Joule heating methanol hydrogen production membrane catalytic reactor and parameter optimization method

Abstract

The invention relates to the technical field of methanol-to-hydrogen membrane catalytic reactors, and discloses a Joule heating methanol-to-hydrogen membrane catalytic reactor and a parameter optimization method.The membrane catalytic reactor comprises a heating reforming pipe fitting, a resistance wire coil and a heat insulation shell which are sequentially arranged from inside to outside, and the resistance wire coil is wound around the periphery of the heating reforming pipe fitting in the length direction; the heating reforming pipe fitting comprises a heating pipe and a porous reforming film pipe of which the end parts are connected in series, so that the heating pipe and the porous reforming film pipe are heated by Joule heat generated by the resistance wire coil; the heating pipe and the porous reforming membrane pipe are respectively electric insulation pipes; membrane pore channels penetrating through the pipe wall are formed in the pipe wall of the porous reforming membrane pipe, and catalyst particles for hydrogen production by methanol reforming are immobilized in the membrane pore channels in situ. The invention aims to solve the problems of large equipment volume, complex equipment structure and uneven temperature distribution caused by the adoption of an electromagnetic induction heating technology in the existing methanol-to-hydrogen membrane catalytic reactor.

Description

Technical Field

[0001] The present invention relates to the technical field of methanol-to-hydrogen membrane catalytic reactors, and particularly to a Joule heating methanol-to-hydrogen membrane catalytic reactor and a parameter optimization method. Background Art

[0002] As an important clean energy carrier, hydrogen energy shows broad application prospects in fields such as distributed energy systems, fuel cells, and emergency energy supply. However, the low volumetric energy density of hydrogen at room temperature and atmospheric pressure significantly increases its storage and transportation costs. Methanol, with advantages such as high hydrogen density, safe and economical storage and transportation, is an important liquid hydrogen carrier. In addition, green methanol prepared by coupling renewable energy electrolysis hydrogen production with CO2 capture technology can achieve raw material recycling and reduce carbon emissions. The methanol steam reforming reaction has advantages such as mild reaction conditions, high hydrogen production rate, and low energy consumption, and has great application potential in distributed / mobile hydrogen-consuming terminals.

[0003] Currently, industrial methanol steam reforming mainly uses fixed-bed membrane catalytic reactors, which are limited by internal and external diffusion effects and flow non-uniformity caused by the accumulation of large-particle catalysts, resulting in problems such as low reaction intensity, large volume of membrane catalytic reactors, insufficient catalyst utilization, and high energy consumption.

[0004] Methanol steam reforming to produce hydrogen is an endothermic reaction. The traditional combustion gas heat exchange method will cause large heat losses and it is difficult to form a uniform and controllable temperature field inside the membrane catalytic reactor. To overcome this technical problem, existing technologies adopt electromagnetic induction heating technology for heating methanol reforming hydrogen production membrane catalytic reactors. This type of technology forms induced eddy currents on magnetic or conductive materials and directly transfers heat to the catalytic layer, thereby improving energy utilization efficiency. For example, the patent with the application number CN2021114869351 uses the method of coating the inner wall of magnetically conductive tubes with catalysts and applying induction heating for methanol steam reforming. However, this technology is prone to problems such as large equipment volume, complex equipment structure, and uneven temperature distribution in large-scale hydrogen production designs.

[0005] Therefore, a new heating method for methanol-to-hydrogen membrane catalytic reactors needs to be proposed. Summary of the Invention

[0006] The main object of the present invention is to provide a Joule heating methanol-to-hydrogen membrane catalytic reactor and a parameter optimization method, aiming to solve the problems of large equipment volume, complex equipment structure, and uneven temperature distribution caused by the use of electromagnetic induction heating technology in existing methanol-to-hydrogen membrane catalytic reactors.

[0007] To achieve the above object, a membrane catalytic reactor for hydrogen production by Joule heating methanol provided by the present invention includes a heating and reforming pipe fitting, a resistance wire coil, and an adiabatic outer shell arranged in sequence from inside to outside. The resistance wire coil is wound around the outer periphery of the heating and reforming pipe fitting along the length direction of the heating and reforming pipe fitting. The heating and reforming pipe fitting includes a heating pipe and a porous reforming membrane pipe connected in series at the ends to heat the heating pipe and the porous reforming membrane pipe by Joule heat generated by the resistance wire coil. The heating pipe and the porous reforming membrane pipe are respectively electrically insulating pipes. The pipe wall of the porous reforming membrane pipe is provided with membrane pore channels penetrating the pipe wall, and catalyst particles for methanol reforming to produce hydrogen are in-situ immobilized in the membrane pore channels. One end of the heating pipe is an inlet for methanol aqueous solution, to preheat and vaporize the methanol aqueous solution under the heating action of the resistance wire coil to obtain methanol water vapor. The other end of the heating pipe is communicated with one end of the porous reforming membrane pipe, so that the methanol water vapor enters the membrane pore channels to react with the catalyst particles to produce hydrogen-rich reformed gas, and the hydrogen-rich reformed gas flows out of the membrane pore channels to the outside of the porous reforming membrane pipe, so that the hydrogen-rich reformed gas flows out from the outlet of the membrane catalytic reactor for hydrogen production.

[0008] Optionally, the heating pipe is a ceramic heating pipe, and / or the porous reforming membrane pipe is any one of a silicon carbide membrane pipe, an aluminum nitride membrane pipe, a beryllium oxide membrane pipe, a silicon nitride membrane pipe, and a boron nitride membrane pipe.

[0009] Optionally, a reduced-diameter connection section is provided at one end of the heating pipe for connecting with the porous reforming membrane pipe to be hermetically connected with the porous reforming membrane pipe through the reduced-diameter connection section.

[0010] Optionally, the methanol aqueous solution storage device is communicated with the inlet through a conveying device, and the outlet is communicated with a condensation device, a flow detection unit, and a gas chromatograph, and the detection data is fed back to the computer terminal through the gas chromatograph.

[0011] Optionally, the membrane catalytic reactor includes a plurality of the heating and reforming pipe fittings arranged in parallel in the adiabatic outer shell.

[0012] Optionally, the membrane pore channels are micro-nano scale membrane pore channels.

[0013] Optionally, the diameter of the membrane pore channels is 1 μm to 10 μm, the catalyst particles adopt a Cu-based catalyst, and the particle size of the catalyst particles is 10 nm to 200 nm.

[0014] Optionally, the heating pipe includes a preheating section and an evaporation section; the length of the heating pipe is calculated according to the mass of methanol consumed by the porous reforming membrane pipe, the mass of water, and the flow heat transfer in the heating pipe.

[0015] To achieve the above object, the present invention also provides a method for optimizing the parameters of a membrane catalytic reactor for hydrogen production by Joule heating methanol, which is used for optimizing the calculation of the length of the heating tube of the membrane catalytic reactor for hydrogen production by Joule heating methanol; the heating tube includes a preheating section and an evaporation section; the method includes the following steps: Establish an iterative model for calculating the length of the heating tube; wherein, the iterative model includes: the heat balance formula of the preheating section, the heat balance formula of the evaporation section, and the heat transfer and heat absorption balance formula in the heating tube; Obtain the initial wall temperature preset for the heating tube and the initial length of the preheating section; Input the initial wall temperature and the initial length of the preheating section into the iterative model for iteration until each balance formula in the iterative model holds; Obtain the length of the preheating section and the length of the evaporation section calculated by the iterative model, and calculate the length of the heating tube through the length of the preheating section and the length of the evaporation section.

[0016] Optionally, the calculation formula of the iterative model is as follows: (1); Wherein is the mass flow rate of the methanol aqueous solution, is the specific heat capacity at constant pressure at the qualitative temperature, t sat is the saturation temperature, t in is the inlet temperature; t m is the qualitative temperature of the preheating section, , is the logarithmic mean temperature difference; is the thermal conductivity of the heating tube; is the inner diameter of the evaporation section, d is the outer diameter of the evaporation section, r is the evaporation latent heat of the methanol aqueous solution; is the convective heat transfer coefficient of the preheating section, is the length of the preheating section; is the convective heat transfer coefficient of the evaporation section, is the length of the evaporation section; t w is the wall temperature; The convective heat transfer coefficient of the preheating section The calculation formula of is: (2); Wherein, is the Nusselt number, is the liquid thermal conductivity at the qualitative temperature; The convective heat transfer coefficient of the evaporation section The calculation formula is: (3); Where is the mass flow rate of the methanol - water solution at the saturation temperature, is the average dryness of the evaporation section, is the liquid - phase viscosity at the saturation temperature, is the Prandtl number at the saturation temperature, is the liquid - phase thermal conductivity at the saturation temperature, E is the enhancement factor; (4); Among them, ρ l,sat is the liquid - phase density at the saturation temperature, ρ v,sat is the gas - phase density at the saturation temperature, is the boiling number, is the Froude number; The boiling number The calculation formula is: (5); Among them, is the heat dissipation of the membrane catalytic reactor, is the reaction heat of the reforming reaction, is the length of the porous reforming membrane tube; The Froude number The calculation formula is: (6); Among them, , is the acceleration due to gravity; The heat dissipation of the membrane catalytic reactor The calculation formula is: (7); Among them, is the convective heat transfer coefficient of the annular gap gas in the membrane catalytic reactor, is the ambient temperature, is the temperature of the reforming tube wall, is the average diameter of the annular gap part, is the inner diameter of the adiabatic shell of the membrane catalytic reactor, is the outer diameter of the adiabatic shell of the membrane catalytic reactor, is the outer diameter of the insulation layer of the adiabatic shell, is the outer diameter of the flange, is the thermal conductivity of the adiabatic shell of the membrane catalytic reactor, L is the length of the heating tube, L = L pre + Levap , is the thermal conductivity of the thermal insulation layer of the adiabatic shell, is the convective heat transfer coefficient of the environment, is the thickness of the flange thermal insulation layer, is the thickness of the flange.

[0017] In the technical solution of the present invention, the membrane catalytic reactor integrates three functions: raw material preheating, raw material evaporation, and reforming reaction of methanol steam. Among them, raw material preheating and raw material evaporation are realized by heating tubes using Joule heating, and the reforming reaction is realized by porous reforming membrane tubes. Specifically: the resistance wire coil is wound outside the heating tube and outside the porous reforming membrane tube; one end of the heating tube is the inlet of the methanol aqueous solution, and under the heating action of the resistance wire coil, the methanol aqueous solution is preheated and vaporized to obtain methanol steam; the other end of the heating tube is communicated with one end of the porous reforming membrane tube, so that the methanol steam enters the membrane pore channel to generate a methanol reforming to hydrogen reaction with the catalyst particles to obtain a hydrogen-rich reformed gas, and the hydrogen-rich reformed gas flows out of the membrane pore channel to the outside of the porous reforming membrane tube, so that the hydrogen-rich reformed gas flows out from the outlet of the membrane catalytic reactor for hydrogen production. Therefore, the present invention is beneficial to solving the problems of large equipment volume, complex equipment structure, and uneven temperature distribution caused by the electromagnetic induction heating technology used in the existing methanol-to-hydrogen membrane catalytic reactor.

[0018] Specifically, compared with the existing technical solution, the present invention has the following advantages: (1) The membrane catalytic reactor has a compact structure: raw material preheating, raw material evaporation, and reforming are integrated into the same structure, heat can be concentratedly utilized, and only one set of power supply, one group of resistance wire coils and a control system are required for the heating device. The diameter of the resistance wire coil is smaller than that of the electromagnetic induction coil; the equipment structure is simple, no additional evaporation device is required, the floor area is small, and the equipment is convenient to move. At the same time, the catalyst particles are uniformly fixed in the micro-nano scale pore channels of the porous reforming membrane tube. When the reaction fluid flows through the micro-nano scale pore channels of the porous reforming membrane tube, the reforming reaction occurs, and the mass transfer distance can be shortened by 3-4 orders of magnitude compared with the conventional membrane catalytic reactor to achieve transfer strengthening. The porous reforming membrane tube can realize the coordination of catalytic micro-particles and micro-fluids and achieve the uniform distribution of the field.

[0019] (2) Uniform heat distribution in the reforming zone: The resistance wire coil is closely and evenly wound around the outer wall of the porous reforming membrane tube. Due to the high thermal conductivity of the membrane tube, the heat generated by the resistance wire coil can be quickly and evenly transferred to the reaction zone, reducing hot spots and cold spots, ensuring the efficient utilization of the catalyst, improving the conversion rate and hydrogen production rate, and reducing the generation of by-products. Compared with the electromagnetic induction heating method, it can provide a more uniform heating method. And compared with induction heating, the Joule heating structure is more compact, without the need for special induction coils or magnetic materials, easy to achieve distributed miniaturized design, and can be integrated with the porous membrane carrier.

[0020] (3) High energy utilization efficiency: Joule heating has a high heating efficiency, fast start-up and heating speed. In addition, the integrated design of the resistance wire coil, heating tube and porous reforming membrane tube makes the heat source concentrated in the endothermic reaction section and evaporation section, reducing ineffective energy consumption, thereby improving the overall energy utilization efficiency of the device. Description of the Drawings

[0021] Figure 1 It is the flow chart of the Joule heating methanol-to-hydrogen membrane catalytic reaction in the present invention; Figure 2 It is the internal structure diagram of the membrane catalytic reactor in the present invention; Figure 3 It is the flow path diagram of the fluid in the porous reforming membrane tube in the present invention; Figure 4 It is the flow chart of an embodiment of the method for optimizing the parameters of the Joule heating methanol-to-hydrogen membrane catalytic reactor in the present invention.

[0022] Explanation of the reference numerals in the drawings: 10 - Resistance wire coil; 20 - Insulating shell; 30 - Heating tube; 40 - Porous reforming membrane tube; 50 - Terminal; 60 - Blind plate; 70 - Flange; 80 - First thermocouple interface; 90 - Second thermocouple interface; 100 - Third thermocouple interface; 110 - Fourth thermocouple interface; 120 - Sealing gasket.

[0023] The realization of the object, functional characteristics and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific Embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] It should be noted that all the directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0026] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0027] In the present invention, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0029] Please refer to Figures 1 to 3 , to achieve the above object, the present invention provides a membrane catalytic reactor for hydrogen production by Joule heating of methanol, which includes a heating and reforming pipe fitting, a resistance wire coil 10, and a heat-insulating outer shell 20 arranged in sequence from inside to outside. The resistance wire coil 10 is wound around the outer periphery of the heating and reforming pipe fitting along the length direction of the heating and reforming pipe fitting. The heating and reforming pipe fitting includes a heating pipe 30 and a porous reforming membrane tube 40 connected in series at the ends, so as to heat the heating pipe 30 and the porous reforming membrane tube 40 by the Joule heat generated by the resistance wire coil 10. The heating pipe 30 and the porous reforming membrane tube 40 are respectively electrically insulating pipes. The tube wall of the porous reforming membrane tube 40 is provided with membrane pores penetrating the tube wall, and catalyst particles for methanol reforming to produce hydrogen are in-situ immobilized in the membrane pores. One end of the heating tube 30 is an inlet for the methanol aqueous solution, which preheats and vaporizes the methanol aqueous solution under the heating of the resistance wire coil 10 to obtain methanol water vapor; the other end of the heating tube 30 is communicated with one end of the porous reforming membrane tube 40, so that the methanol water vapor enters the membrane pore channel to generate a methanol reforming hydrogen production reaction with the catalyst particles to obtain a hydrogen-rich reformed gas, and the hydrogen-rich reformed gas flows out of the membrane pore channel to the outside of the porous reforming membrane tube 40, so that the hydrogen-rich reformed gas flows out from the outlet of the membrane catalytic reactor for hydrogen production.

[0030] In the technical solution of the present invention, the membrane catalytic reactor integrates three functions of raw material preheating, raw material evaporation and reforming reaction of methanol water vapor. Among them, raw material preheating and raw material evaporation are realized by the heating tube 30 using Joule heating, and the reforming reaction is realized by the porous reforming membrane tube 40. Specifically: the resistance wire coil 10 surrounds the outside of the heating tube 30 and the outside of the porous reforming membrane tube 40; one end of the heating tube 30 is an inlet for the methanol aqueous solution, which preheats and vaporizes the methanol aqueous solution under the heating of the resistance wire coil 10 to obtain methanol water vapor; the other end of the heating tube 30 is communicated with one end of the porous reforming membrane tube 40, so that the methanol water vapor enters the membrane pore channel to generate a methanol reforming hydrogen production reaction with the catalyst particles to obtain a hydrogen-rich reformed gas, and the hydrogen-rich reformed gas flows out of the membrane pore channel to the outside of the porous reforming membrane tube 40, so that the hydrogen-rich reformed gas flows out from the outlet of the membrane catalytic reactor for hydrogen production. Thus, the present invention is beneficial to solving the problems of large equipment volume, complex equipment structure and uneven temperature distribution caused by the electromagnetic induction heating technology used in the existing methanol hydrogen production membrane catalytic reactor.

[0031] Specifically, compared with the existing technical solution, the present invention has the following advantages: (1) The structure of the membrane catalytic reactor is compact: raw material preheating, raw material evaporation and reforming are integrated into the same structure, heat can be concentratedly utilized, and only one set of power supply, one group of resistance wire coils 10 and a control system are required for the heating device. The diameter of the resistance wire coil 10 is smaller than that of the electromagnetic induction coil; the equipment structure is simple, no additional evaporation device is required, the floor area is small, and the equipment is convenient to move. At the same time, the catalyst particles are uniformly fixed in the micro-nano scale pore channels of the porous reforming membrane tube 40. When the reaction fluid flows through the micro-nano scale pore channels of the porous reforming membrane tube 40, a reforming reaction occurs, and the mass transfer distance can be shortened by 3-4 orders of magnitude compared with the conventional membrane catalytic reactor to achieve transfer enhancement. The porous reforming membrane tube 40 can realize the synergy of catalytic microparticles and microfluids and achieve the uniform distribution of the field.

[0032] (2) Uniform heat distribution in the reforming zone: The resistance wire coil 10 is closely and evenly wound around the outer wall of the porous reforming membrane tube 40. Due to the high thermal conductivity of the membrane tube, the heat generated by the resistance wire coil 10 can be quickly and evenly transferred to the reaction zone, reducing hot spots and cold spots, ensuring the efficient utilization of the catalyst, enhancing the conversion rate and hydrogen production rate, and reducing the generation of by-products. Compared with the electromagnetic induction heating method, it can provide a more uniform heating method. And compared with induction heating, the Joule heating structure is more compact, without the need for special induction coils or magnetic materials, easy to achieve distributed miniaturized design, and can be integrated with the porous membrane carrier.

[0033] (3) High energy utilization efficiency: Joule heating has a high heating efficiency, fast startup and heating speed. In addition, the integrated design of the resistance wire coil 10 with the heating tube 30 and the porous reforming membrane tube 40 makes the heat source concentrated in the endothermic reaction section and the evaporation section, reducing ineffective energy consumption, thereby enhancing the overall energy utilization efficiency of the device.

[0034] Specifically, the chemical equation for methanol steam reforming in the present invention is: ; Specifically, the porous reforming membrane tube 40 can be various types of membrane tubes, which are provided with a large number of microscale membrane pores. Catalytic microparticles for methanol steam reforming can be immobilized in the membrane pores to form the porous reforming membrane tube 40 for methanol steam reforming. Among them, when the reaction is incomplete, CO will also be generated.

[0035] Further, the heating tube 30 and the porous reforming membrane tube 40 are respectively electrically insulating tubes, and the heating tube 30 and the porous reforming membrane tube 40 are respectively high thermal conductivity tubes.

[0036] Compared with the micro-membrane catalytic reactor formed by the foam structure, the porous reforming membrane tube 40 has a smaller channel size, which can be 2-3 orders of magnitude smaller than that of the foam metal, and its specific surface area is also correspondingly about 1 order of magnitude larger than that of the foam metal. When the reaction fluid is forced to flow through the microscale membrane pores of the porous reforming membrane tube 40, the reaction fluid will flow rather than diffuse to contact with the catalytic microparticles, shortening the mass transfer distance, thereby effectively reducing the influence of external diffusion. Secondly, due to the better dispersion of the porous membrane in the porous reforming membrane tube 40, the aggregation of catalyst particles can be effectively prevented and the size of the catalyst particles can be reduced, increasing the specific surface area of the particles and eliminating the internal diffusion caused by large particle catalysts. At the same time, the good dispersion of the membrane can also make the reaction fluid reach better uniformity, so that the reactant concentration and residence time are evenly distributed. Using the porous reforming membrane tube 40 for methanol steam reforming can achieve the synergy of catalytic microparticles and microfluids and achieve the uniform distribution of the field.

[0037] To simplify the device structure and further improve the thermal efficiency, the present invention proposes to directly heat the reaction zone by means of Joule heating. In this method, an electric current flows through a porous material or a catalyst support with a certain resistance to generate in-situ heat in the reaction zone, which can rapidly increase the temperature and make the temperature distribution uniform, thereby effectively reducing the heat loss caused by traditional external heating and improving the overall energy utilization efficiency of the system. Compared with induction heating, the Joule heating structure is more compact, does not require a dedicated induction coil or magnetic material, is easy to realize a distributed miniaturized design, and can be integrated with a porous membrane support.

[0038] Furthermore, the membrane catalytic reactor of the present invention does not require the additional installation of a heat exchanger and a vaporizer (the additional setting of a heat exchanger and a vaporizer requires the system to operate under high pressure, which puts higher requirements on the equipment materials and safety, and increases the design difficulty and maintenance cost of the system). It directly preheats and evaporates inside the membrane catalytic reactor, with high device integration, high heat concentration, and simple structure; it reduces the difficulty of thermal management and the system integration degree.

[0039] Specifically, the components of the membrane catalytic reactor from the inside out are: a heating and reforming pipe fitting (i.e., the connected heating pipe 30 and porous reforming membrane pipe 40), a resistance wire coil 10 spirally wound outside the heating and reforming pipe fitting, and a heat-insulating outer shell 20 arranged outside the resistance wire coil 10, which form the raw material heating zone (including the preheating zone and the evaporation zone) and the reforming zone of the membrane catalytic reactor. Its additional devices should also include a conveying device (such as a peristaltic pump), a temperature measuring probe, a temperature display, and an adjustable DC switching power supply.

[0040] The resistance wire coil 10 is uniformly wound outside the heating pipe 30 and the porous reforming membrane pipe 40 as a heating element. The heating pipe 30 and the porous reforming membrane pipe 40 can be centrally arranged inside the heat-insulating outer shell 20 of the membrane catalytic reactor. The heating pipe 30, the porous reforming membrane pipe 40, the resistance wire coil 10, and the outer heat-insulating shell 20 together constitute the overall membrane catalytic reactor.

[0041] Optionally, the heating pipe 30 is a ceramic heating pipe 30, and / or the porous reforming membrane pipe 40 is any one of a silicon carbide membrane pipe, an aluminum nitride membrane pipe, a beryllium oxide membrane pipe, a silicon nitride membrane pipe, and a boron nitride membrane pipe.

[0042] The heating pipe 30 and the porous reforming membrane pipe 40 are coaxially connected in series.

[0043] Specifically, the heating pipe 30 can be a ceramic heating pipe, and insulating materials such as alumina or aluminum nitride are recommended.

[0044] Optionally, one end of the heating pipe 30 for connecting with the porous reforming membrane pipe 40 is provided with a reduced-diameter connecting section to be hermetically connected with the porous reforming membrane pipe 40 through the reduced-diameter connecting section.

[0045] Specifically, one end of the heating tube 30 is an externally threaded straight tube section for connecting the flange 70, and the other end is a reducing connection section (a reducing straight tube section in this embodiment) for connecting the porous reforming membrane tube 40. Further, the reducing connection section is used to connect the porous reforming membrane tube 40, and the diameter of the part of the tube is reduced to be nested in the end of the porous reforming membrane tube 40, and connected to the inner wall of one end of the porous reforming membrane tube 40, and the connection method can be a detachable connection or a non-detachable connection.

[0046] The insulating shell 20 is welded by a plurality of connecting pipes, a flange 70 and a cylinder. The main structure of the membrane catalytic reactor can be a hollow cylinder, on which a plurality of connecting pipes are welded for fixing temperature measuring thermocouples. The material of the membrane catalytic reactor can be a high-temperature resistant metal material, such as stainless steel, carbon steel, aluminum alloy, etc., or a high-temperature resistant non-metallic material, such as quartz tube, silicon carbide, silicon nitride, etc.

[0047] A flange plate is welded at each end of the membrane catalytic reactor (i.e. Figure 2 The middle flange 70 is provided, and the two ends are sealed with blind plates 60 respectively, and the cylinder of the heat-insulating shell 20 is insulated with high-temperature resistant heat-insulating materials.

[0048] A plurality of temperature measuring thermocouples are respectively fixed by connecting pipes (i.e., each thermocouple interface) welded on the insulating shell 20, and a part of the temperature measuring thermocouples directly contacts the outer wall of the heating tube 30, and another part of the temperature measuring thermocouples directly contacts the outer wall of the porous reforming membrane tube 40. Specifically, in this embodiment, a first thermocouple interface 80 (corresponding to the first temperature measuring point, used to measure the wall temperature of the heating tube 30), a second thermocouple interface 90 (corresponding to the second temperature measuring point, used to measure the wall temperature of the heating tube 30), a third thermocouple interface 100 (corresponding to the third temperature measuring point, used to measure the wall temperature of the porous reforming membrane tube 40), and a fourth thermocouple interface 110 (corresponding to the fourth temperature measuring point, used to measure the wall temperature of the porous reforming membrane tube 40) are sequentially arranged on the insulating shell 20 along the direction from the heating tube 30 to the porous reforming membrane tube 40 to connect four thermocouples. Of course, the number of thermocouple interfaces can be set as needed, and is not limited thereto.

[0049] Specifically, each blind plate 60 has an internal thread at the eccentric and central positions, the eccentric hole is connected to the terminal 50 of the resistance wire coil 10, and is insulated from the membrane catalytic reactor as a whole. The central hole of one blind plate 60 is used to connect the heating tube 30 and the porous reforming membrane tube 40, respectively, and the central hole of the other blind plate 60 is used to discharge the hydrogen-rich reforming gas.

[0050] The end of the porous reforming membrane tube 40 that is away from the heating tube 30 is a closed end. Specifically, the reaction temperature of the heated reforming tube is controlled by the power applied to the resistance wire coil 10 and measured by the temperature measuring thermocouple.

[0051] The preparation of the porous reforming membrane tube 40 uses a forced flow method to in-situ immobilize the catalytic material in the membrane pore channels, and in-situ immobilize catalyst particles in the membrane pore channels of the porous reforming membrane tube 40 with micro-nano scale (for example, silicon carbide porous membrane). The catalytic material for methanol reforming to hydrogen is preferably a Cu-based catalyst, and the porous reforming membrane tube 40 with catalytic function is prepared; Specifically, the porous reforming membrane tube 40 uses an impregnation and forced flow method to in-situ immobilize the catalytic material in the micro-nano scale membrane pore channels. Specifically, the precursor solution of the nano-material with catalytic function is percolated into the membrane pore channels of the porous reforming membrane tube 40, and the nano-catalytic material is synthesized by reaction in the confined space and uniformly distributed in the membrane pore channels along the membrane thickness direction, obtaining the porous reforming membrane tube 40 with nano-structure.

[0052] The Joule heating process in the present invention is as follows: First, start the adjustable voltage switch DC power supply, and the current directly generates heat through the resistance wire coil 10. After the heating reforming pipe fitting has a certain heat capacity, the raw material is introduced. Its heating and reforming heat is completely provided by electric energy; Working principle: The methanol aqueous solution is pumped into the heating tube 30 as a cold fluid under the action of a conveying device (such as a flow pump), preheated and vaporized after absorbing the heat generated by the resistance wire coil 10 wound outside the heating tube 30, and then the high-temperature methanol steam directly enters the porous reforming membrane tube 40, and enters the internal cavity of the porous reforming membrane tube 40 along the axial direction of the membrane tube, and then flows through the membrane pore channels in the radial direction of the porous reforming membrane tube 40, and undergoes a methanol reforming reaction with the catalyst particles loaded in the membrane pore channels.

[0053] Optionally, the methanol aqueous solution storage device is connected to the inlet through a conveying device (such as a peristaltic pump), and the outlet is connected to a condensation device (such as a condenser), a flow detection unit (such as a wet gas meter) and a gas chromatograph, and the detection data is fed back to the computer terminal through the gas chromatograph. Among them, the condensation device is used to condense the unreacted methanol in the hydrogen-rich reformed gas, and the condensed methanol can be recovered to the methanol aqueous solution storage device, and at the same time, the hydrogen discharged from the condensation device is collected.

[0054] Specifically, the conveying device is a pump, specifically it can be Figure 1 a peristaltic pump.

[0055] Optionally, the membrane catalytic reactor includes a plurality of the heating reforming pipe fittings arranged in parallel with each other in the adiabatic housing 20.

[0056] Among them, the heating reforming pipe fittings are arranged in a polygonal pattern (such as triangular arrangement, quadrilateral arrangement, pentagonal arrangement, hexagonal arrangement), annular arrangement, etc., and are arranged in parallel to form a tube bundle, which can realize the amplification of the membrane catalytic reactor. When amplifying, a resistance wire coil 10 can be wound around each heating reforming pipe fitting respectively, or at least one heating reforming pipe fitting can be arranged inside each resistance wire coil 10.

[0057] Optionally, the membrane pore channels are micro-nano scale membrane pore channels.

[0058] Optionally, the diameter of the membrane pore channels is 1 μm to 10 μm, the catalyst particles are Cu-based catalysts, and the particle size of the catalyst particles is 10 nm to 200 nm.

[0059] Optionally, the heating tube 30 includes a preheating section and an evaporation section; the length of the heating tube 30 is calculated according to the mass of methanol consumed by the porous reforming membrane tube 40, the mass of water, and the flow heat transfer inside the heating tube 30.

[0060] Please refer to Figure 4 , to achieve the above object, the present invention also proposes a parameter optimization method for a Joule heating methanol reforming membrane catalytic reactor, which is used for optimizing the calculation of the length of the heating tube of the Joule heating methanol reforming membrane catalytic reactor; the heating tube includes a preheating section and an evaporation section; the method includes the following steps: Step S10, establishing an iterative model for calculating the length of the heating tube 30; wherein, the iterative model includes: a heat balance formula for the preheating section, a heat balance formula for the evaporation section, and a heat transfer and heat absorption balance formula in the heating tube 30; Step S20, obtaining the preset initial wall temperature and the initial length of the preheating section for the heating tube 30; Step S30, inputting the initial wall temperature and the initial length of the preheating section into the iterative model for iteration until each balance formula in the iterative model holds; Step S40, obtaining the length of the preheating section and the length of the evaporation section calculated by the iterative model, and calculating the length of the heating tube 30 through the length of the preheating section and the length of the evaporation section.

[0061] Specifically, in order to ensure the complete vaporization of the methanol aqueous solution, the length of the methanol evaporation tube is determined according to the methanol and water masses consumed by the reforming reaction tube and the flow heat transfer inside the evaporation tube. Assuming the initial wall temperature t w and the evaporation section length L evap perform heat transfer calculation, compare whether the heat transfer amount is approximately equal to the heat absorption amount. If so, obtain the wall temperature value and the lengths of the evaporation section and the preheating section. If not, change the wall temperature and the evaporation section length for calculation until the heat transfer amount is approximately equal to the heat absorption amount.

[0062] Optionally, the calculation formula of the iterative model is as follows: (1); where is the mass flow rate of the methanol aqueous solution, is the specific heat capacity at constant pressure at the qualitative temperature, t sat is the saturation temperature, t in is the inlet temperature; t m is the qualitative temperature of the preheating section, , is the logarithmic mean temperature difference, is the thermal conductivity of the heating pipe 30; is the inner diameter of the evaporation section, d is the outer diameter of the evaporation section, r is the latent heat of vaporization of the methanol aqueous solution; is the convective heat transfer coefficient of the preheating section, is the length of the preheating section; is the convective heat transfer coefficient of the evaporation section, is the length of the evaporation section; t w is the wall temperature; In formula (1), from top to bottom are: the heat balance formula of the preheating section, the heat balance formula of the evaporation section, and the heat transfer and heat absorption balance formula in the heating pipe 30; The calculation formula of the convective heat transfer coefficient of the preheating section is: (2); where, is the Nusselt number, is the liquid thermal conductivity at the qualitative temperature; The calculation formula of the convective heat transfer coefficient of the evaporation section is: (3); where is the mass flow rate of the methanol aqueous solution at the saturation temperature, is the average dryness of the evaporation section, is the liquid phase viscosity at the saturation temperature, is the Prandtl number at the saturation temperature, is the liquid phase thermal conductivity at the saturation temperature, E is the enhancement factor; (4); where, ρ l,sat is the liquid phase density at the saturation temperature, ρ v,satis the gas density at saturation temperature, is the boiling number, is the Froude number; The boiling number is calculated as follows: (5); wherein, is the heat dissipation of the membrane catalytic reactor, is the heat of reaction of the reforming reaction, is the length of the porous reforming membrane tube 40; The Froude number is calculated as follows: (6); wherein, , is the acceleration of gravity; The heat dissipation of the membrane catalytic reactor is calculated as follows: (7); wherein, is the convective heat transfer coefficient of the annulus gas in the membrane catalytic reactor, is the ambient temperature, is the temperature of the reforming tube wall, is the average diameter of the annulus part, is the inner diameter of the adiabatic shell of the membrane catalytic reactor, is the outer diameter of the adiabatic shell of the membrane catalytic reactor, is the outer diameter of the insulation layer of the adiabatic shell 20, is the outer diameter of the flange 70, L is the length of the heating tube, L = L pre + L evap , is the thermal conductivity of the adiabatic shell 20 of the membrane catalytic reactor, is the thermal conductivity of the insulation layer of the adiabatic shell 20, is the ambient convective heat transfer coefficient, is the thickness of the insulation layer of the flange 70, is the thickness of the flange 70.

[0063] In the joule-heated methanol steam reforming membrane catalytic reactor of the present invention, compared with the electromagnetic-heated methanol steam reforming membrane catalytic reactor, it can achieve better catalyst utilization, volume yield and energy efficiency with a smaller length of the internal pipe fittings in the membrane catalytic reactor. In industrial applications, it is of great significance for reducing the size of the membrane catalytic reactor. Specifically, the hydrogen volume yield of the joule-heated catalytic membrane tube reaches 157.96 kmol·m -3 ·h-1 , higher than 148 kmol·m of the electromagnetic heating membrane catalytic reactor -3 ·h -1 ; At the same time, the energy efficiency reaches 43.84%, which is also better than 42% of the electromagnetic heating membrane catalytic reactor. In terms of structure, the overall diameter of a single catalytic membrane tube of the Joule heating membrane catalytic reactor after winding the resistance wire is 22.4 mm, while the electromagnetic induction heating method is limited by the outer diameter design of the spiral coil. The outer diameter of a single catalytic membrane tube of the same pipe diameter wound with an electromagnetic induction heating coil reaches 40 mm, resulting in a significant increase in the space occupied by a single catalytic membrane tube, thus limiting the structural compactness of the membrane catalytic reactor. From the perspective of the overall volume of the membrane catalytic reactor, at the laboratory scale, the Joule heating membrane catalytic reactor only requires 0.0015 m 3 The overall volume of the membrane catalytic reactor can achieve a hydrogen production rate of 0.066 Nm 3 h -1 , while the electromagnetic induction membrane catalytic reactor requires 0.0067 m 3 The overall volume of the membrane catalytic reactor realizes a hydrogen production rate of 0.12 Nm 3 h -1 . Under the same hydrogen production capacity, the volume required by the Joule heating membrane catalytic reactor is reduced by nearly 60%. The above results show that the Joule heating membrane catalytic reactor still exhibits better hydrogen production capacity per unit volume and energy efficiency level, reflecting its significant advantages in terms of structural compactness and thermal efficiency.

[0064] Example 1: In this example, the flow synthesis method was used to immobilize Cu / ZnO / Al2O3 catalyst particles in the pores of a sintered tubular silicon carbide membrane tube with a length of 100 mm, an outer diameter of 20 mm, a wall thickness of 3.5 mm, a pore diameter of 10 μm, and a porosity of 0.3 (effective reaction volume 18607 mm 3 ), thus making a porous reforming membrane tube 40 with catalytic function, constituting the reforming zone of this example. The raw material heating zone (i.e., the heating tube) is an alumina ceramic tube with an outer diameter of 20 mm, a wall thickness of 5.75 mm, and a length of 120 mm. The number of turns of the resistance wire coil 10 is 100, the pitch is 2.2 mm, the wire diameter is 1.2 mm, and the inner diameter of the helix is 20 mm. The reaction temperature is measured by a thermocouple, and the adiabatic shell 20 is insulated with fiberglass felt, and the insulation layer thickness is 40 mm. The specific assembly schematic diagrams of the raw material heating zone, the reforming zone (i.e., the porous reforming membrane tube), and the adiabatic shell 20 are as shown in Figure 2 . The catalytic performance at different temperatures, water-alcohol ratios, and methanol molar feed amounts during Joule heating was tested. The specific implementation steps are as follows: A sealing gasket 120 (which can be a silicone gasket) is used as the sealing material for the flange 70. The heating tube 30, the porous reforming membrane tube 40, and the resistance wire coil 10 are respectively centered and fixed in the adiabatic housing 20 and sealed. The heating tube 30 is connected to the flange blind plate by threads and sealed. A clearance fit connection and sealing are adopted between the porous reforming membrane tube 40 and the heating tube 30. The resistance wire coil 10 is helically wound around the outer surfaces of the heating tube 30 and the porous reforming membrane tube 40 and connected to the ceramic terminal posts 50 at both ends of the flange blind plate. A thermal resistance probe is arranged axially at intervals of 60 mm inside the adiabatic housing 20 for temperature monitoring.

[0065] After the device is installed, the reformed gas outlet end is blocked, and compressed nitrogen is introduced to test the airtightness of the device. After confirming good sealing, nitrogen is continuously introduced into the device at a flow rate of 100 mL min -1 for 30 min to discharge the residual air inside the device. The fluid passage inside the porous reforming membrane tube 40 is as Figure 3 shown. Subsequently, the switch power supply is turned on, the heating temperature is controlled by adjusting the output power, and the inlet flow rate is controlled by adjusting the rotational speed of the peristaltic pump. The temperature at the third temperature measurement point is used as the reaction temperature.

[0066] The nitrogen flow rate is adjusted to 0, the peristaltic pump is turned on, and the methanol molar flow rate is controlled to be 0.01835 mol min -1 , the water-to-alcohol ratio is 1.5 (the water-to-alcohol ratio in the present invention is: the molar ratio of water to methanol, and the same meaning applies hereinafter), and the catalytic performance at different reaction temperatures is tested. It is experimentally measured that under the condition of lower than 240 °C, the conversion rate of methanol is at a lower level (lower than 40%), while at 280 °C, the methanol conversion rate is higher than 60%, and at 300 °C, the methanol conversion rate is higher than 90%. The catalyst utilization rate can reach 21.03 Nm 3 H2h -1 kg -1 , the volume yield can reach 157.96 kmol m -3 h -1 , and the energy efficiency can reach 43.84%.

[0067] Example 2: In this example, a sintered tubular silicon carbide membrane tube with a length of 100 mm, an outer diameter of 20 mm, a wall thickness of 3.5 mm, a pore diameter of 10 μm, and a porosity of 0.3 (effective reaction volume 18607 mm 3 ) is selected. Catalyst particles of Cu / ZnO / Al2O3 are immobilized in the pores of the tube to make the porous reforming membrane tube 40, and the catalytic performance of the porous reforming membrane tube 40 during Joule heating is tested. The specific implementation steps are as follows: Install and check the airtightness of the device according to the steps described in Example 1, and test the methanol conversion rate and volume yield under different water-to-alcohol ratio conditions; Control the temperature of the third temperature measurement point to 300 °C, and the methanol molar flow rate to 0.01835 mol min -1 , and test the methanol conversion rate at water-alcohol ratios of 1.0, 1.25, 1.5, 1.75, and 2.0 respectively. The experimental results show that under different water-alcohol ratio conditions, the methanol conversion rate is higher than 80%, and the volume yield is higher than 138 kmol m -3 h -1 , and when the water-alcohol ratio is 1.5, the methanol conversion rate reaches 94.7% and the volume yield reaches 142.51 kmol m -3 h -1 .

[0068] Example 3: In this example, a sintered tubular silicon carbide membrane tube with a length of 100 mm, an outer diameter of 20 mm, a wall thickness of 3.5 mm, a pore diameter of 10 μm, and a porosity of 0.3 is selected (the effective reaction volume is 18607 mm 3 ). Cu / ZnO / Al2O3 catalyst particles are immobilized in the pores of the membrane tube to form a porous reforming membrane tube 40, and the catalytic performance of the porous reforming membrane tube 40 during Joule heating is tested. The specific implementation steps are as follows: Install and check the airtightness of the device according to the steps described in Example 1, and test the methanol conversion rate and volume yield at different methanol molar flow rates; Control the temperature of the third temperature measurement point to 300 °C and the water-alcohol ratio to 1.5, and test the methanol conversion rate at methanol molar flow rates of 0.0095 mol min -1 , 0.0184 mol min -1 , 0.0275 mol min -1 , 0.0367 mol min -1 , and 0.0459 mol min -1 respectively. The experimental results show that when the methanol molar flow rate is lower than 0.0184 mol min -1 , the methanol conversion rate is higher than 90%, and when it is higher than 0.0357 mol min -1 , the methanol conversion rate is lower than 60%. The volume yield increases from 85.96 kmol m -3 h -1 to 197.17 kmol m -3 h -1 as the methanol molar flow rate increases.

[0069] In the description of this specification, the descriptions with reference to the terms "one embodiment", "another embodiment", "other embodiments", or "the first embodiment to the Xth embodiment", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, method steps, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0070] It should be noted that in this article, the term "comprising", "including", or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or system. Without further limitation, the element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article, or system comprising such element.

[0071] The serial numbers of the embodiments of the present invention above are only for description and do not represent the superiority or inferiority of the embodiments.

[0072] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A membrane catalytic reactor for hydrogen production from methanol by Joule heating, characterized in that, It includes a heating reforming pipe fitting, a resistance wire coil, and a heat-insulating outer shell arranged in sequence from the inside to the outside. The resistance wire coil is wound around the outer periphery of the heating reforming pipe fitting along the length direction of the heating reforming pipe fitting. The heating reforming pipe fitting includes a heating pipe and a porous reforming membrane pipe connected in series at the ends to heat the heating pipe and the porous reforming membrane pipe by the Joule heat generated by the resistance wire coil. The heating pipe and the porous reforming membrane pipe are respectively electrically insulating pipes. The pipe wall of the porous reforming membrane pipe is provided with membrane pore channels penetrating the pipe wall, and catalyst particles for methanol reforming to produce hydrogen are in-situ immobilized in the membrane pore channels. One end of the heating pipe is an inlet for methanol aqueous solution, so as to preheat and vaporize the methanol aqueous solution under the heating action of the resistance wire coil to obtain methanol water vapor. The other end of the heating pipe is communicated with one end of the porous reforming membrane pipe, so that the methanol water vapor enters the membrane pore channels to react with the catalyst particles to produce hydrogen-rich reformed gas through methanol reforming to produce hydrogen, and the hydrogen-rich reformed gas flows out of the membrane pore channels to the outside of the porous reforming membrane pipe, so that the hydrogen-rich reformed gas flows out from the outlet of the membrane catalytic reactor for hydrogen production.

2. The membrane catalytic reactor for hydrogen production from methanol by Joule heating according to claim 1, wherein, The heating pipe is a ceramic heating pipe, and / or the porous reforming membrane pipe is any one of a silicon carbide membrane pipe, an aluminum nitride membrane pipe, a beryllium oxide membrane pipe, a silicon nitride membrane pipe, and a boron nitride membrane pipe.

3. The membrane catalytic reactor for hydrogen production from methanol by Joule heating according to claim 1, characterized in that, One end of the heating pipe for connecting with the porous reforming membrane pipe is provided with a reduced-diameter connecting section to be hermetically connected with the porous reforming membrane pipe through the reduced-diameter connecting section.

4. The catalytic membrane reactor for hydrogen production from methanol by Joule heating according to claim 1, wherein The methanol aqueous solution storage device is communicated with the inlet through a conveying device. The outlet is communicated with a condensing device, a flow detection unit, and a gas chromatograph, and feeds back detection data to a computer terminal through the gas chromatograph.

5. The membrane catalytic reactor for hydrogen production from methanol by Joule heating according to claim 1, characterized in that, The membrane catalytic reactor includes a plurality of the heating reforming pipe fittings arranged in parallel in the heat-insulating outer shell.

6. The membrane catalytic reactor for hydrogen production from methanol by Joule heating according to claim 1, wherein The membrane pore channels are micro-nano scale membrane pore channels.

7. The catalytic membrane reactor for hydrogen production from methanol by Joule heating according to claim 1, wherein The diameter of the membrane pore channels is 1 μm to 10 μm, the catalyst particles adopt a Cu-based catalyst, and the particle size of the catalyst particles is 10 nm to 200 nm.

8. The catalytic membrane reactor for hydrogen production from methanol by Joule heating according to any one of claims 1 to 7, characterized in that, The heating pipe includes a preheating section and an evaporation section. The length of the heating pipe is calculated according to the mass of methanol consumed by the porous reforming membrane pipe, the mass of water, and the flow heat transfer in the heating pipe.

9. A method for optimizing the parameters of a membrane catalytic reactor for hydrogen production from methanol by Joule heating, characterized in that, It is used for optimizing the calculation of the length of the heating pipe of the Joule heating methanol hydrogen production membrane catalytic reactor according to any one of claims 1 to 8. The heating pipe includes a preheating section and an evaporation section. The method includes the following steps: Establish an iterative model for calculating the length of the heating pipe. Among them, the iterative model includes: the heat balance formula of the preheating section, the heat balance formula of the evaporation section, and the heat transfer and heat absorption balance formula in the heating pipe. Obtain the initial wall temperature preset for the heating pipe and the initial length of the preheating section. Input the initial wall temperature and the initial length of the preheating section into the iterative model for iteration until each balance formula in the iterative model holds. Obtain the length of the preheating section and the length of the evaporation section calculated by the iterative model, and calculate the length of the heating pipe through the length of the preheating section and the length of the evaporation section.

10. The method for optimizing the parameters of the membrane catalytic reactor for hydrogen production from methanol by Joule heating according to claim 9, characterized in that, The calculation formula of the iterative model is as follows: (1)； Among them is the mass flow rate of the methanol aqueous solution is the specific heat capacity at constant pressure at the qualitative temperature t sat is the saturation temperature t in is the inlet temperature t m is the qualitative temperature of the preheating section , is the logarithmic mean temperature difference is the thermal conductivity of the heating tube is the inner diameter of the evaporation section d is the outer diameter of the evaporation section r is the latent heat of vaporization of the methanol aqueous solution is the convective heat transfer coefficient of the preheating section is the length of the preheating section is the convective heat transfer coefficient of the evaporation section is the length of the evaporation section t w is the wall temperature Convective heat transfer coefficient in the preheating section The calculation formula is as follows: （2）； Among them, is the Nusselt number, is the liquid thermal conductivity at the qualitative temperature; Convective heat transfer coefficient of the evaporation section The calculation formula is as follows: (3)； wherein is the mass flow rate of the methanol aqueous solution at the saturation temperature, is the average dryness of the evaporation section, is the liquid-phase viscosity at the saturation temperature, is the Prandtl number at the saturation temperature, is the liquid-phase thermal conductivity at the saturation temperature, E is the enhancement factor; (4)； wherein, ρ l,sat is the liquid phase density at the saturation temperature, ρ v,sat is the gas phase density at the saturation temperature, is the boiling number, is the Froude number; Boiling number The calculation formula is as follows: (5)； Among them, is the heat dissipation of the membrane catalytic reactor, is the heat of reaction of the reforming reaction, is the length of the porous reforming membrane tube; Froude number The calculation formula is as follows: (6)； Among them, , is the acceleration due to gravity; Heat dissipation of the membrane catalytic reactor The calculation formula is as follows: (7)； Among them, is the convective heat transfer coefficient of the annulus gas in the membrane catalytic reactor, is the ambient temperature, is the temperature of the reforming tube wall, is the average diameter of the annulus part, is the inner diameter of the adiabatic shell of the membrane catalytic reactor, is the outer diameter of the adiabatic shell of the membrane catalytic reactor, is the outer diameter of the thermal insulation layer of the adiabatic shell, is the outer diameter of the flange, L is the length of the heating tube, L = L pre + L evap , is the thermal conductivity of the adiabatic shell of the membrane catalytic reactor, is the thermal conductivity of the thermal insulation layer of the adiabatic shell, is the ambient convective heat transfer coefficient, is the thickness of the thermal insulation layer of the flange, is the thickness of the flange.

Images