present invention shows a more excellent demulsification ability.

[0038] 2. Solutions of demulsifiers with different concentrations prepared in Example 1 were used to characterize the demulsification performance of demulsifiers with different concentrations in crude oil emulsions.

[0039] Different weight portions of the demulsifier prepared in Example 1 were added to xylene / ethanol (volume ratio of 75:25) to prepare demulsifier solutions with mass fractions of 0.2%, 0.4%, 0.6%, 0.8% and 1%, respectively. The obtained samples were recorded as experimental groups 7 to 11; the blank group was 0%, and the sample was recorded as experimental group 6.

[0040] 1 volume part of the above experimental groups 6 to 11 was added to 19 volume parts of crude oil emulsion and then fully shaken to mix evenly, then transferred to a 50°C water bath and allowed to stand for 2 hours, and the dehydration rate was measured. The results are shown in Table 2.

[0041] Table 2 Demulsification results of experimental groups 6 to 11

[0042] Note: "Demulsifier (mg / L)" in the table refers to the concentration of demulsifier in crude oil emulsion.

[0043] As shown in Table 2, the demulsifier provided by the present invention has good demulsification performance. A demulsification efficiency of 94.46% can be achieved with 200 mg / L of demulsifier. When the demulsifier concentration is 500 mg / L, the demulsification efficiency reaches 98.63%.

[0044] 3. Based on the demulsifier prepared in Example 1, experimental groups 12 to 14 were established in sequence to characterize the demulsification performance of the demulsifier at different temperatures and times.

[0045] The demulsifier prepared in Example 1 was added into xylene / ethanol (volume ratio of 75:25) to prepare a solution with a mass fraction of 1%.

[0046] 1 volume part of the above demulsifier was added to 19 volume parts of crude oil emulsion and then fully shaken to mix evenly, and then transferred to water baths set at different temperatures and allowed to stand for 2 hours. The dehydration rates were measured at 60 minutes, 90 minutes and 120 minutes. The results are shown in Table 3.

[0047] Table 3 Demulsification results of experimental groups 12 to 14

[0048] It can be seen from Table 3 that the demulsifier provided by the present invention can achieve a demulsification efficiency of 97.46% at 50°C for 60 minutes, a demulsification efficiency of 97.53% at 60°C for 60 minutes, and a demulsification efficiency of 98.92% at 70°C for 60 minutes.

[0049] In summary, the demulsifier of the present invention has the advantages of simple synthesis steps, low required demulsification temperature, fast demulsification rate and high demulsification efficiency. It is of great significance to solve the chemical demulsification problems of crude oil emulsion in the petroleum industry, such as high demulsification cost, low demulsification efficiency and high required demulsification temperature. Specifically, the three long carbon chains of the demulsifier make it have better dispersibility in the oil phase, and have stronger interaction with natural surfactants, so it is easy to penetrate the interface film, change the tension of the oil-water interface, promote the coalescence of water droplets, and thus achieve oil-water separation.

[0050] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An ionic compound, characterized in that Its chemical structure is as follows: 。 2. The method for preparing the ionic compound according to claim 1, characterized in that: The method comprises the following steps: carrying out a ring-opening reaction on glycerol triglycidyl ether and N,N-dibutylethanolamine to obtain a ring-opening product; carrying out an ionization reaction on the ring-opening product and a halogenated hydrocarbon in a solvent A to obtain the ionic compound.

3. The method for preparing the ionic compound according to claim 2, characterized in that: The molar ratio of glycerol triglycidyl ether to N,N-dibutylethanolamine is 1:3; The molar ratio of glycerol triglycidyl ether to halogenated hydrocarbon is 1:

3.

4. The method for preparing the ionic compound according to claim 2, characterized in that: The ring-opening reaction temperature is 110-130°C and the time is 8-10h; The temperature of the ionization reaction is 60-70° C. and the time is 12-14 hours.

5. The method for preparing the ionic compound according to any one of claims 2 to 4, characterized in that: The halogenated hydrocarbon is at least one of dodecane bromide, hexadecane bromide, hexadecane chloride and octadecane bromide; The solvent A is at least one of ethanol and xylene.

6. A demulsifier, characterized in that: Comprising the ionic compound according to claim 1.

7. Use of the demulsifier according to claim 6 in demulsifying crude oil emulsion.

8. The use according to claim 7, characterized in that: The method comprises the following steps: firstly dissolving the ionic compound in solvent B to obtain a solution, and then mixing the solution with crude oil emulsion to break the emulsion.

9. The use according to claim 8, characterized in that: The mass percentage of the ionic compound in the solution is 0.2-1wt%; The volume ratio of the solution to the crude oil emulsion is 1:(10-20).

10. The use according to claim 8, characterized in that: The solvent B is at least one of water, ethanol and xylene; The demulsification temperature is 50-70°C and the time is 0.5-3h.

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