Intelligent porous carrier capable of dynamically monitoring and regulating temperature field in reaction area

Abstract

An intelligent porous carrier capable of dynamically monitoring and regulating a temperature field in a reaction area, which is specifically a three-dimensional porous structure composed of materials having different properties. The three-dimensional porous structure is manufactured using a multi-material 3D printing technology and selective carbonization process. The three-dimensional porous structure is composed of three parts: a thermoelectric phase, a conductor phase and a structural phase, which are responsible for temperature field perception, temperature field regulation and electrical isolation, respectively. Temperature field perception is achieved by the thermoelectric phase combining with a conductor to form a thermocouple using the Seebeck effect; temperature field regulation is achieved by means of inputting current into the conductor phase, to generate Joule heat; the temperature field perception and temperature field regulation processes are achieved by means of the structural phase maintaining structural interconnection and electrical isolation, which is achieved by utilizing the insulating properties of the structural phase. By combining multi-material 3D printing technology with selective carbonization technology to construct an intelligent porous carrier composed of a thermoelectric phase, a conductor phase and a structural phase, closed-loop intelligent control of a three-dimensional temperature field in a reaction area is implemented.

Description

An intelligent porous carrier that can dynamically monitor and control the temperature field in the reaction area Technical Field

[0001] The present invention belongs to the technical field of microreactors, and in particular relates to an intelligent porous carrier capable of realizing dynamic monitoring and regulation of the temperature field in a reaction area. Background Art

[0002] Microreactor technology involves conducting chemical reactions using miniature reactors, where the volume and mass of reactants are scaled to the micrometer level. This facilitates precise and efficient heat and mass transfer, improving reaction efficiency. Compared to traditional large-scale reactors, microreactor technology offers advantages such as rapid heat and mass transfer, high reaction efficiency, and sustainable production, providing an innovative and effective approach for the research, development, and production of fine chemicals. In recent years, researchers have conducted extensive research on reaction carrier structures, reactor design, catalysts, and heat supply methods, driving the rapid development of microreactor technology. However, the application of microreactors in fine chemicals faces the "black box" dilemma: the difficulty in observing and controlling the reaction process at the microscopic scale during actual operation. Temperature, as one of the core variables in chemical reactions, reflects the energy conversion process. For most chemical reactions, the dynamic equilibrium between reaction energy changes and the ambient temperature is difficult to maintain, which can easily lead to localized positive feedback effects, resulting in runaway reactions or even failure. Therefore, dynamic temperature selection and control are critical to achieving ideal reaction results.

[0003] In terms of temperature control, traditional microreactors use external heating rods, supplying heat to the reaction zone through heat conduction. However, this approach can cause large temperature gradients within the reaction zone and hinders local temperature control. Emerging applications of endogenous heat sources in microreactors, such as Joule heating, microwave heating, and ultrasonic heating, have effectively reduced temperature gradients within the reaction zone. However, dynamic control of local reaction temperatures remains difficult. The first step in achieving dynamic temperature control is obtaining dynamic temperature information within the reaction zone. Regarding temperature sensing, currently, due to the confines of the reaction zone and its relatively extreme operating environment, the temperature distribution within the reaction zone is mostly inferred from the final product. Simulations or measurements of the reactor's outer wall temperature, for example, cannot accurately represent the actual internal conditions. Invasive devices such as thermocouples and RTDs can interfere with the actual reaction, and the deviation from the actual conditions increases with the number of measurement points. Fiber optic sensors, while advantageous in size, can mitigate this effect to some extent, but they struggle to reconcile the trade-off between measurement locations and distortion, hindering scalability. In addition, due to the limitations of material properties, fiber optic sensors have problems such as poor chemical compatibility, limited application temperature range, and affected local heat transfer, making it difficult to become an effective solution for obtaining the three-dimensional temperature field of the reaction area.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the existing technology and provide an intelligent porous carrier that can realize dynamic monitoring and regulation of the temperature field of the reaction area, realize dynamic monitoring and regulation of the temperature field of the reaction process, solve the "black box" dilemma faced by microreactors in fine chemical applications, and improve the dynamic controllability of chemical reactions.

[0006] In order to achieve the above objectives, one of the technical solutions of the present invention is: an intelligent porous carrier that can realize dynamic monitoring and regulation of the temperature field in the reaction area, which is a three-dimensional porous structure composed of materials with multiple different properties; the three-dimensional porous structure is manufactured using multi-material 3D printing technology and selective carbonization process; the three-dimensional porous structure has temperature field perception and temperature field regulation functions, and is composed of three parts: thermoelectric phase, conductor phase and structural phase; the temperature field perception is achieved by combining the thermoelectric phase and the conductor to form a thermocouple using the Seebeck effect; the temperature field regulation is achieved by generating Joule heat by inputting current into the conductor phase; the part of the carrier that realizes the temperature field perception and temperature field regulation process is kept interconnected by the electrically insulating structural phase.

[0007] In a preferred embodiment of the present invention, the shape of the smart porous carrier is a regular or irregular cuboid or cylinder.

[0008] Further preferably, the length of the rectangular parallelepiped is 5 mm to 1000 mm, the width is 5 mm to 1000 mm, and the thickness is 1 mm to 20 mm; the length of the cylinder is 5 mm to 1000 mm, and the diameter is 1 mm to 20 mm.

[0009] In a preferred embodiment of the present invention, the smart porous carrier is composed of lattice-like truss structural units.

[0010] In a preferred embodiment of the present invention, the cross-sectional characteristic size of the truss structure unit is 10 μm to 500 μm, and the cross-sectional shape is a standard shape such as a circle, an ellipse, a rectangle, a triangle, or an irregular shape such as a random polygon or a random porous shape.

[0011] In a preferred embodiment of the present invention, the material properties mainly refer to electrical conductivity and Seebeck coefficient.

[0012] In a preferred embodiment of the present invention, the carbon material is formed by pyrolysis of a polymer; the polymer is one or more of polylactic acid (PLA), acrylonitrile-butadiene-styrene (ABS), nylon (PA), polycarbonate (PC), thermoplastic polyurethane (TPU), epoxy resin and the like.

[0013] Further preferably, the polymer pyrolysis is achieved by using a vacuum sintering furnace, an atmosphere sintering furnace, a plasma sintering furnace or the like in combination with a certain temperature rising program.

[0014] More preferably, the heating program is as follows: pyrolysis temperature is 300-1000°C, heating rate is 0.5-25°C / min, and pyrolysis time is 20-500 min.

[0015] In a preferred embodiment of the present invention, the multi-material 3D printing technology includes inkjet 3D printing, fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography 3D printing (SLA), composite stereolithography 3D printing (DLP) and powder pressing technology.

[0016] In a preferred embodiment of the present invention, the selective carbonization process utilizes the characteristic that the carrier concentration of the polymer varies greatly at different carbonization degrees, and controls the carbonization degree at different spatial positions of the porous structure by changing the catalyst content in the polymer, thereby controlling its electrical properties.

[0017] More preferably, the catalyst is one or more of a metal catalyst, a carbon-based catalyst, an oxide catalyst, and a calcium-based catalyst.

[0018] More preferably, the metal catalyst includes transition metal catalysts such as iron (Fe), cobalt (Co), nickel (Ni) and precious metal catalysts such as platinum (Pt) and palladium (Pd); the carbon-based catalyst includes carbon nanotubes, carbon black, etc.; the oxide catalyst includes ferric oxide (Fe2O3), ferrosoferric oxide (Fe3O4), zinc oxide (ZnO), etc.; the calcium-based catalyst includes calcium oxide (CaO), calcium carbonate (CaCO3), etc.

[0019] In a preferred embodiment of the present invention, the thermoelectric phase is formed by adding a relatively low content of catalyst to the pre-carbonized polymer, so that the partial structure has a certain Seebeck coefficient and a relatively low resistance after carbonization under the same temperature conditions.

[0020] Further preferably, the catalyst content is 10-25% wt; the Seebeck coefficient is 30-200 μV / K; and the resistance is 0.5-20 kΩ.

[0021] In a preferred embodiment of the present invention, the conductor phase is formed by adding a relatively high content of catalyst to the carbonized prepolymer, so that the partial structure has a very small Seebeck coefficient and resistance after carbonization under the same temperature conditions.

[0022] More preferably, the catalyst content is 30-60% wt. The Seebeck coefficient is 0-5 μV / K, and the resistance is 0-5Ω.

[0023] In a preferred embodiment of the present invention, the structural phase is formed without adding any catalyst to the pre-carbonized polymer, so that the structural phase has a larger resistance after carbonization under the same temperature conditions, and the resistance is greater than 150 MΩ.

[0024] In a preferred embodiment of the present invention, the temperature sensing function of the intelligent porous carrier is to combine the thermoelectric phase with the conductor to form a plurality of thermocouple junctions, and to sense the point temperature using the Seebeck effect.

[0025] Further preferably, the intelligent porous carrier has 10 to 100 thermocouple junctions formed by combining thermoelectric phases with conductors, which can constitute a three-dimensional temperature field in the reaction area.

[0026] Further preferably, the thermoelectric phase output voltage of each node and the conductor phase input voltage of each module form a closed loop through a computer program, and the input voltage of each module is adjusted in combination with the temperature range requirements of different reaction systems to perform intelligent temperature field control of the reaction area.

[0027] In a preferred embodiment of the present invention, the intelligent porous carrier has 2 to 25 heating modules, each of which is connected to input leads at both ends, and Joule heating is used to provide heat to the reaction area. By adjusting the input power of each heating module, fine control of the temperature of the reaction area can be achieved.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention combines multi-material 3D printing technology with selective carbonization technology to construct a thermally controlled intelligent porous carrier consisting of three phases: thermoelectric phase, conductor phase and structural phase. In addition to the structural functions of the porous medium such as enhanced heat and mass transfer and enhanced diffusion during chemical reactions, the carrier itself also has the functions of modular heating and three-dimensional temperature field sensing, which restores the real-time temperature field of the reaction area under actual working conditions and realizes closed-loop intelligent control of the three-dimensional temperature field of the reaction area. It is suitable for any reaction process that requires precise control of the temperature range, and provides an effective solution to the controllability problem of fine chemicals. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram and structural design diagram of a thermal control intelligent carrier according to the present invention;

[0031] Figure 2 is a planar structural design diagram of the thermoelectric layer. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to these embodiments. The same reference numerals throughout the text represent the same elements, and similar reference numerals represent similar elements.

[0033] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "horizontal", "vertical", "top", "bottom", "inside" and "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the stereoscopic diagrams in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] An intelligent porous carrier that can realize dynamic monitoring and regulation of the temperature field in the reaction area is a three-dimensional porous structure composed of materials with different properties; the three-dimensional porous structure is manufactured using multi-material 3D printing technology and selective carbonization process; the three-dimensional porous structure consists of three parts: a thermoelectric phase, a conductor phase and a structural phase, which are respectively responsible for temperature field perception, temperature field regulation and electrical isolation; the temperature field perception function is achieved by combining the thermoelectric phase and the conductor to form a thermocouple using the Seebeck effect; the temperature field regulation function is achieved by generating Joule heat by inputting current into the conductor phase; the temperature field perception and temperature field regulation process is achieved by the structural phase maintaining structural interconnection and electrical isolation, and is achieved by utilizing the insulating properties of the structural phase.

[0035] The shape of the intelligent porous carrier is a regular or irregular cuboid or cylinder.

[0036] The length of the rectangular parallelepiped is 5mm to 400mm, the width is 5mm to 400mm, and the thickness is 1mm to 20mm; the length of the cylindrical body is 5mm to 400mm, and the diameter is 1mm to 20mm.

[0037] The intelligent porous carrier is composed of lattice-shaped truss structure units.

[0038] The characteristic size of the cross section of the truss structure unit is 10 μm to 500 μm, and the cross section shape is a standard shape such as a circle, an ellipse, a rectangle, a triangle, or an irregular shape such as a random polygon, a random porous shape, etc.

[0039] The material properties mainly refer to electrical conductivity and Seebeck coefficient.

[0040] The carbon material is formed by pyrolysis of a polymer; the polymer is one or more materials such as polylactic acid (PLA), acrylonitrile-butadiene-styrene (ABS), nylon (PA), polycarbonate (PC), thermoplastic polyurethane (TPU), epoxy resin, etc.

[0041] The polymer pyrolysis is achieved by using a vacuum sintering furnace, an atmosphere sintering furnace, a plasma sintering furnace and other equipment in combination with a certain temperature increase program.

[0042] The heating program is as follows: the pyrolysis temperature is 300-1000° C., the heating rate is 0.5-25° C. / min, and the pyrolysis time is 20-500 min.

[0043] The multi-material 3D printing technology includes inkjet 3D printing, fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography 3D printing (SLA), composite stereolithography 3D printing (DLP) and powder pressing technology.

[0044] The selective carbonization process utilizes the characteristic that the carrier concentration of polymers varies greatly at different carbonization degrees, and controls the carbonization degree at different spatial positions of the porous structure by changing the catalyst content in the polymer, thereby controlling its electrical properties.

[0045] The catalyst is one or more of a metal catalyst, a carbon-based catalyst, an oxide catalyst, and a calcium-based catalyst.

[0046] The metal catalysts include transition metal catalysts such as iron (Fe), cobalt (Co), nickel (Ni) and precious metal catalysts such as platinum (Pt) and palladium (Pd); carbon-based catalysts include carbon nanotubes, graphene, etc.; oxide catalysts include ferric oxide (Fe2O3), ferrous oxide (Fe3O4), zinc oxide (ZnO), etc.; calcium-based catalysts include calcium oxide (CaO), calcium carbonate (CaCO3), etc.

[0047] The thermoelectric phase is obtained by adding a low content of catalyst to the polymer before carbonization, so that the partial structure has a certain Seebeck coefficient and a smaller resistance after carbonization under the same temperature conditions.

[0048] The catalyst content is 10-25% wt; the Seebeck coefficient is 30-200 μV / K; and the resistance is 0.5-20 kΩ.

[0049] The conductor phase is formed by adding a high content of catalyst into the pre-carbonized polymer, so that the partial structure has extremely small Seebeck coefficient and resistance after carbonization under the same temperature conditions.

[0050] The catalyst content is 30-60% wt. The Seebeck coefficient is 0-5 μV / K, and the resistance is 0-5Ω.

[0051] The structural phase is formed without adding any catalyst to the polymer before carbonization, so that the resistance of the structural phase is greater than 150 MΩ after carbonization under the same temperature conditions.

[0052] The temperature sensing function of the intelligent porous carrier is to combine the thermoelectric phase with the conductor to form multiple thermocouple junctions, and use the Seebeck effect to sense the point temperature.

[0053] The intelligent porous carrier has 10 to 100 thermocouple junctions formed by combining thermoelectric phases with conductors, which can form a three-dimensional temperature field in the reaction area.

[0054] The thermoelectric phase output voltage of each node and the conductor phase input voltage of each module form a closed loop through a computer program. Combined with the temperature range requirements of different reaction systems, the input voltage of each module is adjusted to perform intelligent temperature field control of the reaction area.

[0055] The intelligent porous carrier has 2 to 25 heating modules, each of which is connected to input leads at both ends. Joule heating is used to provide heat to the reaction area. By adjusting the input power of each heating module, fine control of the temperature of the reaction area can be achieved.

[0056] Example 1

[0057] An intelligent porous carrier capable of dynamically monitoring and controlling the temperature field in a reaction region comprises a thermoelectric phase, a conductor phase, and a structural phase. All three phases are carbon-based composite materials formed by carbonizing polymer precursors. In the embodiments, carbon nanotubes are used as a catalyst. Adding 40% of the carbon nanotubes to acrylate as a pre-carbonized precursor for the conductor phase results in a resistance of 10Ω and a Seebeck coefficient of 2μV / K. Adding 20% ​​of the carbon nanotubes to acrylate as a pre-carbonized precursor for the thermoelectric phase results in a resistance of 5kΩ and a Seebeck coefficient of 50μV / K. Using acrylate without the catalyst as a pre-carbonized precursor for the structural phase results in a resistance of >200MΩ for the conductor phase.

[0058] A three-dimensional porous carrier structure is generated by three-dimensional modeling software, as shown in Figure 1. The intelligent porous carrier adopts a layered design, and the three-dimensional porous structure is composed of alternating stacking of heating units and sensing units. The sensing units and heating units are structurally interconnected and electrically isolated through the structural phase; the main material of the heating unit is the conductor phase, and currents of different sizes are input to both ends of multiple heating units, and the temperature field can be controlled by Joule heating; the sensing unit is composed of three materials: thermoelectric phase, conductor phase, and structural phase. As shown in Figure 2, the thermoelectric phase and the conductor phase intersect to form multiple thermocouple junctions, and the Seebeck effect is used to sense the temperature field, while the rest of the part maintains the shape of the porous structure through the structural phase.

[0059] The pre-carbonized carrier structure was formed using multi-material photocuring 3D printing technology. The shape of the intelligent porous carrier is a regular rectangular parallelepiped with a length of 300 mm, a width of 700 mm, and a thickness of 2 mm. The interior of the intelligent porous carrier is composed of lattice-like truss structural units with a circular cross-section and a characteristic size of 300 μm. The pre-carbonized porous carrier was placed in a vacuum sintering furnace for carbonization. The program was set as follows: heating rate of 5°C / min, holding temperature of 650°C, and holding time of 60 min. The intelligent porous carrier has 50 thermocouple junctions formed by combining thermoelectric phases with conductors, which can form a three-dimensional temperature field in the internal area of ​​the carrier. The intelligent porous carrier also has 10 heating modules, each of which has input leads connected at both ends to generate the required heat inside the carrier using Joule heat. The Seebeck output voltage of each sensor node and the input current of each heating module form a closed-loop control through a computer program. Combining the temperature range requirements of different reaction systems with the three-dimensional temperature field information output by the sensor units, the Joule heat intensity generated by each heating module is adjusted, achieving real-time intelligent control of the three-dimensional temperature field in the reaction area. The fabricated intelligent porous carrier is placed as a reaction carrier in a methanol reforming hydrogen production microreactor. The control software is set to a temperature range of 260-280°C. The closed-loop control of the intelligent porous carrier's sensor modules and heating modules maintains the temperature of the microreactor reaction area within the optimal reaction temperature range, achieving dynamic monitoring and control of the temperature field within the methanol reforming hydrogen production microreactor.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An intelligent porous carrier capable of realizing dynamic monitoring and regulation of the temperature field in the reaction area, characterized in that: A three-dimensional porous structure composed of a plurality of materials with different properties; the three-dimensional porous structure is manufactured by using a multi-material 3D printing technology and a selective carbonization process; The three-dimensional porous structure has the functions of temperature field sensing and temperature field regulation, and is composed of three parts: a thermoelectric phase, a conductor phase, and a structural phase; the temperature field sensing is achieved by combining the thermoelectric phase with the conductor to form a thermocouple using the Seebeck effect; The temperature field control is achieved by generating Joule heat by inputting current into the conductor phase; and the partial carriers that realize the temperature field sensing and temperature field control process are connected to each other by electrically insulating structural phases.

2. The smart porous carrier according to claim 1, characterized in that: The shape of the intelligent porous carrier is a regular or irregular cuboid or cylinder, etc.; the length of the cuboid is 5mm to 400mm, the width is 5mm to 400mm, and the thickness is 1mm to 20mm; the length of the cylinder is 5mm to 400mm, and the diameter is 1mm to 20mm.

3. The smart porous carrier according to claim 1, characterized in that: The intelligent porous carrier is composed of lattice truss structure units; the cross-sectional characteristic size of the truss structure unit is 10 μm to 500 μm, and the cross-sectional shape is a standard shape such as a circle, an ellipse, a rectangle, a triangle, or an irregular shape such as a random polygon or a random porous shape.

4. The smart porous carrier according to claim 1, characterized in that: The material is formed by pyrolysis of a polymer; the polymer is one or more of polylactic acid (PLA), acrylonitrile-butadiene-styrene (ABS), nylon (PA), polycarbonate (PC), thermoplastic polyurethane (TPU), epoxy resin and the like.

5. The smart porous carrier according to claim 1, characterized in that: The polymer pyrolysis is achieved by using a vacuum sintering furnace, an atmosphere sintering furnace, a plasma sintering furnace and other equipment in combination with the following heating program: the pyrolysis temperature is 300-1000°C, the heating rate is 0.5-25°C / min, and the pyrolysis time is 20-500min.

6. The smart porous carrier according to claim 1, characterized in that: The multi-material 3D printing technology includes inkjet 3D printing, fused deposition modeling (FDM), selective laser sintering (SLS), photo-stereolithography 3D printing (SLA), composite photo-stereolithography 3D printing (DLP) and powder pressing technology.

7. The smart porous carrier according to claim 1, characterized in that: The selective carbonization process utilizes the characteristic that the carrier concentration of polymers at different carbonization degrees varies greatly, and controls the carbonization degree at different spatial positions of the porous structure by changing the content of the catalyst in the polymer, thereby controlling its electrical properties.

8. The smart porous carrier according to claim 1, characterized in that: The catalyst is one or more of a metal catalyst, a carbon-based catalyst, an oxide catalyst and a calcium-based catalyst; the metal catalyst includes a transition metal catalyst and a noble metal catalyst, the carbon-based catalyst includes carbon nanotubes and graphene, the oxide catalyst includes ferric oxide, ferrosoferric oxide and zinc oxide, and the calcium-based catalyst includes calcium oxide and calcium carbonate.

9. The smart porous carrier according to claim 1, characterized in that: The thermoelectric phase is a catalyst with a content of 10 to 25 wt% added to the pre-carbonized polymer, so that the Seebeck coefficient of the partial structure after carbonization under the same temperature conditions is 30 to 200 μV / K and the resistance is 0.5 to 20 kΩ; the conductor phase is a catalyst with a content of 30 to 60 wt% added to the pre-carbonized polymer, so that the Seebeck coefficient of the partial structure after carbonization under the same temperature conditions is 0 to 5 μV / K and the resistance is 0 to 5Ω; the structural phase is a catalyst without adding any additional catalyst to the pre-carbonized polymer, so that the resistance of the partial structure after carbonization under the same temperature conditions is greater than 150 MΩ.

10. The smart porous carrier according to claim 1, characterized in that: The temperature sensing function of the intelligent porous carrier is to combine the thermoelectric phase with the conductor to form a plurality of thermocouple nodes, and use the Seebeck effect to sense the point temperature; the intelligent porous carrier has 10 to 100 thermocouple nodes formed by combining the thermoelectric phase with the conductor, and 2 to 25 heating modules; the output voltage of the thermoelectric phase and the input voltage of each heating module form a closed loop through a computer program, and the input voltage of each module is adjusted in combination with the temperature range requirements of different reaction systems to perform intelligent control of the temperature field of the reaction area.

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