Preparation system and method of porous carbon precursor
The porous carbon precursor preparation system solves the problems of insufficient raw material adaptability and process control in existing technologies, realizes the efficient processing of complex heavy raw materials and the stable preparation of porous carbon precursors, and improves the economic benefits and application scope of production.
Patent Information
- Application Number
- CN202511346320.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2025-11-25
AI Technical Summary
Existing porous carbon precursor preparation technologies suffer from poor raw material adaptability, difficulty in handling complex and heavy raw materials, insufficient process control methods, poor product structure uniformity, strong production uniformity, and lack of flexible adjustment capabilities, which limit the economic benefits and application scope of the production line.
A porous carbon precursor preparation system is adopted, including equipment such as a feed tank, a reformer, a membrane filter, and a purification distillation column. The precursor is prepared through thermal reforming, purification and distillation separation, mixing and reaction. By utilizing the multi-mode operation of the reformer, the precise control of the membrane filter and the vacuum separation of the purification distillation column, combined with the cross-linking reaction in the reactor, a stable porous structure is constructed and the light oil is recycled.
This technology enables efficient processing of complex and heavy raw materials, producing porous carbon precursors with regular structures and stable performance. This improves the energy efficiency and environmental friendliness of production, and meets the performance requirements of different application scenarios.
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Figure CN121005401A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of materials preparation technology and provides a system and method for preparing porous carbon precursors. Background Technology
[0002] Carbon precursors are basic raw materials that can be converted into carbon materials through a series of heat treatments. Their molecular structure and chemical composition directly determine the microstructure, pore structure, and physicochemical properties of the final carbon material. Porous carbon precursors are a specific type of precursor. After carbonization and activation, porous carbon materials with high specific surface area, well-developed pore structure, and excellent adsorption / energy storage performance can be prepared. These materials are widely used in supercapacitors, lithium / sodium-ion batteries, catalyst supports, and gas separation.
[0003] Currently, there are various methods for synthesizing porous carbon precursors. Common methods include: direct carbonization using biomass as raw material; template-based methods using synthetic polymers as precursors; and synthesis methods using carbon-rich heavy oils, such as coal tar pitch and petroleum pitch. Among these, the route using heavy oil as raw material has attracted much attention due to its wide availability and low cost. Typical processes usually involve steps such as thermal polymerization, physical separation, or chemical cross-linking of the heavy oil feedstock to initially construct the basic framework and pore structure of the precursor.
[0004] However, existing porous carbon precursor preparation technologies, especially those based on heavy oil feedstocks, still have several significant limitations: First, they suffer from poor feedstock adaptability. Many processes have strict requirements on the purity, composition, and rheological properties of the feedstocks, making it difficult to directly and efficiently process heavy feedstocks with complex compositions and high impurity content, such as ethylene tar and catalytic cracking slurry, thus limiting the utilization of inexpensive feedstocks. Second, they lack sufficient and flexible process control methods. Existing methods often lack the ability to precisely and continuously control key steps such as mesophase growth, impurity removal, component separation, and crosslinking reactions, resulting in poor product structural uniformity and difficulty in directionally controlling the pore size distribution and chemical composition of the precursor according to downstream application requirements. Finally, they exhibit strong product homogeneity. A single system is usually limited to producing only one type of porous carbon precursor, lacking the ability to flexibly adjust process parameters to produce other types of carbon materials, such as hard carbon precursors, thus limiting the economic efficiency and application scope of the production line. Summary of the Invention
[0005] To address the aforementioned deficiencies, the present invention aims to provide a system and method for preparing porous carbon precursors, thereby solving the problems mentioned in the background art. The system includes a raw material tank, a heater, and a reactor. The raw material tank is connected to a modifier via a pipeline. The outlet of the modifier is connected to a modified raw material tank via a pipeline. The modified raw material tank is connected to a membrane filter via a pipeline. The membrane filter is connected to a purified raw material tank via a pipeline. The purified raw material tank is connected to a purified material distillation column via a pipeline. The two outlets of the purified material distillation column are respectively connected to a refined raw material tank and a light oil tank via pipelines. The outlets of the refined raw material tank and the light oil tank are respectively connected to the inlet of the heater via pipelines. The outlet of the heater is connected to the reactor via a pipeline. The light oil tank is connected to a vacuum pump via a pipeline.
[0006] Furthermore, the raw material tank is connected to a first heat exchanger via a raw material pump. The first heat exchanger is a heating heat exchanger and is a two-inlet, two-outlet heat exchanger device. The outlet of the raw material pump is connected to the first inlet of the first heat exchanger, the first outlet of the first heat exchanger is connected to the feed inlet of the modifier, the discharge outlet of the modifier is connected to the second inlet of the first heat exchanger, and the second outlet of the first heat exchanger is connected to the feed inlet of the modified raw material tank via a pipeline.
[0007] Furthermore, a first pipe tee is installed on the pipe connecting the raw material pump and the first heat exchanger, and the other outlet of the first pipe tee is connected to the raw material tank through a pipe.
[0008] Furthermore, the modified raw material tank is equipped with an electromagnetic heater for heating.
[0009] Furthermore, it also includes an oil tank. The reactor is equipped with a light oil outlet, and both the light oil outlet and the second outlet on the modified raw material tank are connected to the oil tank via pipelines.
[0010] Furthermore, the light oil outlet and the second outlet on the modified raw material tank are respectively connected to the two inlets of the second heat exchanger through pipes. The second heat exchanger is a refrigeration heat exchanger, and the outlet of the second heat exchanger is connected to the oil tank through a pipe.
[0011] A method for preparing a porous carbon precursor, based on a porous carbon precursor preparation system, includes the following steps:
[0012] S1. Raw material modification treatment; through thermal modification, the mesophase in the raw material is fully grown, including the following sub-steps:
[0013] S1.1 One or more heavy raw materials selected from ethylene tar, coal tar, oil slurry, petroleum, and coal tar pitch are transported from the raw material tank to the reformer;
[0014] S1.2. The raw materials are thermally modified using the electrically heated reaction equipment in the modifier;
[0015] S1.3 During the process, the reforming mode is used for control. The working mode of the reformer is switched through the first heat exchanger. First, in the conveying mode, the raw material is continuously conveyed through the reformer for single-pass reforming. Then, the internal circulation mode is adopted so that the raw material undergoes multiple heat cycles inside the reformer. Finally, the reformed raw material is transported to the reforming raw material tank by the reforming raw material pump for temporary storage.
[0016] S2. Purification and distillation separation; including the following steps:
[0017] S2.1 The modified raw materials temporarily stored in the modified raw material tank are transported to the membrane filter through the modified raw material pump, and the purified raw materials enter the purified raw material tank.
[0018] S2.2 The purified raw material is transported from the purified raw material tank to the purified material distillation column by the purified raw material pump, and the vacuum pump maintains it at a vacuum degree of -0.092~-0.098MPa, while controlling the column bottom temperature to be maintained at 290~330℃.
[0019] Under these conditions, the low-boiling-point oil in the raw material is distilled off at the top of the tower, condensed, and collected in a light oil tank; the refined raw material rich in the mesophase is discharged from the bottom of the tower and temporarily stored in a refined raw material tank.
[0020] S3. Preparation of Precursor through Mixing and Reaction: This step involves mixing and reacting specific components in the following sub-steps to construct a precursor with ideal pores and thermal stability. The specific steps include:
[0021] S3.1 Take light oil and refined raw materials from the light oil tank and refined raw material tank respectively, and transport them to the heater for preliminary mixing in a mass ratio of 1:3~5;
[0022] S3.2. Heat the mixed raw materials in the heater to 420~480℃;
[0023] S3.3. The preheated mixed raw materials are fed into the reactor, and nitrogen is introduced into the system as a protective gas. Oxygen-containing organic acids and epoxy resins are added into the system through the second feed port to carry out cross-linking polycondensation reaction.
[0024] Furthermore, the electric heating reaction equipment in the reformer controls the internal temperature at 350~420℃; the reforming raw material tank is kept warm by an electromagnetic heater, maintaining the temperature at 250-300℃.
[0025] Furthermore, the membrane filter uses a sintered metal microporous membrane with a filtration accuracy of 10-50 μm.
[0026] Furthermore, the vacuum pump maintains a vacuum level of -0.092 to -0.098 MPa inside the purified material distillation column, while controlling the temperature inside the purified material distillation column to be maintained at 290 to 330°C.
[0027] This invention not only optimizes mesophase growth through multi-mode operation of the modulator, precisely controls the size of the α-component through a membrane filter, and efficiently separates light and heavy components through a purification distillation column under vacuum pump, but also synergistically constructs a stable porous structure for the carbon precursor by introducing oxygen-containing organic acids and generating shear force using light oil pumped into the reactor. The resulting porous carbon precursor exhibits a regular structure and stable performance. Furthermore, the system can recover the distilled light oil from the reaction in an oil tank, achieving material recycling. Thus, while ensuring high product performance, the production process is energy-saving, environmentally friendly, and highly efficient. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the system's structural connection logic;
[0029] Figure 2 A schematic diagram of the connection logic of the cyclic modification structure of the quality modifier;
[0030] In the diagram: 01-Valve Body 1; 02-Valve Body 2; 03-Valve Body 3; 04-Valve Body 4; 05-Valve Body 5; 1-Raw Material Tank; 11-Raw Material Pump; 12-First Heat Exchanger; 2-Modifier; 3-Modified Raw Material Tank; 31-Electromagnetic Heater; 32-Second Heat Exchanger; 33-Modified Raw Material Pump; 34-Oil Tank; 4-Membrane Filter; 5-Purified Raw Material Tank; 51-Purified Raw Material Pump; 6-Purified Raw Material Distillation Column; 61-Third Heat Exchanger; 7-Refined Raw Material Tank; 71-Refined Raw Material Pump; 8-Light Oil Tank; 81-Light Oil Pump; 82-Heater; 83-Vacuum Pump; 9-Reactor. Detailed Implementation
[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0032] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0033] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0035] See appendix Figure 1 Appendix Figure 2 The purpose of this invention is to provide a system for preparing porous carbon precursors, including a raw material tank 1, a modifier 2, a modified raw material tank 3, a membrane filter 4, a purified raw material tank 5, a purified material distillation column 6, a refined raw material tank 7, a light oil tank 8, a heater 82, a reactor 9, and an oil tank 34; the device also includes a raw material pump 11, a modified raw material pump 33, a purified raw material pump 51, a refined raw material pump 71, a light oil pump 81, and a vacuum pump 83 for providing a reduced pressure environment for the light oil tank 8.
[0036] The raw material tank 1 is used to store heavy raw materials, including liquid solids such as ethylene tar, coal tar, oil slurry, and petroleum / coal tar.
[0037] Raw material tank 1 is connected to reformer 2 via a pipeline. Raw material tank 1 is connected to first heat exchanger 12 via raw material pump 11. It is worth noting that the first heat exchanger 12 is a four-way heat exchanger with two inlets and two outlets, meaning it has two material inlets and two material outlets. Specifically, the outlet of raw material tank 1 is connected to the inlet of raw material pump 11 via a pipeline, the outlet of raw material pump 11 is connected to the first inlet of first heat exchanger 12 via a pipeline, and the first outlet of first heat exchanger 12 is connected to the inlet of reformer 2 via a pipeline. The first inlet and first outlet of first heat exchanger 12 serve as the flow path for the raw material, which is heated by the heat exchanger and then enters reformer 2. The outlet of reformer 2 is connected to the second inlet of first heat exchanger 12 via a pipeline, and the second outlet of first heat exchanger 12 is connected to the inlet of reforming raw material tank 3 via a pipeline. The second inlet and second outlet of first heat exchanger 12 serve as the flow path for the heated raw material. After heat exchange with the raw material, the reformed raw material undergoes preliminary cooling and enters reforming raw material tank 3 along with the grown solid material.
[0038] In the above setup, raw material tank 1 is connected to a heat exchanger via raw material pump 11. The heat source for the heat exchanger is the raw material that has been heated and modified by the modifier 2. Specifically, part of the raw material is heated to a superheated state of 350-420℃ by the modifier 2 to promote impurity growth. The heated material is then passed into the first heat exchanger 12 as a heat source. The raw material flowing through the first heat exchanger 12 is preheated before entering the modifier 2. During this process, since the raw material is cold, it cools down the modified raw material that has been heated to 350-420℃, facilitating solid-liquid separation filtration in the subsequent membrane filter 4. Therefore, through heat exchange, both preheating of the raw material and further cooling of the modified raw material are achieved, greatly improving the energy-saving effect of the system and avoiding energy waste.
[0039] The modifier 2 uses an electromagnetic heating device to raise the temperature of the incoming raw material to 350-420℃. Impurities (quinoline-insoluble substances) in the raw material then grow within the modifier, facilitating membrane filtration. Specifically, during the electromagnetic heating process, the modifier 2 used in this invention undergoes a thermal condensation reaction. As the temperature continues to rise until the deposition point, liquid-phase coking occurs. The coking grows around the impurities, increasing their particle size and making them easier to remove via membrane filtration. The uncoked portion of the material also undergoes a thermal condensation reaction, partially generating a raw material rich in polycyclic aromatic hydrocarbons and some intermediate phases.
[0040] Optionally, under the control of the control terminal, all four ports of the first heat exchanger 12 can be opened or closed. Specifically, corresponding controlled solenoid valves or other types of on / off valves can be installed on the pipes connected to the four ports of the first heat exchanger 12 to control the flow of the pipes.
[0041] An electromagnetic heater 31 for heating is installed on the modified raw material tank 3 to maintain the temperature of the raw material tank; the outlet of the modified raw material tank 3 is connected to the inlet of the modified raw material pump 33 through a pipe, and the outlet of the modified raw material pump 33 is connected to the membrane filter 4 through a pipe. The membrane filter 4 has an impurity discharge port and a discharge port, and the discharge port of the membrane filter 4 is connected to the purified raw material tank 5 through a pipe.
[0042] Specifically, the membrane filter 4 has a filtration accuracy of 10-50 μm and is connected between the modified raw material tank 3 and the purified raw material tank 5. It is used to remove impurities and some α-components from the raw material. The α-component is quinoline insoluble matter. The filtered purified raw material enters the purified raw material tank 5, while the removed impurities and some α-components are discharged through the impurity outlet. Specifically, the membrane filter 4 used in this invention is a 2-4 stage inorganic membrane with backwashing structure. The material passes through 1-2 stages of 30-50 μm membranes to remove impurities, and then passes through 1-2 stages of membranes for concentration and separation. The clear liquid is retained, and the concentrated liquid is sent for distillation separation.
[0043] Based on the above settings, this paper provides several embodiments to complete the cyclic modification process of the modifier. See the appendix. Figure 2 This system also includes valve body 1 (01), valve body 2 (02), valve body 3 (03), valve body 4 (04), and valve body 5 (05).
[0044] Preferably, a first pipe tee is installed on the pipe connecting the raw material pump 11 and the first heat exchanger 12. The other outlet of the first pipe tee is connected to the raw material tank 1 via a pipe, and a valve body 01 is installed on the pipe. Thus, when the first inlet of the first heat exchanger 12 is closed, the raw material in the raw material tank 1 can circulate internally under the drive of the raw material pump 11. At the same time, the modification process in the modifier 2 can also circulate internally, thereby achieving simultaneous processing of multiple steps in the processing, greatly saving the raw material processing time, and maintaining the stability of the flow rate and pressure of the raw material entering the modifier.
[0045] Valve body 202 is installed on the pipeline connecting the raw material pump 11 and the first heat exchanger 12 (installed on the pipeline connecting the first pipeline tee and the first heat exchanger 12); Valve body 303 is installed on the pipeline connecting the first outlet of the first heat exchanger 12 and the inlet of the reformer 2; a second pipeline tee and valve body 505 are installed on the pipeline connecting the outlet of the reformer raw material pump 33 and the membrane filter 4; a third pipeline tee is installed on the pipeline connecting valve body 303 and the reformer 2; the second pipeline tee is connected to the third pipeline tee through a pipeline; and valve body 404 is installed on the pipeline connecting the third pipeline tee and the second pipeline tee.
[0046] Therefore, under controlled conditions for each valve and pump body, this system has the following operating modes:
[0047] Example 1
[0048] When valve body 2 02, valve body 3 03 and valve body 5 05 are all open and valve body 4 04 is closed, the material completes the process of being transported from raw material tank 1 to first heat exchanger 12 and then to reformer 2 under the drive of raw material pump 11. Then it continues to enter the first heat exchanger 12 to be heated, directly enters reformed raw material tank 3, and is then transported to membrane filter 4 by reformed raw material pump 33.
[0049] Example 2
[0050] When valve body 2 02, valve body 3 03 and valve body 4 04 are all open and valve body 5 05 is closed, the material completes the conveying process from raw material tank 1 to first heat exchanger 12 and then to modifier 2 under the drive of raw material pump 11. Then it continues to enter the first heat exchanger 12 to be heated, directly enters the modified raw material tank 3, and is then pumped back to modifier 2 by modified raw material pump 33, completing the feeding and cyclical modification at the same time.
[0051] Example 3
[0052] When valve body 404 is open and valve body 202, valve body 303 and valve body 505 are all closed, the material completes the cycle of reforming from reformer 2 to first heat exchanger 12, then to reforming raw material tank 3, and then is pumped back to reformer 2 by reforming raw material pump 33.
[0053] Example 4
[0054] When valve body 2 (02), valve body 3 (03), and valve body 4 (04) are all closed, and valve body 5 (05) is closed, the material is pumped from the reformer 2 to the first heat exchanger 12, then to the reformer raw material tank 3, and then pumped by the reformer raw material pump 33 to the membrane filter 4, thus completing the pumping and discharge of the material.
[0055] Through the above coordination, the raw material pump 11 transports the raw material to the modifier 2. The modifier 2 is an electrically heated device with a heating temperature controlled between 350 and 420°C. Its function is to promote the growth of the α-component in the raw material, facilitating subsequent purification treatment. The modified raw material is then temporarily stored in the modified raw material tank 3.
[0056] The outlet of the purified feed tank 5 is connected to the inlet of the purified feed pump 51 via a pipeline, and the outlet of the feed pump 51 is connected to the inlet of the purified feed distillation column 6 via a pipeline. The purified feed distillation column 6 has a light component outlet and a heavy component outlet. The light component outlet is connected to the light oil tank 8 via a pipeline, and a vacuum pump 83 is connected to the light oil tank 8 via a pipeline. The heavy component outlet is connected to the refined feed tank 7 via a pipeline. Specifically, the light component outlet is first connected to the inlet of the third heat exchanger 61, and the outlet of the third heat exchanger 61 is connected to the light oil tank 8 via a pipeline. The third heat exchanger 61 is a refrigeration heat exchanger, which can condense part of the gaseous light component oil and discharge it into the light oil tank 8.
[0057] Through the above coordination, the purified feed pump 51 transports the feed from the purified feed tank 5 to the purified feed distillation column 6. The purified feed distillation column 6 operates under reduced pressure under the action of the vacuum pump 83, with the vacuum level controlled at -0.092 to -0.098 MPa and the column bottom temperature at 290 to 330°C. Light components are distilled off at the top of the column, condensed, and then enter the light oil tank 8; the refined feed enters the refined feed tank 7 through the heavy component outlet.
[0058] The outlet of the light oil tank 8 is connected to the inlet of the light oil pump 81 via a pipe; the outlet of the light oil pump 81 is connected to the first inlet of the heater 82 via a pipe; the heater 82 also has a second inlet; the outlet of the refined raw material tank 7 is connected to the inlet of the refined raw material pump 71 via a pipe; the outlet of the refined raw material pump 71 is connected to the second inlet of the heater 82 via a pipe; the outlet of the heater 82 is connected to the first inlet of the reactor 9 via a pipe.
[0059] The light oil in the light oil tank 8 is mixed with the refined raw materials in the refined raw material tank 7 at a mass ratio of 1:3 to 1:5. The mixed raw materials are heated to 420 to 480°C by the heater 82 and then enter the reactor 9. The reactor 9 has a light oil outlet, a gas inlet and a second feed inlet.
[0060] The gas inlet is used by external equipment to introduce protective nitrogen gas into reactor 9, and the second feed inlet is used by external equipment to introduce oxygen-containing organic acids and epoxy resin into reactor 9; the organic acids include benzoic acid and / or phthalic acid. Under high temperature conditions, the oxygen-containing organic acids undergo partial cross-linking and condensation reactions with the refined raw materials to form a porous carbon precursor. The role of the oxygen-containing organic acids is to cross-link the precursor layers, enhance its thermodynamic stability, and graft oxygen-containing groups onto its surface, facilitating the subsequent formation of mesopores; the addition of light oil generates radial shear force in the precursor, increasing the true density of the precursor.
[0061] The light oil outlet of reactor 9 is used to discharge the distilled light oil for recovery; the second outlet of reactor 9 is the non-condensable gas outlet; the light oil outlet is connected to the first inlet of the second heat exchanger 32 via a pipeline; specifically, the second heat exchanger 32 is a three-way heat exchange device with two inlets and one outlet, meaning it has two material inlets and one material outlet, and all three ports can be opened or closed under the control of the control terminal. The second inlet of the second heat exchanger 32 is connected to the second outlet of the modified feedstock tank 3 via a pipeline. The light components escaping from the modified feedstock tank 3 are cooled to 40-60℃ by the water in the second heat exchanger 32 and then enter the oil tank 34 for storage. The outlet of the second heat exchanger 32 is connected to the oil tank 34 via a pipeline. Thus, the light oil distilled from the modified feedstock tank 3 and the reactor can be recovered through the oil tank 34.
[0062] Both the light oil outlet and the second outlet on the modified feedstock tank 3 enter the oil tank 34 after condensation.
[0063] Preferably, the bottom of the purified material distillation column 6 is equipped with a temperature sensor. The temperature sensor is electrically connected to a control terminal for real-time monitoring of the bottom temperature and sending a signal to the control terminal. The control terminal adjusts the heating power according to the temperature signal to ensure that the bottom temperature is stable at 290~330℃.
[0064] Preferably, the reactor 9 is equipped with a pressure sensor and a temperature sensor, both electrically connected to a control terminal for monitoring pressure and temperature changes within the reactor. Based on the pressure and temperature signals, the control terminal adjusts the heating power of the heater 82 and the feed rate of the raw materials in real time to ensure stable reaction conditions.
[0065] Preferably, the device further includes an automatic controller (with attachment) Figure 1 (Not shown in the diagram) The automatic controller is electrically connected to the raw material pump 11, the conditioner 2, the membrane filter 4, the purified raw material pump 51, the vacuum pump 83, the light oil pump 81, the heater 82, and the reactor 9. During operation, the automatic controller controls the operating status of each device based on signals from various sensors, thereby achieving automated control of the entire process.
[0066] It is worth noting that the raw material inlets and outlets of the above equipment can be controlled by various valves currently available on the market, thereby meeting the process coordination requirements between multiple devices.
[0067] Therefore, the operating principle of the porous carbon precursor preparation device is as follows:
[0068] Initially, the heavy raw material in raw material tank 1 is transported to the modifier 2 by raw material pump 11. After being modified by electric heating in the modifier 2, it enters the modified raw material tank 3 for temporary storage. The modified raw material passes through the membrane filter 4 to filter impurities and some α components, and the purified raw material enters the purified raw material tank 5.
[0069] During operation, the purification feed pump 51 transports the feed from the purification feed tank 5 to the purification feed distillation column 6. The vacuum pump 83 provides a reduced-pressure environment for the purification feed distillation column 6, where light components are distilled off at the top of the column and condensed before entering the light oil tank 8; the refined feed enters the refined feed tank 7. The light oil pump 81 mixes the light oil from the first light oil tank 8 with the refined feed from the refined feed tank 7 in a specific ratio. The mixed feed is then heated to a set temperature by the heater 82 before entering the reactor 9.
[0070] In reactor 9, oxygen-containing organic acids and epoxy resin are introduced and react with the heated raw materials to generate porous carbon precursors. Thus, in practical use, this porous carbon precursor preparation system cycles through initial and operational states to modify, purify, distill, mix, and react heavy raw materials, ultimately producing porous carbon precursors. An automatic controller, through precise control of each device, automates and stabilizes the entire process, ensuring the quality and performance of the porous carbon precursors.
[0071] The present invention discloses a method for preparing a porous carbon precursor, which is based on the aforementioned preparation system and includes the following steps:
[0072] S1. Raw material modification treatment; This step aims to fully grow the mesophase in the raw material through thermal modification. This step consists of the following sub-steps:
[0073] S1.1 Heavy raw materials such as ethylene tar, coal tar, oil slurry or petroleum / coal tar pitch are transported from raw material tank 1 to the reformer 2.
[0074] S1.2 The raw material is thermally modified using the electrically heated reaction equipment in the modifier 2; the internal temperature is controlled at 350~420℃. At this temperature, the raw material undergoes a thermal condensation reaction, in which aromatic hydrocarbon molecules associate and grow, forming and promoting the growth of the intermediate phase, i.e., the α component.
[0075] S1.3. During the process, the reforming mode is controlled by switching the working mode of the reformer 2 through the first heat exchanger 12. First, in the conveying mode, the raw material is continuously conveyed through the reformer 2 for single-pass reforming. Then, the internal circulation mode is adopted to circulate the raw material inside the reformer 2 for cyclic heating. By extending the residence time of the raw material in the reformer, it undergoes multiple thermal cycles, thereby making the growth of the meso phase more sufficient and uniform, effectively avoiding the problem of uneven reforming caused by single-pass. Subsequently, the reformed raw material is conveyed to the reforming raw material tank 3 for temporary storage. The reforming raw material tank 3 is kept warm by the electromagnetic heater 31, and the temperature is maintained at 250-300℃ to prevent the solidification of high-viscosity materials. During this process, the original raw material is preheated through the first heat exchanger 12, while the reformed raw material, which is in a superheated state, is initially cooled.
[0076] S2. Purification and Distillation Separation: This step aims to remove impurities from the modified feedstock and separate light components to obtain a purified feedstock rich in the mesophase. This step consists of the following sub-steps:
[0077] S2.1 The modified raw material temporarily stored in the modified raw material tank 3 is transported to the membrane filter 4 via the modified raw material pump 33. The membrane filter 4 uses a sintered metal microporous membrane with a filtration accuracy of 10-50μm. Its working principle is as follows: driven by pressure difference, the raw material passes through the membrane pores, thereby intercepting and removing solid impurities such as coke powder, catalyst particles, and some over-polymerized and excessively large α components from the raw material. The purified raw material enters the purified raw material tank 5.
[0078] This step allows for precise control of the size distribution of the α component in the precursor, avoiding damage to the final pore structure caused by excessively large particles and ensuring the formation of a regular hierarchical pore structure.
[0079] S2.2 The purified raw material is transported from the purified raw material tank 5 to the purified material distillation tower 6 by the purified raw material pump 51, and the vacuum pump 83 maintains it at a vacuum degree of -0.092~-0.098MPa, while controlling the tower bottom temperature to be maintained at 290~330℃.
[0080] Under these conditions, the low-boiling-point oil in the raw material is distilled off at the top of the tower and collected in the light oil tank 8 after condensation; the refined raw material rich in the mesophase is discharged from the bottom of the tower and temporarily stored in the refined raw material tank 7.
[0081] S3. Preparation of Precursor through Mixing and Reaction: This step involves mixing and reacting specific components in the following sub-steps to construct a precursor with ideal pores and thermal stability. The specific steps include:
[0082] S3.1 Take light oil and refined raw materials from light oil tank 8 and refined raw material tank 7 respectively, and transport them to heater 82 for preliminary mixing in a mass ratio of 1:3~5;
[0083] S3.2. Heat the mixed raw materials to 420~480℃ in heater 82;
[0084] S3.3. The preheated mixed raw materials are fed into reactor 9. At the same time, nitrogen gas is introduced into the system as a protective gas, and oxygen-containing organic acids (including benzoic acid and phthalic acid) and epoxy resin are added into the system through the second feed port to carry out cross-linking polycondensation reaction.
[0085] Under high-temperature conditions, oxygen-containing organic acids undergo partial cross-linking and condensation reactions with aromatic molecules in the refined raw materials. In this process, the acid molecules act as cross-linking agents, bridging multiple aromatic layers and significantly enhancing the three-dimensional network structure and thermodynamic stability of the precursor. This makes it less prone to graphitization during subsequent carbonization, facilitating the formation of a disordered layer structure while retaining porosity. Simultaneously, oxygen-containing functional groups are grafted onto the surface. The decomposition of these functional groups at high temperatures generates gas, thereby creating abundant mesopores in situ, with the mesopores maintaining a diameter of 2-50 nm.
[0086] In this step, the addition of light oil, besides acting as a diluent to adjust viscosity, plays a key role in the following: In the reaction system, the light oil evaporates and flows when heated, generating shear force on the condensate in the radial direction, thereby prompting the aromatic lamellae to adopt a more ordered orientation, compressing the interlamellae spacing, effectively improving the true density and mechanical strength of the precursor, and avoiding the problem of the precursor being too loose in traditional methods.
[0087] In addition, the following steps are also included:
[0088] S3.4 The light oil vapors distilled during the reaction process are discharged from the light oil outlet of reactor 9 and guided to oil tank 34 for recovery via the second heat exchanger 32. This portion of light oil can be recycled, thus achieving environmental protection and economic regeneration.
[0089] In the above process, the control of each piece of equipment is achieved through an automated control system, which enables full-process automated control, thereby achieving a continuous, stable, and repeatable production process.
[0090] Specifically, during the above process, the automatic controller collects the temperature sensor signal from the bottom of the purified feed distillation column 6 in real time and controls the heating power through PID regulation to ensure that the distillation temperature is stable at 290~330℃. At the same time, the automatic control system collects the pressure and temperature sensor signals inside the reactor 9 in real time and dynamically adjusts the power of the heater 82 and the feed rate of each pump to ensure that the reaction conditions are always in the optimal state.
[0091] In addition, the automatic control system precisely controls the start-up, shutdown and linkage of the first heat exchanger 12, the second heat exchanger 32, the third heat exchanger 61 and all other pumps and heating devices according to preset programs or logic, realizing the full-process automation, continuous or batch operation from raw material modification to precursor synthesis, which greatly reduces human operation errors.
[0092] In summary, in practical application, this technical solution, through the coordinated operation of equipment such as feed tank 1, reformer 2, membrane filter 4, purified feed distillation tower 6, and reactor 9, can convert heavy oil resources such as ethylene tar, coal tar, and catalytic cracking slurry into high-value-added products. The reaction process involves sequential thermal reforming, impurity filtration, component separation, mixing, and cross-linking reactions, ultimately generating a porous carbon precursor with excellent structure in reactor 9.
[0093] The entire process, under the precise control of the automatic controller, has a variety of precise control methods: the degree of mesophase growth can be controlled by adjusting the temperature and circulation mode of the reformer 2; the size distribution of the α component can be adjusted by selecting the filtration precision of the membrane filter 4; the light and heavy components can be precisely separated by setting the vacuum degree and temperature of the purification distillation column 6; and finally, by changing the raw material ratio and reaction parameters in the reactor 9, the crosslinking degree and pore structure of the precursor can be effectively adjusted, thereby flexibly customizing its component distribution to meet the specific requirements of porous carbon performance in different application scenarios such as adsorption and energy storage.
[0094] Therefore, this invention not only optimizes mesophase growth through multi-mode operation of the modulator 2, precisely controls the size of the α-component through the membrane filter 4, and efficiently separates light and heavy components through the purification distillation column 6 under the action of the vacuum pump 83, but also synergistically constructs a stable porous structure for the carbon precursor by introducing oxygen-containing organic acids into the reactor 9 and generating shear force using light oil pumped by the light oil pump 81. The resulting porous carbon precursor has a regular structure and stable performance. Simultaneously, the system can also recover the light oil distilled from the reaction through the oil tank 34, realizing the recycling of materials. Thus, while ensuring high product performance, the production process achieves energy saving, environmental protection, and high efficiency.
[0095] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.
Claims
1. A system for preparing porous carbon precursors, characterized in that, The system includes a raw material tank (1), a heater (82), and a reactor (9); the raw material tank (1) is connected to a modifier (2) via a pipe, the outlet of the modifier (2) is connected to a modified raw material tank (3) via a pipe, the modified raw material tank (3) is connected to a membrane filter (4) via a pipe, the membrane filter (4) is connected to a purified raw material tank (5) via a pipe, the purified raw material tank (5) is connected to a purified material distillation column (6) via a pipe, the two outlets of the purified material distillation column (6) are respectively connected to a refined raw material tank (7) and a light oil tank (8) via pipes, the outlets of the refined raw material tank (7) and the light oil tank (8) are respectively connected to the inlet of the heater (82) via pipes, the outlet of the heater (82) is connected to the reactor (9) via a pipe; the light oil tank (8) is connected to a vacuum pump (83) via a pipe.
2. The porous carbon precursor preparation system according to claim 1, characterized in that, The raw material tank (1) is connected to a first heat exchanger (12) via a raw material pump (11). The first heat exchanger (12) is a heating heat exchanger and is a two-inlet, two-outlet heat exchanger device. The outlet of the raw material pump (11) is connected to the first inlet of the first heat exchanger (12), the first outlet of the first heat exchanger (12) is connected to the feed inlet of the modifier (2), the discharge outlet of the modifier (2) is connected to the second inlet of the first heat exchanger (12), and the second outlet of the first heat exchanger (12) is connected to the feed inlet of the modified raw material tank (3) via a pipe.
3. The porous carbon precursor preparation system according to claim 1, characterized in that, A first pipe tee is installed on the pipe connecting the raw material pump (11) and the first heat exchanger (12), and the other outlet of the first pipe tee is connected to the raw material tank (1) through a pipe.
4. The porous carbon precursor preparation system according to claim 1, characterized in that, The modified raw material tank (3) is equipped with an electromagnetic heater (31) for heating.
5. The porous carbon precursor preparation system according to claim 1, characterized in that, It also includes an oil tank (34), and the reactor (9) is provided with a light oil outlet. The light oil outlet and the second outlet provided on the modified raw material tank (3) are both connected to the oil tank (34) through pipelines.
6. The porous carbon precursor preparation system according to claim 5, characterized in that, The light oil outlet and the second outlet on the modified raw material tank (3) are respectively connected to the two inlets of the second heat exchanger (32) through pipes. The second heat exchanger (32) is a refrigeration heat exchanger, and the outlet of the second heat exchanger (32) is connected to the oil tank (34) through a pipe.
7. A method for preparing a porous carbon precursor, based on the porous carbon precursor preparation system of claim 1, characterized in that, Includes the following steps: S1. Raw material modification treatment; Thermal modification allows the mesophase in the raw material to grow sufficiently, including the following steps: S1.1 One or more heavy raw materials, including ethylene tar, coal tar, oil slurry, petroleum, and coal tar pitch, are transported from the raw material tank (1) to the modifier (2). S1.
2. Use the electric heating reaction equipment in the modifier (2) to perform thermal modification of the raw materials; S1.3 During the process, the working mode of the reformer (2) is switched through the first heat exchanger (12). First, in the conveying mode, the raw material is continuously conveyed through the reformer (2) for single-pass reforming. Then, the internal circulation mode is adopted so that the raw material undergoes multiple heat cycles inside the reformer (2). Finally, the reformed raw material is conveyed to the reforming raw material tank (3) for temporary storage. S2, purification and distillation separation; It includes the following steps: S2.1 The modified raw material temporarily stored in the modified raw material tank (3) is transported to the membrane filter (4) through the modified raw material pump (33), and the purified raw material enters the purified raw material tank (5). S2.2 The purified raw material is transported from the purified raw material tank (5) to the purified material distillation tower (6) by the purified raw material pump (51), and the vacuum pump (83) maintains it at a vacuum of -0.092~-0.098MPa, while controlling the tower bottom temperature to be maintained at 290~330℃. Under these conditions, the low-boiling-point oil in the raw material is distilled off at the top of the tower and collected in the light oil tank (8) after condensation; the refined raw material rich in the intermediate phase is discharged from the bottom of the tower and temporarily stored in the refined raw material tank (7); S3. Preparation of Precursor through Mixing and Reaction: This step involves mixing and reacting specific components in the following sub-steps to construct a precursor with ideal pores and thermal stability. The specific steps include: S3.1 Take light oil and refined raw materials from the light oil tank (8) and the refined raw material tank (7) respectively, and transport them to the heater (82) for preliminary mixing in a mass ratio of 1:3~5; S3.2, Heat the mixed raw materials to 420~480℃ in heater (82); S3.
3. The preheated mixed raw materials are fed into the reactor (9), and nitrogen is introduced into the system as a protective gas. Oxygen-containing organic acids and epoxy resins are added into the system through the second feed port to carry out cross-linking polycondensation reaction.
8. The method for preparing the porous carbon precursor according to claim 7, characterized in that, The electric heating reaction equipment in the reformer (2) controls the internal temperature at 350~420℃; the reforming raw material tank (3) is kept warm by an electromagnetic heater (31) and the temperature is maintained at 250-300℃.
9. The method for preparing the porous carbon precursor according to claim 7, characterized in that, The membrane filter (4) uses a sintered metal microporous membrane with a filtration accuracy of 10-50 μm.
10. The method for preparing the porous carbon precursor according to claim 7, characterized in that, The vacuum pump (83) maintains a vacuum of -0.092 to -0.098 MPa inside the purified material distillation tower (6), while controlling the temperature inside the purified material distillation tower (6) to be maintained at 290 to 330°C.