A Joule-heated reaction system for high-pressure continuous catalytic reactions
By designing a Joule heating reaction system with a coaxial inner and outer tube structure and a bidirectional pressure-balanced gas path, the problem of rapid heating and temperature control for catalyst performance evaluation under high pressure was solved, achieving efficient electrothermal conversion and ease of operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANDE PRECISION (XIAMEN) TECH CO LTD
- Filing Date
- 2026-06-17
- Publication Date
- 2026-07-31
AI Technical Summary
Existing Joule heating devices cannot evaluate catalyst performance under high-pressure continuous flow conditions, and traditional high-pressure fixed-bed reactors suffer from problems such as heating lag, uneven field, and high energy consumption.
Design a Joule heating reaction system comprising a metal tube and a quartz tube, employing a coaxial inner and outer tube structure and a bidirectional pressure-balanced gas path, achieving consistent internal and external pressures through forward and reverse unidirectional pipelines, allowing electrodes to directly heat the catalyst bed, and combining temperature detection and a controllable DC power supply module to achieve precise temperature control.
It achieves rapid heating and precise temperature control of the catalyst under high pressure, has high electrothermal conversion efficiency, reduces thermal hysteresis and hollow tube effect, improves energy utilization, and is easy to operate.
Smart Images
Figure CN122479657A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of Joule heating catalytic reaction technology, specifically to a Joule heating reaction system for high-pressure continuous catalytic reactions, which is particularly suitable for the continuous evaluation of catalyst performance under high-pressure conditions. Background Technology
[0002] Traditional catalytic reaction technologies primarily employ external indirect heating methods, such as electric furnace heating of fixed-bed reactors, which are widely used in chemical, energy, and new materials fields. However, this technology suffers from technical bottlenecks including heating lag, uneven field distribution, and high energy consumption: Indirect heating via electric furnace wires typically results in a heating rate not exceeding 5°C / min; the furnace wall has a large heat capacity, a long heat transfer path, and a significant lag in thermal response, making it difficult to examine the instantaneous response behavior of the catalyst under rapid heating or process fluctuations; indirect heating leads to a temperature distribution within the reaction tube where the furnace wall is hot while the bed is cold, with axial and radial temperature differences reaching 10-30°C, making it difficult to accurately control the actual reaction temperature, affecting experimental repeatability, and potentially masking the intrinsic properties of the catalyst; the heat must first be applied to the heavy furnace body, resulting in a large amount of heat loss to the environment, with energy utilization typically below 50%.
[0003] In recent years, Joule heating technology (also known as resistance heating or Joule thermal heating) has emerged as a new technology and is gradually being explored for application in catalyst performance evaluation. It generates heat by directly applying voltage to conductive catalytic materials, utilizing the material's own resistance, and boasts advantages such as rapid heating rate and high thermal efficiency. This technology transforms the traditional "indirect, external heating" process into "direct, internal heating," potentially triggering a chain reaction of changes from reactor design to the entire production process, and is of great significance in the green and low-carbon transformation of the energy structure. However, most existing Joule heating devices operate under atmospheric pressure and are mostly intermittent, making it difficult to meet the evaluation requirements of high-pressure continuous catalytic reactions. For example, some Joule-heated sample stage devices are mainly used for material heat treatment or atmospheric pressure reactions, not for continuous flow reactions under high-pressure gas environments. Furthermore, while traditional high-pressure fixed-bed reactors can achieve high-pressure continuous operation, they still rely on external heating methods, failing to overcome the problems of heating lag and uneven field distribution.
[0004] Therefore, how to organically combine the rapid heating advantage of Joule heating with the evaluation requirements of high-pressure continuous catalytic reaction, and solve the technical problems such as the easy rupture of thin-walled reaction tubes and the imbalance of internal and external pressure under high pressure, is a key issue that urgently needs to be addressed in this field. Summary of the Invention
[0005] To address the limitations of existing Joule heating devices in evaluating catalyst performance under high-pressure continuous flow conditions, and the problems of heating lag, uneven field, and high energy consumption in traditional high-pressure fixed-bed reactors, this invention provides a Joule heating reaction system for high-pressure continuous catalytic reactions, which features precise temperature control and high electrothermal conversion efficiency.
[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: it includes a metal tube, a quartz tube, two electrodes, and a forward and reverse unidirectional pipe; the metal tube is nested outside the quartz tube to form an outer annular balance cavity, and an inner balance cavity is formed inside the quartz tube, with the outer annular balance cavity and the inner balance cavity not connected to each other; the two electrodes are respectively insulated and fixed at both ends of the quartz tube, and the two electrodes form a catalytic heating zone with the quartz tube in the middle; one end of the outer annular balance cavity is connected to one end of the inner balance cavity through a forward and reverse unidirectional pipe, the forward and reverse unidirectional pipe is connected to a mixer pipe, and the other end of the inner balance cavity is connected to a pilot gas pipe.
[0007] Furthermore, an insulation and heating device is installed on the outside of the metal tube.
[0008] Furthermore, the two ends of the quartz tube and the metal tube are respectively connected to a first end connector and a second end connector. The first end connector and the second end connector are used to fix the quartz tube and the metal tube and cooperate to form an outer annular balance cavity. A first end tee connector is connected to the outside of the first end connector, and a second end tee connector is connected to the outside of the second end connector. One electrode passes through the horizontal end of the first end tee connector, the first end connector, and the quartz tube in sequence. Another electrode passes through the horizontal end of the quartz tube, the second end connector, and the second end tee connector in sequence. Insulating sleeves are provided between the first end tee connector, the second end tee connector, and the electrode. The first end connector, the second end connector, and the quartz tube are all clearance-fitted with the electrode. The first end connector and the second end connector are all sealed to the outside of the quartz tube. The vertical end of the first end tee connector is connected to a forward and reverse unidirectional pipeline.
[0009] Furthermore, the first end connector and the second end connector have the same structure. The first end connector includes a first connector body, a combined nut, a first sealing ring, a knurled liner, a support ring, a second sealing ring, and a second connector body. One end of the first connector body is sealed to the first end tee connector, and the second connector body is sealed to the metal tube. The first connector body and the second connector body are connected by a combined nut. A first sealing ring is provided between the first connector body and the second connector body. The knurled liner is installed and fixed inside the connection end of the first connector body and the second connector body. The inner wall of the knurled liner is sealed to the quartz tube. A support ring is provided on the side of the knurled liner that mates with the second connector body. A second sealing ring is provided between the support ring and the second connector body.
[0010] Furthermore, the forward and reverse unidirectional pipelines include a first unidirectional channel loop and a second unidirectional channel loop arranged in parallel. The medium in the first unidirectional channel loop flows to the outer annular balance chamber, and the medium in the second unidirectional channel loop flows to the mixer pipeline. A first unidirectional valve is provided on the first unidirectional channel loop, and a second unidirectional valve is provided on the second unidirectional channel loop.
[0011] Furthermore, the mixer pipeline includes a gas mixer and several mixer branch pipelines connected to the gas mixer; each mixer branch pipeline is sequentially equipped with a filter, a second two-way ball valve, a mass flow controller and a check valve along the gas inlet direction, a second pressure sensor is installed between the mass flow controller and the second two-way ball valve, and a reaction system pressure sensor and a safety valve are installed on the gas mixer.
[0012] Furthermore, a first two-way ball valve, a first pressure reducing valve, and a back pressure valve are sequentially arranged along the air intake direction on the pilot gas pipeline. An air vent valve is arranged between the back pressure valve and the first pressure reducing valve, and a first pressure sensor is arranged on the back pressure valve.
[0013] Furthermore, insulating sleeves are provided between one electrode and the first end tee connector, and between the other electrode and the second end tee connector; the first end tee connector and the second end tee connector are sealed with the insulating sleeves, and the electrodes are sealed with the insulating sleeves.
[0014] Furthermore, an electrode axial pre-tightening mechanism is provided at the outer end of each electrode. The two electrode axial pre-tightening mechanisms are used to axially press the two electrodes inward, so that the electrodes and catalyst are in contact to form an electrical circuit. The electrode axial pre-tightening mechanism includes a fixed adjusting support plate, an adjusting screw, and a top block that contacts the electrode. The adjusting support plate is provided with a threaded hole that mates with the adjusting screw, and the top block is fixedly connected to the small end of the adjusting screw.
[0015] Furthermore, a temperature detection port is provided at the position where the metal tube mates with the catalytic heating zone. A temperature detection component is provided on the temperature detection port, and a temperature sensor is provided on the temperature detection component. The temperature detection component includes a third connector body, a first support ring, a third sealing ring, a quartz window, a nut, a second support body, a fourth sealing ring, a connecting pipe, and a connecting threaded cap. The connecting pipe is sealed and installed on the temperature detection port. The bottom of the third connector body and the top of the connecting pipe are sealed and connected by the connecting threaded cap. The first support ring, the third sealing ring, the quartz window, and the fourth sealing ring are arranged sequentially from bottom to top on the inner side of the top of the third connector body. The second support body is located on the top of the third connector body and is fixed to the third connector body by the nut thread.
[0016] Furthermore, it also includes a temperature control module and a controllable DC power supply module. The temperature control module is electrically connected to the temperature sensor, and the positive and negative terminals of the controllable DC power supply module are electrically connected to two electrodes, respectively. A power-carrying circuit is formed between the controllable DC power supply module, the two electrodes, and the catalyst. The temperature sensor is used to feed back the monitored catalyst temperature to the temperature control module. The temperature control module adjusts the voltage of the controllable DC power supply in real time based on the temperature feedback from the temperature sensor, and further adjusts the heating power in real time, thereby achieving precise automatic control of the catalyst temperature.
[0017] The beneficial effects of this invention are as follows: The reactor of this invention consists of an outer metal tube and an inner quartz tube. The first and second end connectors at both ends of the reactor are quick-release structures, and electrodes pass through both ends. The first and second end connectors are separated from the electrodes by insulating sleeves made of polytetrafluoroethylene or other insulating materials. The reactor inlet has two unidirectional structures, one positive and one negative, i.e., positive and negative unidirectional pipelines. When the system is pressurized, the reactant gas enters the quartz tube while simultaneously entering the space between the inside of the metal tube and the outside of the quartz tube through the positive structure, ensuring consistent pressure inside and outside the quartz tube. When depressurized, the gas inside the metal tube and the space outside the quartz tube enters the system through the negative structure, ensuring consistent pressure inside and outside the quartz tube. A temperature detection component is installed at the center of the reactor for temperature detection. The catalyst is packed in the center of the quartz tube, corresponding to the catalyst's catalytic heating zone.
[0018] This invention enables continuous catalytic reaction evaluation under high-pressure conditions via Joule heating. Through the coordinated design of a coaxial inner and outer tube structure and a bidirectional pressure-balanced gas path, the pressure on the inner and outer walls of the quartz tube remains consistent throughout the entire pressurization and depressurization process, thus preventing thin-walled tube rupture caused by pressure differences. Based on this, the Joule heating assembly can rapidly heat the catalyst under high pressure and continuous gas flow conditions, filling a gap in existing technologies.
[0019] The present invention features precise temperature control and extremely fast thermal response: because the current passes directly through the catalyst bed itself, the Joule effect generates heat directly within the catalyst, rather than through indirect heat transfer via the furnace wall and tube wall. Therefore, the heating rate can reach over 100℃ / s with almost no thermal hysteresis. Simultaneously, the radial temperature difference of the bed can be controlled within 1℃, far superior to the 10-30℃ of traditional fixed beds.
[0020] This invention features high electrothermal conversion efficiency and significant energy-saving effect: the Joule heating method of this invention directly converts electrical energy into thermal energy of the catalyst bed without passing through multiple heat transfer media such as furnace body and tube wall. The electrothermal conversion efficiency is close to 100%, which is more than 30% higher than the energy utilization efficiency of traditional electric furnace heating methods (usually less than 50%).
[0021] This invention effectively reduces the empty tube effect: Through the sealed fit between different structures, this invention allows the raw material gas to pass entirely through the interior of the quartz tube and the catalyst bed without contacting the external metal tube during the entire process, effectively reducing the empty tube effect caused by the reaction between the metal tube and the raw material gas at high temperatures.
[0022] The present invention is easy to construct and operate: the reactor ends are designed with quick-release connectors, which facilitates catalyst loading and replacement; the system integrates gas mixing, pressure control, temperature detection and data recording functions, and can realize fully automatic programmed operation. Attached Figure Description
[0023] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the overall structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the Joule heating catalytic component in this invention; Figure 4 for Figure 3 A magnified view of a portion of the image; Figure 5 This is a schematic diagram of the temperature detection component. The symbols for each component are as follows: 1. Metal tube; 2. Quartz tube; 3. Electrode; 31. Top block; 32. Adjusting support plate; 33. Adjusting screw; 4. First end connector; 41. First connector body; 42. Combined nut; 43. First sealing ring; 44. Knurled liner; 45. Support ring; 46. Second sealing ring; 47. Second connector body; 5. Second end connector; 6. Insulating sleeve; 7. First end tee connector; 8. Second end tee connector; 9. One-way and reverse directional piping; 91. First tee connector; 92. Second tee connector; 93. Third tee connector; 94. First check valve; 95. Second check valve; 10. Temperature detection component; 101. Third connector body; 102. First support ring; 103. Third sealing ring; 104. Quartz window; 105. Nut; 106. Second support body; 107. Fourth sealing ring; 108. Connecting pipe; 109. Connecting threaded cap; 110. Temperature sensor; 11. Catalyst; 12. Pilot gas line; 121. Back pressure valve; 122. First pressure sensor; 123. First pressure reducing valve; 124. First two-way ball valve; 125. Vent valve; 13. Mixer branch line; 131. Safety valve; 132. Reaction system pressure sensor; 133. Check valve; 134. Mass flow controller; 135. Second pressure sensor; 136. Second two-way ball valve; 137. Filter; 138. Raw material gas cylinder; 14. Gas mixer; 15. Tubular furnace; 16. Controllable DC power supply. Detailed Implementation
[0024] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.
[0025] 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 and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0026] In the description of this invention, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "High pressure" typically refers to a reaction system pressure of 0.5 to 10 MPa, but is not limited to this; depending on improvements in reactor material and sealing design, it can also be applied to higher pressure ranges. "Continuous catalytic reaction" refers to a reaction gas continuously flowing through the catalyst bed, with products continuously carried out of the reactor, rather than a batch-type static reaction.
[0027] Example 1 like Figure 1 , Figure 2 and Figure 3As shown, a Joule-heated reaction system for high-pressure continuous catalytic reaction includes a metal tube 1, a quartz tube 2, two electrodes 3, a first end connector 4, a second end connector 5, a first end tee connector 7, a second end tee connector 8, forward and reverse unidirectional pipes 9, a temperature detection component 10, a mixer pipe, and a pilot gas pipe 12. The two electrodes 3 are insulated and fixed at both ends of the quartz tube 2, forming a catalytic heating zone with the quartz tube 2 in the middle. The two electrodes 3 are connected to a controllable DC power supply module 16. The quartz tube 2 and the metal tube 1 are respectively connected to a first end connector 4 and a second end connector 5 at both ends. The first end connector 4 and the second end connector 5 are used to fix the quartz tube 2 and the metal tube 1. The metal tube 1 is nested outside the quartz tube 2 to form an outer annular balance cavity. An inner balance cavity is formed inside the quartz tube 2. One end of the outer annular balance cavity is connected to one end of the inner balance cavity through a forward and reverse one-way pipe 9. The forward and reverse one-way pipe 9 is connected to a mixer pipe. The other end of the inner balance cavity is connected to a pilot gas pipe 12. The outside of the first end connector 4 is connected to a first end tee connector 7, and the outside of the second end connector 5 is connected to a second end tee connector 8. An insulating sleeve 6 is provided between one electrode 3 and the first end tee connector 7, and between another electrode 3 and the second end tee connector 8. The two electrodes 3 are sealed to the first end tee connector 7 and the second end tee connector 8 respectively through the insulating sleeve 6. The first end tee connector 7 and the second end tee connector 8 are sealed to the insulating sleeve 6, and the electrode 3 is also sealed to the insulating sleeve 6. A heat-insulating and heating device is installed outside the metal tube 1. This heat-insulating and heating device can be a tubular furnace 15. Figure 2 As shown in the dashed box, the tubular heating furnace 15 can achieve heat preservation and heating of the metal tube 1. The heat preservation and heating device can also use heating elements such as heating jackets.
[0028] One electrode 3 passes sequentially through the horizontal end of the first end tee connector 7, the first end connector 4, and the quartz tube 2. Another electrode 3 passes sequentially through the quartz tube 2, the horizontal end of the second end connector 5, and the second end tee connector 8. The first end tee connector 7 and the second end tee connector 8 are fixed to the electrode 3 with insulation. The first end connector 4, the second end connector 5, and the quartz tube 2 are all clearance-fitted with the electrode 3. The first end connector 4 and the second end connector 5 are all externally sealed to the quartz tube 2. A balance gas port is provided on the metal tube body 1. A one-way pipe 9 is connected between the vertical end of the first end tee connector 7 and the balance gas port. The input end of the one-way pipe 9 is connected to a mixer pipe, which includes a gas mixer 14 and several mixer branch pipes 13 connected to the gas mixer 14. The gas mixer 14 mixes the raw material gas before it enters the reaction system. The vertical end of the second end tee connector 8 is connected to a pilot gas pipe 12. An electrode axial pre-tightening mechanism is provided at the outer end of each electrode 3. The two electrode axial pre-tightening mechanisms axially tighten the electrode 3, and the electrode 3 is in contact with the catalyst 11 to form an electrical circuit. The electrode axial pre-tightening mechanism includes an adjusting support plate 32 fixed on the housing, an adjusting screw 33, and a top block 31 in contact with the electrode 3. The adjusting support plate 32 is provided with a threaded hole for installing the adjusting screw 33. The adjusting screw 33 is threadedly connected to the adjusting support plate 32 through the threaded hole, and the top block 31 is fixed to the small end of the adjusting screw 33.
[0029] It also includes a housing and a control instrument assembly 20 housed within the housing. The control instrument assembly 20 includes a flow control module, a temperature control module, a pressure monitoring module, a current monitoring module, and a voltage monitoring module. The Joule heating catalytic converter is located at the top of the housing, while the mixer pipeline and pilot gas pipeline 12 are located inside the housing. The housing also has an opening and closing door, on which a display control terminal and several control buttons are mounted.
[0030] The forward and reverse unidirectional pipeline 9 includes a first unidirectional channel loop and a second unidirectional channel loop arranged in parallel. The medium in the first unidirectional channel loop flows to the outer annular balance chamber, and the medium in the second unidirectional channel loop flows to the mixer pipeline. The vertical end of the first end tee connector 7 is connected to the balance port through the first and second unidirectional channel loops. A first unidirectional valve 94 is provided on the first unidirectional channel loop, and a second unidirectional valve 95 is provided on the second unidirectional channel loop. It also includes a first tee connector 91, a second tee connector 92, and a third tee connector 93. One horizontal end of the first tee connector 91 is connected to the vertical end of the first end tee connector 7 through a pipeline. One horizontal end of the second tee connector 92 is connected to the balance air port through a pipe. The vertical end of the first tee connector 91 and the vertical end of the second tee connector 92 form a first one-way channel circuit for installing the first one-way valve 94. The other horizontal end of the first tee connector 91 and the other vertical end of the third tee connector 93 form a second one-way channel circuit for installing the second one-way valve 95.
[0031] The mixer piping includes a gas mixer 14 and four mixer branch lines 13 connected to the gas mixer 14. Each mixer branch line 13 is sequentially equipped with a filter 137, a second two-way ball valve 136, a mass flow controller 134, and a check valve 133 along the gas inlet direction. A second pressure sensor 135 is installed between the mass flow controller 134 and the second two-way ball valve 136. The filter 137 is connected to a raw material gas cylinder 138. The mass flow controller 134 controls the flow rate of the raw material gas, and the second pressure sensor 135 monitors the pressure at the front end of the gas mass flow control. The second two-way ball valve 136 controls the flow of the raw material gas. A reaction system pressure sensor 132 and a safety valve 131 are installed on the gas mixer 14. The safety valve 131 automatically releases pressure when the system pressure exceeds a set value.
[0032] A first two-way ball valve 124, a first pressure reducing valve 123 and a back pressure valve 121 are sequentially arranged along the air intake direction on the pilot air line 12. An air vent valve 125 is arranged between the back pressure valve 121 and the first pressure reducing valve 123. A first pressure sensor 122 is arranged on the back pressure valve 121.
[0033] like Figure 4As shown, the first end connector 4 and the second end connector 5 have the same structure. The first end connector 4 includes a first connector body 41, a connecting nut 42, a first sealing ring 43, a knurled liner 44, a support ring 45, a second sealing ring 46, and a second connector body 47. One end of the first connector body 41 is sealed to the first end tee connector 7, and the second connector body 47 is sealed to the metal tube 1. The first connector body 41 and the second connector body 47 are connected by the connecting nut 42. A first sealing ring 43 is provided between the first connector body 41 and the second connector body 47. The knurled liner 44 is installed and fixed inside the connection end between the first connector body 41 and the second connector body 47. The inner wall of the knurled liner 44 is sealed to the quartz tube 2. A support ring 45 is provided on the side of the knurled liner 44 that mates with the second connector body 47. A second sealing ring 46 is provided between the support ring 45 and the second connector body 47.
[0034] like Figure 5 As shown, a temperature detection port is provided in the metal tube 1 at a position that mates with the catalytic heating zone. A temperature sensor 110 is provided on the temperature detection assembly. The temperature sensor 110 can be an infrared temperature sensor or the like. The temperature sensor 110, together with the temperature detection assembly 10, is used to detect the temperature of the catalyst inside the metal tube 1. A temperature detection assembly 10 is provided on the temperature detection port. The temperature detection assembly 10 includes a third connector body 101, a first support ring 102, a third sealing ring 103, a quartz window 104, a nut 105, a second support body 106, a fourth sealing ring 107, a connecting pipe 108, and a connecting threaded cap 109. The temperature detection port of the connecting pipe 108 is sealed and connected. The bottom of the third connector body 101 and the top of the connecting pipe 108 are sealed and connected by the connecting threaded cap 109. The first support ring 102, the third sealing ring 103, the quartz window 104, and the fourth sealing ring 107 are arranged sequentially from bottom to top on the inner side of the top of the third connector body 101. The second support body 106 is arranged on the top of the third connector body 101 and is threadedly fixed to the third connector body 101 by the nut 105.
[0035] In this embodiment, a temperature control module and a controllable DC power supply module 16 are also included. The temperature control module is electrically connected to the temperature sensor 110. The positive and negative terminals of the controllable DC power supply module 16 are electrically connected to the outer sides of the two electrodes 3, respectively, forming a power-conducting circuit between the controllable DC power supply module 16, the two electrodes, and the catalyst 11. The temperature sensor 110 is used to feed back the monitored catalyst temperature to the temperature control module. The temperature control module adjusts the voltage of the controllable DC power supply in real time based on the temperature feedback from the temperature sensor 110, and further adjusts the heating power in real time, thereby achieving precise automatic control of the catalyst temperature.
[0036] The working principle of the Joule heating reaction system for high-pressure continuous catalytic reaction: The entire reactor consists of an outer metal tube 1 and an inner quartz tube 2. The first end connector 4, the second end connector 5, the first end tee connector 7, and the second end tee connector 8 at both ends of the reactor are quick-release structures. Electrodes 3 pass through both ends. The first end tee connector 7 and the second end tee connector 8 are separated from the electrodes 3 by insulating sleeves 6, which are made of polytetrafluoroethylene (PTFE), but other insulating materials can be used. The reactor inlet has two unidirectional structures, one positive and one negative. The system features a reverse unidirectional pipeline. During system pressurization, the reactant gas enters the interior of the quartz tube 2 and simultaneously enters the outer annular balance chamber between the interior of the metal tube 1 and the exterior of the quartz tube 2 through the forward structure, ensuring consistent pressure inside and outside the quartz tube 2. During depressurization, the gas inside the metal tube 1 and the space outside the quartz tube 2 enters the reaction system through the reverse structure, ensuring consistent pressure inside and outside the quartz tube 2. A temperature detection component 10 is installed at the center of the reactor for temperature detection. The catalyst 11 is filled in the center of the quartz tube 2, specifically in the catalytic heating zone in the middle of the quartz tube 2.
[0037] The specific operating procedure for the Joule-heated reaction system used in high-pressure continuous catalytic reactions is as follows: A: Catalyst reduction process: A1: Open the main valve of reducing gas cylinder 139 and adjust the outlet pressure of material gas cylinder 139; A2: Open the second two-way ball valve 136 on the side panel to control the reducing gas passage; A3: Set the required flow rate value on the display control terminal, the mass flow controller 134 starts working, the reducing gas enters the gas mixer 14, enters the reactor after mixing, and then exits through the back pressure valve; A4: Catalyst reduction by heating can be divided into two heating methods. Heating method one: Fix the positive and negative terminals of the power supply to the two ends of electrode 3 respectively, set the reduction temperature program on the display control terminal, and perform catalyst reduction after the temperature stabilizes. Heating method two: If the catalyst cannot be directly reduced by Joule heating due to its resistance, it can also be reduced by heating it through a tubular furnace 15 installed outside the metal tube.
[0038] B: Catalyst reaction process: B1: After catalyst reduction, close the main valve of reducing gas cylinder 139; B2: Open the main valve of raw material gas cylinder 138 and adjust the outlet pressure of raw material gas cylinder 138; B3: Open the second two-way ball valve 136 on the side panel to control the raw material gas passage; B4: Observe whether the pressure at the front end of the flow meter is normal; B5. Set the required flow rate value on the display control terminal, and the mass flow controller 134 starts working. The raw material gas enters the gas mixer 14, is mixed, and then enters the reactor, and is discharged through the back pressure valve. B6: Close the pilot gas vent valve 125, open the pilot gas first two-way ball valve 124, and then adjust the pilot gas first pressure reducing valve 123 clockwise to adjust the pilot gas pressure to the pressure required by the reaction system. B7: At this point, the system begins to slowly increase in pressure. Once the pilot gas setpoint is reached (at this point, the system pressure is consistent with the pilot gas pressure), observe whether the back pressure valve is discharging gas normally. B8: Fix the positive and negative terminals of the power supply to the two ends of electrode 3 respectively; B9: Set the reaction temperature program on the display control terminal, and conduct a high-pressure Joule heating continuous catalytic reaction experiment after the temperature stabilizes.
[0039] C: Shutdown procedure: C1: After the reaction is complete, turn off the temperature control and close the main valve of the reaction gas cylinder 139; C2: Close the second two-way ball valve 136 on the side panel that controls the raw material gas passage; C3: Close the pilot gas vent valve 125, close the pilot gas first two-way ball valve 124, and slowly adjust the pilot gas vent valve 125 counterclockwise to reduce the pilot gas pressure to atmospheric pressure. At the same time, the system pressure will also slowly decrease to atmospheric pressure. C4: Turn off the main power supply to the system.
[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A Joule-heated reaction system for high-pressure continuous catalytic reactions, characterized in that, It includes a metal tube, a quartz tube, two electrodes, and positive and negative unidirectional conduits; The metal tube is nested outside the quartz tube to form an outer annular balance cavity, and an inner balance cavity is formed inside the quartz tube. The outer annular balance cavity and the inner balance cavity are not connected to each other. The two electrodes are respectively insulated and fixed at both ends of the quartz tube, and the two electrodes form a catalytic heating zone with the quartz tube in the middle. One end of the outer annular balance chamber is connected to one end of the inner balance chamber via a forward and reverse unidirectional pipeline. The forward and reverse unidirectional pipeline is connected to a mixer pipeline, and the other end of the inner balance chamber is connected to a pilot gas pipeline.
2. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, The metal tube is equipped with a heat insulation and heating device on its exterior.
3. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, The quartz tube and the metal tube are respectively connected to a first end connector and a second end connector at both ends. The first end connector and the second end connector are used to fix the quartz tube and the metal tube and cooperate to form an outer annular balance cavity. A first end tee connector is connected to the outside of the first end connector, and a second end tee connector is connected to the outside of the second end connector. One electrode passes through the horizontal end of the first end tee connector, the first end connector, and the quartz tube in sequence. The other electrode passes through the horizontal end of the quartz tube, the second end connector, and the second end tee connector in sequence. Insulating sleeves are provided between the one electrode and the first end tee connector, and between the other electrode and the second end tee connector. The first end connector, the second end connector, and the quartz tube are all clearance-fitted with the electrodes. The first end connector and the second end connector are all sealed to the outside of the quartz tube. The vertical end of the first end tee connector is connected to a forward and reverse unidirectional pipeline.
4. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 3, characterized in that, The first end connector and the second end connector have the same structure. The first end connector includes a first connector body, a connecting nut, a first sealing ring, a knurled liner, a support ring, a second sealing ring, and a second connector body. One end of the first connector body is sealed to the first end tee connector, and the second connector body is sealed to the metal tube. The first connector body and the second connector body are connected by a connecting nut. A first sealing ring is provided between the first connector body and the second connector body. The knurled liner is installed and fixed at the inner connection end of the first connector body and the second connector body. The inner wall of the knurled liner is sealed to the quartz tube. A support ring is provided on the side of the knurled liner that mates with the second connector body. A second sealing ring is provided between the support ring and the second connector body.
5. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, The forward and reverse unidirectional pipelines include a first unidirectional channel circuit and a second unidirectional channel circuit arranged in parallel. The medium in the first unidirectional channel circuit flows to the outer annular balance cavity, and the medium in the second unidirectional channel circuit flows to the mixer pipeline.
6. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, The mixer pipeline includes a gas mixer and several mixer branch pipelines connected to the gas mixer; each mixer branch pipeline is provided with a filter, a second two-way ball valve, a mass flow controller and a one-way valve in sequence along the gas inlet direction; a second pressure sensor is provided between the mass flow controller and the second two-way ball valve; and a reaction system pressure sensor and a safety valve are provided on the gas mixer.
7. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, The pilot gas pipeline is provided with a first two-way ball valve, a first pressure reducing valve and a back pressure valve in sequence along the air intake direction. An air vent valve is provided between the back pressure valve and the first pressure reducing valve. A first pressure sensor is provided on the back pressure valve.
8. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, An electrode axial pre-tightening mechanism is provided at the outer end of each electrode. The two electrode axial pre-tightening mechanisms are used to axially press the two electrodes inward, so that the electrodes and catalyst are in contact to form an electric circuit. The electrode axial pre-tightening mechanism includes a fixed adjusting support plate, an adjusting screw, and a top block that contacts the electrode. The adjusting support plate is provided with a threaded hole that mates with the adjusting screw, and the top block is fixedly connected to the small end of the adjusting screw.
9. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 1, characterized in that, The metal tube is provided with a temperature detection port at a position that mates with the catalytic heating zone. A temperature detection component is provided on the temperature detection port, and a temperature sensor is provided on the temperature detection component.
10. The Joule-heated reaction system for high-pressure continuous catalytic reaction according to claim 9, characterized in that, It also includes a temperature control module and a controllable DC power supply module. The temperature control module is electrically connected to a temperature sensor, and the positive and negative terminals of the controllable DC power supply module are electrically connected to two electrodes, respectively. A power-carrying circuit is formed between the controllable DC power supply module, the two electrodes, and the catalyst. The temperature sensor is used to feed back the monitored catalyst temperature to the temperature control module, and the temperature control module adjusts the voltage of the controllable DC power supply in real time based on the temperature feedback from the temperature sensor.