A barrel-shaped carbon membrane and a method for manufacturing the same, and a separation assembly and a separation method

Abstract

The present application provides a barrel-shaped carbon membrane and a preparation method thereof, and a separation assembly and a separation method. The barrel-shaped carbon membrane has a mesoporous-microporous structure, and the barrel-shaped structure of the barrel-shaped carbon membrane is obtained by one-time forming. The present application directly utilizes the barrel-shaped carbon membrane, without element manufacturing, device assembly, or even module construction, and simple cooperation with a tee-shaped filter and other standard parts can realize separation of mixed gas or liquid, and realizes simple and efficient application of the carbon membrane.

Description

Technical Field

[0001] This invention relates to the field of carbon membranes, and more specifically, to a barrel-shaped carbon membrane and its preparation method, as well as a separation component and separation method. Background Technology

[0002] Porous carbon materials, due to their well-developed pore structure, good chemical stability, corrosion resistance, and high conductivity, are widely used in adsorption, catalysis, electrochemistry, and energy and environmental fields. Carbon membranes are outstanding representatives of porous carbon materials. As a novel, efficient, and energy-saving inorganic separation membrane, they also possess advantages such as high specific surface area, high thermal stability, biocompatibility, and renewability, along with a well-developed pore structure. Carbon membranes can distinguish gas molecules by size, making them particularly suitable for separating small molecules in mixed gases or separating liquids (isomers) with small kinetic radii in mixed liquids (such as mixtures of isomers). They exhibit high separation selectivity and permeability, thus demonstrating promising application prospects.

[0003] Permeability and selectivity are crucial parameters determining the application scenarios and industrial prospects of carbon membranes, and are also key foundations for the success or failure of subsequent industrial applications. As the two most important performance indicators of carbon membranes, permeability and selectivity often exhibit a seesaw effect, meaning that improving selectivity often comes at the cost of decreased permeability, or improving permeability requires sacrificing selectivity. Researchers have racked their brains to improve molding and fabrication methods, hoping to achieve an optimal combination of both to meet the requirements of practical applications. For example, Kita et al. used porous aluminum with an average pore size of 1 μm and a porosity of 50% as a support, coated it with a phenolic resin solution, and then prepared a carbon membrane after drying and carbonization. They found that the number of coatings had a significant impact on gas permeability and selectivity, with three coatings showing the best results. Centeno and Fuertes et al. coated a carbon support with a phenolic resin solution on an average pore size of 0.5 μm, and the prepared carbon membrane exhibited molecular sieving properties. Furthermore, Kolar et al. prepared a flat carbon support using thermosetting phenolic resin as a raw material, and then coated it with a phenolic resin solution, but it lacked selectivity.

[0004] While the aforementioned studies have achieved significant improvements in carbon film performance, performance testing, particularly for industrial applications, still requires component fabrication, device assembly, and even module construction. These processes are not only cumbersome and complex but also frequently involve a failure rate. According to the success rate propagation mechanism, even a 99% success rate will rapidly decrease to 90% after 10 steps, resulting in a substantial drop in success rate and yield, leading to significant losses. Furthermore, the combined amplification of the cumbersome preparation process and the losses during fabrication ultimately hinders the progress, application, and success of carbon film manufacturing. In a sense, it's not that carbon film performance is inherently inferior, but rather that the numerous and progressively increasing success rates (99% success rate becomes 90% after 10 steps, and 95% success rate drops to less than 60%) prevent the effective realization of the superior and advanced performance of carbon films, thus delaying industrial trials and even industrial applications. Summary of the Invention

[0005] To address the challenges of existing technologies, this invention provides a simple, rapid, efficient, and reproducible method for preparing barrel-shaped carbon membranes. The key is the use of phenols and aldehydes as raw materials, which, guided by surfactants in solution, are injected into a barrel-shaped mold to rapidly generate a cross-linked network of mesoporous organic membranes. These membranes are then carbonized at high temperature, resulting in a one-step preparation of the mesoporous-microporous barrel-shaped carbon membrane. Furthermore, this invention also provides a separation process based on the barrel-shaped carbon membrane. It directly utilizes the barrel-shaped carbon membrane prepared by this invention, eliminating the need for membrane device fabrication or membrane assembly (including element fabrication, device assembly, and module construction). It can be directly used in conjunction with existing technologies (such as three-way filters) for the separation of mixed gases or liquids.

[0006] One of the objectives of this invention is to provide a barrel-shaped carbon membrane, which has a mesoporous-microporous structure, and the barrel-shaped structure of the barrel-shaped carbon membrane is obtained by one-time molding.

[0007] The second objective of this invention is to provide a method for preparing the barrel-shaped carbon membrane, comprising loading a mixture of phenolic resin precursors into a barrel-shaped mold, then transferring the entire barrel-shaped mold into an environment at a set temperature for low-temperature aging to obtain a mesoporous-microporous organic membrane; removing the mesoporous-microporous organic membrane, and finally carbonizing it at a high temperature.

[0008] The phenolic resin precursor mixture includes phenolic compounds, aldehyde compounds, amine compounds, surfactants, and solvents.

[0009] This invention uses phenolic compounds, amine compounds, and aldehyde compounds as raw materials. Under the structural guidance of a template agent, a cross-linked network of phenolic resin, namely a benzoxazine-phenolic resin precursor, is generated. In this process, organic amines participate in catalytic copolymerization, promoting the formation of a regular mesoporous structure. At the same time, nitrogen-containing functional groups are introduced, which not only rapidly forms a regular mesoporous organic polymer, but also allows the obtained polymer to be directly dried in air. After conventional high-temperature heat treatment (carbonization), a mesoporous-microporous carbon membrane is obtained.

[0010] The phenolic compound is preferably at least one of phenol, resorcinol, and phloroglucinol.

[0011] The amine compound is preferably at least one of ethylenediamine, propylenediamine, butanediamine, and hexamethylenediamine.

[0012] The surfactant is preferably at least one of F127, P123, F108, and B50.

[0013] The aldehyde compound is preferably at least one of formaldehyde, polyoxymethylene, and furfural.

[0014] The molar ratio of the phenolic compound to the aldehyde compound is (1:1) to (1:3), with a preferred molar ratio of (1:1.5) to (1:3), and can specifically be 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, etc.

[0015] The molar ratio of the phenolic compound to the amine compound is (1:0.005) to (1:0.05), with a preferred molar ratio of (1:0.005) to (1:0.01). Specifically, it can be 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.015, 1:0.02, 1:0.025, 1:0.03, 1:0.035, 1:0.04, 1:0.045, 1:0.05, etc.

[0016] The molar ratio of the phenolic compound to the surfactant is (1:0.004) to (1:0.02), preferably (1:0.004) to (1:0.01), and specifically can be 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.010, 1:0.011, 1:0.012, 1:0.013, 1:0.014, 1:0.015, 1:0.016, 1:0.017, 1:0.018, 1:0.019, 1:0.02, etc.

[0017] The solvent is selected from at least one of water and ethanol, preferably a mixture of water and ethanol, and more preferably a water to alcohol mass ratio of (3:7) to (7:3).

[0018] Preferably, the molar ratio of the phenolic compound to water and / or alcohol is (1:20) to (1:300).

[0019] In the preparation method of the present invention, preferably, the preparation method of the phenolic resin precursor mixture may include: (1) dissolving phenolic compounds in a solvent; (2) adding surfactants and dissolving them completely; (3) adding amine compounds; and (4) rapidly adding aldehyde compounds.

[0020] The order of steps (3) and (4) can be interchanged.

[0021] The ambient temperature for low-temperature aging is 70–110℃, preferably 80–100℃.

[0022] The low-temperature aging time is 0.5 to 10 hours, preferably 1 to 4 hours.

[0023] Before low-temperature aging, the phenolic resin precursor mixture can be defoamed. The defoaming method can be at least one of vibration, ultrasound, or long-term static stopping, with ultrasound defoaming being the preferred method.

[0024] After low-temperature aging and demolding, the process may also include a step of drying the organic film.

[0025] High-temperature carbonization involves raising the temperature from room temperature to 150–450°C at a rate of 0.5–3°C / min under inert gas conditions, holding the temperature for 30 min–2 h, and then raising the temperature to 500–1000°C at a rate of 1–5°C / min and holding the temperature for 60 min–5 h.

[0026] A third objective of this invention is to provide a barrel-shaped mold for use in the above-described preparation method. The barrel-shaped mold includes an outer cylindrical barrel, a middle electrode-shaped cylinder, and a top round cover. The middle electrode-shaped cylinder is connected to the top round cover and is concentric in the axial direction. The height of the middle electrode-shaped cylinder is less than the height of the outer cylindrical barrel, and the diameter of the middle electrode-shaped cylinder is less than the diameter of the outer cylindrical barrel.

[0027] Preferably, the top cover is stepped, and when the top cover and the middle electrode cylinder are inserted into the outer cylindrical barrel, the smaller diameter end of the stepped top cover fits against the inner wall of the outer cylindrical barrel. The number of steps in the top cover can be one, two, or more.

[0028] The barrel-shaped mold of this invention comprises three parts: an outer cylindrical barrel (hereinafter referred to as the barrel), a middle electrode-shaped cylinder (hereinafter referred to as the cylinder), and a top cover (round cover). The middle electrode-shaped cylinder (cylinder) and the top cover (round cover) are connected as a single unit. The connection between the middle electrode-shaped cylinder and the top round cover can be achieved using a conventional method. The cylinder and the round cover are concentric in the axial projection plane, that is, the barrel and the cylinder are concentric in the axial direction. Furthermore, the distance between the outer surface of the cylinder and the inner surface of the barrel is completely equal in the radial direction, that is, the barrel and the cylinder are coaxial in the radial direction. After the round cover (along with the cylinder) of the barrel-shaped mold is tightly fitted to the barrel, the distance between the cylinder and the barrel is appropriate (including the barrel membrane wall thickness expressed radially and the barrel membrane bottom thickness expressed axially). Moreover, it can be flexibly adjusted to increase or decrease according to the comprehensive requirements of the separation process for carbon membrane strength and permeability.

[0029] The fourth objective of this invention is to provide a separation component, comprising the barrel-shaped carbon membrane described above or the barrel-shaped carbon membrane obtained by the preparation method, and a standard filter, wherein the barrel-shaped carbon membrane is installed at the position of the membrane filter element in the standard filter.

[0030] The standard filter can be any existing model of standard filter. The barrel-shaped carbon membrane can replace the membrane filter element in the standard filter, or it can be directly installed in a standard filter without a membrane filter element.

[0031] Preferably, the barrel-shaped carbon membrane is connected to the standard filter using adhesive or by spring compression. Spring compression is simpler, and for quick disassembly and sealing, a combination of spring compression and O-ring seals is preferred.

[0032] In this invention, the barrel-shaped carbon membrane can be adjusted in size and height according to the specifications of existing standard filters. Size adjustment includes changing the inner diameter of the barrel and the outer diameter of the cylinder, thereby changing the wall thickness of the membrane; height adjustment includes changing the amount of phenolic resin injected into the mold or adjusting the height of the mold, thereby changing the height of the membrane.

[0033] The fifth objective of this invention is to provide a separation method, which includes feeding a mixture into a separation system through a feeding system to obtain separated materials, wherein a portion of the separated materials flows out and the remaining separated materials flow back into the separation system through a reflux system for re-separation; the separation system includes the separation components described above.

[0034] The separation process of the barrel-shaped carbon membrane includes two core elements: the barrel-shaped carbon membrane and a standard filter. Together, they form the separation assembly and ultimately the separation system. To improve the separation efficiency or selectivity of the barrel-shaped carbon membrane, auxiliary systems such as a feeding system and a circulation system may be optionally added, but these are not necessary.

[0035] Standard filters can include either three-way filters (standard parts) or straight-through filters (standard parts). When replacing standard filters with different models, such as replacing a three-way filter with a straight-through filter, the installation procedure for the cylindrical carbon membrane differs. When using a cylindrical carbon membrane with a three-way filter, the three-way filter mounting hardware can be installed first, followed by the cylindrical carbon membrane, or both can be pre-installed and then installed as a whole into the system. However, for straight-through filters, only the latter method can be used; that is, the cylindrical carbon membrane must be installed inside the straight-through filter first, and then the whole system can be installed. Straight-through filters will make online replacement inconvenient, requiring the separation system (composed of the cylindrical carbon membrane and the straight-through filter) to be removed from the system first.

[0036] In addition, the feeding system and circulation system selected for this separation system will also be changed accordingly, but this is common knowledge among practitioners in this field.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. Because it uses a barrel-shaped mold for one-time molding, without the need for secondary or multiple surface modifications, the preparation cycle is greatly shortened and the yield of carbon film is significantly improved.

[0039] 2. By directly utilizing this barrel-shaped carbon membrane, there is no need for component manufacturing, device assembly, or even module construction. Simply by combining it with standard components such as a three-way filter, the separation of mixed gases or liquids can be achieved, thus simplifying and increasing the efficiency of carbon membrane applications. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the cross-sectional structure of the outer cylindrical barrel of the barrel-shaped mold.

[0041] Figure 2 This is a schematic diagram of the cross-sectional structure of a barrel-shaped mold.

[0042] Figure 3 The mesoporous-microporous organic membrane obtained in Example 1.

[0043] Figure 4 The barrel-shaped carbon film obtained in Example 1.

[0044] Figure 5 This is a schematic diagram of the separate components.

[0045] Figure description: 1 is a barrel-shaped carbon film.

[0046] Figure 6 This is a flowchart of the separation process. Detailed Implementation

[0047] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0048] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0049] According to a preferred embodiment of the present invention, the method for preparing the barrel-shaped carbon membrane may include the following steps: ① injecting a mixture of phenolic resin precursors into a barrel-shaped mold; ② moving the barrel-shaped mold containing the mixture into an environment at a set temperature for polymerization molding to generate a cross-linked network mesoporous organic membrane, followed by demolding and drying; ③ carbonizing the organic membrane at high temperature to prepare a mesoporous-microporous barrel-shaped carbon membrane in one step.

[0050] The phenolic resin precursor mixture can be prepared using phenol (phenol, resorcinol, phloroglucinol), aldehyde (formaldehyde, polyoxymethylene, furfural), and amine compounds (ethylenediamine, propylenediamine, butanediamine, hexamethylenediamine) as raw materials, under the guidance of surfactants in a solvent.

[0051] The barrel-shaped mold consists of three parts: an outer cylindrical barrel (referred to as barrel), a middle electrode-type cylinder (referred to as cylinder), and a top cover (round cover). The middle electrode-type cylinder and the top cover are integrated, and the barrel and cylinder are coaxial in the radial direction and concentric in the axial direction, with an appropriate distance between the bottom of the cylinder and the barrel.

[0052] The barrel-shaped mold containing the mixture is transferred into a set stable constant temperature environment for low-temperature aging for a set time. Under the guidance of the surfactant template, the phenol, aldehyde, and amine that make up the phenolic resin undergo condensation and copolymerization reactions according to the preferred structural shape formed by the template agent. This causes the lower molecular weight oligomers or dimers to crosslink with each other, generating a crosslinked network mesoporous organic membrane with a certain strength.

[0053] A cross-linked network of mesoporous organic membranes is carbonized at high temperature under vacuum or inert gas protection to prepare mesoporous-microporous barrel-shaped carbon membranes in one step.

[0054] Example 1: Preparation of barrel-shaped carbon film

[0055] The preparation of a barrel-shaped carbon membrane involves first preparing a phenolic-based unsupported mesoporous-microporous carbon membrane. Phenolic compounds, amine compounds (organic amines), and formaldehyde are used as raw materials to generate a cross-linked network similar to phenolic resin, namely a benzoxazine resin precursor. The precursor is loaded into a mold and subjected to condensation and copolymerization to obtain an organic membrane rich in mesopores. After high-temperature carbonization, the unsupported mesoporous-microporous carbon membrane is obtained.

[0056] The first step is to prepare a mesoporous organic membrane, and the specific steps are as follows:

[0057] 1) Dissolve 10g of resorcinol in a solution of 30g water and 30g ethanol;

[0058] 2) Add 4.6g (0.365mmol) of soft template agent F127 and dissolve it completely;

[0059] 3) Add 0.074 g of hexamethylenediamine during stirring;

[0060] 4) Quickly add 18.5g of a 37wt% formaldehyde solution;

[0061] 5) Put 5.6g of the above mixture into a barrel-shaped mold to form a barrel shape with a bottom thickness of 3.0mm, a wall thickness of 1.8mm and a height of 40mm, and place it in an ultrasonic vibration tank to drive the bubbles for 5 minutes;

[0062] 6) Quickly move the device into a stable environment at a set temperature of 90℃ for 4 hours of low-temperature aging;

[0063] 7) After demolding, dry at 50℃ for 24 hours to obtain a non-supported mesoporous organic membrane precursor;

[0064] The second step is to prepare mesoporous-microporous carbon membranes:

[0065] Unsupported mesoporous-microporous carbon membranes are obtained by high-temperature carbonization of mesoporous organic membranes. Specifically, the prepared organic membrane precursor is placed in a carbonization furnace for heat treatment. Under the protection of inert gas N2, the temperature is increased from room temperature to 400℃ at a rate of 1℃ / min and held at that temperature for 50 min. Then, the temperature is increased to 790℃ at a rate of 1℃ / min and held at that temperature for 300 min. The membrane is then naturally cooled to room temperature, resulting in unsupported mesoporous-microporous carbon membranes with uniform size and well-preserved morphology.

[0066] The membrane was placed in an Instron mechanical property testing machine, and the compressive strength was measured to be 16.5 MPa.

[0067] The mesoporous-microporous barrel-shaped carbon film obtained in this embodiment is shown in the figure. Figure 4 As shown.

[0068] Example 2 Preparation of barrel-shaped carbon film 2

[0069] The preparation process is similar to that in Example 1. 10g of resorcinol is weighed and placed in a beaker, 30g of water and 30g of ethanol are added, and the mixture is stirred at room temperature. After dissolution, 5.75g (0.456mmol) of surfactant F127 is added, and after complete stirring, 0.096g of hexamethylenediamine is added, followed by the rapid addition of 22.1g of 37% formaldehyde solution. Stirring continues until a white colloid is obtained. 6.0g of the above reaction solution is weighed and placed into a barrel-shaped mold to form a barrel shape with a bottom thickness of 3.1mm, a wall thickness of 1.9mm, and a height of 42mm. The mold containing the reaction solution is then placed in an ultrasonic vibration bath for 5 minutes to remove bubbles. After sealing, it is transferred to an oven set at 90℃ for 4 hours of low-temperature aging. After demolding, the formed polymer is removed and dried in an oven at 50℃ for 24 hours to obtain the non-supported mesoporous organic membrane precursor.

[0070] The above-mentioned organic membrane precursor was placed in a carbonization furnace for heat treatment. Under the protection of inert gas N2, the temperature was increased from room temperature to 400℃ at a rate of 1℃ / min and held for 60 min. Then, the temperature was increased to 790℃ at a rate of 1℃ / min and held for 300 min. The membrane was then naturally cooled to room temperature to obtain a non-supported mesoporous-microporous carbon membrane with uniform size and good morphological preservation.

[0071] The membrane was placed in an Instron mechanical property testing machine, and the compressive strength was measured to be 16.3 MPa.

[0072] Example 3 Preparation of barrel-shaped carbon film 3

[0073] The preparation process is similar to that in Example 1. 10g of resorcinol was weighed and placed in a beaker, 30g of water and 30g of ethanol were added and stirred at room temperature. After dissolving, 4.6g (0.365mmol) of surfactant F127 was added and stirred completely. 22.1g of 37% formaldehyde solution was added, followed by the rapid addition of 0.11g of hexamethylenediamine. Stirring continued until a white colloid was obtained. 5.4g of the above reaction solution was weighed and placed into a barrel-shaped mold to form a barrel shape with a bottom thickness of 2.5mm, a wall thickness of 1.7mm, and a height of 38mm. The mold containing the reaction solution was then placed in an ultrasonic vibration bath for 5 minutes to expel bubbles. After sealing, it was transferred to an oven set at 90℃ for 4 hours of low-temperature aging. After unmolding, the formed polymer was removed and dried in an oven at 50℃ for 24 hours to obtain the non-supported mesoporous organic membrane precursor.

[0074] The above-mentioned organic membrane precursor was placed in a carbonization furnace for heat treatment. Under the protection of inert gas N2, the temperature was increased from room temperature to 400℃ at a rate of 1℃ / min and held for 70 min. Then, the temperature was increased to 790℃ at a rate of 1℃ / min and held for 240 min. The membrane was then naturally cooled to room temperature to obtain a non-supported mesoporous-microporous carbon membrane with uniform size and good morphology.

[0075] The membrane was placed in an Instron mechanical property testing machine, and the compressive strength was measured to be 16.1 MPa.

[0076] Comparative Example 1:

[0077] 10g of resorcinol was weighed and placed in a beaker. 50g of water and 50g of ethanol were added and stirred at room temperature until dissolved. 15.3g (2.64mmol) of surfactant P123 was added and stirred completely. 0.43g (3.7mmol) of hexamethylenediamine was then added, followed by the rapid addition of 14.8g (0.182mol) of 37% formaldehyde solution. Stirring continued until a white colloid was obtained. 5.6g of the reaction solution was weighed and placed into a barrel-shaped mold. The mold containing the reaction solution was then placed in an ultrasonic vibration bath for 5 minutes to remove bubbles. After sealing, it was transferred to an oven set at 90℃ for 4 hours of low-temperature aging. Upon opening the lid, it was found that the polymer failed to polymerize effectively and no barrel-shaped precursor was formed.

[0078] Comparative Example 2:

[0079] Weigh 10g of resorcinol and place it in a beaker. Add 35g of water and 35g of ethanol and stir at room temperature. After dissolving, add 11.4g (0.91mmol) of surfactant F127 and stir completely. Then add 0.64g of hexamethylenediamine and quickly add 14.8g (0.182mol) of 37% formaldehyde solution. Continue stirring until a white colloid is obtained. Weigh 5.6g of the above reaction solution and put it into a barrel-shaped mold. Then place the mold containing the reaction solution in an ultrasonic vibration tank to remove bubbles for 5 minutes. After sealing, transfer it to an oven set at 90℃ for 4 hours of low-temperature aging. After opening the lid, it was found that the polymer failed to polymerize effectively and no barrel-shaped precursor was formed.

[0080] Example 4 Separation Component 1 of Barrel-Shaped Carbon Membrane

[0081] The unsupported mesoporous-microporous barrel-shaped carbon membrane prepared in Example 1 is inserted into a standard three-way filter, and its membrane filter element is replaced. For example, a Weagelok TF series filter SS-8TF-F5-05 is used, and the filter element in this standard filter is replaced to obtain a separation assembly for the barrel-shaped carbon membrane. Alternatively, the standard three-way filter SS-8TF-F5-LE without filter elements provided by Weagelok can be used directly with the barrel-shaped carbon membrane of this invention. SS-8TF-F5-LE is a standard three-way filter without filter elements provided by Weagelok. When used with the barrel-shaped carbon membrane prepared in this invention and spring-loaded, it can be inserted into the corresponding pipeline for the separation of relevant materials. This barrel-shaped carbon membrane separation assembly includes two core elements: the barrel-shaped carbon membrane and the three-way filter, which together constitute the three-way separation assembly.

[0082] Example 5: Separation Component 2 of Barrel-Shaped Carbon Membrane

[0083] The unsupported mesoporous-microporous barrel-shaped carbon membrane prepared in Example 3 is inserted into a standard straight-through filter, and its filter element is replaced. For example, a Swagelok F-series filter SS-8F-K4-05 is used, and its filter element is replaced, to obtain a barrel-shaped carbon membrane separation assembly. SS-8F-K4-05 is a standard straight-through filter provided by Swagelok. Its filter element is removed, and combined with the barrel-shaped carbon membrane prepared in this invention, and spring-loaded, it is inserted into the corresponding pipeline for the separation of relevant materials. This barrel-shaped carbon membrane separation assembly includes two core elements: the barrel-shaped carbon membrane and the straight-through filter, which together constitute the straight-through separation assembly.

[0084] Example 6: A separation process for a barrel-shaped carbon membrane

[0085] The separation component obtained in Example 4 is connected to... Figure 6 In the process pipeline shown, 98% of the material in the feed system is returned, with the remaining 2% entering the separation system. This separation process uses pervaporation, i.e., a pressure of 0.5 MPa at the top and a vacuum of 100 Pa at the bottom. Because a single membrane (with a small separation area and limited material separation during the experiment) is used to separate the mixed xylene simulation material, no replenishment of the material to be separated is required within the 4-hour separation test period. The simulated material composition of the feed system is a mixture of 22.5 wt% para-xylene (22.5 wt% PX) and 77.5 wt% o-xylene (77.5 wt% OX). After one separation and concentration step (multiple concentrations can be performed as needed) as shown in the diagram, the material at the bottom is collected by condensation and chromatographic analysis. The results show that the PX concentration has increased by more than 100%, reaching approximately 50 wt% (i.e., the material composition is 50.1 wt% OX and 49.9 wt% PX), indicating good membrane separation performance.

Claims

1. A barrel-shaped carbon membrane having a meso-microporous structure, and a barrel-shaped structure of the barrel-shaped carbon membrane being obtained by one-step molding; the barrel-shaped carbon membrane being obtained by loading a phenolic-based resin precursor mixture into a barrel-shaped mold, then transferring the barrel-shaped mold as a whole into an environment with a set temperature to perform low-temperature aging to obtain a meso-microporous organic membrane, taking out the meso-microporous organic membrane, and finally performing carbonization; the phenolic-based resin precursor mixture comprising a phenolic compound, an aldehyde compound, an amine compound, a surfactant, and a solvent, a molar ratio of the phenolic compound to the amine compound being (1:0.005)-(1:0.01), and a molar ratio of the phenolic compound to the surfactant being (1:0.004)-(1:0.01).

2. A preparation method of the barrel-shaped carbon membrane according to claim 1, comprising loading a phenolic-based resin precursor mixture into a barrel-shaped mold, then transferring the barrel-shaped mold as a whole into an environment with a set temperature to perform low-temperature aging to obtain a meso-microporous organic membrane, taking out the meso-microporous organic membrane, and finally performing carbonization, wherein the phenolic-based resin precursor mixture comprises a phenolic compound, an aldehyde compound, an amine compound, a surfactant, and a solvent.

3. The preparation method of the barrel-shaped carbon membrane according to claim 2, wherein: the phenolic compound is at least one of phenol, resorcinol, and phloroglucinol; the aldehyde compound is at least one of formaldehyde, polyformaldehyde, and furfural; the amine compound is at least one of ethylenediamine, propylenediamine, butylenediamine, and hexylenediamine; the surfactant is at least one of F127, P123, F108, and B50; and the solvent is at least one of ethanol and water.

4. The preparation method of the barrel-shaped carbon membrane according to claim 2, wherein: a molar ratio of the phenolic compound to the aldehyde compound is (1:1)-(1:3); a molar ratio of the phenolic compound to the amine compound is (1:0.005)-(1:0.01); and a molar ratio of the phenolic compound to the surfactant is (1:0.004)-(1:0.01).

5. The preparation method of the barrel-shaped carbon membrane according to claim 4, wherein: a molar ratio of the phenolic compound to the aldehyde compound is (1:1.5)-(1:3).

6. The preparation method of the barrel-shaped carbon membrane according to claim 2, wherein: an environment temperature for the low-temperature aging is 70-110°C; and a time for the low-temperature aging is 0.5-10h.

7. The preparation method of the barrel-shaped carbon membrane according to claim 6, wherein: an environment temperature for the low-temperature aging is 80-100°C; and a time for the low-temperature aging is 1-4h.

8. Use of a barrel-shaped mold in the preparation method according to any one of claims 2-7, the barrel-shaped mold comprising an outer cylindrical barrel, an intermediate electrode-type cylinder, and a top circular cover; the intermediate electrode-type cylinder being connected with the top circular cover and being axially concentric; a height of the intermediate electrode-type cylinder being less than a height of the outer cylindrical barrel, and a diameter of the intermediate electrode-type cylinder being less than a diameter of the outer cylindrical barrel. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The use according to claim 8, wherein: the top circular cover is in a stepped type, and when the top circular cover and the middle electrode type cylindrical insert into the outer cylindrical barrel, the small diameter end of the stepped top circular cover is in contact with the inner wall of the outer cylindrical barrel.

10. A separation assembly comprising the barrel-shaped carbon membrane according to claim 1 or the barrel-shaped carbon membrane prepared by the method according to any one of claims 2 to 7, and a standard filter, wherein the barrel-shaped carbon membrane is installed in the position of the membrane filter element in the standard filter.

11. The separation assembly according to claim 10, wherein: the barrel-shaped carbon membrane and the standard filter are connected by an adhesive or are pressed together by a spring.

12. A separation method comprising feeding a mixture into a separation system through a feeding system to separate the mixture to obtain a separated material, wherein part of the separated material flows out, and the remaining separated material flows back to the separation system through a reflux system to be separated again; the separation system comprises the separation assembly according to claim 10 or 11.

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