Process for the separation of toluene-ethanol-water ternary azeotrope

Abstract

Embodiments of the present disclosure disclose a separation method of toluene-ethanol-water ternary azeotrope. A specific embodiment of the method includes separating toluene-ethanol-water ternary azeotrope by a preferential water-permeable membrane module to obtain a first treated material including retentate and gaseous product water collected in a mixing tank; condensing the gaseous product water to obtain product water; feeding the retentate to a rectifying column to obtain a rectified material including liquid azeotrope and toluene product; treating the liquid azeotrope by a preferential toluene-permeable membrane module to obtain a second treated material including ethanol product and toluene-containing steam; condensing the toluene-containing steam to obtain liquid toluene-containing material; feeding the liquid toluene-containing material to the mixing tank for treatment with the retentate; and collecting the product water, the toluene product and the ethanol product. By coupling the two membrane modules with the rectifying column, the embodiment can simplify the separation process.

Description

Technical Field

[0001] The embodiments disclosed herein relate to the field of chemical separation technology, specifically to a method for separating toluene-ethanol-water three-phase azeotropes. Background Technology

[0002] Toluene and ethanol are widely used basic chemical raw materials and common solvents in organic chemistry, synthetic pharmaceuticals, and fine chemicals. Their mixtures, especially the toluene-ethanol-water ternary azeotrope formed in the presence of water, are prevalent in many industrial processes. Currently, extractive distillation is commonly used to separate toluene-ethanol-water ternary azeotropes.

[0003] However, when using the above method to separate toluene-ethanol-water ternary azeotropes, in addition to separating the ternary azeotropes, it is necessary to add steps such as the selection, use, and recovery of the extractant, which often presents technical problems with high process complexity.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background of the present disclosure concept, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The summary portion of this disclosure is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description portion. This summary portion is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0006] Some embodiments of this disclosure propose a method for separating toluene-ethanol-water three-phase azeotropes to solve one or more of the technical problems mentioned in the background section above.

[0007] Some embodiments of this disclosure provide a method for separating a toluene-ethanol-water three-phase azeotrope. The method includes separating the toluene-ethanol-water three-phase azeotrope using a priority permeable membrane assembly to obtain a primary processed material, wherein the primary processed material includes residual material and vaporized product water, and the residual material is collected in a mixing tank; condensing the vaporized product water using a condenser to obtain product water; conveying the residual material from the mixing tank to a distillation column; distilling the residual material in the distillation column to obtain a distilled material, wherein the distilled material includes a liquid azeotrope and toluene product; pervaporating the liquid azeotrope using a priority permeable toluene membrane assembly to obtain a secondary processed material, wherein the secondary processed material includes ethanol product and toluene-containing vapor; condensing the toluene-containing vapor to obtain a liquid toluene-containing material; conveying the liquid toluene-containing material to the mixing tank using a transfer pump, where it is processed along with the residual material; and separately collecting the product water, the toluene product, and the ethanol product.

[0008] Optionally, the above-mentioned separation treatment of the toluene-ethanol-water three-phase azeotrope through a priority permeable membrane module to obtain a primary treated material includes: heating the toluene-ethanol-water three-phase azeotrope to a preset temperature to obtain a heated azeotrope, wherein the heated azeotrope is located on the permeate side of the priority permeable membrane module; and controlling the permeate side gas pressure of the priority permeable membrane module to be lower than the permeate side gas pressure to obtain the primary treated material.

[0009] Optionally, the above-mentioned conveying of the residual material from the mixing tank to the distillation column includes: drawing the residual material from the residual side of the preferred permeable membrane assembly to the mixing tank; preheating the residual material in the mixing tank to obtain preheated residual material; and conveying the preheated residual material to the distillation column.

[0010] Optionally, the above-mentioned distillation treatment of the residual material through the distillation column to obtain the distilled material includes: heating the residual material to obtain a vapor azeotrope and a toluene product; and condensing the vapor azeotrope to obtain a liquid azeotrope.

[0011] Optionally, the above-mentioned pervaporation treatment of the liquid azeotrope through the preferential toluene permeation membrane module to obtain secondary treated material includes: heating the liquid azeotrope to 30-50°C to obtain a preheated azeotrope; controlling the permeate-side gas pressure of the preferential toluene permeation membrane module to be lower than the saturated vapor pressure of toluene at 30-50°C; and passing the preheated azeotrope to the preferential toluene permeation membrane module to obtain secondary treated material.

[0012] Optionally, before the above-mentioned residue material is distilled through the above-mentioned distillation column to obtain the distilled material, the above method further includes: controlling the number of trays of the above-mentioned distillation column to be 10 to 30, the bottom temperature of the column to be 110 to 120°C, and the reflux ratio to be 0.5 to 2.

[0013] Optionally, controlling the permeable membrane module's permeable side pressure to be less than the residual pressure to obtain primary treated material includes: controlling the residual pressure of the preferred permeable membrane module to be between 0.05 and 0.3 MPaG; and controlling the permeable side pressure of the preferred permeable membrane module to be between 0.5 and 10 kPaA.

[0014] Optionally, controlling the permeate-side gas pressure of the preferential toluene permeate membrane module to be less than the saturated vapor pressure of toluene at 30 to 50°C includes controlling the permeate-side gas pressure of the preferential toluene permeate membrane module to be between 0.5 and 10 kPaA.

[0015] Optionally, before pervaporating the liquid azeotrope through the preferred toluene membrane assembly to obtain the secondary treated material, the method further includes: dissolving methyltriethoxysilane in n-heptane to obtain a mixed solution; dispersing SBA-15 molecular sieve into the mixed solution to obtain a mixture; heating the mixture under nitrogen atmosphere in a reflux reaction at 100°C for 12-24 hours to obtain a reaction product, wherein stirring of the mixture is maintained during the oil bath process; washing the reaction product with n-heptane to obtain a washed reaction product; drying the washed reaction product to obtain a modified molecular sieve; dissolving vinyl-terminated polydimethylsiloxane in n-heptane to obtain a polymer solution, wherein the mass of n-heptane is 8-1 / 3 the mass of vinyl-terminated polydimethylsiloxane. 0 times; The modified molecular sieve is dispersed in the polymer solution to obtain a homogeneous mixture; under stirring conditions, tetraethyl orthosilicate and dibutyltin dilaurate are added to the homogeneous mixture to obtain a primary casting solution; under increased stirring speed, the primary casting solution is stirred for a preset time to obtain a secondary casting solution; the secondary casting solution is degassed to obtain a finished casting solution; the finished casting solution is coated onto a support membrane to obtain a coated membrane; the coated membrane is dried in a vacuum environment at room temperature for 12 hours to obtain a primary cured membrane; the primary cured membrane is dried in a vacuum environment at 120°C for 4 hours to obtain a secondary cured membrane; after the secondary cured membrane is cooled to room temperature, it is washed with deionized water to obtain a washed cured membrane; the washed cured membrane is air-dried at room temperature to obtain a toluene-permeable membrane.

[0016] Some embodiments of this disclosure provide a method for separating toluene-ethanol-water three-phase azeotropes, which can simplify the process flow for separating toluene-ethanol-water three-phase azeotropes. Specifically, the reason why the separation process of most toluene-ethanol-water three-phase azeotropes is relatively complex is that extractive distillation is currently commonly used to separate toluene-ethanol-water ternary azeotropes. When using the above method to separate toluene-ethanol-water ternary azeotropes, in addition to separating the ternary azeotropes, additional steps such as the selection, use, and recovery of the extractant are required. Based on this, some embodiments of this disclosure provide a method for separating a toluene-ethanol-water three-phase azeotrope. The method includes separating the toluene-ethanol-water three-phase azeotrope using a priority permeable membrane assembly to obtain a primary processed material, wherein the primary processed material includes residual material and vaporized product water, and the residual material is collected in a mixing tank; condensing the vaporized product water using a condenser to obtain product water; conveying the residual material from the mixing tank to a distillation column; distilling the residual material in the distillation column to obtain a distilled material, wherein the distilled material includes a liquid azeotrope and toluene product; pervaporating the liquid azeotrope using a priority permeable toluene membrane assembly to obtain a secondary processed material, wherein the secondary processed material includes ethanol product and toluene-containing vapor; condensing the toluene-containing vapor to obtain a liquid toluene-containing material; conveying the liquid toluene-containing material to the mixing tank using a transfer pump, where it is processed along with the residual material; and separately collecting the product water, the toluene product, and the ethanol product. By combining membrane separation technology with distillation technology, a solvent-free dual-membrane module separation system is formed. This simplifies the process for separating toluene-ethanol-water three-phase azeotropes. Attached Figure Description

[0017] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and elements are not necessarily drawn to scale.

[0018] Figure 1 This is a flowchart of some embodiments of the method for separating toluene-ethanol-water three-phase azeotropes according to the present disclosure. Detailed Implementation

[0019] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0020] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0021] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0022] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0023] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0024] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Figure 1 A flow chart 100 illustrating some embodiments of a method for separating toluene-ethanol-water three-phase azeotropes according to the present disclosure is shown. The method for separating toluene-ethanol-water three-phase azeotropes includes the following steps:

[0026] Step 101: Separate the toluene-ethanol-water three-phase azeotrope using a priority water-permeable membrane module to obtain primary processed material.

[0027] In some embodiments, a toluene-ethanol-water three-phase azeotrope can be separated using a preferentially permeable membrane assembly to obtain a primary processed material. The preferentially permeable membrane assembly may include a preferentially permeable membrane. This membrane can be a pervaporation membrane capable of preferentially permeating water. The main body of the preferentially permeable membrane assembly can be a cylindrical stainless steel pressure vessel. The preferentially permeable membrane can be installed inside the main body of the preferentially permeable membrane assembly. The primary processed material may include residual material and vaporized product water, and the residual material can be collected in a mixing tank. The mixing tank can be a cylindrical stainless steel storage tank, used to store material that has not passed through the preferentially permeable membrane assembly, and to collect recycled material generated in subsequent steps that can continue to participate in the separation process.

[0028] In some optional implementations of certain embodiments, the primary processing material can be obtained through the following steps:

[0029] The first step involves heating the toluene-ethanol-water three-phase azeotrope to a preset temperature to obtain a heated azeotrope. This heated azeotrope is located on the permeate side of the preferential water-permeable membrane assembly. The preset temperature can be adjusted according to the type of preferential water-permeable membrane. For example, if the preferential water-permeable membrane is a polyvinyl alcohol (PVA) film, the preset temperature can be set to ≥30°C. At ≥30°C, the PVA film exhibits good permeability to water molecules. This is because the PVA molecular chain contains a large number of hydroxyl groups, and the molecules form certain crystalline and amorphous regions through hydrogen bonds. Above 30°C, as the temperature increases, molecular thermal motion intensifies, hydrogen bonding weakens, the proportion of amorphous regions increases, and the inter-chain gaps widen, allowing water molecules to more easily diffuse through the membrane. In practice, the toluene-ethanol-water three-phase azeotrope can be heated to the preset temperature using an electric heater to obtain the heated azeotrope.

[0030] The second step involves controlling the pressure on the permeate side of the preferential permeable membrane module to be lower than the pressure on the residual side, resulting in primary treated material. This primary treated material can include residual material and vaporized product water. In practice, a vacuum pump can be connected to the permeate side of the preferential permeable membrane module. The vacuum pump draws the pressure on the permeate side down to a level lower than the residual side pressure, driving the heated azeotrope to transfer to the permeate side of the membrane. Because the preferential permeable membrane module has the ability to preferentially allow water to permeate, it can achieve the purpose of separating water from the heated azeotrope. After water permeates through the preferential permeable membrane module, a toluene-ethanol azeotrope remains on the residual side, which is the residual material. This toluene-ethanol azeotrope on the residual side can be transported to the mixing tank for further processing. When the pressure on the permeate side is lower than the saturated vapor pressure of water at the preset temperature, even if the toluene-ethanol-water three-phase azeotrope enters the preferential permeable membrane module in a liquid state, the water obtained on the permeate side will exist in a vaporized form, which is the vaporized product water.

[0031] Optionally, the preferred water-permeable membrane in the above-mentioned preferred water-permeable membrane assembly can be prepared by the following steps:

[0032] The first step is to add polyvinyl alcohol powder to deionized water to obtain a solid-liquid mixture. The amount of polyvinyl alcohol powder used is not specifically limited here, as long as the mass fraction of the polyvinyl alcohol solution is between 5% and 8%.

[0033] The second step involves stirring the solid-liquid mixture in a constant-temperature water bath at 85±5℃ at a speed of 200-400 rpm for 2-3 hours until completely dissolved, yielding a polyvinyl alcohol solution. The mass fraction of the polyvinyl alcohol solution can be 5-8%. In practice, the solid-liquid mixture can be placed in a constant-temperature water bath and stirred with an electric stirrer, while continuously monitoring the thermometer reading to ensure it falls within the target temperature range. Maintaining the temperature within the target range improves dissolution efficiency and prevents molecular chain degradation due to high temperatures. The stirring time can be adjusted flexibly according to actual conditions, as long as the polyvinyl alcohol powder is completely dissolved.

[0034] The third step involves adding 0.1%–0.5% (by mass) of a nonionic defoamer to the polyvinyl alcohol solution to obtain a pre-defoaming solution. The nonionic defoamer can be polyethylene glycol (PEG). PEG has good compatibility with polyvinyl alcohol and possesses both defoaming and thickening properties, reducing membrane structural defects. In practice, 0.1%–0.5% (by mass) of the nonionic defoamer can be added to the polyvinyl alcohol solution using a pipette to obtain the pre-defoaming solution.

[0035] The fourth step is to stir the pre-defoaming solution for 0.5 hours to obtain the defoaming casting solution. Note that although defoamer has been added to the pre-defoaming solution, it is not fully dispersed. In practice, to ensure better defoaming effect, the pre-defoaming solution can be stirred at 100-200 rpm for 0.5 hours to obtain the defoaming casting solution.

[0036] The fifth step is to let the defoaming casting solution stand for 12 hours to remove bubbles, thus obtaining the casting solution. Although the above defoaming casting solution has had large bubbles and a foam layer removed by the defoamer treatment, bubbles generated during the stirring process may still remain inside. In practice, the above defoaming casting solution can be transferred to a wide-mouthed container, sealed, and left to stand for 12 hours to allow the bubbles to rise and dissipate naturally, ensuring the purity of the casting solution and reducing the possibility of pinholes after film formation.

[0037] Step 6: Immerse the base membrane in a 30% (w / w) ethanol aqueous solution and ultrasonically clean it for 20 minutes to obtain the cleaned base membrane. The base membrane can be a polyacrylonitrile (PAN) ultrafiltration membrane or a polysulfone (PSf) ultrafiltration membrane. This base membrane acts as a carrier for the coating casting solution, providing support. In practice, the base membrane can be immersed in a 30% (w / w) ethanol aqueous solution. Then, place the ethanol aqueous solution containing the base membrane in an ultrasonic cleaner. Ultrasonically clean the base membrane for 20 minutes to obtain the cleaned base membrane. This operation utilizes the degreasing ability of ethanol and the cavitation effect of ultrasound to remove organic matter, dust, and other impurities from the surface of the base membrane, improving the adhesion between the base membrane and the casting solution. Using a 30% ethanol aqueous solution balances cleaning effectiveness and economy; too high a concentration can cause the base membrane to swell, while too low a concentration will result in insufficient cleaning power.

[0038] Step 7: Rinse the cleaned base membrane with deionized water until the conductivity of the effluent is below 5 μS / cm, obtaining the rinsed base membrane. Note that ethanol may remain on the surface of the cleaned base membrane, and ions may dissolve during ultrasonic cleaning. In practice, the cleaned base membrane can be repeatedly rinsed with deionized water until the conductivity of the rinse water is <5 μS / cm. This operation can improve the purity of the base membrane surface and reduce the possibility of impurities affecting membrane performance.

[0039] Step 8: Dry the rinsed base film for 2 hours to obtain an activated base film. In practice, the rinsed base film can be placed in a forced-air drying oven and dried at 40–60°C for 2 hours to obtain an activated base film. This operation can remove moisture from the surface of the base film and activate the hydroxyl groups on the surface of the base film, enhancing its compatibility and adhesion with the casting solution. The temperature range of 40–60°C can reduce the possibility of base film deformation or oxidation caused by high temperatures while achieving rapid drying.

[0040] Step nine involves dispersing silica nanoparticles in a 10% (w / w) deionized water solution of polyvinyl alcohol to obtain a dispersion. The silica nanoparticles may include hydrophilic silica nanoparticles with a particle size of 20–50 nm. In practice, the silica nanoparticles can be added to a 10% (w / w) deionized water solution of polyvinyl alcohol and dispersed using an ultrasonic disperser for 30 minutes until homogeneous. The amount of silica nanoparticles used can be 1–3% of the mass of the polyvinyl alcohol powder added in step one.

[0041] Step 10: Add the dispersion to the casting solution to obtain the composite casting solution. The silica nanoparticles in the dispersion can improve the mechanical strength, hydrophilicity, and water permeability of the membrane. In practice, the dispersion can be slowly added to the casting solution, and stirred at 100–200 rpm for 1–2 hours until uniformly mixed. There is no specific limit to the stirring time; simply ensure the mixture is homogeneous.

[0042] Step 11: Apply the composite casting solution to the surface of the activated base film using an automatic coating machine to obtain a wet-coated film. The automatic coating machine can be any device that uses the mechanical movement of a doctor blade to evenly spread the slurry onto the surface of a substrate such as metal foil, glass, or plastic film to form a thin film. In practice, the doctor blade gap of the automatic coating machine can be set to 100±10μm, and the travel speed controlled at 2~5cm / s to obtain the wet-coated film.

[0043] Step 12: Arrange the wet-coated membrane in an environment with a relative humidity of 60±5% and a temperature of 25±1℃ for 10-15 minutes to obtain a gel-state primary wet membrane. In practice, the wet-coated membrane can be placed in a constant temperature and humidity chamber, controlling the relative humidity at 60±5% and the temperature at 25±1℃, and left to stand for 10-15 minutes. Aging allows for the slow exchange of solvent and non-solvent in the wet-coated membrane, promoting the phase separation process, forming a preliminary gel network structure, and improving the membrane's density and selectivity. Using a humidity of 60±5% can, to some extent, prevent rapid drying of the wet membrane, which could lead to surface cracking, while also promoting a uniform solvent evaporation rate. The temperature of 25±1℃ controls the phase separation rate; too high a temperature results in rapid phase separation and the formation of a loose structure, while too low a temperature prolongs the aging time.

[0044] Step 13: Perform gradient crosslinking and curing treatment on the gel-state primary wet membrane to obtain a crosslinked film. In practice, the above-mentioned gel-state primary wet membrane can be immersed in a crosslinking solution and treated in two stages: the first stage is constant temperature oscillation treatment at 50±2℃ for 20 minutes; the second stage is static crosslinking at 65±2℃ for 40 minutes. The crosslinking solution can be a deionized aqueous solution containing 3-4 wt% maleic acid and 0.8-1.2 wt% concentrated sulfuric acid. Furthermore, the pH value of the crosslinking solution needs to be adjusted to 2.5±0.2 with citric acid. Using the above crosslinking solution can improve the crosslinking efficiency and reduce the swelling rate of the finished membrane. This is because maleic acid contains two carboxyl groups, which can undergo esterification crosslinking with the hydroxyl groups on the polyvinyl alcohol (PVA) molecular chain to form a three-dimensional network structure. Each maleic acid molecule can connect two PVA chains, resulting in a 100% increase in crosslinking efficiency compared to single-carboxyl crosslinking agents similar to acetic acid. Furthermore, the ester bonds formed by esterification exhibit high chemical stability and strong resistance to acids and alkalis, which can reduce the swelling rate of the finished film and make it more suitable for environments containing high concentrations of toluene and ethanol. Concentrated sulfuric acid, as a strong acid catalyst, lowers the activation energy of the esterification reaction by providing hydrogen ions, thereby further increasing the crosslinking rate.

[0045] Step fourteen: Rinse the cross-linked membrane with deionized water until the effluent pH is >6.0 to obtain a washed membrane. In practice, the cross-linked membrane can be rinsed with deionized water until the effluent pH is >6.0 to remove residual cross-linking agents and other impurities on the membrane surface, reducing the impact on the membrane's water permeability and safety.

[0046] Step 15 involves multi-stage drying and shaping of the washed membrane to obtain a dried membrane. In practice, the washed membrane can be placed horizontally in a clean, dust-free room at room temperature with an ambient wind speed controlled at 0.5 m / s for 4 hours. Then, the membrane is transferred to a hot air circulating drying oven and treated at 50°C for 2 hours. Finally, it is heat-treated at a vacuum of -0.095 MPa and a temperature of 80°C for 1.5 hours to obtain the dried membrane. Multi-stage heating and drying can reduce stress concentration within the membrane, remove free water in the low-temperature stage, and remove bound water in the high-temperature stage, thus optimizing the membrane's pore structure and density.

[0047] Step sixteen: The dried film is subjected to hot-press strengthening treatment to obtain a preferentially permeable membrane. In practice, the dried film can be placed in a flat vulcanizing machine and hot-pressed at 120±5℃ and 0.5MPa pressure for 10 minutes to allow the composite casting liquid layer and the base film interface to fuse more fully, thus obtaining a preferentially permeable membrane.

[0048] The first to sixteenth steps described above are an inventive aspect of this disclosure, solving the technical problem of "poor crosslinking rate during the preparation of a water-permeable membrane." The specific factors leading to the poor crosslinking rate during the preparation of the water-permeable membrane are as follows: traditional crosslinking agents (such as glutaraldehyde) have limited activity and lack efficient catalytic systems, resulting in a slow esterification crosslinking reaction rate between polyvinyl alcohol molecular chains. Solving these factors can improve the crosslinking rate. To achieve this effect, this disclosure also provides a method for preparing a water-permeable membrane. By selecting a crosslinking agent containing maleic acid and catalyzing it with concentrated sulfuric acid, the esterification reaction rate is accelerated. This improves the crosslinking rate.

[0049] Step 102: The vaporized product water is condensed using a condenser to obtain product water.

[0050] In some embodiments, the above-mentioned vaporized product water can be condensed in a condenser to obtain product water. The condenser can be a shell-and-tube condenser, and is not specifically limited thereto.

[0051] Step 103: The residual material is transported from the mixing tank to the distillation column.

[0052] In some embodiments, the residual material can be transported from the mixing tank to the distillation column by a centrifugal pump, wherein the distillation column can be an atmospheric distillation column.

[0053] In some alternative implementations of certain embodiments, the residue can be conveyed from the mixing tank to the distillation column via the following steps:

[0054] The first step is to draw the residual material from the permeable membrane module's permeable side to the mixing tank. In practice, a centrifugal pump can be used to draw the residual material to the mixing tank.

[0055] The second step is to preheat the residual material in the mixing tank to obtain preheated residual material. In practice, the residual material in the mixing tank can be preheated to 70-85°C using an electric heater to obtain preheated residual material.

[0056] The third step is to transfer the preheated residue to the distillation column. In practice, the temperature difference between the preheated residue (70-85℃) and the inside of the distillation column is small, which can avoid a sudden drop in the column temperature caused by cold material, maintain a stable gas-liquid balance, and reduce the decrease in separation efficiency caused by temperature fluctuations to a certain extent.

[0057] Alternatively, the above-mentioned distillation column can be adjusted using the following parameters:

[0058] The distillation column should be controlled with 10–30 trays, a bottom temperature of 110–120°C, and a reflux ratio of 0.5–2. When the number of trays is less than 10, the azeotropic composition cannot be broken, resulting in lower toluene purity. While a number of trays greater than 30 can further improve toluene purity, it also increases energy consumption. Considering practical application requirements, a tray count of 10–30 yields toluene that meets the required purity. A bottom temperature of 110–120°C is higher than the boiling point of ethanol in the distillation column, ensuring sufficient vaporization of ethanol at the bottom without excessive energy consumption. A reflux ratio greater than 2 results in a high liquid load within the column, potentially hindering liquid flow; a reflux ratio less than 0.5 leads to insufficient gas velocity, increasing the risk of liquid leakage from the tray openings. The range of 0.5–2 allows for a proper balance of gas and liquid loads within the column.

[0059] Step 104: The residual material is distilled through a distillation column to obtain the distilled material.

[0060] In some implementations, the residual material can be distilled using a distillation column to obtain a purified material. This purified material may include liquid azeotropes and toluene products.

[0061] In some optional implementations of certain embodiments, the distillation material can be obtained through the following steps:

[0062] The first step is to heat the residual material to obtain a vapor azeotrope and toluene product. In practice, the bottom temperature of the distillation column can be controlled at 110-120℃ to heat the residual material, obtaining a vapor azeotrope (including ethanol-toluene azeotrope) at the top of the column and a toluene product at the bottom.

[0063] The second step is to condense the vapor azeotrope to obtain a liquid azeotrope. In practice, a condenser can be installed at the top of the distillation column to condense the vapor azeotrope and obtain a liquid azeotrope.

[0064] Step 105: The liquid azeotrope is pervaporated through a toluene-permeable membrane module to obtain secondary treated material.

[0065] In some embodiments, liquid azeotropes can be pervaporated using a toluene-selective membrane module to obtain secondary treated materials. The toluene-selective membrane module can have a similar main structure to the water-selective membrane module, except that a toluene-selective membrane is installed inside the toluene-selective membrane module. This toluene-selective membrane can be a membrane with selective permeability to toluene.

[0066] Optionally, the above-mentioned preferential toluene-permeable membrane can be prepared by the following steps:

[0067] The first step is to dissolve methyltriethoxysilane in n-heptane to obtain a mixed solution. In practice, 5 mmol (approximately 1.04 g) of methyltriethoxysilane can be dissolved in 15 g of n-heptane to obtain a mixed solution.

[0068] The second step involves dispersing the SBA-15 molecular sieve into the mixed solution to obtain a mixture. SBA-15 molecular sieve is an ordered mesoporous molecular sieve composed of silica, belonging to the category of mesoporous materials. In practice, 0.5–1 gram of SBA-15 molecular sieve powder can be added to the above mixed solution, and the powder can be uniformly dispersed in the solution using an ultrasonic disperser to obtain the mixture.

[0069] The third step involves heating the mixture under a nitrogen atmosphere in a 100°C oil bath under reflux for 12–24 hours to obtain the reaction product. During the oil bath process, the mixture must be continuously stirred. In practice, the oil bath, reaction flask, and condenser can be installed from bottom to top and from left to right, ensuring a tight seal at the interfaces. The mixture is then added to the reaction flask. Nitrogen gas is then introduced into the reaction flask to purge air until the reaction is complete. The reaction flask is heated to 100°C in the oil bath, and the heating power is adjusted to maintain a reflux rate of 1–2 drops / second in the condenser. Stirring is performed at 300–500 rpm to ensure uniform dispersion of the SBA-15 particles and prevent sedimentation. Once the reaction is complete, the oil bath is closed, and the mixture is allowed to cool naturally to room temperature. The oil bath is removed first, then the nitrogen gas is turned off, and finally the condenser is disassembled to prevent backflow. The reaction product is then removed from the reaction flask. The reaction flask can be a three-necked round-bottom flask; no specific limitation is made here.

[0070] The fourth step involves washing the reaction product with n-heptane to obtain the washed reaction product. This operation utilizes the property of n-heptane to dissolve residual organic matter, thereby removing unreacted silane, solvent, and byproducts remaining on the surface of the reaction product and improving the purity of the modified molecular sieve.

[0071] The fifth step is to dry the washed reaction product to obtain the modified molecular sieve. In practice, the washed reaction product can be placed in a vacuum drying oven and dried at 120°C to obtain the modified molecular sieve. The methyl groups on the surface of the modified molecular sieve have a strong adsorption capacity for toluene, allowing toluene molecules to preferentially pass through the membrane pores.

[0072] Step 6: Dissolve the vinyl-terminated polydimethylsiloxane in n-heptane to obtain a polymer solution. The mass of n-heptane can be 8 to 10 times that of the vinyl-terminated polydimethylsiloxane. In practice, the vinyl-terminated polydimethylsiloxane can be placed in a beaker, n-heptane slowly poured in, a magnetic stir bar inserted, and the beaker placed on a magnetic stirrer. Stir at a low speed of 100-200 rpm for 5 minutes, then increase the speed to 300-400 rpm until the solution becomes clear.

[0073] Step 7: Disperse the modified molecular sieve in the polymer solution to obtain a homogeneous mixture. In practice, the modified molecular sieve can be added to the polymer solution in 2-3 batches, stirring at a low speed of 200-300 rpm for 5 minutes after each addition. After all the sieve has been added, increase the speed to 400-500 rpm and stir for 30 minutes. There is no specific limit to the stirring time; the goal is for the molecular sieve to be evenly dispersed.

[0074] Step 8: Under stirring conditions, add tetraethyl orthosilicate and dibutyltin dilaurate to the homogeneous mixture to obtain the primary casting solution. In practice, under stirring conditions, tetraethyl orthosilicate and dibutyltin dilaurate can be added to the homogeneous mixture sequentially or simultaneously. Stir with an electric stirrer at 300–400 rpm while adding. The amount of tetraethyl orthosilicate added can be 5%–35% of the mass of the vinyl-terminated polydimethylsiloxane. Dibutyltin dilaurate, as a catalyst, can be added at an amount of 0.5%–1% of the mass of the vinyl-terminated polydimethylsiloxane.

[0075] Step 9: While increasing the stirring speed, stir the primary casting solution for a preset time to obtain the secondary casting solution. In practice, the stirrer speed can be increased to 500-800 rpm, and high-speed stirring can be maintained for 30-60 minutes to obtain the secondary casting solution.

[0076] Step 10: Degas the secondary casting solution to obtain the finished casting solution. In practice, the secondary casting solution can be degassed under vacuum or by static degassing to obtain the finished casting solution. Taking vacuum degassing as an example, the secondary casting solution can be poured into a vacuum degassing tank, sealed, and connected to a vacuum pump. The vacuum level is slowly evacuated to ≤50Pa. Maintain the negative pressure for 15–30 minutes. After observing that no obvious bubbles rise to the surface, slowly introduce air to break the vacuum and obtain the finished casting solution.

[0077] Step 11: The finished casting solution is scraped onto the support membrane to obtain the coated membrane. The support membrane may include a fluorinated membrane, such as a membrane formed by hot-pressing a porous polytetrafluoroethylene (PTFE) membrane with a polyphenylene sulfide (PPS) nonwoven fabric, or a membrane formed by hot-pressing a porous polyvinylidene fluoride (PVDF) membrane with a PPS nonwoven fabric. In practice, the finished casting solution can be scraped onto the support membrane to obtain the coated membrane.

[0078] Step 12: Dry the coated film in a vacuum environment at room temperature for 12 hours to obtain a primary cured film. In practice, the coated film can be placed in a vacuum drying oven, the door closed, and the vacuum level ≤100Pa maintained at room temperature. Dry for 12 hours, avoiding frequent opening of the oven door during this period to prevent air from entering and affecting curing. After drying, the film should be transparent or translucent and not sticky to the touch.

[0079] Step 13: Dry the primary cured film in a vacuum environment at 120°C for 4 hours to obtain the secondary cured film. In practice, the primary cured film can be placed in a vacuum drying oven and heated to 120°C, maintaining a vacuum degree ≤100Pa, and dried for 4 hours.

[0080] Step 14: After the secondary cured membrane cools to room temperature, wash it with deionized water to obtain a cleaned cured membrane. In practice, after drying, turn off the heating power and wait for the temperature inside the chamber to drop naturally below 50°C before slowly introducing air to break the vacuum and removing the membrane. Place the secondary cured membrane into a beaker containing deionized water and gently stir with a glass rod for 3–5 minutes. Replace the deionized water and repeat the washing process 3–4 times until the conductivity of the washing solution is ≤10 μS / cm. Note that during washing, use tweezers to hold the membrane edges to avoid contact with the membrane surface and prevent contamination or damage.

[0081] Step 15: Air-dry the cleaned and cured membrane at room temperature to obtain a toluene-permeable membrane. In practice, the cleaned and cured membrane can be laid flat on clean filter paper, placed on a drying rack, and air-dried at room temperature in a ventilated area to obtain a toluene-permeable membrane.

[0082] In some optional implementations of certain embodiments, secondary processed materials can be obtained through the following steps:

[0083] The first step is to heat the liquid azeotrope to 30–50°C to obtain a preheated azeotrope.

[0084] The second step is to control the permeate-side gas pressure of the preferential toluene permeate membrane module to be lower than the saturated vapor pressure of toluene at 30–50°C. The saturated vapor pressure of toluene at 30–50°C is approximately 4–17 kPa. In practice, the permeate-side gas pressure can be reduced to 0.5–10 kPa using a vacuum pump connected to the permeate-side of the preferential toluene permeate membrane module.

[0085] The third step involves passing the preheated azeotrope through a toluene-preferential membrane module to obtain the secondary treated material. In practice, after completing the first and second steps, passing the preheated azeotrope through the toluene-preferential membrane module yields the secondary treated material. This secondary treated material includes the ethanol product obtained on the osmosis side and the toluene-containing vapor obtained on the permeation side.

[0086] In some optional implementations of certain embodiments, the pressure across the preferential toluene permeation membrane assembly can be controlled by a pressure control component. This pressure control component can be a device comprising a pressure sensor, a temperature sensor, and a controller. Both the pressure sensor and the temperature sensor can be communicatively connected to the controller. There can be two pressure sensors, respectively installed on the permeate side and the permeate side of the preferential toluene permeation membrane assembly. There can also be two temperature sensors, each installed next to one of the two pressure sensors, enabling more accurate detection of the operating ambient temperature of the pressure sensors. The controller can be an industrial computer, without specific limitations. The pressure control component is configured to perform the following steps:

[0087] The first step involves controlling the pressure sensor to sample both sides of the preferential toluene permeation membrane module at a preset frequency to obtain primary pressure information. This primary pressure information can be an array containing two values. These two values ​​represent the pressure values ​​on the permeate side and the osmotic side of the preferential toluene permeation membrane module, respectively, collected by the pressure sensor. For example, if the primary pressure information is (0.2, 0.3), it means that the permeate side pressure of the preferential toluene permeation membrane module is 0.2 MPa and the osmotic side pressure is 0.3 MPa. In practice, the controller can control the pressure sensor to sample both sides of the preferential toluene permeation membrane module at a preset frequency and encode the values ​​obtained from each sampling into an array to obtain the primary pressure information. For example, the controller can sample both sides of the preferential toluene permeation membrane module at a frequency of 3 times per second.

[0088] The second step involves filtering the primary pressure information obtained after a preset number of samplings to obtain secondary pressure information. This secondary pressure information can be an array. In practice, the controller can calculate the average pressure values ​​on both sides of each primary pressure information sampled by the pressure sensor after a preset number of samplings. These average values ​​are then combined into a new array as the secondary pressure information. For example, assuming the preset number of samplings is three, three arrays (1,2), (2,3), and (3,4) are obtained. The average of the numbers representing the same pressure value within these three arrays can be calculated. This involves adding the first three digits of each array and dividing by 3, then adding the third and fourth digits and dividing by 3, and using the resulting two numbers to form a new array. That is, 1+2+3=6, 6 / 3=2; 2+3+4=9, 9 / 3=3, and the new array is (2,3).

[0089] Furthermore, due to the piezoresistive effect, the resistivity of the semiconductor material in most pressure sensors increases as the temperature rises, causing the output signal to deviate from the true pressure value. Since the priority toluene membrane module primarily separates toluene from other substances through pervaporation, its operating environment temperature is typically higher than room temperature. Therefore, the pressure value measured by the pressure sensor needs to be compensated and corrected to more accurately control the process parameters.

[0090] The third step involves using a temperature sensor to detect the temperature of the environment in which the pressure sensor operates, thus obtaining the ambient temperature value. In practice, the controller described above can control the temperature sensor to collect the ambient temperature value during the pressure sensor's operation. If multiple temperature sensors are present, the average value obtained from the temperature values ​​detected by these sensors can be calculated and used as the ambient temperature value.

[0091] The fourth step is to determine the pressure compensation coefficient based on the ambient temperature value. This pressure compensation coefficient can be a numerical value used to correct the pressure value measured by the pressure sensor. In practice, the controller can use a preset temperature-compensation coefficient mapping table to match the pressure compensation coefficient corresponding to the current ambient temperature value.

[0092] The fifth step is to determine the current pressure information based on the secondary pressure information and the pressure compensation coefficient. This current pressure information may include the residual pressure value and the permeable pressure value, and these values ​​can be stored in an array format, referencing the secondary pressure information. In practice, the controller can determine the current pressure information using the following formula:

[0093] Residual pressure value = Secondary pressure value + (1 + compensation coefficient × (temperature value - 25℃)).

[0094] Wherein, "secondary pressure value" can be the value representing the residual pressure included in the above-mentioned secondary pressure information. "Compensation coefficient" can be the above-mentioned pressure compensation coefficient. "Temperature value" can be the above-mentioned ambient temperature value.

[0095] Osmotic pressure value = Secondary pressure value + (1 + Compensation coefficient × (Temperature value - 25℃)).

[0096] The "secondary pressure value" can be the value representing the permeable side pressure included in the aforementioned secondary pressure information. The "compensation coefficient" can be the aforementioned pressure compensation coefficient. The "temperature value" can be the aforementioned ambient temperature value.

[0097] The residual pressure and permeability pressure values ​​determined by the formula are compiled into an array and used as the current pressure information.

[0098] Step 6: In response to a mismatch between the residual pressure value and the first target pressure range, first deviation information is generated based on the residual pressure value and the first target pressure range. The first target pressure range can be a preset residual pressure range. The mismatch between the residual pressure value and the first target pressure range can mean that the residual pressure value does not belong to the first target pressure range; it may be greater than or less than the range. In practice, the controller can generate the first deviation information from the following two aspects:

[0099] Firstly, when the controller determines that the residual pressure value is greater than the first target pressure range, it subtracts the maximum value of the first target pressure range from the residual pressure value and determines the difference as the first deviation information. For example, if the first target pressure range is [2,3] and the residual pressure value is 4, then the first deviation information can be "1".

[0100] Secondly, when the controller determines that the residual pressure value is less than the first target pressure range, it subtracts the residual pressure value from the minimum value of the first target pressure range to obtain the difference. For example, if the first target pressure range is [2,3] and the residual pressure value is 1, then 2-1=1. It should be noted that the differences obtained from the first and second aspects may be equal, but they represent different meanings. The first aspect requires reducing the residual pressure, while the second aspect requires increasing it. Therefore, to distinguish the different meanings represented by the two aspects, the controller can perform preset processing on the difference obtained from the second aspect (or the first aspect, without specific limitation) to obtain the first deviation information. For example, the controller can multiply the obtained difference by "-1" and then determine the product as the first deviation information.

[0101] Step 7: Determine the first control parameter based on the first deviation information. This first control parameter can be a parameter used to adjust the pressure on the permeate side, such as the change in the feed pump speed. In practice, the controller can match the first control parameter corresponding to the current first deviation information from a preset deviation information-control parameter mapping table. For example, when the first deviation information is "-1", the corresponding first control parameter can be "increase the speed by 80 rpm"; when the first deviation information is "1", the corresponding first control parameter can be "decrease the speed by 80 rpm".

[0102] Step 8: Adjust the speed of the feed pump according to the first control parameter. The feed pump can be connected to the permeate side of the preferential toluene permeation membrane module. In practice, the controller can adjust the feed pump speed through the following steps:

[0103] Step 1: Add the original speed of the feed pump to the speed adjustment amount corresponding to the first control parameter to obtain the target speed. When the speed needs to be increased, the speed adjustment amount is positive; when the speed needs to be decreased, the speed adjustment amount is negative. The controller can determine that the speed adjustment amount is positive when it detects that the first control parameter contains the word "increase," and negative when it detects that the first control parameter contains the word "decrease." The specific value of the speed adjustment amount can be directly extracted from the numerical part of the first control parameter. Then, add the determined speed adjustment amount to the original speed to obtain the target speed. For example, when the first control parameter is "speed increase of 80 rpm," the speed adjustment amount can be determined as +80. Assuming the original speed of the feed pump is 200 rpm, the target speed is 200 + 80 = 280 rpm.

[0104] Step two: Compare the obtained target speed with the preset speed-power relationship table to obtain the target power value. For example, the target power value corresponding to 280 rpm could be 50W.

[0105] Step 3: Adjust the actual power value of the feed pump to the target power value.

[0106] Step 9: In response to a mismatch between the permeate-side pressure value and the second target pressure range, second deviation information is generated based on the permeate-side pressure value and the second target pressure range. The second target pressure range can be a preset permeate-side pressure range. A mismatch between the permeate-side pressure value and the second target pressure range can mean that the permeate-side pressure value does not belong to the second target pressure range; it may be greater than or less than the range. It should be noted that since the permeate side of the preferential toluene permeate membrane module is under negative pressure, its actual pressure value may be negative. This means that the greater the negative pressure, the smaller the corresponding pressure value. To avoid errors, both the permeate-side pressure value and the second target pressure range use the absolute value of the actual pressure value to represent the degree of negative pressure. For example, if the permeate-side pressure value is 1, it actually means that the pressure on the permeate side is -1 MPa. In practice, the controller can generate second deviation information from two aspects:

[0107] Firstly, when the controller determines that the permeation-side pressure value is greater than the second target pressure range, it subtracts the maximum value of the second target pressure range from the permeation-side pressure value and uses the difference as the second deviation information. For example, if the second target pressure range is [2,3] and the permeation-side pressure value is 4, then the second deviation information can be "1".

[0108] Secondly, when the controller determines that the permeation-side pressure value is less than the second target pressure range, it subtracts the permeation-side pressure value from the minimum value of the second target pressure range to obtain the difference. For example, if the second target pressure range is [2,3] and the permeation-side pressure value is 1, then 2-1=1. It should be noted that the differences obtained from the first and second aspects may be equal, but their meanings are different. The first aspect requires decreasing the permeation-side negative pressure, while the second aspect requires increasing it. Therefore, to distinguish the different meanings represented by the two aspects, the controller can perform preset processing on the difference obtained from the second aspect (or the first aspect, without specific limitation) to obtain second deviation information. For example, the controller can multiply the obtained difference by "-1" and then determine the product as the second deviation information.

[0109] Step 10: Determine the second control parameter based on the second deviation information. This second control parameter can be a parameter used to adjust the permeation-side pressure, such as the change in vacuum pump power. In practice, the controller can match the second control parameter corresponding to the current second deviation information from a preset deviation information-control parameter mapping table. For example, when the second deviation information is "-1", the corresponding second control parameter can be "power increase by 20W"; when the second deviation information is "1", the corresponding second control parameter can be "power decrease by 20W".

[0110] Step 11: Adjust the power of the vacuum pump according to the second control parameter. The vacuum pump is connected to the permeation side of the priority toluene permeation membrane module. In practice, the controller can first add the original power value of the vacuum pump to the power adjustment amount corresponding to the second control parameter to obtain the target power. Then, adjust the power of the vacuum pump to the target power. When the second control parameter indicates a need to increase power, the power adjustment amount is positive; when a need to decrease power, the power adjustment amount is negative. The controller can determine that the power adjustment amount is positive when it detects the word "increase" in the second control parameter, and negative when it detects the word "decrease". The specific value of the power adjustment amount can be directly extracted from the numerical part of the second control parameter. For example, when the second control parameter is "power increase 20W", the power adjustment amount can be determined as +20W. Assuming the original power of the feed pump is 60W, the target power is 60 + 20 = 80W. Then, adjust the power of the vacuum pump to 80W.

[0111] The steps 1 through 11 described above are an inventive point of this disclosure, solving the technical problem of "low filtration efficiency of the priority toluene permeate membrane module". The specific factors leading to the low filtration efficiency of the priority toluene permeate membrane module are as follows: Using a priority toluene permeate membrane module requires real-time and accurate detection of the pressure on its refractory and permeate sides in an environment above room temperature to adjust the pressure to the high-efficiency range. Currently, pressure sensors are commonly used to detect the pressure on both sides of the priority toluene permeate membrane module in real time. However, due to the piezoresistive effect in environments above room temperature, the pressure value measured by the pressure sensor has a large error compared to the actual value. Solving the above factors can improve the filtration efficiency of the priority toluene permeate membrane module. To achieve this effect, this disclosure also provides a pressure measurement method based on "sampling-filtering-compensation". Multiple sets of pressure data are obtained through multiple samplings, and after filtering these data sets, the pressure values ​​are compensated and corrected according to the operating environment temperature, improving the accuracy of the pressure sensor's pressure measurement. This improves the filtration efficiency of the priority toluene permeate membrane module.

[0112] Step 106: The toluene-containing vapor is condensed to obtain a liquid toluene-containing material.

[0113] In some embodiments, toluene vapor can be condensed using a condenser to obtain a liquid toluene-containing material. It should be noted that the toluene content in the aforementioned liquid toluene-containing material is 45–60 wt%, and it cannot be directly collected as a toluene product.

[0114] Step 107: The liquid toluene-containing material is transported to the mixing tank by a transfer pump and treated together with the leachate.

[0115] In some embodiments, a transfer pump can be used to transport the liquid toluene-containing material to a mixing tank for processing along with the residual material. The toluene content in the liquid toluene-containing material is between 45 and 60 wt%, and it cannot be directly collected as a toluene product. Therefore, the liquid toluene-containing material can be recycled back to the mixing tank for further separation processing, thus achieving material recycling.

[0116] Step 108: Collect the product water, toluene and ethanol respectively.

[0117] In some embodiments, a transfer pump can be used to extract product water, toluene and ethanol from their respective storage devices.

[0118] Some embodiments of this disclosure provide a method for separating toluene-ethanol-water three-phase azeotropes, which can simplify the process flow for separating toluene-ethanol-water three-phase azeotropes. Specifically, the reason why the separation process of most toluene-ethanol-water three-phase azeotropes is relatively complex is that extractive distillation is currently commonly used to separate toluene-ethanol-water ternary azeotropes. When using the above method to separate toluene-ethanol-water ternary azeotropes, in addition to separating the ternary azeotropes, additional steps such as the selection, use, and recovery of the extractant are required. Based on this, some embodiments of this disclosure provide a method for separating a toluene-ethanol-water three-phase azeotrope. The method includes separating the toluene-ethanol-water three-phase azeotrope using a priority permeable membrane assembly to obtain a primary processed material, wherein the primary processed material includes residual material and vaporized product water, and the residual material is collected in a mixing tank; condensing the vaporized product water using a condenser to obtain product water; conveying the residual material from the mixing tank to a distillation column; distilling the residual material in the distillation column to obtain a distilled material, wherein the distilled material includes a liquid azeotrope and toluene product; pervaporating the liquid azeotrope using a priority permeable toluene membrane assembly to obtain a secondary processed material, wherein the secondary processed material includes ethanol product and toluene-containing vapor; condensing the toluene-containing vapor to obtain a liquid toluene-containing material; conveying the liquid toluene-containing material to the mixing tank using a transfer pump, where it is processed along with the residual material; and separately collecting the product water, the toluene product, and the ethanol product. By combining membrane separation technology with distillation technology, a solvent-free dual-membrane module separation system is formed. This simplifies the process for separating toluene-ethanol-water three-phase azeotropes.

[0119] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A method for separating toluene-ethanol-water three-phase azeotrope, the method comprising: The toluene-ethanol-water three-phase azeotrope is separated by a priority permeable membrane module to obtain a primary treated material, wherein the primary treated material includes residual material and vaporized product water, and the residual material is collected in a mixing tank. The vaporized product water is condensed using a condenser to obtain product water; The residual material is conveyed from the mixing tank to the distillation column; The residue is distilled through the distillation column to obtain a distillate, wherein the distillate includes a liquid azeotrope and a toluene product. The liquid azeotrope is pervaporated using a toluene-preferred permeate membrane module to obtain a secondary processed material, wherein the secondary processed material includes ethanol product and toluene-containing vapor. The toluene-preferred permeate membrane in the toluene-preferred permeate membrane module is prepared through the following steps: Dissolve methyltriethoxysilane in n-heptane to obtain a mixed solution; The SBA-15 molecular sieve was dispersed into the mixed solution to obtain a mixture; Under a nitrogen atmosphere, the mixture is heated and refluxed in an oil bath at 100°C for 12-24 hours to obtain the reaction product. During the oil bath process, the mixture is stirred. The reaction product was washed with n-heptane to obtain the washed reaction product. The reaction product after cleaning was dried to obtain a modified molecular sieve. Vinyl-terminated polydimethylsiloxane is dissolved in n-heptane to obtain a polymer solution, wherein the mass of n-heptane is 8 to 10 times that of vinyl-terminated polydimethylsiloxane. The modified molecular sieve is dispersed in the polymer solution to obtain a homogeneous mixture; Under stirring conditions, tetraethyl orthosilicate and dibutyltin dilaurate are added to the homogeneous mixture to obtain a primary casting solution; By increasing the stirring speed, the primary casting solution is stirred for a preset time to obtain the secondary casting solution; The secondary casting solution is defoamed to obtain the finished casting solution; The finished casting solution is scraped onto the support film to obtain a coated film; The coating film was dried in a vacuum environment at room temperature for 12 hours to obtain a primary cured film. The primary cured film was dried at 120°C for 4 hours under vacuum to obtain the secondary cured film; After the secondary cured film is cooled to room temperature, it is washed with deionized water to obtain a cleaned cured film. The cleaned and cured film was air-dried at room temperature to obtain a toluene-permeable membrane. The toluene-containing vapor is condensed to obtain a liquid toluene-containing material; The liquid toluene-containing material is transported to the mixing tank by a transfer pump, where it is treated together with the residual material. The product water, the toluene product, and the ethanol product were collected separately.

2. The method according to claim 1, wherein, The separation of the toluene-ethanol-water three-phase azeotrope using a priority water-permeable membrane module yields a primary processed material, including: The toluene-ethanol-water three-phase azeotrope is heated to a preset temperature to obtain a heated azeotrope, wherein the heated azeotrope is located on the permeate side of the preferred water-permeable membrane assembly; By controlling the permeable membrane module to have a lower permeable side pressure than the residual permeable side pressure, primary treated material is obtained.

3. The method according to claim 1, wherein, The step of conveying the residual material from the mixing tank to the distillation column includes: The residual material is drawn from the residual side of the preferred permeable membrane assembly to the mixing tank; The residual material in the mixing tank is preheated to obtain preheated residual material. The preheated residual material is conveyed to the distillation column.

4. The method according to claim 1, wherein, The process of distilling the residue through the distillation column to obtain a distillate includes: Heating the permeate yields a vapor azeotrope and a toluene product; The vapor azeotrope is condensed to obtain a liquid azeotrope.

5. The method according to claim 1, wherein, The process of pervaporating the liquid azeotrope through a preferential toluene-permeable membrane module to obtain secondary processed materials includes: The liquid azeotrope is heated to 30-50°C to obtain a preheated azeotrope; The permeate-side gas pressure of the preferred toluene membrane module is controlled to be less than the saturated vapor pressure of toluene at 30~50°C; The preheated azeotrope is passed to the preferred toluene permeate membrane assembly to obtain secondary processed material.

6. The method according to claim 1, wherein, Before the distillation treatment of the residue material through the distillation column to obtain the distilled material, the method further includes: The number of trays in the distillation column is controlled to be 10-30, the bottom temperature to be 110-120℃, and the reflux ratio to be 0.5-2.

7. The method according to claim 2, wherein, The process of controlling the permeable membrane module to have a lower permeable side pressure than a residual side pressure yields primary treated material, including: The permeate pressure of the preferred permeable membrane module is controlled at 0.05~0.3 MPaG; The permeable membrane module is controlled to have a permeable side pressure of 0.5~10 kPaA.

8. The method according to claim 5, wherein, Controlling the permeate-side gas pressure of the preferential toluene permeate membrane module to be lower than the saturated vapor pressure of toluene at 30-50°C includes: The permeate-side gas pressure of the preferred toluene membrane module is controlled at 0.5~10 kPaA.

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