Apparatus and method for producing olefins by flash heating of coal dust

Abstract

The application provides a device for preparing olefins by flash heating pulverized coal, comprising a pulse power source and a reaction chamber, further comprising electrode pieces connected to the positive and negative poles of the pulse power source respectively and extending to the inside of the reaction chamber from the end far away from the pulse power source and forming an electric field, the reaction chamber is provided with a conveying mechanism capable of forming an airflow channel along the inside and outside of the reaction chamber, and the electric pulse characteristics of the pulse power source are as follows: the time required for the pulse current to rise from 0A to a set value is less than 10ms, the pulse width is 20-500ms, and the set value of the pulse current is 0-500A. In the application, the preparation of low-carbon olefins is realized by using flash Joule heating technology and high-voltage electric shock technology, the mixed powder can reach a temperature of more than 3000K in less than 100ms, the volatile components in the pulverized coal are effectively converted into low-carbon olefins, the clean and efficient conversion and utilization of coal are realized, the preparation is simple and controllable, the cost is low, and meanwhile, the application can be carried on other structures and has good transferability.

Description

An apparatus and method for preparing olefins by flash heating of pulverized coal. Technical Field

[0001] This invention relates to the field of olefin material preparation technology, specifically to an apparatus and method for preparing olefins by flash heating of pulverized coal. Background Technology

[0002] Low-carbon olefins such as ethylene, propylene, and butene are key organic raw materials in modern chemical engineering, accounting for a significant portion of the petrochemical industry. Downstream products include dichloroethylene, isopropylene, polyethylene, and polypropylene. Meanwhile, my country's demand for the performance of low-carbon olefins is increasing, and the market demand is also growing.

[0003] Currently, the common method for producing low-carbon olefins is the thermal cracking of petroleum hydrocarbons. This process is highly dependent on petroleum, and since my country imports 73% of its petroleum, existing processes urgently need improvement and transformation for the domestic olefin industry. In recent years, various processes for producing low-carbon olefins (MTO) using methanol have emerged. Specifically, preheated gaseous methanol is catalyzed by molecular sieves at specific temperatures and pressures to produce low-carbon olefins as the main product. Although the MTO process uses a single raw material, the reaction products and processes are very complex. Therefore, traditional methods for producing low-carbon olefins have disadvantages such as complex equipment structure, high investment, difficult operation, and numerous by-products. Summary of the Invention

[0004] This invention provides a method for preparing low-carbon olefins using flash Joule heating technology and high-voltage electric discharge technology. Amorphous conductive mixed powder is compressed between two electrode plates and placed in a high-temperature reaction chamber maintained at atmospheric pressure and an inert gas atmosphere. The high-temperature reaction chamber can be made of temperature- and pressure-resistant materials such as stainless steel or aluminum, while the electrode materials can be copper, stainless steel, or any conductive and refractory material. High-voltage discharge causes the mixed powder to reach a temperature above 3000K in less than 100 milliseconds, effectively converting the volatiles in coal powder into low-carbon olefins, achieving clean and efficient conversion and utilization of coal. The preparation method is simple and controllable, with low cost, and can be mounted on other structures with good transferability.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An apparatus for flash heating coal powder to prepare olefins includes a pulse power supply and a reaction chamber, and also includes electrode components that are respectively connected to the positive and negative terminals of the pulse power supply and extend into the interior of the reaction chamber at the end away from the pulse power supply to form an electric field. The reaction chamber is provided with a conveying mechanism that can form airflow channels along its inner and outer sides.

[0007] Preferably, the pulse characteristics of the pulse power supply are as follows: the time required for the pulse current to rise from 0A to the set value is less than 10ms, the pulse width is 20-500ms, and the pulse current set value is 0-500A.

[0008] Preferably, the electrode includes an electrode rod connected to a pulse power supply and an electrode sheet disposed at one end of the electrode rod located inside the pulse power supply.

[0009] Preferably, the electrode rod includes a connecting portion connected to the pulse power supply and an extension portion disposed at the end of the connecting portion away from the pulse power supply, the end of the extension portion away from the connecting portion extending into the pulse power supply.

[0010] Preferably, an insulating component is further provided between the electrode and the reaction chamber. The insulating component includes an insulating tube sleeved on the outer layer of the extension, an insulating and heat-insulating layer disposed inside the reaction chamber to isolate the electrode sheet from the bottom wall of the reaction chamber, and an insulating sheet to isolate the electrode sheet from the side wall of the reaction chamber.

[0011] Preferably, the conveying mechanism includes an air inlet and an air outlet disposed on the side wall of the reaction chamber, and an inert or reducing gas cylinder is connected to the air inlet, and a gas collection bag is connected to the air outlet.

[0012] Preferably, the electrode rod is made of brass, graphite, or stainless steel.

[0013] Preferably, the insulating tube is made of acrylic, polytetrafluoroethylene, or epoxy resin.

[0014] Preferably, the insulating and heat-insulating layer is made of ceramic.

[0015] A method for preparing olefins by flash heating of pulverized coal includes the following steps:

[0016] S10: Weigh an appropriate amount of coal powder and dry it, then mix the dried coal powder with conductive powder in a ratio of 1:1 to 2:3.

[0017] S20: Place the thoroughly mixed sample evenly in the middle of the electrode sheet, press it firmly, and control the resistance range to 0.1~10Ω;

[0018] S30: Connect the air inlet to an inert or reducing gas cylinder and the air outlet to a gas collection bag;

[0019] S40: Set the flash evaporation parameters as follows: discharge current of 20-200A, discharge pulse of 50-500ms, and number of discharges of 1-5 times;

[0020] S50: After flash evaporation, blow the product outside the reaction chamber.

[0021] As can be seen from the above technical solutions, the present invention has the following beneficial effects: In the present invention, the preparation of low-carbon olefins is achieved by using flash Joule heating technology and high-voltage electric shock technology. That is, the amorphous conductive mixed powder is placed in the reaction chamber and compressed between two electrode plates. The reaction chamber is maintained in an atmospheric pressure and inert gas atmosphere. The pulse power supply enables the mixed powder to reach a temperature of over 3000K in less than 100ms, effectively converting the volatiles in coal powder into low-carbon olefins, realizing the clean and efficient conversion and utilization of coal. The preparation is simple and controllable, with low cost. At the same time, the present invention can be mounted on other structures and has good transferability. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the structure of the present invention;

[0023] Figure 2 is a three-dimensional structural cross-sectional view of the present invention.

[0024] In the diagram: 10, pulse power supply; 20, reaction chamber; 311, connecting part; 312, extension part; 320, electrode plate; 410, insulating tube; 420, insulating and heat-insulating layer; 430, insulating sheet; 510, air inlet; 520, air outlet. Detailed Implementation

[0025] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0026] Referring to Figures 1 and 2, an apparatus for flash heating coal powder to prepare olefins includes a pulse power supply 10 and a reaction chamber 20, as well as two electrodes connected to the positive and negative terminals of the pulse power supply 10, respectively. The ends of the electrodes away from the pulse power supply 10 extend into the reaction chamber 20, forming an electric field within the pulse power supply 10. Furthermore, the reaction chamber 20 is equipped with a conveying mechanism capable of forming airflow channels along its inner and outer sides. In use, a mixed conductive powder to be subjected to high-voltage discharge, such as coal powder and conductive powder, is placed between the two electrodes in the reaction chamber and compressed. The reaction chamber is maintained at atmospheric pressure and an inert gas atmosphere. When the pulse power supply 10 is operating, the mixed powder reaches a temperature above 3000K in less than 100 milliseconds, effectively converting the volatiles in the coal powder into low-carbon olefins, achieving clean and efficient conversion and utilization of coal. Therefore, the olefin preparation of this invention is simple and controllable, with low cost, and can be mounted on other structures, exhibiting good transferability.

[0027] It should be noted that the pulse characteristics of the pulse power supply 10 are as follows: the time required for the current to rise from 0A to the set value is less than 10ms, the pulse width can be set to 20~500ms, the current magnitude can be set to 0~500A, and it can perform continuous discharge and single discharge.

[0028] The reaction chamber 20 is made of stainless steel or aluminum and other temperature and pressure resistant materials, and the shape and size of the reaction chamber 20 can be set to have an inner wall length of 50mm, a width of 35mm, and a height of 25mm.

[0029] As a preferred technical solution of the present invention, the electrode component includes an electrode rod and an electrode sheet 320. The electrode rod is directly connected to the pulse power supply 10, and the electrode sheet 320 is disposed at the end of the electrode rod, specifically at the end of the electrode rod located inside the pulse power supply 10. It should be noted that the electrode rod and the electrode sheet 320 can be made of conductive solids such as brass and stainless steel. At the same time, the connection between the electrode sheet 320 and the electrode rod can be a threaded connection, that is, matching internal and external threads are provided at the part of the electrode sheet 320 and the electrode rod that are in contact, so as to achieve a fixed connection between the two.

[0030] Furthermore, the electrode rod includes a connecting portion 311 and an extension portion 312. The connecting portion 311 is connected to the positive or negative terminal of the pulse power supply 10, and the extension portion 312 is disposed at the end of the connecting portion 311 away from the pulse power supply 10, and the end of the extension portion 312 away from the connecting portion 311 extends into the pulse power supply 10.

[0031] Furthermore, to achieve insulation between the connection between the extension 312 and the reaction chamber 20, an insulating component is provided between the electrode and the reaction chamber 20. Specifically, the insulating component includes an insulating tube 410, an insulating and heat-insulating layer 420, and an insulating sheet 430. The insulating tube 410 is sleeved on the outer layer of the extension 312, the insulating and heat-insulating layer 420 is disposed inside the reaction chamber 20 to isolate the electrode sheet 320 from the bottom wall of the reaction chamber 20, and the insulating sheet 430 is also disposed inside the reaction chamber 20 to isolate the electrode sheet 320 from the side wall of the reaction chamber 20. It should be noted that the insulating tube 410 is made of insulating materials such as acrylic, polytetrafluoroethylene, or epoxy resin. The insulating tube 410 is completely covered around the extension 312. In this way, the contact part between the extension 312 and the reaction chamber 20 becomes the insulating tube 410, thereby achieving insulation between the extension 312 and the reaction chamber 20.

[0032] Furthermore, the insulating and heat-insulating layer 420 can be disposed on the bottom wall of the reaction chamber 20, and the material of the insulating and heat-insulating layer 420 is a high-temperature resistant material such as ceramic, so as to isolate the electrode sheet 320 from the contact with the bottom wall of the reaction chamber 20. Similarly, the insulating sheet 430 is disposed on the side wall of the reaction chamber 20, so as to isolate the electrode sheet 320 from the side wall of the reaction chamber 20. In this invention, the electrode sheet 320 is isolated from the inner cavity of the reaction chamber 20 by setting the insulating tube 410, the insulating and heat-insulating layer 420 and the insulating sheet 430, thereby forming an electric field between the two electrode sheets 320 to perform high-voltage electric shock on the mixed powder placed between the two electrode sheets 320, so as to convert the volatiles in the coal powder into low-carbon olefins.

[0033] As a preferred technical solution of the present invention, the conveying mechanism includes an air inlet 510 and an air outlet 520, both of which are disposed on the side wall of the reaction chamber 20. Further, an inert or reducing gas bottle is connected to the air inlet 510, wherein the inert gas can be nitrogen and the reducing gas can be hydrogen. A gas collection bag is connected to the air outlet 520. The air inlet 510 and the air outlet 520 can be disposed on the same side of the side wall of the reaction chamber 20 or on opposite sides of the side wall of the reaction chamber 20, as long as a continuous airflow channel can be formed between the air inlet 510 and the air outlet 520. In this way, before the mixed powder raw materials are flash-distilled in the reaction chamber 20, the interior of the reaction chamber 20 can be flushed by the formed airflow channel to prevent impurities from adversely affecting the flash-distillation process. In addition, after the flash-distillation is completed, the olefins generated by the reaction can be blown into the gas collection bag by the formed airflow channel to collect the product.

[0034] This invention also provides a method for preparing olefins by heating pulverized coal using flash evaporation technology, comprising the following steps:

[0035] S10: Weigh an appropriate amount of coal powder and dry it, then mix the dried coal powder with conductive powder in a certain proportion.

[0036] Specifically, an appropriate amount of coal powder can be weighed using an electronic balance, and after drying the coal powder, it can be mixed with conductive powder in a certain proportion to obtain raw materials. Then, the raw materials can be placed in a reaction chamber for flash evaporation to prepare olefins.

[0037] S10': Clean the reaction chamber.

[0038] Specifically, before flash evaporation, the reaction chamber needs to be cleaned to remove dust, dirt, and oil stains adhering to the surface of the reaction chamber, so as to avoid the above impurities from having an adverse effect on the subsequent flash evaporation process.

[0039] S20: Place the thoroughly mixed sample evenly in the middle of the electrode sheet, press it down, and control the resistance.

[0040] Specifically, after the aforementioned S10' cleans the reaction chamber, the raw material obtained by S10 is placed between two electrode plates, and the mixed raw material is evenly spread inside the reaction chamber. The resistance value of the spread raw material is controlled within a certain range, so that the raw material can be electrically charged between the two electrode plates, thereby preparing olefins through coal powder.

[0041] S30: Connect the air inlet to an inert or reducing gas cylinder and the air outlet to a gas collection bag.

[0042] Specifically, an inert or reducing gas cylinder is connected to the inlet, and a gas collection bag is connected to the outlet. During use, the gas in the inert or reducing gas cylinder can form a circulating flow channel along the inlet, reaction chamber, and outlet. This airflow channel can be used to flush the reaction chamber before flash evaporation and to blow the olefins generated by the reaction to the gas collection bag outside the reaction chamber for collection after flash evaporation.

[0043] S40: Set flash evaporation parameters.

[0044] Specifically, in order to achieve high-voltage electric shock of the mixed raw material formed in S30 through the electrode plates on both sides, it is also necessary to set the relevant parameters of the pulse power supply. In this invention, the flash evaporation parameters are as follows: discharge current of 20-200A, discharge pulse of 50-500ms, and discharge times of 1-5 times.

[0045] S50: After flash evaporation, blow the product outside the reaction chamber.

[0046] Specifically, since the vent is connected to the external gas collection bag, olefins will be present in the reaction chamber after flash evaporation. Therefore, air can be blown into the reaction chamber through an inert gas bottle or a reducing gas bottle to form an airflow channel between the vent, the reaction chamber, and the vent, thereby blowing the olefins formed by flash evaporation into the gas collection bag and collecting the flash evaporation products.

[0047] As a preferred technical solution of the present invention, step S10 includes the following steps:

[0048] S110: Place clean weighing paper inside the electronic balance and zero the electronic balance.

[0049] Specifically, an electronic balance can be used to weigh coal powder. During the weighing process, a clean weighing paper needs to be placed on the electronic balance to hold the coal powder, avoiding direct contact between the coal powder and the electronic balance. After placing the weighing paper, the electronic balance needs to be zeroed to improve the accuracy of the coal powder weighing.

[0050] S120: Weigh an appropriate amount of coal powder and dry it with a dryer.

[0051] Specifically, after weighing an appropriate amount of coal powder using an electronic balance, the coal powder needs to be dried using a dryer to remove moisture from the coal powder and avoid moisture from adversely affecting the subsequent flash evaporation process.

[0052] S130: Place clean weighing paper in the electronic balance again and zero the electronic balance.

[0053] Specifically, after the coal powder is dried, the weight of the dried coal powder needs to be weighed. Similarly, an electronic balance can be used for weighing. As mentioned in S110 above, a clean weighing paper needs to be placed on the electronic balance and the electronic balance needs to be zeroed.

[0054] S140: Weigh the dried coal powder again.

[0055] Specifically, after the aforementioned S130 is completed, the actual mass of the dried coal powder is weighed using an electronic balance.

[0056] Furthermore, S10 also includes the following steps:

[0057] S150: Place clean weighing paper inside the electronic balance and zero the electronic balance.

[0058] Specifically, after the coal powder is dried, an appropriate amount of coal powder needs to be weighed for flash evaporation treatment, that is, a clean weighing paper is placed on the electronic balance and the electronic balance is zeroed.

[0059] S160: Weigh an appropriate amount of coal powder.

[0060] Specifically, after the aforementioned S150 electronic balance is zeroed, an appropriate amount of pulverized coal is weighed for flash evaporation.

[0061] S170: Place clean weighing paper inside the electronic balance and zero the electronic balance again.

[0062] Specifically, since the raw material is a mixture of coal powder and conductive powder, it is necessary to weigh the conductive powder quantitatively. Similarly, place clean weighing paper on the electronic balance, and weigh the conductive powder after zeroing the electronic balance.

[0063] S180: Weigh an appropriate amount of conductive powder and mix the coal powder weighed in step S160 with the conductive powder in a ratio of 1:1 to 2:3.

[0064] Specifically, it should be noted that the ratio of coal powder to conductive powder in the mixed raw materials used in the flash evaporation of this invention is 1:1 to 2:3.

[0065] As a preferred technical solution of the present invention, S10' includes the following steps:

[0066] S110': The reaction chamber is soaked in deionized water and anhydrous ethanol respectively.

[0067] Specifically, the reaction chamber is soaked in deionized water and anhydrous ethanol respectively to clean the impurities on the surface of the reaction chamber.

[0068] S120': Use an ultrasonic cleaner to wash away impurities from the surface of the reaction chamber.

[0069] Specifically, in S110', the reaction chamber is soaked in deionized water and anhydrous ethanol, and then ultrasonically vibrated for a certain period of time, such as 10 minutes, to wash away the dust, dirt and oil stains inside the reaction chamber.

[0070] S130': Invert the cleaned reaction chamber onto absorbent paper to dry it.

[0071] Specifically, in order to absorb the moisture in the reaction chamber after cleaning, the reaction chamber can be inverted and placed on absorbent paper to dry the remaining moisture.

[0072] As a preferred technical solution of the present invention, step S20 includes the following steps:

[0073] S210: Take an appropriate amount of the mixed sample and spread it evenly between the electrode components.

[0074] Specifically, after the coal powder and conductive powder are fully mixed to form a sample, the mixed sample can be evenly spread between the two electrodes in the reaction chamber.

[0075] S220: The sample is compressed to a thickness of 1 mm and a resistance of 1 to 10 Ω using a hydraulic press.

[0076] Specifically, the mixed sample, which is spread flat in the reaction chamber, is compressed into a shape with a thickness of 1 mm by a pressure device, such as a hydraulic press, so that the sample resistance between the two electrode plates is 1 to 10 Ω, in order to meet the requirements of flash evaporation.

[0077] It should be noted that the method for preparing olefins by heating pulverized coal using flash evaporation technology provided by the present invention further includes a step of rinsing the reaction chamber before flash evaporation. That is, after connecting the inlet to an inert gas bottle or a reducing gas bottle and the outlet to a gas collection bag, inert gas or reducing gas is introduced into the reaction chamber through the inlet of the inert gas bottle or reducing gas bottle to rinse the reaction chamber. The gas flow rate during rinsing is 0.5 slm, and the rinsing time can be set to 2 min.

[0078] Similarly, S50 also includes the step of introducing an inert gas or a reducing gas into the reaction chamber after flash evaporation. The gas is introduced by forming an airflow channel along the gas inlet, the reaction chamber and the gas outlet, thereby blowing the product out of the reaction chamber. The gas flow rate is 0.1 slm and the time is 1 min.

[0079] The technical effects of the apparatus and method for preparing olefins by flash heating coal powder according to the present invention will be further explained below by listing specific embodiments.

[0080] Example 1:

[0081] An apparatus for flash heating coal powder to prepare olefins includes a pulse power supply 10 and a reaction chamber 20, and two electrodes connected to the positive and negative terminals of the pulse power supply 10, respectively. The ends of the electrodes away from the pulse power supply 10 extend into the reaction chamber 20, forming an electric field within the pulse power supply 10. Furthermore, the reaction chamber 20 is equipped with a conveying mechanism capable of forming airflow channels along its inner and outer sides. In use, a mixed conductive powder to be subjected to high-voltage discharge, such as coal powder and conductive powder, is placed between the two electrodes in the reaction chamber and compressed. The reaction chamber is maintained at atmospheric pressure and an inert gas atmosphere. When the pulse power supply 10 is operating, the mixed powder reaches a temperature above 3000K in less than 100 milliseconds, effectively converting the volatiles in the coal powder into low-carbon olefins, achieving clean and efficient conversion and utilization of coal. Therefore, the olefin preparation of this invention is simple and controllable, with low cost, and can be mounted on other structures, exhibiting good transferability.

[0082] It should be noted that the pulse characteristics of the pulse power supply 10 are as follows: the time required for the current to rise from 0A to the set value is less than 10ms, the pulse width can be set to 20~500ms, the current magnitude can be set to 0~500A, and it can perform continuous discharge and single discharge.

[0083] The reaction chamber 20 is made of stainless steel or aluminum and other temperature and pressure resistant materials, and the shape and size of the reaction chamber 20 can be set to have an inner wall length of 50mm, a width of 35mm, and a height of 25mm.

[0084] As a preferred technical solution of the present invention, the electrode component includes an electrode rod and an electrode sheet 320. The electrode rod is directly connected to the pulse power supply 10, and the electrode sheet 320 is disposed at the end of the electrode rod, specifically at the end of the electrode rod located inside the pulse power supply 10. It should be noted that the electrode rod and the electrode sheet 320 can be made of conductive solids such as brass and stainless steel. At the same time, the connection between the electrode sheet 320 and the electrode rod can be a threaded connection, that is, matching internal and external threads are provided at the part of the electrode sheet 320 and the electrode rod that are in contact, so as to achieve a fixed connection between the two.

[0085] Furthermore, the electrode rod includes a connecting portion 311 and an extension portion 312. The connecting portion 311 is connected to the positive or negative terminal of the pulse power supply 10, and the extension portion 312 is disposed at the end of the connecting portion 311 away from the pulse power supply 10, and the end of the extension portion 312 away from the connecting portion 311 extends into the pulse power supply 10.

[0086] Furthermore, to achieve insulation between the connection between the extension 312 and the reaction chamber 20, an insulating component is provided between the electrode and the reaction chamber 20. Specifically, the insulating component includes an insulating tube 410, an insulating and heat-insulating layer 420, and an insulating sheet 430. The insulating tube 410 is sleeved on the outer layer of the extension 312, the insulating and heat-insulating layer 420 is disposed inside the reaction chamber 20 to isolate the electrode sheet 320 from the bottom wall of the reaction chamber 20, and the insulating sheet 430 is also disposed inside the reaction chamber 20 to isolate the electrode sheet 320 from the side wall of the reaction chamber 20. It should be noted that the insulating tube 410 is made of insulating materials such as acrylic, polytetrafluoroethylene, or epoxy resin. The insulating tube 410 is completely covered around the extension 312. In this way, the contact part between the extension 312 and the reaction chamber 20 becomes the insulating tube 410, thereby achieving insulation between the extension 312 and the reaction chamber 20.

[0087] Furthermore, the insulating and heat-insulating layer 420 can be disposed on the bottom wall of the reaction chamber 20, and the material of the insulating and heat-insulating layer 420 is a high-temperature resistant material such as ceramic, so as to isolate the electrode sheet 320 from the contact with the bottom wall of the reaction chamber 20. Similarly, the insulating sheet 430 is disposed on the side wall of the reaction chamber 20, so as to isolate the electrode sheet 320 from the side wall of the reaction chamber 20. In this invention, the electrode sheet 320 is isolated from the inner cavity of the reaction chamber 20 by setting the insulating tube 410, the insulating and heat-insulating layer 420 and the insulating sheet 430, thereby forming an electric field between the two electrode sheets 320 to perform high-voltage electric shock on the mixed powder placed between the two electrode sheets 320, so as to convert the volatiles in the coal powder into low-carbon olefins.

[0088] As a preferred technical solution of the present invention, the conveying mechanism includes an air inlet 510 and an air outlet 520, both of which are located on the side wall of the reaction chamber 20. Further, an inert gas bottle is connected to the outside of the air inlet 510, and a gas collection bag is connected to the outside of the air outlet 520. In this embodiment, the inert gas bottle is a nitrogen bottle. The air inlet 510 and the air outlet 520 can be located on the same side of the side wall of the reaction chamber 20 or on opposite sides of the side wall of the reaction chamber 20, as long as a continuous airflow channel can be formed between the air inlet 510 and the air outlet 520. In this way, before the mixed powder raw materials are flash-distilled in the reaction chamber 20, the interior of the reaction chamber 20 can be flushed using the formed airflow channel to prevent impurities from adversely affecting the flash-distillation process. In addition, after the flash-distillation is completed, the olefins generated by the reaction can be blown into the gas collection bag using the formed airflow channel to collect the product.

[0089] In an embodiment of the present invention, a method for preparing olefins using the above-described flash heating coal powder olefin preparation apparatus specifically includes the following steps:

[0090] 1) Weigh an appropriate amount of coal powder and dry it, and weigh the mass after drying.

[0091] 1a) Zeroing the electronic balance: Place clean weighing paper inside the electronic balance and use the zeroing program to zero it.

[0092] 1b) Weigh 30g of coal powder with a particle size of 100 mesh;

[0093] 1c) Dry the pulverized coal in a dryer at a temperature of 200°C for 200 minutes;

[0094] 1d) Zero the electronic balance again: Place clean weighing paper inside the electronic balance and use the zeroing program to zero it;

[0095] 1e) Weigh the dried coal powder again.

[0096] 2) Mix the dried coal powder with the conductive powder in a certain proportion.

[0097] 2a) Zeroing the electronic balance: Place clean weighing paper inside the electronic balance and use the zeroing program to zero it.

[0098] 2b) Weigh 3g of coal powder with a particle size of 100 mesh.

[0099] 2c) Zero the electronic balance again: Place clean weighing paper inside the electronic balance and use the zeroing program to zero it.

[0100] 2d) Weigh 3g of conductive carbon black.

[0101] 2e) Mix the weighed coal powder and conductive carbon black thoroughly in a grinding mortar.

[0102] 3) Clean the high-temperature reaction chamber.

[0103] 4) Place the thoroughly mixed sample evenly in the middle of the electrode sheet, press it down, and control the resistance at 5 ohms.

[0104] 5) Connect the high-voltage electrode rod directly to the pulse power supply, connect the air inlet of the high-temperature reaction chamber to the nitrogen cylinder, and connect the air outlet of the high-temperature reaction chamber to the machine bag.

[0105] 6) Before flash evaporation begins, flush the high-temperature reaction chamber with nitrogen. The specific parameters are: nitrogen flow rate of 0.5 slm and flushing time of 2 min.

[0106] 7) Set the flash evaporation parameters, specifically: discharge current 100A, discharge pulse 200ms, and discharge times 5.

[0107] 8) After flash evaporation, the gaseous products are blown into the gas collection bag with nitrogen and the products are detected by gas chromatograph. The specific parameters are: nitrogen flow rate 0.1 slm, rinsing time 1 min.

[0108] Example 2:

[0109] Compared with Example 1, the difference in this example is that the flash evaporation parameters are set as follows: discharge current 150A, discharge pulse width 200ms, and discharge times 5.

[0110] Example 3:

[0111] Compared with Example 1, the difference in this example is that the flash evaporation parameters are set as follows: discharge current 200A, discharge pulse width 200ms, and discharge times 5.

[0112] Example 4:

[0113] Compared with Example 1, the difference in this example is that the drying parameters for the coal powder are set as follows: drying temperature is 250℃ and drying time is 200min.

[0114] Example 5:

[0115] Compared with Example 1, the difference in this example is that the drying parameters are set as follows: drying temperature is 300℃ and drying time is 200min.

[0116] Example 6:

[0117] Compared with Example 1, the difference in this example is that the fully mixed sample is evenly placed in the middle of the electrode sheet, pressed tightly, and the resistance is controlled at 8 ohms.

[0118] Example 7:

[0119] Compared to Example 1, the difference in this example is that the thoroughly mixed sample is evenly placed in the middle of the electrode sheet, pressed tightly, and the resistance is controlled at 3 ohms.

[0120] Example 8:

[0121] The difference between this embodiment and Example 1 is that the particle size of the coal powder is 200 mesh.

[0122] Example 9:

[0123] Compared with Example 1, the difference in this example is that the particle size of the coal powder is 325 mesh.

[0124] Example 10:

[0125] The difference between this embodiment and Example 1 is that the particle size of the coal powder is 500 mesh.

[0126] This invention utilizes flash Joule heating technology and high-voltage electric shock technology to prepare low-carbon olefins. Specifically, amorphous conductive mixed powder is placed in a reaction chamber and compressed between two electrode plates. The reaction chamber is maintained at atmospheric pressure and in an inert gas atmosphere. The pulsed power supply causes the mixed powder to reach a temperature above 3000K in less than 100ms, effectively converting volatiles in coal powder into low-carbon olefins, achieving clean and efficient conversion and utilization of coal. The preparation is simple, controllable, and low-cost. Furthermore, this invention can be mounted on other structures, exhibiting good transferability.

[0127] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An apparatus for flash heating pulverized coal to prepare olefins, comprising a pulse power supply (10) and a reaction chamber (20), characterized in that, It also includes electrode components that are respectively connected to the positive and negative terminals of the pulse power supply (10) and extend into the reaction chamber (20) at the end away from the pulse power supply (10) to form an electric field. The reaction chamber (20) is provided with a conveying mechanism that can form an airflow channel along its inner and outer sides. The pulse characteristics of the pulse power supply (10) are as follows: the time required for the pulse current to rise from 0A to the set value is less than 10ms, the pulse width is 20 to 500ms, and the pulse current set value is 0 to 500A. The electrode components include an electrode rod connected to the pulse power supply (10) and an electrode plate (320) disposed at one end of the electrode rod located inside the pulse power supply (10). The electrode rod includes a connecting part (311) connected to the pulse power supply (10) and an extension part (312) disposed at the end of the connecting part (311) away from the pulse power supply (10). The extension part (312) is located away from the connecting part (311). One end of the electrode (311) extends into the pulse power supply (10); an insulating component is also provided between the electrode and the reaction chamber (20). The insulating component includes an insulating tube (410) sleeved on the outer layer of the extension (312), an insulating heat insulation layer (420) provided inside the reaction chamber (20) to isolate the electrode (320) from the bottom wall of the reaction chamber (20), and an insulating sheet (430) to isolate the electrode (320) from the side wall of the reaction chamber (20); the conveying mechanism includes an air inlet (510) and an air outlet (520) provided on the side wall of the reaction chamber (20), and an inert or reducing gas bottle is connected to the air inlet (510), and a gas collection bag is connected to the air outlet (520); the electrode rod is made of brass, graphite or stainless steel; the insulating tube (410) is made of acrylic, polytetrafluoroethylene or epoxy resin; the insulating heat insulation layer (420) is made of ceramic.

2. A method for preparing olefins using the flash heating coal powder preparation apparatus according to claim 1, characterized in that, The process includes the following steps: S10: Weigh an appropriate amount of coal powder and dry it, then mix the dried coal powder with conductive powder in a ratio of 1:1 to 2:3; S20: Place the fully mixed sample evenly in the middle of the electrode sheet, press it down, and control the resistance range to 0.1 to 10Ω; S30: Connect the air inlet to an inert or reducing gas bottle and the air outlet to a gas collection bag; S40: Set the flash evaporation parameters as follows: discharge current of 20 to 200A, discharge pulse of 50 to 500ms, and discharge times of 1 to 5 times; S50: After flash evaporation, blow the product to the outside of the reaction chamber.

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