Interconvertible portable multiphase oil-water separation experimental device

Abstract

A mutually convertible portable multiphase oil-water separation experimental device is characterized in that a first interface is arranged at the lower part of a lower separation shell, a second interface is arranged at the upper end of the other side opposite to the first interface, an upper port of the lower separation shell is an inclined port, and an upper separation shell is arranged on the upper port of the lower separation shell in a matched manner; a lower filter plate is arranged at an upper port of the lower separation shell, an upper filter plate is arranged at a lower port of the upper separation shell, an oil-water separation composite membrane is arranged between the upper filter plate and the lower filter plate, the upper surface of the oil-water separation composite membrane is a hydrophobic surface, the lower surface of the oil-water separation composite membrane is a hydrophilic surface, or the upper surface and the lower surface of the oil-water separation composite membrane are both hydrophilic surfaces; and a third interface is arranged at the upper end of the upper separation shell. According to the oil-water separation device, the separation requirements of light oil-water and heavy oil-water systems are met through forward and reverse installation switching of the oil-water separation composite membrane or forward or reverse placement switching of the whole device, the limitation that a traditional device can only separate a single oil phase is thoroughly solved, and the oil-water separation device has the advantages of being simple in structure and convenient to operate.

Description

Technical Field

[0001] This invention belongs to the technical field of oil-water separation equipment, specifically relating to a portable multiphase oil-water separation experimental device that can be converted between different phases. Background Technology

[0002] With the continuous advancement of global industrialization and urbanization, the scale of industries such as oil extraction, refining and processing, machinery manufacturing, and food production is constantly expanding, leading to a significant increase in the discharge of oily wastewater. This has become a key issue threatening the balance of aquatic ecosystems and restricting the green development of these industries. This type of oily wastewater is complex and diverse, containing not only oil phases of different properties (such as light oil with a density less than water, heavy oil with a density greater than water, and mixed oil phases of light and heavy oil), but also, in some cases, the addition of surfactants, alkaline substances, or oil emulsification to form highly stable and difficult-to-separate oil-water systems, posing a severe challenge to traditional treatment technologies.

[0003] Currently, oil-water separation devices have formed multiple technical routes. For example, the technical solution based on solid particle adsorption-cyclone separation disclosed in CN 121177804 A achieves separation by forming an adhesion between special solid particles and the oil phase, which solves the problem of non-recyclable separation medium in traditional air flotation. However, this device relies on the particle feeding and recovery system, has a relatively complex structure, and is not suitable for separating light and heavy oil mixtures. The multi-unit series / parallel separation system proposed in CN 121177805 A can switch the separation path through valve control to meet the needs of different processing scales. However, the system consists of multiple separation units, buffer tanks, membrane filters and other components, making it bulky, not portable, and difficult to adapt to mobile scenarios such as on-site emergency treatment and experimental research.

[0004] In addition, existing technologies have significant functional limitations: most separation devices can only handle a single type of oil phase (either light oil-water separation or heavy oil-water separation), lacking compatibility with light oil, heavy oil, and mixed light-heavy oil-water systems. Different equipment or core components need to be replaced to complete separation operations under various working conditions, making operation cumbersome and inefficient. At the same time, some devices adopt complex structural designs to improve separation performance, further reducing the portability and practicality of the equipment, and failing to meet the needs of outdoor emergency response, miniaturized laboratory experiments, and other scenarios for equipment flexibility and multifunctionality.

[0005] Therefore, developing a device that is simple in structure, highly portable, and capable of converting and separating light oil-water, heavy oil-water, and mixed light-heavy oil-water systems has become an urgent need to solve the current pain points in oily wastewater treatment and expand the application scenarios of oil-water separation technology. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a portable multiphase oil-water separation experimental device with simple structure and interchangeable upright and inverted bidirectional cooperative working modes.

[0007] The technical solution adopted to solve the above technical problems is: a portable multiphase oil-water separation experimental device that can be converted between each other. The lower part of the lower separation shell is provided with a first interface, and the upper end of the opposite side of the first interface is provided with a second interface. The upper port of the lower separation shell is an inclined port. An upper separation shell is matched and provided on the upper port of the lower separation shell. A lower filter plate is provided at the upper port of the lower separation shell, and an upper filter plate is provided at the lower port of the upper separation shell. An oil-water separation composite membrane is provided between the upper filter plate and the lower filter plate. The oil-water separation composite membrane has a hydrophobic upper surface and a hydrophilic lower surface, or both surfaces are hydrophilic. A third interface is provided at the upper end of the upper separation shell.

[0008] As a preferred technical solution, a flexible heating film is provided on the outer surface of the lower separation shell.

[0009] As a preferred technical solution, the flexible heating film is a graphene flexible electrothermal film.

[0010] As a preferred technical solution, the tilt angle of the tilted opening is 30° to 60°.

[0011] As a preferred technical solution, the water contact angle of the hydrophilic surface is 0° to 40° and the underwater oil contact angle is 140° to 170°; the water contact angle of the hydrophobic surface is 110° to 170° and the oil contact angle is 0° to 20°.

[0012] As a preferred technical solution, the oil-water separation composite membrane is composed of a polyvinylidene fluoride and polydopamine composite hydrophilic layer, a metal mesh layer, and a cerium oxide hydrophobic layer in sequence. The metal mesh layer is made of copper, titanium, or stainless steel, and has a mesh size of 100 to 300 mesh.

[0013] As a preferred technical solution, the oil-water separation composite membrane is composed of a polydopamine hydrophilic layer, a cotton cloth layer, and a polyvinylidene fluoride hydrophobic layer in sequence.

[0014] As a preferred technical solution, the oil-water separation composite membrane is composed of a polyvinylidene fluoride and polydopamine composite hydrophilic layer and a metal mesh layer in sequence. The metal mesh layer is made of copper, titanium or stainless steel and has a mesh size of 100 to 300.

[0015] As a preferred technical solution, the oil-water separation composite membrane is composed of a polydopamine hydrophilic layer and a cotton cloth layer connected in sequence.

[0016] This invention also provides a method for preparing an oil-water separation composite membrane:

[0017] Step 1. Take a 300-mesh copper mesh as a substrate and prepare copper oxide nanoneedles on its surface;

[0018] The method for preparing copper oxide nanoneedles is as follows:

[0019] The copper mesh was immersed in dilute hydrochloric acid for 10 min, and then ultrasonicated with anhydrous ethanol and deionized water for 10-15 min respectively. This process was repeated 3 times to clean the oxide impurities and organic contaminants on the surface of the copper mesh. The copper mesh was then vacuum dried at 60-80℃ for 12 h to complete the pretreatment of the copper mesh.

[0020] Sodium hydroxide flakes were added to deionized water and stirred for 10-20 min. After the beaker cooled, potassium persulfate powder was added and stirred together for another 10-20 min to prepare a precursor solution. The mass ratio of sodium hydroxide to potassium persulfate was 3-4:1. The pretreated copper mesh was then placed in the precursor solution and reacted at room temperature for 15 min to grow copper oxide nanoneedles on the surface of the copper mesh. The surface of the copper mesh was then repeatedly rinsed with deionized water to remove residual liquid and impurities. The copper mesh with grown copper oxide nanoneedles was then placed in a vacuum drying oven and dried at 60°C for 3 h to obtain a blue product attached to the copper mesh.

[0021] The dried copper mesh was placed in a muffle furnace and calcined at 130-150℃ for 50 min to obtain a black product adhering to the copper mesh.

[0022] Step 2. Add polyvinylidene fluoride powder and polyvinylpyrrolidone powder to N,N-dimethylformamide solvent at a mass ratio of 2-3:1:25-30. Stir vigorously at 65℃-75℃ for 5 hours to form a transparent solution. Use an air pump and spray gun to evenly spray the transparent solution onto the surface of the copper mesh. Transfer the copper mesh coated with polyvinylidene fluoride and polyvinylpyrrolidone to a deionized water coagulation bath at 25℃ and let it stand for a period of time to allow polyvinylpyrrolidone to precipitate from polyvinylidene fluoride and form a porous polyvinylidene fluoride membrane structure. Take out the copper mesh membrane structure and dry it at 60℃ for 6 hours to obtain a copper mesh coated with polyvinylidene fluoride.

[0023] Step 3. Add tris(hydroxymethyl)aminomethane to deionized water, then adjust the pH of the solution to 8-8.5 with 0.1 mol / L HCl, add dopamine hydrochloride, and when the solution begins to change color, add a copper mesh coated with polyvinylidene fluoride and soak for 12 hours to allow polydopamine to deposit onto the polyvinylidene fluoride for hydrophilic modification. Remove excess polydopamine with deionized water. The mass ratio of tris(hydroxymethyl)aminomethane, dopamine hydrochloride and water is 6-7:7-8:5000. Then dry at 40-60℃ for 6 hours to obtain a hydrophilic copper mesh.

[0024] Step 4. Prepare a hydrophobic spraying solution. Spray the hydrophobic spraying solution onto one side of the copper mesh prepared in step 3, and dry it in a vacuum drying oven at 60°C for 2 hours to obtain a hydrophobic side surface, thus completing the preparation of the oil-water separation composite membrane.

[0025] The method for preparing the hydrophobic spraying solution is as follows: weigh cerium oxide particles and octadecylamine particles, add them to anhydrous ethanol and ultrasonically disperse for 20 min, then add epoxy resin and curing agent, mix the two solutions and heat and stir at room temperature until a uniform solution is formed as the spraying solution. The mass ratio of cerium oxide, octadecylamine and anhydrous ethanol is 2:1:50-55, and the mass ratio of epoxy resin to curing agent is 3-4:1.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. This invention allows for rapid adaptation to the separation needs of light oil-water and heavy oil-water systems by switching between the forward and reverse installation of the oil-water separation composite membrane, or by switching the overall device to be upright or inverted, without replacing core components. This completely solves the limitation of traditional devices that can only separate a single oil phase. Combined with the graphene flexible electrothermal film on the outer surface of the lower separation shell, precise heating is possible during heavy oil separation, significantly improving the fluidity of heavy oil and effectively avoiding separation blockage and low efficiency caused by high-viscosity heavy oil. It is particularly suitable for low-temperature environments or complex heavy oil systems.

[0028] 2. The oil-water separation composite membrane of this invention possesses both hydrophilic and hydrophobic functions. The water contact angle on the hydrophilic side is controlled between 0° and 40°, and the underwater oil contact angle reaches 140° to 170°. On the hydrophobic side, the water contact angle is 110° to 170°, and the oil contact angle is only 0° to 20°. This enables highly efficient selective permeation of the oil and water phases, resulting in high purity of both the oil and water phases after separation. Furthermore, the composite membrane offers various support structures, including metal mesh layers or cotton cloth layers, combined with composite coatings such as polyvinylidene fluoride and polydopamine. This not only enhances the membrane's structural strength and durability but also optimizes separation permeability, ensuring that separation efficiency does not decrease during long-term use and exhibiting outstanding stability.

[0029] 3. This invention adopts a split upper and lower shell structure, which is compact, easy to assemble and disassemble, and convenient to carry and transport. It can be flexibly applied to outdoor emergency situations, mobile experiments, and other scenarios lacking fixed equipment. The upper port of the lower separation shell is designed with a 30° to 60° inclined opening. Compared with the traditional flat opening structure, this design creates a directional flow-guiding slope, guiding the separated oil phase to quickly converge to the corresponding interface, reducing oil phase residue and loss. It also optimizes the contact path between the oil-water mixture and the separation membrane, avoiding fluid dead zones and turbulence, and improving the separation rate. Simultaneously, the inclined opening perfectly adapts to both upright and inverted bidirectional working modes, ensuring smooth oil discharge under both conditions and enhancing structural compatibility. Furthermore, each interface is equipped with a valve, which can precisely control the inflow and outflow rhythm, further reducing operational difficulty.

[0030] 4. The inclined surface design of the present invention has no obvious dead corners for liquid accumulation, which can reduce the adhesion of oil stains. Cleaning can be completed with just a simple rinse. Compared with the repeated wiping of the traditional flat structure, the maintenance efficiency is greatly improved and the service life of the device is extended. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the portable multiphase oil-water separation experimental device of the present invention, which can be converted into one another.

[0032] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0033] Figure 3 This is a schematic diagram of the light oil separation structure in Embodiment 1 of the present invention.

[0034] Figure 4 This is a schematic diagram of the heavy oil separation structure in Embodiment 1 of the present invention.

[0035] Figure 5 This is a separation flux diagram of the oil-water separation composite membrane in Embodiment 1 of the present invention.

[0036] Figure 6 This is a diagram showing the separation efficiency of the present invention.

[0037] The components include: upper separation shell 1, lower separation shell 2, upper end cover 3, lower end cover 4, first interface 5, second interface 6, third interface 7, flexible heating membrane 8, upper filter plate 9, lower filter plate 10, and oil-water separation composite membrane 11. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0039] Example 1

[0040] exist Figure 1 , 2In this embodiment, the portable multiphase oil-water separation experimental device that can be converted between each other has a first interface 5 at the lower part of the lower separation shell 2 and a second interface 6 at the upper end of the opposite side of the first interface 5. The upper port of the lower separation shell 2 is an inclined port with an inclination angle of 45°. An upper separation shell 1 is connected to the upper port of the lower separation shell 2 via a flange. A lower filter plate 10 is fixedly installed at the upper port of the lower separation shell 2. The filter hole diameter of the lower filter plate 10 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. The upper separation shell 1... An upper filter plate 9 is fixedly installed at the lower port. The filter hole diameter of the upper filter plate 9 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. An oil-water separation composite membrane 11 is provided between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 has a hydrophobic upper surface and a hydrophilic lower surface. The water contact angle of the hydrophilic surface is 0°~40°, and the underwater oil contact angle is 140°~170°. The water contact angle of the hydrophobic surface is 110°~170°, and the oil contact angle is 0°~20°. A third interface 7 is provided at the upper end of the upper separation shell 1. Valves are installed on the first interface 5, the second interface 6, and the third interface 7.

[0041] In this embodiment, the lower separation shell 2 is a lower separation cylinder with a lower end cap 4 threadedly connected to its lower port. A flexible heating film 8, which is a graphene flexible electrothermal film, is provided on the outer surface of the lower separation shell 2. This film is used for heating during the heavy oil separation process to improve the fluidity of the heavy oil. The upper separation shell 1 is an upper separation cylinder with an upper end cap 3 threadedly connected to its upper port.

[0042] The oil-water separation composite membrane 11 in this embodiment is composed of a polyvinylidene fluoride and polydopamine composite hydrophilic layer, a metal mesh layer, and a cerium oxide hydrophobic layer in sequence. The metal mesh layer is made of copper, titanium, or stainless steel, and has a mesh size of 100 to 300 mesh.

[0043] The preparation method of the oil-water separation composite membrane 11 in this embodiment is as follows:

[0044] Step 1. Take a 300-mesh copper mesh as a substrate and prepare copper oxide nanoneedles on its surface;

[0045] The method for preparing copper oxide nanoneedles is as follows:

[0046] The copper mesh was immersed in dilute hydrochloric acid for 10 min, and then ultrasonicated with anhydrous ethanol and deionized water for 10-15 min respectively. This process was repeated 3 times to clean the oxide impurities and organic contaminants on the surface of the copper mesh. The copper mesh was then vacuum dried at 60-80℃ for 12 h to complete the pretreatment of the copper mesh.

[0047] Sodium hydroxide flakes were added to deionized water and stirred for 10-20 min. After the beaker cooled, potassium persulfate powder was added and stirred together for another 10-20 min to prepare a precursor solution. The mass ratio of sodium hydroxide to potassium persulfate was 3-4:1. The pretreated copper mesh was then placed in the precursor solution and reacted at room temperature for 15 min to grow copper oxide nanoneedles on the surface of the copper mesh. The surface of the copper mesh was then repeatedly rinsed with deionized water to remove residual liquid and impurities. The copper mesh with grown copper oxide nanoneedles was then placed in a vacuum drying oven and dried at 60°C for 3 h to obtain a blue product attached to the copper mesh.

[0048] The dried copper mesh was placed in a muffle furnace and calcined at 130-150℃ for 50 min to obtain a black product adhering to the copper mesh.

[0049] Step 2. Add polyvinylidene fluoride powder and polyvinylpyrrolidone powder to N,N-dimethylformamide solvent at a mass ratio of 2-3:1:25-30. Stir vigorously at 65℃-75℃ for 5 hours to form a transparent solution. Use an air pump and spray gun to evenly spray the transparent solution onto the surface of the copper mesh. Transfer the copper mesh coated with polyvinylidene fluoride and polyvinylpyrrolidone to a deionized water coagulation bath at 25℃ and let it stand for a period of time to allow polyvinylpyrrolidone to precipitate from polyvinylidene fluoride and form a porous polyvinylidene fluoride membrane structure. Take out the copper mesh membrane structure and dry it at 60℃ for 6 hours to obtain a copper mesh coated with polyvinylidene fluoride.

[0050] Step 3. Add tris(hydroxymethyl)aminomethane to deionized water, then adjust the pH of the solution to 8-8.5 with 0.1 mol / L HCl, add dopamine hydrochloride, and when the solution begins to change color, add a copper mesh coated with polyvinylidene fluoride and soak for 12 hours to allow polydopamine to deposit onto the polyvinylidene fluoride for hydrophilic modification. Remove excess polydopamine with deionized water. The mass ratio of tris(hydroxymethyl)aminomethane, dopamine hydrochloride and water is 6-7:7-8:5000. Then dry at 40-60℃ for 6 hours to obtain a hydrophilic copper mesh.

[0051] Step 4. Prepare a hydrophobic spraying solution. Spray the hydrophobic spraying solution onto one side of the copper mesh prepared in step 3, and dry it in a vacuum drying oven at 60°C for 2 hours to obtain a hydrophobic side surface, thus completing the preparation of the oil-water separation composite membrane 11.

[0052] The method for preparing the hydrophobic spraying solution is as follows: Cerium oxide particles and octadecylamine particles are weighed, added to anhydrous ethanol, and ultrasonically dispersed for 20 min. Then, epoxy resin and a curing agent are added. The two solutions are mixed and heated and stirred at room temperature until a homogeneous solution is formed, which serves as the spraying solution. The mass ratio of cerium oxide, octadecylamine, and anhydrous ethanol is 2:1:50–55, and the mass ratio of epoxy resin to curing agent is 3–4:1.

[0053] The separation method of the portable multiphase oil-water separation experimental device that can be interchanged in this embodiment is as follows:

[0054] When separating light oil, the light oil-water mixture is injected into the lower separation shell 2 cavity through the first port 5. The device is filled with water. Since the oil-water separation composite membrane 11 has a hydrophobic upper surface and a hydrophilic lower surface, the water enters the upper separation shell 1 cavity through the oil-water separation composite membrane 11 and is discharged through the third port 7. The light oil accumulates at the second port 6 and is discharged through the second port 6.

[0055] There are two operating modes for separating heavy oil:

[0056] The first operating mode is as follows: the oil-water separation composite membrane 11 is reversed so that its lower surface is hydrophobic and its upper surface is hydrophilic. The graphene flexible electric heating membrane is opened, and the heavy oil-water mixture is injected into the upper separation shell cavity through the third interface 7. The heavy oil passes through the oil-water separation composite membrane into the lower separation shell cavity and is discharged through the first interface 5 and the second interface 6.

[0057] The second operating mode: Invert the entire device so that the lower separation shell 2 is at the top and the upper separation shell 1 is at the bottom. Fill the device with water, open the graphene flexible electric heating film, and inject the heavy oil-water mixture into the lower separation shell cavity through the first port 5. The water enters the upper separation shell cavity through the oil-water separation composite membrane and is discharged through the third port 7. The heavy oil accumulates in the lower separation shell and is discharged through the second port 6.

[0058] Example 2

[0059] In this embodiment, a first interface 5 is provided at the lower part of the lower separation housing 2, and a second interface 6 is provided at the upper end of the opposite side of the first interface 5. The upper port of the lower separation housing 2 is an inclined port with an inclination angle of 45°. An upper separation housing 1 is matched and provided on the upper port of the lower separation housing 2. A lower filter plate 10 is fixedly installed at the upper port of the lower separation housing 2. The filter hole diameter of the lower filter plate 10 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. An upper filter plate 1 is fixedly installed at the lower port of the upper separation housing 1. The filter plate 9 has a filter hole diameter of 2.8 mm and a center distance of 3.8 mm between adjacent filter holes. An oil-water separation composite membrane 11 is disposed between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 has a hydrophobic upper surface and a hydrophilic lower surface. The water contact angle of the hydrophilic surface is 0° to 40° and the underwater oil contact angle is 140° to 170°; the water contact angle of the hydrophobic surface is 110° to 170° and the oil contact angle is 0° to 20°. A third interface 7 is provided at the upper end of the upper separation shell 1. Valves are installed on the first interface 5, the second interface 6, and the third interface 7. The oil-water separation composite membrane 11 is disposed between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 is composed of a polydopamine hydrophilic layer, a cotton cloth layer, and a polyvinylidene fluoride hydrophobic layer in sequence. Other components and their connection methods are the same as in Example 1.

[0060] The separation method of the portable multiphase oil-water separation experimental device that can be interchanged in this embodiment is the same as that in Embodiment 1.

[0061] Example 3

[0062] In this embodiment, a first interface 5 is provided at the lower part of the lower separation shell 2, and a second interface 6 is provided at the upper end of the opposite side of the first interface 5. The upper port of the lower separation shell 2 is an inclined port with an inclination angle of 45°. An upper separation shell 1 is matched and provided on the upper port of the lower separation shell 2. A lower filter plate 10 is fixedly installed at the upper port of the lower separation shell 2. The diameter of the filter holes of the lower filter plate 10 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. An upper filter plate 9 is fixedly installed at the lower port of the upper separation shell 1. The diameter of the filter holes of the upper filter plate 9 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. An oil-water separation composite membrane 11 is provided between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 is a hydrophilic composite membrane with a water contact angle of 0° to 40° and an underwater oil contact angle of 140° to 170°. A third interface 7 is provided at the upper end of the upper separation shell 1. Valves are installed on the first interface 5, the second interface 6, and the third interface 7. An oil-water separation composite membrane 11 is disposed between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 is composed of a polyvinylidene fluoride and polydopamine composite hydrophilic layer and a metal mesh layer in sequence. The metal mesh layer is made of copper, titanium, or stainless steel, and has a mesh size of 100-300 mesh. Other components and their connection methods are the same as in Example 1.

[0063] The separation method of the portable multiphase oil-water separation experimental device that can be interchanged in this embodiment is as follows:

[0064] When separating light oil, the device is filled with water, and the light oil-water mixture is injected into the device from the first port 5. Due to the presence of the hydrophilic membrane, the water is discharged from the third port 7 through the membrane, while the light oil is collected at the second port 6 and discharged through the second port 6.

[0065] When separating heavy oil, the device is filled with water, then the device is inverted and the graphene flexible electric heating membrane is opened. The heavy oil-water mixture is injected into the device from the first port 5. Due to the hydrophilic membrane and gravity, the water is discharged from the third port 7 through the membrane, while the heavy oil is collected at the second port 6 and discharged through the second port 6.

[0066] Example 4

[0067] In this embodiment, a first interface 5 is provided at the lower part of the lower separation shell 2, and a second interface 6 is provided at the upper end of the opposite side of the first interface 5. The upper port of the lower separation shell 2 is an inclined port with an inclination angle of 45°. An upper separation shell 1 is matched and provided on the upper port of the lower separation shell 2. A lower filter plate 10 is fixedly installed at the upper port of the lower separation shell 2. The diameter of the filter holes of the lower filter plate 10 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. An upper filter plate 9 is fixedly installed at the lower port of the upper separation shell 1. The diameter of the filter holes of the upper filter plate 9 is 2.8 mm, and the center distance between two adjacent filter holes is 3.8 mm. An oil-water separation composite membrane 11 is provided between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 is a hydrophilic composite membrane with a water contact angle of 0° to 40° and an underwater oil contact angle of 140° to 170°. A third interface 7 is provided at the upper end of the upper separation shell 1. Valves are installed on the first interface 5, the second interface 6, and the third interface 7. An oil-water separation composite membrane 11 is provided between the upper filter plate 9 and the lower filter plate 10. The oil-water separation composite membrane 11 is composed of a polydopamine hydrophilic layer and a cotton cloth layer connected in sequence. Other components and their connection methods are the same as in Example 1.

[0068] The separation method of the portable multiphase oil-water separation experimental device that can be interchanged in this embodiment is the same as that in Embodiment 3.

[0069] experiment

[0070] To verify the beneficial effects of the present invention, the inventors conducted the following experiments using the portable multiphase oil-water separation experimental device of Example 1 (hereinafter referred to as the device of Example 1), which is interchangeable with each other:

[0071] Experiment 1

[0072] Flux tests were performed on the oil-water separation composite membrane in Example 1, and the volume of oil phase discharged per unit time was recorded to obtain the separation flux of different phases. The water flux was 84874.94 L m⁻² h⁻¹. The oil flux was as follows. Figure 3 As shown, petroleum ether had the highest flux at 78864.94 L m⁻² h⁻¹, followed by cyclohexane at 70786.47 L m⁻² h⁻¹. Dichloromethane and kerosene had medium fluxes at 54752.45 L⋅m⁻¹. −2 ⋅h −1 and 47444.37 L⋅m −2 ⋅h −1 ¹, Soybean oil flux is extremely low, at 1626.65 LL⋅m −2 ⋅h −1This is significantly higher than the flux data of 15800 L⁻¹ m⁻¹ published in the paper "Bio-inspired superhydrophobic fiber membrane for oil-water separation and non-destructive transport of liquids in corrosive environments" in the Journal of Membrane Science in May 2024. −2 ⋅h −1 .

[0073] Experiment 2

[0074] The oil-water separation efficiency of five typical oil phases (petroleum ether, dichloromethane, cyclohexane, kerosene, and soybean oil) was tested using the apparatus of Example 1 of this invention. Figure 6 As can be seen, the device of Embodiment 1 of the present invention exhibits excellent separation performance in all test systems, with a separation efficiency generally higher than 97.5%, demonstrating good universality and reliability.

[0075] Specifically, the apparatus of Embodiment 1 of the present invention has the highest separation efficiency for petroleum ether, reaching approximately 99.5%; the separation efficiency for dichloromethane is closely followed, at approximately 99.4%; the separation efficiencies for cyclohexane and kerosene are also maintained at high levels of 99.0% and 98.8%, respectively; even for soybean oil with relatively high viscosity, the separation efficiency remains above 97.5%.

Claims

1. A portable multiphase oil-water separation experimental device that can be interchanged, characterized in that: The lower part of the lower separation shell (2) is provided with a first interface (5) and the upper part of the opposite side of the first interface (5) is provided with a second interface (6). The upper port of the lower separation shell (2) is an inclined port. The upper separation shell (1) is matched with the upper port of the lower separation shell (2). The lower filter plate (10) is provided at the upper port of the lower separation shell (2). The upper filter plate (9) is provided at the lower port of the upper separation shell (1). An oil-water separation composite membrane (11) is provided between the upper filter plate (9) and the lower filter plate (10). The oil-water separation composite membrane (11) has a hydrophobic upper surface and a hydrophilic lower surface or both surfaces are hydrophilic. The upper end of the upper separation shell (1) is provided with a third interface (7).

2. The portable multiphase oil-water separation experimental device with interchangeable configurations according to claim 1, characterized in that: A flexible heating film (8) is provided on the outer surface of the lower separation shell (2).

3. The portable multiphase oil-water separation experimental device with interchangeable configurations according to claim 2, characterized in that: The flexible heating film (8) is a graphene flexible electrothermal film.

4. The portable multiphase oil-water separation experimental device with interchangeable configurations according to claim 1, characterized in that: The tilt angle of the tilted opening is 30° to 60°.

5. The portable multiphase oil-water separation experimental device with interchangeable configurations according to claim 1, characterized in that: The hydrophilic surface has a water contact angle of 0° to 40° and an underwater oil contact angle of 140° to 170°; the hydrophobic surface has a water contact angle of 110° to 170° and an oil contact angle of 0° to 20°.

6. The portable multiphase oil-water separation experimental device that can be interchanged according to claim 1 or 5, characterized in that: The oil-water separation composite membrane (11) is composed of a polyvinylidene fluoride and polydopamine composite hydrophilic layer, a metal mesh layer, and a cerium oxide hydrophobic layer in sequence. The metal mesh layer is made of copper, titanium, or stainless steel, and has a mesh size of 100 to 300 mesh.

7. The portable multiphase oil-water separation experimental device that can be interchanged according to claim 1 or 5, characterized in that: The oil-water separation composite membrane (11) is composed of a polydopamine hydrophilic layer, a cotton cloth layer, and a polyvinylidene fluoride hydrophobic layer in sequence.

8. The portable multiphase oil-water separation experimental device that can be interchanged according to claim 1 or 5, characterized in that: The oil-water separation composite membrane (11) is composed of a polyvinylidene fluoride and polydopamine composite hydrophilic layer and a metal mesh layer in sequence. The metal mesh layer is made of copper, titanium or stainless steel and has a mesh size of 100 to 300 mesh.

9. The portable multiphase oil-water separation experimental device that can be interchanged according to claim 1 or 5, characterized in that: The oil-water separation composite membrane (11) is composed of a polydopamine hydrophilic layer and a cotton cloth layer connected in sequence.

10. The portable multiphase oil-water separation experimental device with interchangeable configurations according to claim 6, characterized in that: The preparation method of the oil-water separation composite membrane (11) is as follows: Step 1. Take a 300-mesh copper mesh as a substrate and prepare copper oxide nanoneedles on its surface; The method for preparing copper oxide nanoneedles is as follows: The copper mesh was immersed in dilute hydrochloric acid for 10 min, and then ultrasonicated with anhydrous ethanol and deionized water for 10-15 min respectively. This process was repeated 3 times to clean the oxide impurities and organic contaminants on the surface of the copper mesh. The copper mesh was then vacuum dried at 60-80℃ for 12 h to complete the pretreatment of the copper mesh. Sodium hydroxide flakes were added to deionized water and stirred for 10-20 min. After the beaker cooled, potassium persulfate powder was added and stirred together for another 10-20 min to prepare a precursor solution. The mass ratio of sodium hydroxide to potassium persulfate was 3-4:

1. The pretreated copper mesh was then placed in the precursor solution and reacted at room temperature for 15 min to grow copper oxide nanoneedles on the surface of the copper mesh. The surface of the copper mesh was then repeatedly rinsed with deionized water to remove residual liquid and impurities. The copper mesh with grown copper oxide nanoneedles was then placed in a vacuum drying oven and dried at 60°C for 3 h to obtain a blue product attached to the copper mesh. The dried copper mesh was placed in a muffle furnace and calcined at 130-150℃ for 50 min to obtain a black product adhering to the copper mesh. Step 2. Add polyvinylidene fluoride powder and polyvinylpyrrolidone powder to N,N-dimethylformamide solvent at a mass ratio of 2-3:1:25-30. Stir vigorously at 65℃-75℃ for 5 hours to form a transparent solution. Use an air pump and spray gun to evenly spray the transparent solution onto the surface of the copper mesh. Transfer the copper mesh coated with polyvinylidene fluoride and polyvinylpyrrolidone to a deionized water coagulation bath at 25℃ and let it stand for a period of time to allow polyvinylpyrrolidone to precipitate from polyvinylidene fluoride and form a porous polyvinylidene fluoride membrane structure. Take out the copper mesh membrane structure and dry it at 60℃ for 6 hours to obtain a copper mesh coated with polyvinylidene fluoride. Step 3. Add tris(hydroxymethyl)aminomethane to deionized water, then adjust the pH of the solution to 8-8.5 with 0.1 mol / L HCl, add dopamine hydrochloride, and when the solution begins to change color, add a copper mesh coated with polyvinylidene fluoride and soak for 12 h to allow polydopamine to deposit onto the polyvinylidene fluoride for hydrophilic modification. Remove excess polydopamine with deionized water. The mass ratio of tris(hydroxymethyl)aminomethane, dopamine hydrochloride and water is 6-7:7-8:5000. Then dry at 40-60℃ for 6 h to obtain a hydrophilic copper mesh. Step 4. Prepare a hydrophobic spraying solution. Spray the hydrophobic spraying solution onto one side of the copper mesh prepared in step 3, and dry it in a vacuum drying oven at 60°C for 2 hours to obtain a hydrophobic side surface, thus completing the preparation of the oil-water separation composite membrane (11). The method for preparing the hydrophobic spraying solution is as follows: weigh cerium oxide particles and octadecylamine particles, add them to anhydrous ethanol and ultrasonically disperse for 20 min, then add epoxy resin and curing agent, mix the two solutions and heat and stir at room temperature until a uniform solution is formed as the spraying solution. The mass ratio of cerium oxide, octadecylamine and anhydrous ethanol is 2:1:50-55, and the mass ratio of epoxy resin to curing agent is 3-4:1.

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