Body catalytic reactor based on Joule heating, reverse water-gas shift reaction method and application

Abstract

The invention provides a body catalytic reactor based on Joule heating, a reverse water gas shift reaction method and application. The body catalytic reactor comprises a reaction kettle for placing a solid catalyst for endothermic gas-solid multiphase reaction and a closed circuit for heating the solid catalyst based on Joule. According to the technical scheme, the solid catalyst (active substance) with reaction catalytic activity is directly used as a heat supply source of the reaction, and the solid catalyst generates Joule heat by adopting an electric heating mode, so that the solid catalyst can be used as the catalyst and the heat supply source at the same time; a real heat transfer process from inside to outside of the solid catalyst is realized, energy is concentrated on the solid catalyst, and the energy utilization efficiency is extremely high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysis technology, in particular to a body catalytic reactor based on Joule heating and a method for reverse water gas shift reaction and application. BACKGROUND

[0002] In today's increasingly severe global climate change and energy crisis, it is particularly important to develop efficient, energy-saving, and mild carbon-neutral technologies. The electrification of energy supply in chemical processes is a very promising means of carbon emission reduction. Traditional external electric heating methods have the disadvantages of low energy utilization rate, large equipment investment, and untimely temperature control. The use of electromagnetic induction heating, microwave heating, and Joule heating (also known as ohmic heating or resistance heating) methods to electrify catalytic reactors provides options for this transformation.

[0003] In terms of heating methods, internal Joule heating in catalytic reactors is a new technology in recent years, which has attracted widespread attention due to its high energy density, precise and rapid temperature control, and sufficient mass and heat transfer. Currently, active components are coated or impregnated on the surface of alloys, ceramic silicon carbide substrates, and foamed metals, or directly using composite materials (such as foamed metals, carbon materials, and conductive polymers) for electric heating catalysis. However, this is still a "from outside to inside" heat transfer process, and the direct object of the electric current is still the carrier part of the alloy, ceramic silicon carbide, or foamed metal, which generates heat, and the heat is transferred to the catalyst, i.e., the active component, in the carrier / body, to indirectly heat the catalyst and catalyze the reaction.

[0004] For example, patent CN112999987B discloses an electric heating monolithic metal-based catalytic reactor and its preparation method, which uses a composite material composed of a metal substrate, a carrier, and an active component as a monolithic catalyst, and generates Joule heat in the metal substrate to directly heat the catalyst to the required reaction temperature for reaction. Patent CN119797279A discloses a method and device for electrically heated catalytic methane dry reforming, which uses an electrically heated catalyst to catalyze a mixture of methane and carbon dioxide. The catalyst used is foamed nickel and foamed nickel impregnated with other solutions. It is well known in the art that whether the foamed nickel is directly electrically heated or the foamed nickel impregnated with other solutions is directly electrically heated, the electric current passes through the carrier part, i.e., the additional heating element, to generate Joule heat, which is then transferred to the active component (metal nickel or other active components impregnated with other solutions) to indirectly heat the catalyst (active component) and perform the reaction.

[0005] Thus, the prior art discloses a scheme that adopts internal Joule heating technical means, but still is a "from outside to inside" heat transfer process, needs other heating elements (carriers, substrates, etc.), has low energy density, and cannot precisely heat the catalyst (active component) part, thereby causing more energy loss. SUMMARY

[0006] In view of the above-mentioned defects of the prior art, the purpose of the present application is to provide a body catalytic reactor based on Joule heating and a method and application of reverse water gas shift reaction, so as to solve the problems in the prior art.

[0007] In order to achieve the above-mentioned purpose and other related purposes, the present application is obtained by the following technical scheme.

[0008] The first aspect of the present application provides a body catalytic reactor based on Joule heating, which comprises a reaction kettle for placing a solid catalyst for endothermic gas-solid heterogeneous reaction and a closed circuit for Joule heating of the solid catalyst.

[0009] Preferably, the closed circuit for Joule heating of the solid catalyst comprises a power supply unit, a wire and the solid catalyst as a load which are in electrical communication in sequence.

[0010] Preferably, one end of the reaction kettle is provided with a gas inlet, and the other end is provided with a gas outlet.

[0011] The body catalytic reactor based on Joule heating in the present application directly provides current for the solid catalyst through the power supply unit, and the current directly contacts the solid catalyst through the wire, so that the solid catalyst directly generates Joule heat, and simultaneously acts as a catalyst and a heat source for the corresponding reaction, and does not contain any carrier or substrate and other heating components in the process.

[0012] The solid catalyst in the present application is an active substance itself that can catalyze the reaction, and does not contain any other carrier or substrate.

[0013] Preferably, the closed circuit further comprises a conductive support, the number of the conductive support is ≥1, and the conductive support is oppositely arranged at both ends of the reaction kettle. More preferably, the number of the conductive support is 2.

[0014] Preferably, any of the conductive supports comprises an electrical connection end and a contact end; the electrical connection end is connected with the wire, and the contact end directly contacts the solid catalyst. The current is provided for the solid catalyst (active substance) so as to make it directly generate Joule heat.

[0015] Preferably, the body catalytic reactor further comprises an insulation layer, and the insulation layer wraps the reaction kettle.

[0016] Preferably, the body catalytic reactor further comprises a temperature measuring device for measuring the temperature of the solid catalyst. In particular, the temperature measuring device is arranged at the center of the solid catalyst.

[0017] Preferably, the electrically conductive support is a hollow structure with both ends passing through. In order to facilitate the installation and fixation of the temperature measuring device.

[0018] Preferably, the solid catalyst comprises one or more of metal, metal oxide and metal carbide.

[0019] Preferably, the contact end is disc-shaped. In order to increase the contact area with the solid catalyst, so as to better generate Joule heat.

[0020] Preferably, the area of the disc-shaped contact end is smaller than the size of the cross-sectional area of the reaction kettle.

[0021] Preferably, a buffer pad is further arranged on the contact end, and the size and shape of the buffer pad are adapted to the size and shape of the cross-sectional area of the reaction kettle.

[0022] Preferably, the buffer pad is a low-resistance buffer pad, and the resistivity of the buffer pad is less than the resistivity of the catalyst particles. In the present application, the resistivity of the buffer pad is not specifically limited, as long as it is less than the resistivity of the catalyst particles, and the resistivity of the buffer pad is ≤ 1 / 10 of the resistivity of the solid catalyst. For example, the resistivity of the buffer pad is 1 / 10, 1 / 100, 1 / 1000 or 1 / 5000 of the resistivity of the solid catalyst.

[0023] For example, the resistivity of the buffer pad can be 1-1x10 -7 Ω·cm, 1x10 -1 -1x10 -7 Ω·cm, 1x10 -1 -1x10 -3 Ω·cm, 1x10 -3 -1x10 -7 Ω·cm, 1x10 -2 -1x10 -7 Ω·cm.

[0024] The buffer pad in the present application can provide a buffer zone for the contact between the electrically conductive support and the solid catalyst, so as to avoid damage to the solid catalyst as much as possible, and at the same time provide good support for the solid catalyst, so that the active material is fixed between the buffer pads in the reaction kettle to avoid falling and scattering. In addition, the buffer pad in the present application uses a specific, conductive and low-resistance buffer pad, which hardly generates Joule heat, so that the heat generated in the present application is entirely from the Joule heat generated by the solid catalyst.

[0025] Preferably, the temperature measuring device comprises one or more of a sliding thermocouple, a fixed position thermocouple, an infrared temperature measuring system, and an optical fiber temperature measuring system.

[0026] The second aspect of the present application provides an application of the body catalytic reactor based on Joule heating as described above in an endothermic gas-solid heterogeneous catalytic reaction as both a catalyst and a heat source.

[0027] Preferably, the endothermic gas-solid heterogeneous catalytic reaction comprises any one of a reverse water gas shift (RWGS) reaction, a steam methane reforming (SMR) reaction, an ethanol dehydration to ethylene reaction, a dry reforming of methane (DRM) reaction, and an NH3 decomposition reaction.

[0028] The third aspect of the present application provides a method for a reverse water gas shift reaction based on Joule heating, which catalyzes the reaction of a mixed raw gas of carbon dioxide and hydrogen using the body catalytic reactor as described above, and the temperature of the solid catalyst under current heating is 300-1000℃. For example, the temperature can be 500-700℃, 300-700℃, 500-1000℃.

[0029] Preferably, the solid catalyst is selected from one or more of molybdenum trioxide, molybdenum dioxide, molybdenum, and molybdenum carbide.

[0030] Preferably, the space velocity of the mixed raw gas introduced into the reactor by the gas inlet is 10-1500 L / g cat / h. For example, it can be 10-28.8 L / g cat / h, 10-50 L / g cat / h, 28.8-100 L / g cat / h, 28.8-1000 L / g cat / h.

[0031] Preferably, the molar ratio of carbon dioxide to hydrogen is 1:0.1-10. For example, it can be 1:0.1-3, 1:3-10.

[0032] Preferably, the reaction pressure is 1-50 bar.

[0033] Preferably, the body catalytic reactor is reduced and pretreated before the reaction, and the conditions of the reduction pretreatment include one or more of the following features:

[0034] The reducing atmosphere at least includes hydrogen;

[0035] The reduction time is 10 min-10 h;

[0036] The reduction temperature is 300-1000℃;

[0037] Reduction air speed: 10-1500 L / g cat / h.

[0038] The reduction time can be 10 min-2 h, 2 h-10 h; the reduction temperature can be 300-600 DEG C, 600-1000 DEG C; the reduction air speed can be 10-60 L / g cat / h, 60-1500 L / g cat / h, 10-100 L / g cat / h, 60-500 L / g cat / h.

[0039] The beneficial effects of the present application are:

[0040] 1) The technical scheme of the present application directly uses the solid catalyst with reaction catalytic activity as the heat source of the reaction, generates Joule heat by using electric heating, and enables the solid catalyst to simultaneously act as a catalyst and a heat source, realizes the real'self-internal to external' heat transfer process of the solid catalyst (active material), and has extremely high energy utilization efficiency.

[0041] 2) In addition, the technical scheme provided in the present application has high energy density, does not need any additional heating and heat transfer elements (carriers, matrices, etc.), miniaturizes the reaction catalyst, and reduces device investment and reaction cost.

[0042] 3) The method for the reverse water gas shift reaction provided in the present application has high catalytic activity and high carbon dioxide conversion rate. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The structure schematic diagram of the body catalytic reactor based on Joule heating provided in the embodiment 1 of the present application is shown.

[0044] Figure 2 The result diagram of the reverse water gas shift reaction in the embodiment 2 and the comparative example 1 of the present application is shown.

[0045] Figure 3 The result diagram of the reverse water gas shift reaction in the embodiments 2-6 of the present application is shown.

[0046] Figure 4 The experimental result diagram of the stability of the reverse water gas shift reaction in the embodiment 7 of the present application is shown.

[0047] Figure 5 The result diagram of the reverse water gas shift reaction in the embodiment 2 and the embodiment 8 of the present application is shown.

[0048] Figure 1 Element number explanation in the drawings

[0049] 1 Power supply unit 2 Electrically conductive support 21 Cushion 3 Reaction vessel 31 Gas inlet 32 Gas outlet 4 Solid catalyst 5 Thermal insulation layer DETAILED DESCRIPTION

[0050] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is to be understood that variations and modifications of the specific embodiments can be made within the scope of the present application.

[0051] Before further description of the application, it is to be understood that the application is not limited to the particular specific embodiments described herein; it is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms and any acronyms used herein have the same meanings as commonly understood by one of ordinary skill in the art in the field of the application. Any methods, devices and materials similar or equivalent to those described herein can be used in the practice of the present application, unless specifically stated otherwise.

[0052] When numerical ranges are given herein, understand that every numerical range is a range of values including the endpoints, and any number within the range. Unless otherwise defined, all technical and scientific terms and any acronyms used herein have the same meaning as commonly understood by one of ordinary skill in the art in the field of the application. Any methods, devices and materials similar or equivalent to those described herein can be used in the practice of the present application, unless specifically stated otherwise.

[0053] The method for measuring the average temperature of the outer wall of the reaction kettle in the following examples and comparative examples of the present application is as follows: a thermocouple is fixedly placed at the outer wall of the reaction kettle, and the thermocouple is located at the outer wall of the reaction kettle corresponding to the solid catalyst, so as to measure the temperature of the outer wall of the reaction kettle. The sample is analyzed every 30 minutes, and the average value is obtained to obtain the average temperature of the outer wall of the reaction kettle.

[0054] The method for obtaining the heating power in the following examples and comparative examples of the present application is as follows: when power is supplied, the corresponding voltage and current are recorded, and the heating power is obtained by multiplying the voltage and the current.

[0055] Example 1

[0056] The present embodiment provides a specific body catalytic reactor based on Joule heating as shown in Figure 1 for placing a solid catalyst for an endothermic gas-solid heterogeneous reaction reaction kettle 3 and a closed circuit for Joule heating of the solid catalyst;

[0057] The closed circuit comprises a power supply unit 1, a wire and a solid catalyst 4 as a load which are in electrical communication in sequence;

[0058] One end of the reaction kettle 3 is provided with a gas inlet 31, and the other end is provided with a gas outlet 32.

[0059] In practical application, the current in the closed circuit flows through the solid-state catalyst and makes the solid-state catalyst directly produce Joule heat. In the endothermic gas-solid heterogeneous reaction, the solid-state catalyst not only catalyzes the reaction as a catalyst, but also provides the required temperature for the reaction as a heat source based on the Joule heat.

[0060] Specifically, the power supply unit 1 is turned on to provide current, so that the current directly reaches the solid-state catalyst 4 through the wire. The power supply unit 1 is adjusted so that the solid-state catalyst 4 can generate Joule heat in the required reaction temperature range. At the same time, the gas inlet 31 of the reaction kettle 3 is in communication with the raw material gas. The raw material gas enters the reaction kettle 3 through the gas inlet 31 and contacts the solid-state catalyst 4 (the solid-state catalyst 4 simultaneously acts as a catalyst and a heat source for the reaction). The raw material gas is catalyzed to react at a certain temperature, and the product is discharged through the gas outlet 32 for collection.

[0061] The material, shape and size of the reaction kettle 3 are not limited in the present application. For example, it can be a quartz reaction kettle, a stainless steel reaction kettle, an alumina ceramic reaction kettle, etc. In the specific embodiment shown in FIG. 1, the reaction kettle 3 is a quartz reaction tube with a length of 400 mm, an outer diameter of 10 mm and a wall thickness of 1 mm. Figure 1

[0062] In one specific embodiment, the closed circuit further comprises two electrically conductive supports 2, which are oppositely arranged at both ends of the reaction kettle 3, and the solid-state catalyst 4 is arranged between the two electrically conductive supports 2. The electrically conductive supports 2 can be 310 stainless steel electrode rods, 316 stainless steel electrode rods or 316L stainless steel electrode rods. In the specific embodiment shown in FIG. 2, the electrically conductive supports 2 are 316L stainless steel hollow electrode rods. Figure 1

[0063] In one specific embodiment, any of the electrically conductive supports 2 comprises a connecting end and a contacting end. The connecting end is connected to the wire and communicates with the power supply unit 1, and the contacting end directly contacts the solid-state catalyst 4. Preferably, as shown in FIG. 3, the contacting end is disc-shaped, and the diameter of the disc-shaped contacting end is 5 mm. In this way, the raw material gas can contact the solid-state catalyst 4 through the electrically conductive support 2. Figure 1

[0064] The distance between the contacting ends of the electrically conductive supports 2 oppositely arranged at both ends of the reaction kettle 3 is not limited in the present application, as long as it can satisfy the filling of the solid-state catalyst 4. In one specific embodiment shown in FIG. 1, the distance between the contacting ends of the electrically conductive supports 2 is 2 mm, i.e. the filling height of the solid-state catalyst 4 is 2 mm.

[0065] ​​​In a preferred embodiment, a buffer pad 21 is further provided on the contact end. The size and shape of the buffer pad 21 are adapted to the size and shape of the cross-section of the reactor 3. The buffer pad 21 is a low-resistance and conductive buffer pad, and its resistivity should be less than that of the catalyst, and the resistivity of the buffer pad 21 should be ≤ 1 / 10 of the resistivity of the solid catalyst 4. For example, the resistivity of the buffer pad is 1 / 10, 1 / 100, 1 / 1000, or 1 / 5000 of the resistivity of the solid catalyst.

[0066] This application does not specifically limit the material of the buffer pad 21, as long as it meets the conditions of low resistance and conductivity as described above, and can play a supporting and buffering role for the catalyst. For example, the buffer pad 21 can be carbon (fiber) felt, carbon fiber paper, carbon cloth, etc. Figure 1 In the specific embodiment shown, the buffer pad 21 is a carbon felt with a resistivity of 0.02 Ω·cm, a diameter of 9 mm, and a thickness of 1 mm.

[0067] The buffer pad 21 on the disc-shaped contact end in this application not only serves to fix and support the solid catalyst 4, securing it between the two opposing disc-shaped contact ends and preventing it from scattering, but also provides a relatively gentle buffer for the contact between the solid catalyst 4 and the contact end, minimizing damage and loss of the solid catalyst 4. Furthermore, because this application uses a specific low-resistance and conductive buffer pad 21, Joule heating is not generated when current passes through the buffer pad 21 itself, ensuring that all heat comes from the Joule heating generated by the solid catalyst 4. Energy is concentrated in the solid catalyst layer, resulting in high energy utilization efficiency.

[0068] like Figure 1 As shown, in a preferred embodiment, the bulk catalytic reactor further includes a heat insulation layer 5 that surrounds the reaction vessel 3 to further ensure stable reaction temperature and reduce heat loss.

[0069] In a preferred embodiment, the bulk catalytic reactor further includes a temperature measuring device located at the center of the solid catalyst 4. This allows for precise control of the temperature of the solid catalyst 4, i.e., the reaction temperature.

[0070] In one specific embodiment, the temperature measuring device is a sliding K-type thermocouple, and the conductive support 2 is a hollow structure with both ends open, so that the sliding thermocouple can be sent to the center of the solid catalyst 4 through the conductive support 2 by adjusting the sliding baffle for temperature measurement.

[0071] In a specific embodiment, the solid-state catalyst 4 comprises one or more of metals, metal oxides and metal carbides, and the appropriate solid-state catalyst is selected according to the actual reaction. The resistance of the solid-state catalyst 4 is significantly higher than that of the conductive support 2 to ensure that the solid-state catalyst 4 is the only source of heat. For example, the solid-state catalyst 4 can be Pd, Pt, CuO, MoO3, perovskite, etc. Figure 1 In a specific embodiment as shown in the specific embodiment, the solid-state catalyst 4 is MoO3, and the resistivity is 467.5 Ω·cm.

[0072] The shape of the solid-state catalyst 4 is not specifically required in this application, as long as it can be filled between the two conductive supports 2. For example, the solid-state catalyst 4 can be in the form of powder, granules, sheets, aerogels, etc. In a preferred embodiment as shown in Figure 1 In a preferred embodiment as shown in the specific embodiment, the solid-state catalyst 4 is in the form of granules. More preferably, the solid-state catalyst 4 granules can be granulated in advance to ensure uniform particle size, and the particle size is preferably 40-100 mesh, to further ensure uniform loading.

[0073] In actual use, the appropriate solid-state catalyst 4 is selected according to the need, and is filled between the contact ends of the conductive support 2, so that the solid-state catalyst 4 is supported by the cushion 21 and does not fall off, and then the temperature measuring device is installed so that it passes through the conductive support 2 and contacts the center of the solid-state catalyst 4 to measure the temperature. Then the power supply unit 1 is turned on to provide current, so that the current reaches the solid-state catalyst 4 through the wire and the conductive support 2, and by adjusting the actual temperature displayed by the power supply unit 1 in combination with the temperature measuring device, the solid-state catalyst 4 can generate Joule heat within the required reaction temperature range; at the same time, the inlet 31 of the reaction kettle 3 is connected to the raw material gas, the raw material gas enters the reaction kettle 3 through the inlet 31, contacts the solid-state catalyst 4 (which simultaneously serves as the catalyst and heat source for the reaction), and the raw material gas is catalyzed to react at a certain temperature, and the product is discharged through the outlet 32 for collection.

[0074] Specifically, in a specific embodiment as shown in Figure 1 In a specific embodiment as shown in the specific embodiment, the power supply unit 1 is turned on to provide a voltage of 2-4 V and a current of 10-20 A when in use, the current reaches the solid-state catalyst 4 through the wire and the conductive support 2, and then reaches the power supply unit 1 through the conductive support 2 and the wire, forming a complete closed circuit; the solid-state catalyst 4 is measured by the sliding K-type thermocouple; after 30 min, the solid-state catalyst 4 is measured by the sliding K-type thermocouple to be 600℃, and the power supply unit 1 automatically controls the temperature by the system to keep the temperature stable; at the same time, the raw material gas is introduced into the inlet 31, and the raw material gas reacts after contacting the solid-state catalyst 4, and the product is discharged through the outlet 32 for collection.

[0075] Example 2

[0076] The embodiment provides a method for reverse water gas shift reaction based on Joule heating, which adopts the bulk catalytic reactor provided in Example 1 shown in the figure, wherein the filling amount of MoO3 powder is 100 mg, and the raw gas is CO2 and H2, and the molar ratio of CO2 and H2 is 1:3. Figure 1

[0077] Specifically, the method comprises the following steps:

[0078] 1) Preparation stage

[0079] The gas inlet of the reaction kettle (quartz tube) is communicated with the external atmosphere, and the hollow conductive support is inserted into the sliding K-type thermocouple at both ends, respectively, the thermocouple is sent to the center of the MoO3 particles and the buffer pad of the conductive support by adjusting the sliding baffle, respectively, so as to measure the reaction temperature and the buffer pad temperature;

[0080] The power supply unit is turned on, the temperature control system is set to heat to 600 DEG C, the current flows through the wire and the conductive support to directly reach the MoO3 particles, so that the MoO3 particles in contact with each other generate Joule heat until 600 DEG C is stable; in the heating stage, the external atmosphere is switched to N2, which is introduced at a flow rate of 50 mL / min, and the pressure is 1 bar.

[0081] 2) Reaction stage

[0082] When the temperature reaches 600 DEG C, the external atmosphere is switched to mixed gas, the mixed gas sample amount is CO2 / H2 / N2=12 / 36 / 51, mL / min, the space velocity of the mixed raw gas (CO2 and H2) is 28.8 L / g cat / h, the reaction is carried out for 10 h, and the pressure is 1 bar. The gas analysis instrument is sampled and analyzed every 30 min, and the specific results are shown in Figure 2 and Table 1.

[0083] Comparative Example 1

[0084] The present comparative example is a comparative example of Example 2, in which the power supply unit of the bulk catalytic reactor is not turned on, and the whole reaction kettle is heated by an external furnace heating method. Except that the heating method is different, the rest of the reaction conditions are the same as those of Example 2. The gas analysis instrument is sampled and analyzed every 30 min, and the specific results are shown in Figure 2 and Table 1.

[0085] Table 1

[0086]

[0087] From Figure 2 ​As shown in Table 1, in Example 2, the CO2 conversion rate is 20.04% when the reverse water gas shift reaction is carried out by using the technical scheme of the present application, while the CO2 conversion rate in Comparative Example 1 is only 11.82%, which is only half of the technical scheme of the present application; and the average conversion rate of H2 in Example 2 is also significantly higher than that in Comparative Example 1. This shows that when the reverse water gas shift reaction is carried out by using the bulk catalytic reactor based on Joule heating provided in the present application, the catalytic activity of the catalyst is good, and the conversion rates of CO2 and H2 are significantly improved.

[0088] As shown in Table 1, in Example 2, the average temperature of the MoO3 particle catalyst is 600°C, which is the target temperature set by the electric heating, while the average temperature of the bottom cushion is 531°C, and the average temperature of the outer wall of the reaction kettle is only 244°C. This shows that the substance for producing Joule heat by electric heating in the present example 2 only includes the MoO3 particle catalyst itself, and as the distance from the MoO3 catalyst becomes farther and farther, the temperature gradually decreases. That is, the MoO3 particle catalyst is the only heat source in the technical scheme of the present application.

[0089] As shown in Table 1, compared with Example 2, in Comparative Example 1, not only the average temperature of the MoO3 particle (solid catalyst) is about 600°C, but also the average temperature of the bottom cushion and the average temperature of the outer wall of the reaction kettle are both about 600°C. This shows that the external heating method in the prior art is overall heating, which has high energy consumption and the heat is not concentrated.

[0090] Examples 3-6

[0091] Examples 3-6 provide a method for reverse water gas shift reaction based on Joule heating at different temperatures, which uses the bulk catalytic reactor provided in Example 1 as shown in Figure 1 , wherein the filling amount of MoO3 particles is 100 mg, the average particle size is 80 mesh, and the raw gas is CO2 and H2. In addition to setting the temperature to 500°C, 550°C, 650°C, and 700°C respectively, the rest of the process is the same as Example 2.

[0092] The specific results are shown in Figure 3 and Table 2.

[0093] Table 2

[0094]

[0095] As shown in Figure 3 and Table 2, during the reverse water gas shift reaction, the average conversion rates of CO2 and H2 increase with the increase of temperature, wherein the highest average conversion rate of CO2 can reach 41.42%, and the highest average conversion rate of H2 can reach 11.83%.

[0096] Furthermore, as shown in Table 2, when using the technical solution of this application for the reverse water-gas shift reaction, only the average temperature of the MoO3 particle catalyst is the target temperature for the reaction. The average temperature of the bottom buffer pad and the average temperature of the outer wall of the reactor both show a gradual decreasing trend with increasing distance from the MoO3 particles. This indicates that in the technical solution of this application, the material used for electrically heating to produce Joule heat in Examples 2-6 only contains the MoO3 particles (solid catalyst) themselves; that is, the MoO3 particles, or solid catalyst, are the only heat source in the technical solution of this application.

[0097] Example 7

[0098] This embodiment tests the stability of the reverse water-gas shift reaction using the bulk catalytic reactor provided in Embodiment 1 of this application. The steps include:

[0099] 1) Preparatory stage

[0100] Same as Example 2.

[0101] 2) Reaction stage

[0102] Except for the reaction lasting 40 hours, the rest of the process was the same as in Example 2. Gas analyzers were used to sample and analyze the gas every 30 minutes. Specific results are as follows: Figure 4 As shown.

[0103] Depend on Figure 4 It is known that when the bulk catalytic reactor provided in this application is applied to the reverse water-gas shift reaction, it can achieve stable operation within a reaction time of 40 hours and maintain the basic stability of the reactant conversion rate.

[0104] Example 8

[0105] This embodiment provides a method for a reverse water-gas shift reaction based on Joule heating, employing, as follows: Figure 1 The bulk catalytic reactor provided in Example 1 has a MoO3 particle loading of 100 mg and a feed gas composition of CO2 and H2 with a CO2 to H2 molar ratio of 1:3. The bulk catalytic reactor is pretreated by reduction before the reaction.

[0106] 1) Preparatory stage

[0107] Same as Example 2.

[0108] 2) Reaction stage

[0109] When the temperature reaches 600℃, the external atmosphere is first switched to a mixture of hydrogen and nitrogen, with an injection rate of H2 / N2 = 50 / 50 mL / min, i.e., a reduction space velocity of 60 L / g. cat / h. After 2 hours of reduction, the external atmosphere was switched to the feed gas mixture, with an injection rate of CO2 / H2 / N2 = 12 / 36 / 51 mL / min, and the space velocity of the mixed feed gas (CO2 and H2) was 28.8 L / g. cat / h. The reaction proceeded for 10 hours at a pressure of 1 bar, and the gas analyzer sampled and analyzed the gas every 30 minutes. Specific results are as follows: Figure 5 As shown in Table 3.

[0110] Table 3

[0111]

[0112]

[0113] Depend on Figure 5 As shown in Table 3, the average conversion rates of CO2 and H2 in Example 8 were significantly improved compared to Example 2. This indicates that pretreatment of the bulk catalytic reactor before the reverse water-gas shift reaction can significantly improve the average conversion rates of CO2 and H2.

[0114] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A joule heating based bulk catalytic reactor characterized in that, The body catalytic reactor comprises a reaction kettle (3) for placing solid catalysts for endothermic gas-solid heterogeneous reactions and a closed circuit for heating solid catalysts based on Joule effect.

2. The bulk catalytic reactor of claim 1, wherein, The closed circuit for heating solid catalysts based on Joule effect comprises a power supply unit (1), a wire and solid catalysts (4) as a load in turn in electrical communication; And / or, one end of the reaction kettle (3) is provided with an air inlet (31), and the other end is provided with an air outlet (32).

3. The bulk catalytic reactor of claim 2, wherein, The closed circuit further comprises one or more electrically conductive supports (2) arranged at both ends of the reaction kettle (3); And / or, any of the electrically conductive supports (2) comprises a power connection end and a contact end; the power connection end is connected to the wire, and the contact end directly contacts the solid catalysts (4); And / or, the body catalytic reactor further comprises an insulation layer (5) wrapping the reaction kettle (3); And / or, the body catalytic reactor further comprises a temperature measuring device for measuring the temperature of the solid catalysts (4); And / or, the electrically conductive support (2) is a hollow structure with two ends passing through; And / or, the solid catalysts (4) comprise one or more of metal, metal oxide and metal carbide.

4. The bulk catalytic reactor of claim 3, wherein, The contact end is disc-shaped; And / or, the contact end is further provided with a buffer pad (21) with a size and shape suitable for the size and shape of the cross section of the reaction kettle (3); And / or, the temperature measuring device comprises one or more of a sliding thermocouple, a fixed position thermocouple, an infrared temperature measuring system and an optical fiber temperature measuring system.

5. The bulk catalytic reactor of claim 4, wherein, The area of the disc-shaped contact end is smaller than the size of the cross-sectional area of the reaction kettle (3); And / or, the buffer pad (21) is a low-resistance buffer pad (21), and the resistivity of the buffer pad (21) is less than or equal to 1 / 10 of the resistivity of the solid catalysts (4).

6. The body catalytic reactor based on Joule heating according to any one of claims 1-5 is used as a catalyst and a heat source simultaneously in an endothermic gas-solid heterogeneous catalytic reaction.

7. Use according to claim 6, characterized in that, The endothermic gas-solid heterogeneous catalytic reaction includes any one of the reverse water gas shift reaction, the steam methane reforming reaction, the ethanol dehydration to ethylene reaction, the methane dry reforming reaction and the NH3 decomposition reaction.

8. A method for the reverse water gas shift reaction based on joule heating, characterized in that, The body catalytic reactor according to any one of claims 1-5 is used to catalyze the reverse water gas shift reaction of a mixed raw gas of carbon dioxide and hydrogen, and the temperature of the solid catalysts (4) under current heating is 300-1000℃.

9. The method of claim 8, wherein, The solid catalysts (4) are selected from one or more of molybdenum trioxide, molybdenum dioxide, molybdenum and molybdenum carbide; And / or, the space velocity of the mixed raw gas introduced into the reaction kettle (3) through the air inlet (31) is 10-1500 L / gcat / h; And / or, the molar ratio of carbon dioxide to hydrogen is 1:0.1-10; And / or, the reaction pressure is 1-50 bar.

10. The method of claim 8, wherein, The body catalytic reactor is reduced and pretreated before the reaction, and the conditions of the reduction pretreatment include one or more of the following features: The reducing atmosphere at least comprises hydrogen; Reduction time is 10 min to 10 h; Reduction temperature is 300 to 1000°C; Reduction space velocity is 10 to 1500 L / gcat / h.

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