Process for the preparation of superparamagnetic demulsifiers with high dewatering performance
By preparing a superparamagnetic demulsifier, silica is coated on the surface of iron oxide nanoparticles with a particle size of 5-20 nanometers and epoxy groups are introduced. The demulsifier reacts with hyperbranched polyamide and the resulting demulsifier can rapidly separate heavy oil-water emulsions under an external magnetic field, which solves the problem of low dehydration rate in the existing technology and achieves efficient separation of heavy oil-water emulsions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUIZHOU UNIV
- Filing Date
- 2023-09-21
- Publication Date
- 2026-07-24
AI Technical Summary
Conventional demulsifiers in the present technology have poor demulsification effect on heavy oil-water emulsions, long dehydration time, and low dehydration rate, which leads to problems such as pipeline and equipment corrosion, oil quality reduction and environmental pollution.
A superparamagnetic demulsifier was prepared using a specific method. By screening iron oxide nanoparticles of suitable particle size, coating their surface with silica and introducing epoxy groups, and finally reacting them with hyperbranched polyamide, a demulsifier with high dehydration performance was formed. Heavy oil-water emulsions were then rapidly separated under the assistance of an external magnetic field.
It achieves complete dehydration of heavy oil-water emulsions in a short time (90 seconds) under normal temperature conditions, with a dehydration rate of 99%, which is significantly better than existing demulsifiers, and provides clear water separation.
Smart Images
Figure CN117431090B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of petroleum-water emulsion demulsification technology, and particularly relates to a method for preparing a superparamagnetic demulsifier with high dehydration performance. Background Technology
[0002] Heavy oil, as a crucial component of petroleum resources, plays a pivotal role in the global energy transition and upgrading process. Currently, during the separation of heavy oil, the coexistence of water and natural surfactants (colloids, asphaltenes, and amphiphilic solid particles) in the heavy oil leads to the formation of extremely stable heavy oil-water emulsions. These emulsions can cause corrosion of pipelines and equipment, reduce oil quality, increase costs, and pollute the environment. Therefore, achieving efficient demulsification of heavy oil-water emulsions has significant practical application value in the industrial processes of heavy oil production.
[0003] Chemical demulsification is widely used for demulsifying heavy oil-water emulsions due to its advantages such as simple process, high demulsification efficiency, and low cost. The key to chemical demulsification lies in the demulsifying material. However, conventional demulsifiers in existing technologies are relatively ineffective for demulsifying heavy oil-water emulsions, resulting in long dehydration times and low dehydration rates. Summary of the Invention
[0004] This invention provides a method for preparing a superparamagnetic demulsifier with high dehydration performance. The resulting demulsifier can quickly and effectively achieve demulsification and separation of heavy oil-water emulsion systems, and has the characteristics of fast demulsification speed and high dehydration rate.
[0005] This invention proposes a method for preparing a superparamagnetic demulsifier with high dehydration performance, comprising the following steps:
[0006] (1) Add Fe3O4@SiO2 nanoparticles and tetraethoxysilane to a heterogeneous solution, stir, add ammonia, react first, disperse the product in ethanol, centrifuge, purify, and obtain Fe3O4@SiO2 microspheres.
[0007] The particle size of the iron oxide nanoparticles is 5–20 nm.
[0008] (2) The above Fe3O4@SiO2 microspheres were ultrasonically dispersed in anhydrous ethanol, and silane coupling agent KH-550 was added. The second reaction was carried out under water bath conditions at 80℃. After the second reaction was completed, the reaction product Fe3O4@SiO2-KH550 microspheres were collected with a magnet, washed, and vacuum dried to obtain dried Fe3O4@SiO2-KH550 microspheres.
[0009] (3) Under a water bath at 70℃, the dried Fe3O4@SiO2-KH550 microspheres were dissolved in methanol, hyperbranched polyamide was added, stirred, cooled, and magnetically separated to obtain a superparamagnetic demulsifier.
[0010] Furthermore, in step (1), the particle size of the iron oxide nanoparticles is 5-10 nm.
[0011] Furthermore, in step (1), the ratio of the amount of iron oxide nanoparticles, tetraethoxysilane, heterogeneous solution and ammonia is 1-5 mg: 80-120 μL: 20-50 mL: 80-120 mL.
[0012] Further, in step (1), the heterogeneous solution is prepared from raw materials comprising the following parts by weight: 20-30 parts of cyclohexane, 4-5 parts of hexanol, 5-8 parts of nonionic surfactant, and 0.5-2 parts of deionized water.
[0013] Further, in step (1), the nonionic surfactant is 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol.
[0014] Furthermore, in step (2), the ratio of Fe3O4@SiO2 microspheres, anhydrous ethanol, and silane coupling agent KH-550 is 0.1-1g, 100-150mL, and 1-3mL, respectively.
[0015] Furthermore, in step (3), the molar ratio of the dried Fe3O4@SiO2-KH550 microspheres to the hyperbranched polyamide is 1:(1-5).
[0016] Furthermore, in step (3), the ratio of dried Fe3O4@SiO2-KH550 microspheres to methanol is 0.1-2g: 20-40mL.
[0017] The present invention also proposes a superparamagnetic demulsifier with high dehydration performance prepared by any of the above-described preparation methods.
[0018] The present invention also proposes the application of any of the superparamagnetic demulsifiers with high dehydration performance described above in emulsion demulsification, wherein the emulsion is a heavy oil-in-water emulsion stabilized by interfacially active asphaltenes.
[0019] This invention has the following advantages:
[0020] The method for preparing a superparamagnetic demulsifier with high dehydration performance proposed in this invention involves a specific process. First, suitable iron oxide nanoparticles of appropriate size are screened. Then, tetraethyl orthosilicate is hydrolyzed in a specific solution to in-situ coat the surface of the iron oxide with silica. Next, a rapid reaction is carried out using silanol groups and a silane coupling agent to further introduce epoxy groups. Finally, the epoxy groups undergo a ring-opening reaction with the surface amino groups of hyperbranched polyamide, thereby attaching the hyperbranched polyamide to the Fe3O4@SiO2-KH550 surface to obtain a superparamagnetic demulsifier with high dehydration performance. The obtained superparamagnetic demulsifier, for heavy water-in-oil emulsions that are difficult to demulsify, can completely remove 99% of the water from the system within a short time (90s) at room temperature under the assistance of an external magnetic field. The dehydration effect is excellent, and the removed water is clear, significantly superior to existing superparamagnetic demulsifiers. Attached Figure Description
[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:
[0022] Figure 1 This is a scanning electron microscope (SEM) image of the demulsifier obtained in Example 1.
[0023] Figure 2 The image shows the effect of the demulsifier obtained in Example 1 after demulsification. Detailed Implementation
[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.
[0025] An embodiment of the present invention provides a method for preparing a superparamagnetic demulsifier with high dehydration performance, comprising the following steps:
[0026] (1) Add Fe3O4 nanoparticles and tetraethoxysilane to a heterogeneous solution, stir, add ammonia, perform the first reaction, disperse the resulting product in ethanol, centrifuge, purify, and obtain Fe3O4@SiO2 microspheres; wherein, the particle size of the Fe3O4 nanoparticles is 5-20 nm.
[0027] (2) The above Fe3O4@SiO2 microspheres were ultrasonically dispersed in anhydrous ethanol, and silane coupling agent KH-550 was added. The second reaction was carried out under water bath conditions at 80℃. After the second reaction was completed, the reaction product Fe3O4@SiO2-KH550 microspheres were collected with a magnet, washed, and vacuum dried to obtain dried Fe3O4@SiO2-KH550 microspheres.
[0028] (3) Under a water bath at 70℃, the dried Fe3O4@SiO2-KH550 microspheres were dissolved in methanol, hyperbranched polyamide was added, stirred, cooled, and magnetically separated to obtain superparamagnetic demulsifiers (S-MNPs).
[0029] The method for preparing a superparamagnetic demulsifier with high dehydration performance proposed in this invention involves a specific process. First, suitable iron oxide nanoparticles of appropriate size are screened. Then, tetraethyl orthosilicate is hydrolyzed in a specific solution to in-situ coat the surface of the iron oxide with silica. Next, a rapid reaction is carried out using silanol groups and a silane coupling agent to further introduce epoxy groups. Finally, the epoxy groups undergo a ring-opening reaction with the surface amino groups of hyperbranched polyamide, thereby attaching the hyperbranched polyamide to the Fe3O4@SiO2-KH550 surface to obtain a superparamagnetic demulsifier with high dehydration performance. The obtained superparamagnetic demulsifier, for heavy water-in-oil emulsions that are difficult to demulsify, can completely remove 99% of the water from the system within a short time (90s) at room temperature under the assistance of an external magnetic field. The dehydration effect is excellent, and the removed water is clear, significantly superior to existing superparamagnetic demulsifiers.
[0030] In step (1) of this embodiment, Fe3O4 nanoparticles of suitable size are screened, and then ammonia is added to a mixed solution consisting of Fe3O4 nanoparticles, tetraethoxysilane and a heterogeneous solution containing a nonionic surfactant to initiate the hydrolysis of tetraethoxysilane (TEOS) and generate Fe3O4@SiO2 microspheres.
[0031] Preferably, in step (1), the Fe3O4 nanoparticles have a particle size of 5–10 nm. More preferably, the Fe3O4 nanoparticles have a particle size of 5 nm. The inventors of this application discovered during their research that the particle size of Fe3O4 nanoparticles has a significant impact on the dehydration effect of the final superparamagnetic demulsifier. When the Fe3O4 nanoparticle size is too large, the diffusion rate of the demulsifier nanoparticles to the oil-water interface is slower under the action of an external magnetic field, thus increasing the interaction time between the demulsifier nanoparticles and the interfacial active asphaltene (IAA) of the stable emulsion, ultimately leading to a slower demulsification rate. Smaller size, on the other hand, is beneficial for improving the dispersibility of the demulsifier nanoparticles in the emulsion system, promoting rapid movement of the demulsifier nanoparticles to the oil-water interface, and accelerating the demulsification speed.
[0032] Furthermore, in step (1), the preparation method of the Fe3O4 nanoparticles can be carried out with reference to the literature [Yiyang Li, et al., Local magnetic spin mismatch promoting photocatalytic overall watersplitting with exceptional solar-to-hydrogen efficiency, EnergyEnviron.Sci.2022].
[0033] Further, in step (1), the ratio of Fe3O4 nanoparticles, tetraethoxysilane (TEOS), heterogeneous solution, and ammonia is 1–5 mg: 80–120 μL: 20–50 mL: 80–120 mL. The mass fraction of ammonia is 30 wt%. Preferably, in step (1), the ratio of Fe3O4 nanoparticles, tetraethoxysilane (TEOS), heterogeneous solution, and ammonia is 2 mg: 100 μL: 30–40 mL: 100 mL.
[0034] Specifically, in step (1), the heterogeneous solution is prepared from raw materials comprising the following parts by weight: 20-30 parts cyclohexane, 4-5 parts hexanol, 5-8 parts nonionic surfactant, and 0.5-2 parts deionized water. Preferably, in step (1), the heterogeneous solution is prepared from raw materials comprising the following parts by weight: 24 parts cyclohexane, 4.8 parts hexanol, 6 parts nonionic surfactant, and 1 part deionized water. More preferably, in step (1), the heterogeneous solution is prepared from a mixture comprising the following raw materials: 24 mL cyclohexane, 4.8 mL hexanol, 6 mL nonionic surfactant, and 1 mL deionized water.
[0035] The nonionic surfactant is 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol (Triton X-100). In this embodiment of the invention, because the nonionic surfactant contains hydroxyl groups, it can form strong hydrogen bonds with water molecules in the system, thereby accelerating the reaction. Therefore, its effect is significantly better than other surfactants.
[0036] Further, in step (1), the centrifugation speed is 10000-15000 rpm, and the centrifugation time is 2-20 min. Preferably, in step (1), the centrifugation speed is 14000 rpm, and the centrifugation time is 10 min.
[0037] Further, in step (1), the first reaction takes 20 to 30 hours. Preferably, in step (1), the first reaction takes 24 hours. The temperature of the first reaction is room temperature.
[0038] Further, in step (1), the stirring time is 1 to 10 hours. Preferably, in step (1), the stirring time is 6 hours.
[0039] In step (2) of this embodiment, since the Fe3O4@SiO2 microspheres contain silanol groups on their surface, they can react rapidly with silane coupling agents, thereby further introducing epoxy groups, which is beneficial for subsequent reactions.
[0040] Further, in step (2), the ratio of Fe3O4@SiO2 microspheres, anhydrous ethanol, and silane coupling agent KH-550 is 0.1–1 g, 100–150 mL, and 1–3 mL. Preferably, in step (2), the ratio of Fe3O4@SiO2 microspheres, anhydrous ethanol, and coupling agent is 0.6 g, 120 mL, and 1.5 mL.
[0041] Specifically, in step (2), the second reaction takes 5 to 10 hours. Preferably, in step (2), the second reaction takes 8 hours.
[0042] Specifically, in step (2), the cleaning is performed using ethanol and distilled water.
[0043] Specifically, in step (2), the drying is a vacuum drying process at a temperature of 50°C for 8 hours.
[0044] In step (3) of this embodiment, the Fe3O4@SiO2-KH550 surface contains epoxy groups, which can undergo ring-opening reaction with the surface amino groups of the hyperbranched polyamide, thereby attaching the hyperbranched polyamide to the Fe3O4@SiO2-KH550 surface.
[0045] Further, in step (3), the ratio of dried Fe3O4@SiO2-KH550 microspheres to methanol is 0.1-2 g: 20-40 mL. Preferably, in step (3), the ratio of dried Fe3O4@SiO2-KH550 microspheres to methanol is 1 g: 30 mL.
[0046] Furthermore, in step (3), the stirring time is 1 to 10 hours. In step (3), the stirring time is 5 hours.
[0047] Further, in step (3), the molar ratio of the dried Fe3O4@SiO2-KH550 microspheres to the hyperbranched polyamide is 1:(1-5); preferably, the molar ratio of the dried Fe3O4@SiO2-KH550 microspheres to the hyperbranched polyamide is 1:2. It should be noted that in step (3), the molecular weight of the hyperbranched polyamide is 6000-8000.
[0048] An embodiment of the present invention also proposes a superparamagnetic demulsifier with high dehydration performance prepared by any of the preparation methods described above.
[0049] An embodiment of the present invention also proposes the application of the aforementioned superparamagnetic demulsifier with high dehydration performance in emulsion demulsification. Specifically, the emulsion can be a heavy water-in-oil (W / O) emulsion stabilized by interfacially active asphaltenes (IAA). The asphaltenes comprise two parts: residual asphaltenes and interfacially active asphaltenes. This application is applicable to heavy water-in-oil (W / O) emulsions with extremely stable emulsion properties.
[0050] The present invention will now be described in detail with reference to the accompanying drawings.
[0051] Example 1 A method for preparing a superparamagnetic demulsifier with high dehydration performance includes the following steps:
[0052] Fe3O4 nanoparticles (2 mg, 5 nm) and 100 μL of tetraethoxysilane (TEOS) were added to a heterogeneous solution containing cyclohexane (24 mL), hexanol (4.8 mL), Triton X-100 (a nonionic surfactant, 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol) (6 mL), and deionized water (1 mL). After stirring for 6 hours, ammonia (30 wt%) (100 mL) was added to initiate the hydrolysis of TEOS. The first reaction was continued at room temperature for 24 hours with stirring. The product was thoroughly dispersed in ethanol and further purified by centrifugation (14000 rpm, 10 min) to obtain Fe3O4@SiO2 microspheres.
[0053] 0.6 g of Fe3O4@SiO2 microspheres obtained in the previous step were weighed and ultrasonically dispersed in 120 mL of anhydrous ethanol. Then, 1.5 mL of coupling agent KH-550 was added, and the reaction mixture was mechanically stirred and refluxed in a water bath at 80 °C for 8 h. After the reaction was completed, the Fe3O4@SiO2-KH550 microspheres were collected with a magnet, washed repeatedly with ethanol and distilled water, and finally, the product was vacuum dried at 50 °C for 8 h to obtain dried Fe3O4@SiO2-KH550 microspheres.
[0054] Under water bath temperature of 70℃, 1g of the dried Fe3O4@SiO2-KH550 microspheres were dissolved in 30mL of methanol in a 100mL three-necked flask, and hyperbranched polyamide (molecular weight of 6000-8000) was added. The molar ratio of the dried Fe3O4@SiO2-KH550 microspheres to the hyperbranched polyamide was 1:2. After stirring for 5 hours, the mixture was cooled and magnetically separated to obtain superparamagnetic demulsifiers (S-MNPs).
[0055] The scanning electron microscope (SEM) image of the demulsifier with the best demulsification effect is shown below. Figure 1 As shown in the figure, the superparamagnetic demulsifier nanoparticles prepared using 5nm Fe3O4 are beneficial for the good dispersion of the demulsifier nanoparticles in the emulsion. Under the action of an external magnetic field, they are conducive to rapid movement to the oil-water interface and interaction with IAA, thereby rapidly achieving emulsion demulsification.
[0056] Examples 2-5 A method for preparing a superparamagnetic demulsifier with high dehydration performance
[0057] Same as Example 1, except that the Fe3O4 nanoparticles are 8nm, 10nm, 15nm, and 20nm respectively.
[0058] Comparative Examples 1-2 A method for preparing a superparamagnetic demulsifier with high dehydration performance
[0059] Same as Example 1, except that the Fe3O4 nanoparticles are 25nm and 30nm respectively.
[0060] Comparative Examples 3-11 A method for preparing a superparamagnetic demulsifier with high dehydration performance
[0061] Similar to Example 1, except that Triton X-100 is replaced with alkylphenol polyoxyethylene ether NP, fatty alcohol polyoxyethylene ether AEO, nonylphenol polyoxyethylene ether, isomeric alcohol polyoxyethylene ether IT 1309, sorbitan sorbate Span 85, stearate octadecyl alcohol ester, anionic (hexadecyltrimethylammonium chloride), anionic (sodium dodecylbenzenesulfonate), and cationic (octadecyldimethylbenzylammonium chloride).
[0062] Experimental Example 1 Demulsification experiments were conducted to evaluate the demulsification performance of S-MNPs.
[0063] First, an interfacially active asphaltene (IAA)-stabilized heavy water-in-oil (W / O) emulsion was prepared according to the method reported in the literature (Jun Ma et al. A novel oxygen-containing demulsifier for efficient breaking of water-in-oil emulsions. Chemical Engineering Journal, 2020, 385, 123826). 1.0 g of IAA was accurately weighed using an analytical balance and dissolved in 100 mL of toluene. The solution was then ultrasonically dissolved for 45 min in an ultrasonic cleaner. The resulting IAA-toluene solution was used as the oil phase, and 10 mL of deionized water was used as the aqueous phase. The aqueous phase was added dropwise to the oil phase using a high-speed homogenizer at 15000 rpm. After emulsification for 5 min, the mixture was allowed to stand for 12 h until the oil phase and emulsion phase separated, thus obtaining the IAA-stabilized heavy water-in-oil emulsion.
[0064] Take several stoppered graduated cylinders and add the heavy water-in-oil emulsion with a water content of 10% prepared above to each cylinder. Then, add 300 ppm of the superparamagnetic demulsifier S-MNPs prepared in the examples and comparative examples. After shaking the stoppered graduated cylinders by hand for 2 minutes, place the stoppered graduated cylinders on a magnet at room temperature and observe the dehydration of the emulsion. At different demulsification times, the dehydration rate of S-MNPs is calculated according to formula (1).
[0065] Among them, the actual photos of the demulsifier obtained in Example 1 after demulsification are as follows: Figure 2 As shown, the left side represents the initial emulsion state, and the right side represents the demulsification effect of S-MNPs.
[0066] Dehydration rate = amount of water removed / initial amount of water in the emulsion, formula (1); where the amount of water is measured by volume in mL.
[0067] Table 1. Demulsification effect of S-MNPs in IAA-stabilized heavy water-in-oil emulsions
[0068]
[0069]
[0070] Based on the data in the table, the experimental results are analyzed as follows: The dehydration rate in Table 1 shows that the superparamagnetic demulsifier nanoparticles (S-MNPs) prepared using iron oxide with a particle size of 5-20 nm exhibit highly efficient demulsification performance. Furthermore, in the preparation of S-MNPs, the demulsifier nanoparticles obtained using Triton X-100 (a nonionic surfactant 4-(1,1,3,3-tetramethylbutylphenyl-polyethylene glycol) showed better demulsification effects than those obtained using other surfactants.
[0071] The above are merely preferred embodiments of the present invention and are 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 within the protection scope of the present invention.
Claims
1. The application of a superparamagnetic demulsifier with high dehydration performance in emulsion demulsification, characterized in that, The emulsion is a heavy water-in-oil emulsion with interfacial active asphaltene stability. The preparation method of the superparamagnetic demulsifier with high dehydration performance includes the following steps: (1) Add Fe3O4@SiO2 nanoparticles and tetraethoxysilane to a heterogeneous solution, stir, add ammonia, perform the first reaction, disperse the resulting product in ethanol, centrifuge, purify, and obtain Fe3O4@SiO2 microspheres; wherein the particle size of the Fe3O4 nanoparticles is 5 ~ 20 nm. The ratio of iron oxide nanoparticles, tetraethoxysilane, heterogeneous solution, and ammonia is 1~5 mg: 80~120 μL: 20~50 mL: 80~120 mL; The heterogeneous solution is prepared from the following raw materials in parts by weight: 20-30 parts cyclohexane, 4-5 parts hexanol, 5-8 parts nonionic surfactant, and 0.5-2 parts deionized water; The nonionic surfactant is 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol; (2) The above Fe3O4@SiO2 microspheres were ultrasonically dispersed in anhydrous ethanol, and silane coupling agent KH-550 was added. The second reaction was carried out under water bath conditions at 80℃. After the second reaction was completed, the reaction product Fe3O4@SiO2-KH550 microspheres were collected with a magnet, washed, and vacuum dried to obtain dried Fe3O4@SiO2-KH550 microspheres. (3) Under a water bath at 70℃, the dried Fe3O4@SiO2-KH550 microspheres were dispersed in methanol, hyperbranched polyamide was added, stirred, cooled, and magnetically separated to obtain a superparamagnetic demulsifier.
2. The application according to claim 1, characterized in that, In step (1), the particle size of the iron oxide nanoparticles is 5 ~ 10 nm.
3. The application according to claim 1, characterized in that, In step (2), the ratio of Fe3O4@SiO2 microspheres, anhydrous ethanol, and silane coupling agent KH-550 is 0.1~1 g, 100~150 mL, and 1~3 mL, respectively.
4. The application according to claim 1, characterized in that, In step (3), the ratio of dried Fe3O4@SiO2-KH550 microspheres to methanol is 0.1~2 g: 20~40 mL.