Corrosion-resistant emulsion separation membrane and preparation method and application thereof

Abstract

The present application relates to a kind of corrosion-resistant emulsion separation membrane, which is composed of porous metal mesh and surface-coated pyrrole polymer layer, the pyrrole polymer layer is coated on the surface of the metal mesh by electrochemical polymerization in the phosphoric acid solution of pyrrole monomer.The present application also relates to a preparation method of corrosion-resistant emulsion separation membrane, and the application of the corrosion-resistant emulsion separation membrane in separating waste lye.The present application solves the problems of traditional emulsion separation membrane, such as complex preparation process, non-reusable and poor corrosion resistance.The present application uses metal mesh as substrate, and generates polypyrrole coating by electrochemical method.The phosphorus oxy group in polypyrrole endows the separation membrane surface with extremely high surface energy and excellent chemical stability, so that the alkaline emulsion can be efficiently separated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of emulsion separation membrane, in particular to a kind of corrosion-resistant emulsion separation membrane and its preparation method and application, especially the basic emulsion produced in the production process of butyraldehyde condensation hydrogenation octanol, pentanal condensation hydrogenation decanol, the separation membrane can be efficiently separated under the condition of not adding any auxiliary agent to basic emulsion. BACKGROUND

[0002] The existing octanol and decanol production in China mainly adopts the method of carbonyl synthesis of propylene, butylene or mixed carbon four. This method first generates n-butyraldehyde or n-pentanal by carbonyl synthesis reaction of propylene, butylene or mixed carbon four with synthesis gas, then generates octenal or decenal by condensation reaction of n-butyraldehyde or n-pentanal under the catalysis of 2% sodium hydroxide, and finally generates octanol or decanol by hydrogenation treatment of octenal or decenal. However, in the second step of condensation reaction, equivalent water is also generated at the same time as octenal or decenal, and the generated water will dilute the catalyst. In order to maintain the balance of the catalyst system, a certain amount of dilute alkali liquor must be continuously discharged from the system, and a part of high-concentration alkali liquor must be added at the same time to maintain the normal progress of the condensation reaction, so a large amount of waste alkali liquor is generated.

[0003] These waste alkali liquors have three main characteristics: first, the alkalinity is strong, the pH value is about 14, and the corrosion is extremely strong; second, the discharge amount is relatively small, generally only about 1-2 t / h; third, the organic matter content is high, in an emulsified state, and it is extremely difficult to separate, the chemical oxygen demand (COD Cr ) is generally 50000-100000 mg / L, and a large amount of organic matter is discharged with water, which not only causes waste of effective resources, but also causes great impact on sewage treatment plants and serious environmental hazards. For the treatment of alcohol aldehyde condensation waste alkali liquor, a large number of methods have been developed at home and abroad, such as acidification extraction method, acidification-thermal separation method, acidification-Fenton oxidation method and acidification-adsorption method, etc.

[0004] US6358419B1 uses acidification extraction method to treat this waste alkali liquor, which first adjusts the pH value of the waste alkali liquor to 3 using sulfuric acid, and then uses hydrocarbons with more than 6 carbons or alcohols with more than 8 carbons as extractants to treat the solution. The COD Cr removal rate after treatment can reach more than 80%, and the extractant can be recycled after rectification and regeneration, and the organic components can be recovered. However, this method not only consumes a large amount of sulfuric acid, but also cannot infinitely regenerate the extractant, which is difficult to recycle and use, and needs to be replaced regularly, so the treatment cost is high.

[0005] CN1530334A employs an acidification-thermal separation method to treat this waste alkaline solution. This method first acidifies the waste alkaline solution, adjusting the pH to below 4.5, and then heats it to 95–100°C to demulsify the solution. After demulsification, the oil and water phases automatically separate, and the organic phase is recovered. This method does not require the addition of an extractant, but the COD... Cr The removal rate is only about 50%, and the energy consumption is relatively high.

[0006] CN101172725A describes the treatment of this waste alkaline solution using an acidification-Fenton oxidation method. This method first acidifies the waste alkaline solution, then allows it to settle for oil removal, and finally performs Fenton oxidation on the acidic aqueous phase. The resulting COD... Cr The removal rate can reach over 97%. However, the COD of the treated wastewater... Cr The concentration remains above 1500 mg / L, resulting in high hydrogen peroxide consumption and high treatment costs. Furthermore, this method cannot achieve the recycling of inorganic alkalis.

[0007] CN103012104A describes an acidification-adsorption method for treating this waste alkaline solution. This method first acidifies the waste alkaline solution, then applies macroporous adsorption resin to the acidic wastewater after oil removal. This method is simple, has low energy consumption, and achieves good treatment results, reducing COD... Cr It can be reduced to below 300 mg / L, but it still does not meet the emission standards. In addition, direct adsorption will result in a large amount of macroporous adsorption resin used, resulting in high investment costs.

[0008] A comprehensive analysis of the advantages and disadvantages of the above methods reveals that although there are many resource-based treatment methods for waste alkaline solutions, each with its own characteristics, the first step in treating these waste alkaline solutions is acidification and demulsification. The acidification and demulsification process consumes a large amount of inorganic acid, and this process is costly and environmentally unfriendly. Therefore, it is essential to develop an emulsion separation method that does not require acidification.

[0009] In recent years, emulsion separation membranes, which can efficiently separate aqueous and organic phases, have attracted widespread attention due to their ease of use and high single-stage separation efficiency.

[0010] CN105251373A discloses a reduced graphene oxide emulsion separation film, its preparation method and application, which can achieve a single-stage separation efficiency of 99.5% for emulsions; however, it cannot be used for a long time under alkaline conditions.

[0011] CN102974226A discloses a kind of by sodium hydroxide and persulfate as reaction solution, copper net is placed in reaction vessel and is reacted, obtain a kind of copper hydroxide nanometer needle coating superhydrophilic / ultra-oleophobic emulsion separation separation membrane, can carry out efficient separation to oil-water mixture or emulsion, separation efficiency is greater than 99%, but the functional substance on this separation membrane is copper hydroxide nanometer needle, this separation membrane is not acid-resistant, not salt-resistant, cannot be used for a long time under acidic, alkaline or salt-containing conditions.

[0012] From the above, it is necessary to develop an emulsion separation membrane with corrosion resistance. SUMMARY

[0013] Based on the above, the purpose of the present application is to provide a corrosion-resistant emulsion separation membrane. The technical problem to be solved is to make the emulsion separation membrane have good corrosion resistance and be able to separate emulsion efficiently in a strong alkaline environment, so as to be applied to the treatment of waste alkali liquor in alcohol aldehyde condensation reaction.

[0014] To achieve the above-mentioned purpose, the present application provides a corrosion-resistant emulsion separation membrane, which is composed of a porous metal mesh and a surface-coated polypyrrole layer. The polypyrrole layer is coated on the surface of the metal mesh by electrochemical polymerization in a phosphoric acid solution of pyrrole monomers.

[0015] Specifically, phosphoric acid solution is selected as a dopant to introduce phosphorus-oxygen groups into the polypyrrole film, greatly enhancing the surface free energy of the polypyrrole film and improving the surface tension when the separation membrane contacts with the emulsion, thereby playing a role in demulsification of the emulsion and achieving separation of the emulsion.

[0016] In the corrosion-resistant emulsion separation membrane of the present application, the metal mesh is preferably selected from one of stainless steel mesh, red copper mesh, brass mesh and titanium mesh, and more preferably is stainless steel mesh.

[0017] In the corrosion-resistant emulsion separation membrane of the present application, the mesh number of the metal mesh is preferably 500-2800, and more preferably 2000-2800.

[0018] Specifically, it is worth noting that the particle size of emulsion particles in the emulsion is generally less than 100 nm, and the emulsion particles are relatively stable. To effectively separate the emulsion, the pore size and surface free energy need to be controlled, therefore the metal mesh specifications and dopant need to be strictly controlled.

[0019] In the corrosion-resistant emulsion separation membrane of the present application, the concentration of the phosphoric acid solution is preferably 0.1-0.5 mol / L.

[0020] The corrosion-resistant emulsion separation membrane, wherein preferably, the electrochemical polymerization is selected from one of cyclic voltammetry, multi-current step method, constant current method, constant voltage method, and more preferably the constant current method with a current density of 0.5-3 mA / cm 2 .

[0021] The corrosion-resistant emulsion separation membrane, wherein preferably, the concentration of the pyrrole monomer is 0.05-0.3 mol / L, and more preferably 0.14-0.16 mol / L.

[0022] The corrosion-resistant emulsion separation membrane, wherein preferably, the reaction time of the electrochemical polymerization is 10-60 min, and more preferably 25-35 min.

[0023] To achieve the above-mentioned purpose, the application provides a preparation method of the above-mentioned corrosion-resistant emulsion separation membrane, comprising the following steps:

[0024] (1) pretreating the metal mesh, preferably, the pretreatment step is: immersing the stainless steel mesh in acetone, ethanol and deionized water respectively for 15-45 minutes of ultrasonic cleaning to remove organic pollutants and oxide layers on the surface of the stainless steel mesh, and then drying in a vacuum oven at 30-90 DEG C;

[0025] (2) fixing the pretreated metal mesh as a working electrode, a platinum electrode as a counter electrode, and a saturated calomel electrode as a reference electrode into an electrolytic cell and passing a constant current through an electrochemical workstation, the electrolyte being a mixture solution of 0.05-0.3 mol / L pyrrole and 0.1-0.5 mol / L phosphoric acid, the current density being 0.5-3 mA / cm 2 , the reaction time being 25-90 min, to obtain a polypyrrole-coated metal mesh that can be used for emulsion separation, and after the reaction, washing with deionized water and drying in a vacuum oven at 30-90 DEG C to obtain the emulsion separation membrane.

[0026] To achieve the above-mentioned purpose, the application provides an application of the above-mentioned corrosion-resistant emulsion separation membrane in separating waste lye.

[0027] The application of the corrosion-resistant emulsion separation membrane in separating waste lye, wherein preferably, the application comprises the following steps:

[0028] Step 1, fixing the emulsion separation membrane into a separation device and wetting the separation membrane with deionized water first;

[0029] Step 2, pouring the waste lye into the separation device, and the water phase will automatically pass through the emulsion separation membrane, and the organic phase will be intercepted on the surface of the separation membrane, and then recycling the organic phase;

[0030] Step 3, the organic acid sodium salt dissolved in the aqueous phase is subjected to macroporous resin adsorption treatment to remove the organic acid, and then concentrated to a NaOH concentration of 2-4wt%, and returned to the reaction device for recycling.

[0031] Specifically, the treatment method of the waste lye is as follows:

[0032] Step 1, the emulsion separation membrane is fixed into two pipes with flanges at one end, and deionized water is used to wet the separation membrane before use; a simple separation device is obtained.

[0033] Step 2, the waste lye is directly poured into the separation device, the aqueous phase automatically passes through the emulsion separation membrane, and the organic phase is intercepted on the surface of the separation membrane, which can be recycled; this step has a demulsification effect on the waste lye, and can remove the organic phase that is not dissolved in the aqueous phase.

[0034] Step 3, the organic acid sodium salt dissolved in the aqueous phase is subjected to macroporous resin adsorption treatment to remove the organic acid, and then concentrated to a NaOH concentration of about 2wt%, and returned to the reaction device such as a condensation device for recycling.

[0035] It should be pointed out that the separation membrane can only treat the organic phase that is not dissolved in the aqueous phase, and the organic acid sodium salt dissolved in the aqueous phase still needs to be subjected to macroporous resin adsorption treatment.

[0036] It should be pointed out that the emulsion separation membrane cannot be used indefinitely, and after treating 200-300 tons of waste water per square meter of emulsion separation membrane, it needs to be washed and dried before being reused, and after being washed for 30-40 times, the emulsion separation membrane needs to be replaced.

[0037] Of course, the emulsion separation membrane can also be used for other types of emulsion separation.

[0038] The beneficial effects of the present application are as follows:

[0039] The emulsion separation membrane with corrosion resistance provided by the present application can efficiently separate the alkaline emulsion without acidification treatment or addition of auxiliary agents, solving the problem of large inorganic acid consumption caused by adjusting the solution to be acidic during the demulsification of waste lye, and simplifying the treatment process of waste lye.

[0040] The emulsion separation membrane with corrosion resistance provided by the present application has a removal rate of organic phase of more than 99.95%, and the organic phase can be recycled, and the aqueous phase can be returned to the reaction device such as a condensation device for recycling after simple macroporous resin adsorption and concentration treatment.

[0041] The application provides a preparation method of the emulsion separation membrane with corrosion resistance, which is prepared by in-situ polymerization of polypyrrole on the surface of a metal mesh through an electrochemical in-situ polymerization method.

[0042] In conclusion, the emulsion separation membrane with corrosion resistance provided by the application can separate alkaline emulsion efficiently without adding any auxiliary agent; the separation membrane can also be used for waste alkali treatment, and the waste alkali does not need to be acidified, so that the process flow is shortened, consumption of a large amount of inorganic acid is avoided, the organic phase after separation can be recycled, the alkaline inorganic phase can be returned to the device for recycling after simple macroporous resin adsorption and concentration treatment, material consumption is reduced, pollution is avoided, and clean production is basically achieved. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The scanning electron microscope image of the original stainless steel mesh in Example 1.

[0044] Figure 2 The scanning electron microscope image of the emulsion separation membrane in Example 1.

[0045] Figure 3 The flowchart of the waste alkali treatment in Example 1. DETAILED DESCRIPTION

[0046] The following detailed description of the embodiments of the application is given on the premise of the technical scheme of the application, and detailed implementation modes and processes are given, but the protection scope of the application is not limited to the following examples, and the experimental method is not specified in the following examples, and the conventional conditions are usually used.

[0047] The emulsion separation membrane with corrosion resistance provided by the application is composed of a porous metal mesh and a polypyrrole layer coated on the surface, and the polypyrrole layer is coated on the surface of the metal mesh by electrochemical polymerization in a phosphoric acid solution of pyrrole monomers.

[0048] Specifically, the phosphoric acid solution is selected as a dopant, the phosphorus-oxygen group is introduced into the polypyrrole film, the surface free energy of the polypyrrole film is greatly enhanced, the surface tension when the separation membrane contacts the emulsion is improved, the demulsification of the emulsion is achieved, and the separation of the emulsion is achieved.

[0049] In some embodiments, preferably, the metal mesh is selected from one of stainless steel mesh, red copper mesh, brass mesh, titanium mesh, and more preferably, stainless steel mesh.

[0050] In some embodiments, preferably, the mesh number of the metal mesh is 500-2800, and more preferably, 2000-2800.

[0051] Specifically, it is worth noting that the emulsion particle size in the emulsion is generally less than 100 nm, and the emulsion particles are relatively stable. In order to effectively separate the emulsion, the pore size and the surface free energy need to be controlled, so the specifications of the metal mesh and the dopant need to be strictly controlled.

[0052] In some embodiments, preferably, the concentration of the phosphoric acid solution is 0.1-0.5 mol / L.

[0053] In some embodiments, preferably, the electrochemical polymerization is selected from one of cyclic voltammetry, multi-current step method, constant current method, constant voltage method, and more preferably, constant current method, and the current density is 0.5-3 mA / cm 2 .

[0054] In some embodiments, preferably, the concentration of the pyrrole monomer is 0.05-0.3 mol / L, and more preferably, 0.14-0.16 mol / L.

[0055] In some embodiments, preferably, the reaction time of the electrochemical polymerization is 10-60 min, and more preferably, 25-35 min.

[0056] The application also provides a preparation method of the corrosion-resistant emulsion separation membrane.

[0057] (1) The metal mesh is pretreated, and preferably, the pretreatment step is: the stainless steel mesh is immersed in acetone, ethanol and deionized water respectively for 15-45 minutes for ultrasonic cleaning, so as to remove the organic pollutants and oxidation layer on the surface of the stainless steel mesh, and then dried in a vacuum oven at 30-90°C.

[0058] (2) The pretreated metal mesh is used as a working electrode, a platinum electrode is used as a counter electrode, and a saturated calomel electrode is used as a reference electrode, which are fixed in an electrolytic cell and connected to a constant current through an electrochemical workstation, the electrolyte is a mixture of 0.05-0.3 mol / L pyrrole and 0.1-0.5 mol / L phosphoric acid, the current density is 0.5-3 mA / cm 2 , the reaction time is 25-90 min, and a polypyrrole-coated metal mesh for emulsion separation is prepared. After the reaction, the product is washed with deionized water and dried in a vacuum oven at 30-90°C to obtain an emulsion separation membrane.

[0059] The application also provides the application of the corrosion-resistant emulsion separation membrane in separating waste lye.

[0060] In some embodiments, it is preferred to include the following steps:

[0061] Step 1, fix the emulsion separation membrane into a separation device, and wet the separation membrane with deionized water first;

[0062] Step 2, pour the waste lye into the separation device, and the water phase will automatically pass through the emulsion separation membrane, while the organic phase will be intercepted on the surface of the separation membrane, and then the organic phase is recycled and reused;

[0063] Step 3, remove the organic acid by macroporous resin adsorption treatment of the organic acid sodium salt dissolved in the water phase, and then perform concentration treatment to control the NaOH concentration to 2-4wt%, and return to the reaction device for recycling.

[0064] Specifically, the treatment method of the waste lye is as follows:

[0065] Step 1, fix the emulsion separation membrane into two pipes with flanges at one end, and wet the separation membrane with deionized water before use; and obtain a simple separation device.

[0066] Step 2, pour the waste lye directly into the separation device, and the water phase will automatically pass through the emulsion separation membrane, while the organic phase will be intercepted on the surface of the separation membrane, and the organic phase can be recycled and reused; this step has the effect of demulsification on the waste lye, and can remove the organic phase that is not dissolved in the water phase in the waste lye.

[0067] Step 3, remove the organic acid by macroporous resin adsorption treatment of the organic acid sodium salt dissolved in the water phase, and then perform concentration treatment to control the NaOH concentration to about 2wt%, and return to the reaction device such as a condensation device for recycling.

[0068] It should be pointed out that the separation membrane can only treat the organic phase that is not dissolved in the water phase, and the organic acid sodium salt dissolved in the water phase still needs to be treated by macroporous resin adsorption.

[0069] It should be pointed out that the emulsion separation membrane cannot be used indefinitely, and after treating 200-300 tons of waste water per square meter of emulsion separation membrane, it needs to be washed and dried before being reused, and after being washed for 30-40 times, the emulsion separation membrane needs to be replaced.

[0070] Of course, the emulsion separation membrane can also be used for other types of emulsion separation.

[0071] Raw material or equipment source: waste lye, COD about 100000 mg / L, pentanal condensation device; stainless steel mesh, 2300 mesh, Hengshui sieve factory; pyrrole, phosphoric acid, ethanol, acetone, high purity, Aladdin reagent Co., Ltd.; gasoline, kerosene, diesel, local gas station; deionized water, self-made; electrochemical workstation, LK2010, Tianjin Lanlike Electronic Co., Ltd.; water quality analyzer, FK-DS06, Fangke instrument.

[0072] Evaluation and analysis method: using water quality analyzer to determine the COD of the treated waste lye.

[0073] Example 1

[0074] The stainless steel mesh was pretreated, and the stainless steel mesh was immersed in acetone, ethanol and deionized water respectively for 30 minutes ultrasonic cleaning to remove the organic pollutants and oxide layer on the surface of the stainless steel mesh, and then dried in a vacuum oven at 50°C. Figure 1

[0075] The pretreated stainless steel mesh was used as the working electrode, platinum electrode as the counter electrode, and saturated calomel electrode as the reference electrode, fixed in the electrolytic cell and passed through the electrochemical workstation to input constant current, the electrolyte was a mixture of 0.145M pyrrole and 0.01M phosphoric acid, the current density was 1.0 mA / cm 2 , the reaction time was 30 min, and the poly-pyrrole coated stainless steel mesh was prepared, washed and dried to obtain the corrosion-resistant emulsion separation membrane, and the scanning electron microscope image is shown in Figure 2 .

[0076] The emulsion separation membrane was fixed into two pipes with flanges at one end, and deionized water was used to wet the separation membrane before use; a simple separation device was obtained.

[0077] Take 1L of pentanal condensation waste lye with COD of 100620 mg / L, pass into the separation device, the water phase will automatically pass through the emulsion separation membrane, and the organic phase will be intercepted on the surface of the separation membrane, the organic phase can be recycled, the removal rate of the separation membrane to the organic phase not dissolved in the water phase is 99.985%, and then the organic acid dissolved in the water phase is treated by macroporous resin adsorption and concentration, and the flowchart is shown in Figure 3 .

[0078] Example 2:

[0079] The stainless steel mesh was pretreated, and the stainless steel mesh was immersed in acetone, ethanol and deionized water respectively for 30 minutes ultrasonic cleaning to remove the organic pollutants and oxide layer on the surface of the stainless steel mesh, and then dried in a vacuum oven at 50°C.

[0080] ​The pretreated stainless steel mesh was used as the working electrode, platinum electrode as the counter electrode, and saturated calomel electrode as the reference electrode, fixed in the electrolytic cell and passed through the constant current by the electrochemical workstation, the electrolyte was a mixed solution of 0.145M pyrrole and 0.01M phosphoric acid, the current density was 1.0mA / cm 2 , the reaction time was 60min, the polypyrrole coated stainless steel mesh was prepared, washed and dried to obtain the corrosion-resistant emulsion separation membrane.

[0081] The emulsion separation membrane was fixed in two pipes with flanges at one end, and the separation membrane was wetted with deionized water before use; a simple separation device was obtained.

[0082] Take 1L of pentanal condensation waste lye with COD of 100620mg / L, pass it into the separation device, the aqueous phase automatically passes through the emulsion separation membrane, and the organic phase is intercepted on the surface of the separation membrane, the organic phase can be recycled, and the removal rate of the separation membrane to the organic phase not dissolved in the aqueous phase is 99.99%.

[0083] Example 3:

[0084] The stainless steel mesh was pretreated, and the stainless steel mesh was immersed in acetone, ethanol and deionized water respectively for 30 minutes of ultrasonic cleaning to remove organic pollutants and oxide layer on the surface of the stainless steel mesh, and then dried in a vacuum oven at 50°C.

[0085] The pretreated stainless steel mesh was used as the working electrode, platinum electrode as the counter electrode, and saturated calomel electrode as the reference electrode, fixed in the electrolytic cell and passed through the constant current by the electrochemical workstation, the electrolyte was a mixed solution of 0.145M pyrrole and 0.03M phosphoric acid, the current density was 1.5mA / cm 2 , the reaction time was 30min, the polypyrrole coated stainless steel mesh was prepared, washed and dried to obtain the corrosion-resistant emulsion separation membrane.

[0086] The emulsion separation membrane was fixed in two pipes with flanges at one end, and the separation membrane was wetted with deionized water before use; a simple separation device was obtained.

[0087] Take 1L of pentanal condensation waste lye with COD of 100620mg / L, pass it into the separation device, the aqueous phase automatically passes through the emulsion separation membrane, and the organic phase is intercepted on the surface of the separation membrane, the organic phase can be recycled, and the removal rate of the separation membrane to the organic phase not dissolved in the aqueous phase is 99.98%.

[0088] Example 4: Separation of water-in-oil emulsion by separation membrane

[0089] Emulsion preparation: 0.1g Tween 80 was added to the mixture of 100mL water and 1mL kerosene, stirred at 1000rpm for 6 hours at room temperature to obtain a stable white water-in-oil emulsion.

[0090] The emulsion separation membrane prepared in Example 1 is used to separate the above-mentioned water-in-kerosene emulsion, the water phase automatically passes through the emulsion separation membrane, and the kerosene is intercepted by the separation membrane and cannot pass through the separation membrane, so that the water-in-kerosene emulsion is separated.

[0091] Test result: The separation efficiency of the emulsion separation membrane prepared in Example 1 on the water-in-kerosene emulsion reaches 99.95%.

[0092] Example 5: Separation of the emulsion separation membrane on the water-in-gasoline emulsion

[0093] Emulsion preparation: 0.1 g of Tween 80 is added to a mixture of 100 mL of water and 1 mL of gasoline, and stirred at 1000 rpm at room temperature for 6 hours to obtain a stable white water-in-kerosene emulsion.

[0094] The emulsion separation membrane prepared in Example 1 is used to separate the above-mentioned water-in-kerosene emulsion, the water phase automatically passes through the emulsion separation membrane, and the kerosene is intercepted by the separation membrane and cannot pass through the separation membrane, so that the water-in-kerosene emulsion is separated.

[0095] Test result: The separation efficiency of the emulsion separation membrane prepared in Example 1 on the water-in-kerosene emulsion reaches 99.95%.

[0096] Example 6: Separation of the emulsion separation membrane on the water-in-diesel emulsion

[0097] Emulsion preparation: 0.1 g of Tween 80 is added to a mixture of 100 mL of water and 1 mL of gasoline, and stirred at 1000 rpm at room temperature for 6 hours to obtain a stable white water-in-kerosene emulsion.

[0098] The emulsion separation membrane prepared in Example 1 is used to separate the above-mentioned water-in-kerosene emulsion, the water phase automatically passes through the emulsion separation membrane, and the kerosene is intercepted by the separation membrane and cannot pass through the separation membrane, so that the water-in-kerosene emulsion is separated.

[0099] Test result: The separation efficiency of the emulsion separation membrane prepared in Example 1 on the water-in-kerosene emulsion reaches 99.95%.

[0100] As can be seen from the above examples, the emulsion separation membrane with corrosion resistance provided by the application can efficiently separate the alkaline emulsion without acidification treatment or addition of auxiliary agents, solves the problem of a large amount of inorganic acid consumption caused by adjusting the solution to be acidic during the demulsification of waste alkali liquor, and simplifies the treatment process of the waste alkali liquor.

[0101] The emulsion separation membrane with corrosion resistance provided by the application has a removal rate of organic phase of more than 99.95%, the organic phase can be recycled, and the water phase can be returned to a reaction device such as a condensation device for recycling after simple macroporous resin adsorption and concentration treatment.

[0102] The preparation method of the emulsion separation membrane with corrosion resistance provided by the application is a method of in-situ polymerization of polypyrrole on the surface of a metal mesh to obtain an emulsion separation membrane with corrosion resistance.

[0103] In summary, the emulsion separation membrane with corrosion resistance provided by the application can separate alkaline emulsion efficiently without adding any auxiliary agent; the separation membrane can also be used for waste alkali treatment, without the need of acidification treatment of the waste alkali, thus shortening the process flow, avoiding the consumption of a large amount of inorganic acid, recycling the organic phase after separation, returning the alkaline inorganic phase to the device after simple macroporous resin adsorption and concentration treatment, reducing material consumption, avoiding pollution, and basically realizing clean production.

[0104] Of course, the application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the application without departing from the spirit and essence of the application, but these corresponding changes and modifications should all belong to the protection scope of the application.

Claims

1. A corrosion-resistant emulsion separation membrane, characterized by, It is composed of a porous metal mesh and a surface-coated pyrrole polymer layer, which is coated on the surface of the metal mesh by electrochemical polymerization of the metal mesh in a phosphoric acid solution of pyrrole monomers. The corrosion-resistant emulsion separation membrane is used for separating waste lye.

2. The emulsion separation membrane according to claim 1, characterized by The metal mesh is selected from one of stainless steel mesh, red copper mesh, brass mesh and titanium mesh.

3. The emulsion separation membrane according to claim 1, wherein The metal mesh has a mesh number of 500-2800.

4. The emulsion separation membrane according to claim 1, wherein The concentration of the phosphoric acid solution is 0.1-0.5 mol / L.

5. The emulsion separation membrane according to claim 1, wherein The electrochemical polymerization is selected from one of cyclic voltammetry, multi-current step method, constant current method and constant voltage method.

6. The emulsion separation membrane according to claim 1, wherein The concentration of the pyrrole monomers is 0.05-0.3 mol / L.

7. The emulsion separation membrane according to claim 3, wherein The metal mesh has a mesh number of 2000-2800.

8. The emulsion separation membrane according to claim 5, wherein The electrochemical polymerization is selected from galvanostatic method, the current density is 0.5-3 mA / cm 2 .

9. The emulsion separation membrane according to claim 6, wherein The concentration of the pyrrole monomers is 0.14-0.16 mol / L.

10. A method for producing the corrosion-resistant emulsion separation membrane according to any one of claims 1 to 9, characterized by, The method comprises the following steps: (1) pretreating the metal mesh; (2) The pretreated metal mesh is used as a working electrode, a platinum electrode is used as a counter electrode, and a saturated calomel electrode is used as a reference electrode, which are fixed in an electrolytic cell and connected to a constant current by an electrochemical workstation, an electrolyte is a mixed solution of 0.05-0.3 mol / L pyrrole and 0.1-0.5 mol / L phosphoric acid, a current density is 0.5-3 mA / cm 2 , and a reaction time is 25-90 min, to obtain a polypyrrole-coated metal mesh for emulsion separation, which is washed with deionized water and dried in a vacuum oven at 30-90°C after the reaction is completed, to obtain an emulsion separation membrane.

11. The method for preparing a corrosion resistant emulsion separation membrane according to claim 10, characterized by, The pretreatment step is that the metal mesh is respectively soaked in acetone, ethanol and deionized water for ultrasonic cleaning for 15-45 minutes to remove organic contaminants and oxide layers on the surface of the metal mesh, and then dried in a vacuum oven at 30-90 ℃.

12. A method for separating spent caustic solution using the corrosion resistant emulsion separation membrane according to any one of claims 1 to 9, characterized by, The method comprises the following steps: Step 1: fixing the emulsion separation membrane into a separation device and wetting the separation membrane with deionized water; Step 2: pouring waste lye into the separation device, and the water phase will automatically pass through the emulsion separation membrane, while the organic phase will be intercepted on the surface of the separation membrane, and then the organic phase is recycled and reused; Step 3: removing organic acids by macroporous resin adsorption treatment of the organic acid sodium salt dissolved in the water phase, and then performing concentration treatment until the NaOH concentration reaches 2-4 wt%, and returning to the reaction device for recycling.

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