Self-heating device and method for dehydrogenation reaction based on hydrogen permeation membrane reactor

Abstract

This invention provides a self-heating device and method for dehydrogenation reaction based on a hydrogen permeation membrane reactor, belonging to the field of dehydrogenation. It includes a reactor body comprising a reaction shell and a hydrogen permeation component disposed within the reaction shell. The reaction shell is divided into a dehydrogenation reaction chamber and a permeation chamber by the hydrogen permeation component. The reaction shell has an inlet for dehydrogenation feedstock, an outlet for dehydrogenation products, an inlet for oxygen-containing gas, and an outlet for tail gas from the permeation chamber. The hydrogen permeation component includes a reaction layer and a hydrogen permeation layer. The reaction layer is filled with a dehydrogenation catalyst bed. As the dehydrogenation reaction proceeds, oxygen in the permeation chamber reacts with separated hydrogen through a porous nickel layer in a redox reaction, releasing heat and providing heat to the dehydrogenation reaction chamber. Compared with existing technologies, this invention solves the technical problems of low gas-phase reaction rates, the generation of unsaturated products, and uncontrollable reactions between introduced oxygen and complex feedstocks in existing oxygen oxidation heating processes by setting up a hydrogen permeation component with single-conduction function.

Description

Technical Field

[0001] This invention belongs to the field of compound dehydrogenation, and more specifically, it relates to a self-heating device for dehydrogenation reaction based on a hydrogen permeable membrane reactor. This invention also relates to a self-heating method for dehydrogenation reaction. Background Technology

[0002] Dehydrogenation reactions of alkanes and aromatic derivatives are a core process in the industrial production of high-value-added olefins and aromatics. Their products are key polymerization raw materials for the synthesis of plastics, rubber, resins, and other polymer materials, playing an indispensable bridging role between the petrochemical and polymer materials industries. These dehydrogenation reactions are all strongly endothermic, requiring a high-temperature environment of 500-800℃. Therefore, stable and efficient heating of the reactor is crucial for reaction efficiency, product selectivity, and process economy.

[0003] Currently, common heating methods for industrial dehydrogenation reactors have many limitations: electric heating has high energy consumption and equipment maintenance costs, and is prone to local overheating due to uneven heat transfer; induction heating is also limited by the reactor material, making it less applicable; when using heat transfer oil as the heat medium, there is a safety hazard of oxidation and coking at high temperatures, which also reduces heat transfer efficiency; steam as the heat medium is limited by pressure conditions in terms of temperature range, and the condensate produced by steam condensation can easily cause equipment corrosion, resulting in energy waste; open flame heating has extremely poor temperature uniformity and low temperature control accuracy, which not only affects reaction stability but also brings environmental problems and fire safety risks from fuel combustion.

[0004] To address the heating challenges of dehydrogenation reactions, the industry has attempted to employ autothermal reforming technology. This technology works by introducing oxygen to induce a partial oxidation-exothermic reaction with the fuel. While this technology offers rapid exothermic action and quick response, allowing for flexible adaptation to production fluctuations by adjusting the oxygen feed and improving energy efficiency through internal utilization of reaction heat, it suffers from several insurmountable drawbacks in practical applications. Firstly, the introduction of oxygen can lead to oxidation side reactions in unsaturated products such as olefins and styrene generated during dehydrogenation, significantly reducing the selectivity of the target product. Secondly, the hydrogen and olefins produced on the dehydrogenation side are flammable gases, which, when mixed with the infiltrated oxygen, can easily form an explosive atmosphere, posing a very high safety risk. Furthermore, the exothermic oxidation process can easily trigger localized high temperatures or temperature fluctuations, exacerbating side reactions such as cracking, isomerization, and catalyst coking in feedstocks and products, and generating water vapor and... It can also damage the structure of the dehydrogenation catalyst or cause deactivation of the active components, and additional separation processes are required to treat CO. Byproducts such as these increase separation costs and energy consumption. These issues create a fundamental contradiction between autothermal reforming technology and the oxygen-free, precisely temperature-controlled environment required for dehydrogenation reactions, thus limiting its practical application value. Summary of the Invention

[0005] The purpose of this invention is to provide a self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor, in order to solve the technical problems of low gas-phase reaction rate, generation of unsaturated products, and uncontrollable reaction between introduced oxygen and raw materials with complex composition in the existing oxygen oxidation heating process.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor, comprising:

[0007] The reactor body includes a reaction shell and a hydrogen permeation assembly disposed within the reaction shell. The interior of the reaction shell is separated by the hydrogen permeation assembly to form a dehydrogenation reaction chamber and a permeation chamber that are physically isolated from each other.

[0008] The reaction shell has a dehydrogenation feedstock inlet, a dehydrogenation product outlet, an oxygen-containing gas inlet, and a permeation chamber tail gas outlet. The dehydrogenation feedstock inlet and the dehydrogenation product outlet are connected to the dehydrogenation reaction chamber, and the oxygen-containing gas inlet and the permeation chamber tail gas outlet are connected to the permeation chamber.

[0009] The hydrogen permeation assembly includes a reaction layer and a hydrogen permeation layer arranged sequentially along the dehydrogenation path. The reaction layer is filled with a dehydrogenation catalyst bed, and the hydrogen permeation layer is a membrane structure with a porous metal layer. As the dehydrogenation reaction proceeds, oxygen reacts with the porous nickel on the hydrogen permeation layer to generate nickel oxide. Hydrogen permeating through the hydrogen permeation layer undergoes a reduction reaction with the nickel oxide. The solid-phase redox reaction of hydrogen and oxygen with the porous nickel provides the heat required for the dehydrogenation reaction chamber.

[0010] In one feasible implementation, the hydrogen permeable layer further includes a palladium alloy film, a palladium-yttrium alloy film, a palladium-silver alloy film, or a porous nickel layer disposed between the reaction layer and the porous nickel layer. One of composite ceramic membranes, iron-based alloy hollow fiber membranes, or SAPO-34 molecular sieve membranes.

[0011] In one feasible implementation, the self-heating device for the dehydrogenation reaction based on the hydrogen permeation membrane reactor further includes a temperature control system, the temperature control system comprising:

[0012] Temperature sensors are installed in the dehydrogenation reaction chamber and the permeation chamber;

[0013] A flow regulating valve is connected to the oxygen-containing gas inlet;

[0014] The controller is communicatively connected to the temperature sensor and the flow regulating valve to adjust the feed flow rate of oxygen-containing gas in real time based on the temperature feedback of the dehydrogenation reaction chamber, so as to control the exothermic rate of the hydrogen-oxygen reduction reaction.

[0015] In one feasible implementation, the self-heating device for dehydrogenation reaction based on the hydrogen permeation membrane reactor further includes an auxiliary heating system, which is an electric heating wire embedded in the reactor wall, an electromagnetic induction coil wound around the outside of the reactor, or a start-up burner connected to the outside of the reactor, used to provide supplementary heat when the device is started up, when the load fluctuates, or when the heat supply on the hydrogen permeation membrane side is insufficient.

[0016] In one feasible implementation, the dehydrogenation catalyst in the dehydrogenation reaction chamber is a supported Pt-Sn catalyst. catalyst or It is one type of catalyst; the permeation chamber is filled with a hydrogen oxidation catalyst, which is a supported platinum or palladium catalyst.

[0017] Compared to existing technologies, the self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor of the present invention, in its specific implementation, utilizes a reaction shell and a hydrogen permeation assembly within the reactor body. The hydrogen permeation assembly physically separates the interior of the reaction shell into a dehydrogenation reaction chamber and a permeation chamber. This is achieved by connecting the dehydrogenation feedstock inlet and the dehydrogenation product outlet to the dehydrogenation reaction chamber, and the oxygen-containing gas inlet and the permeation chamber tail gas outlet to the permeation chamber. The hydrogen permeation assembly is arranged sequentially along the dehydrogenation path, consisting of a reaction layer and a hydrogen permeation layer. The reaction layer is filled with a dehydrogenation catalyst bed to promote the dehydrogenation reaction, while the hydrogen permeation layer, made of a material with high selectivity for hydrogen, allows selective hydrogen permeation. Hydrogen generated during the dehydrogenation reaction permeates through the hydrogen permeation membrane into the permeation chamber under the drive of the partial pressure difference. During this process, oxygen oxidizes with the nickel metal layer to form nickel oxide, and hydrogen reacts with nickel oxide in a redox reaction, releasing heat. This heat is transferred back to the dehydrogenation reaction chamber through the hydrogen permeation assembly, providing thermal energy for the continuous endothermic dehydrogenation reaction, achieving a self-heating effect. This solves the technical problems of high energy consumption and low efficiency caused by the need for an external heat source in traditional dehydrogenation reactions.

[0018] Oxygen reacts with hydrogen on the permeate side, producing water. This reduces the hydrogen pressure on the permeate side, increasing the pressure difference between the reaction and permeate sides, which is beneficial for the smooth progress of the entire dehydrogenation reaction. It also solves the problems caused by oxygen being located on the reaction side, such as uncontrollable exothermic reactions between oxygen and the dehydrogenation feedstock, and the potential for oxidation side reactions involving unsaturated products like olefins and styrene. Furthermore, it addresses the issues of localized high temperatures or temperature fluctuations during the exothermic oxidation process, which can exacerbate side reactions such as cracking, isomerization, and catalyst coking in feedstocks and products. The generated water vapor can also damage the dehydrogenation catalyst structure or deactivate active components, necessitating additional separation processes to treat CO. Byproducts such as these increase separation costs and energy consumption, posing technical challenges.

[0019] In addition, the temperature sensor can monitor the reaction temperature in real time, and the controller can adjust the flow regulating valve to control the flow rate of oxygen-containing gas based on the temperature data feedback, thereby accurately controlling the heat release rate of the permeation chamber and achieving stable control of the temperature of the dehydrogenation reaction chamber. This achieves the technical effect of maintaining the reaction within the optimal temperature range and avoiding the decrease in reaction efficiency or catalyst deactivation caused by temperature fluctuations, which helps to solve the technical problems of the dehydrogenation reaction being sensitive to temperature and the difficulty of adjusting the heat supply in real time by traditional control methods.

[0020] As for the auxiliary heating system in this application, it can be activated in conjunction with the entire self-heating device during startup, load fluctuations, or insufficient heating by the hydrogen permeation membrane through heating wires embedded in the reactor wall, electromagnetic induction coils wound around the outside of the reactor, or start-up burners connected to the outside of the reactor, to supplement heat, ensure that the reactor quickly reaches the reaction temperature, and maintain the stable operation of the reactor.

[0021] Another object of the present invention is to provide a self-heating method for dehydrogenation reaction, which employs a self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor as described above, and includes the following steps:

[0022] S1. Preheat the entire reactor to above the dehydrogenation reaction initiation temperature;

[0023] S2. Introduce alkane or aromatic derivative raw materials into the dehydrogenation reaction chamber, so that they undergo a dehydrogenation reaction under the action of a dehydrogenation catalyst to generate a mixture containing olefin or aromatic products and hydrogen.

[0024] S3. Hydrogen generated in the dehydrogenation reaction chamber selectively permeates through the hydrogen permeation membrane into the permeation chamber under the drive of the partial pressure difference.

[0025] S4. Introduce oxygen-containing gas into the permeation chamber. Hydrogen and oxygen groups undergo an exothermic redox reaction in the porous nickel layer. The hydrogen permeation components and reactor wall transfer the heat to the dehydrogenation reaction chamber, providing thermal energy for the continuous endothermic dehydrogenation reaction.

[0026] S5. Collect the product mixture rich in olefins or aromatics from the dehydrogenation product outlet of the dehydrogenation reaction chamber; discharge the tail gas, mainly water vapor, from the tail gas outlet of the permeation chamber.

[0027] In one feasible implementation, step S4 further includes the following steps:

[0028] S401: Real-time monitoring of the dehydrogenation reaction chamber temperature; precise control of the exothermic rate of the hydrogen-oxygen reduction reaction by adjusting the feed flow rate of oxygen-containing gas, so that the operating temperature of the dehydrogenation reaction chamber is stably maintained between 500℃ and 650℃.

[0029] In one feasible implementation, the hydrogen partial pressure difference across the hydrogen permeation assembly is maintained at 0.1 MPa to 0.5 MPa to ensure an economically feasible hydrogen permeation rate.

[0030] In one feasible implementation, the oxygen-containing gas is air, oxygen-enriched air, or pure oxygen; the molar ratio of the amount of oxygen introduced into the permeation chamber to the amount of hydrogen permeated is (…). / The concentration should be between 0.5 and 1.2 to ensure complete combustion of hydrogen and avoid potential oxidative damage to the membrane material from excessive oxygen.

[0031] In one feasible implementation, the self-heating method for the dehydrogenation reaction is applicable to any one of ethylbenzene dehydrogenation to styrene, propane dehydrogenation to propylene, and isobutane dehydrogenation to isobutene.

[0032] Compared to existing technologies, the aforementioned self-heating method for dehydrogenation preheats the entire reactor to above the dehydrogenation reaction initiation temperature. Alkane or aromatic derivative feedstock is introduced into the dehydrogenation reaction chamber for the reaction. Driven by a partial pressure difference, hydrogen selectively permeates through the hydrogen permeation membrane into the permeation chamber, where it undergoes an exothermic oxidation reaction with the introduced oxygen-containing gas. The heat is transferred back to the dehydrogenation reaction chamber. Combined with the separation effect of the hydrogen permeation membrane and the exothermic characteristics of the redox reaction, a self-heating cycle for the dehydrogenation reaction and a pressure reduction process on the hydrogen permeation side are achieved. No external heat source is required, reducing energy consumption and simplifying operation. Furthermore, in the specific implementation process, oxygen and hydrogen are based on... Nickel metal undergoes a redox reaction, producing water as a byproduct. This reduces the pressure of hydrogen on the permeation side, facilitating the smooth progress of the entire dehydrogenation reaction. It also addresses the problems caused by oxygen being located on the reaction side, leading to uncontrollable exothermic reactions between oxygen and the dehydrogenation feedstock, and the potential for oxidation side reactions involving unsaturated products such as olefins and styrene. Furthermore, it resolves the issues of localized high temperatures or temperature fluctuations during the exothermic oxidation process, which can exacerbate side reactions such as cracking, isomerization, and catalyst coking in the feedstock and products. Additionally, the generated water vapor can damage the dehydrogenation catalyst structure or deactivate active components, necessitating additional separation processes to treat CO. Byproducts such as these increase separation costs and energy consumption, posing technical challenges. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0034] Figure 1 A front view of the self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor provided by the present invention;

[0035] Figure 2 This is a flowchart illustrating the steps of the self-heating method for the dehydrogenation reaction of the present invention.

[0036] In the picture:

[0037] 1. Reactor body; 11. Reaction shell; 110. Dehydrogenation reaction chamber; 111. Permeation chamber; 12. Hydrogen permeation assembly; 121. Reaction layer; 122. Hydrogen permeation layer. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0039] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "back" appear, indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0040] Furthermore, in the description of this invention, unless otherwise explicitly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in light of the specific circumstances.

[0041] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0042] Please refer to the following: Figures 1 to 2The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor provided by the present invention will now be described. This self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor includes a reactor body 1. Specifically, the reactor body 1 includes a reaction shell 11 and a hydrogen permeation component 12 disposed within the reaction shell 11. The interior of the reaction shell 11 is physically separated into a dehydrogenation reaction chamber 110 and a permeation chamber 111 by the hydrogen permeation component 12. The reaction shell 11 has a dehydrogenation feed inlet, a dehydrogenation product outlet, an oxygen-containing gas inlet, and a permeation chamber 111 tail gas outlet. The dehydrogenation feed inlet and the dehydrogenation product outlet are connected to the dehydrogenation reaction chamber 110, and the oxygen-containing gas inlet and the permeation chamber 111 tail gas outlet are connected to the permeation chamber 111. 1; The hydrogen permeation assembly 12 includes a reaction layer 121 and a hydrogen permeation layer 122 arranged sequentially along the dehydrogenation path. The reaction layer 121 is filled with a dehydrogenation catalyst bed. The hydrogen permeation layer 122 is made of a metal or its alloy, ceramic or molecular sieve material with high selectivity for hydrogen. The hydrogen permeation layer 122 is a membrane structure with a porous nickel layer. As the dehydrogenation reaction proceeds, oxygen reacts with the porous nickel on the hydrogen permeation layer 122 to generate nickel oxide. Hydrogen permeating through the hydrogen permeation layer 122 undergoes a reduction reaction with the nickel oxide. The solid-phase redox reaction of hydrogen and oxygen with the porous nickel provides the heat required for the dehydrogenation reaction chamber 110.

[0043] In the specific implementation process of the above embodiments, the hydrogen permeation component 12 can divide the interior of the reaction shell 11 into a physically isolated dehydrogenation reaction chamber 110 and a permeation chamber 111. With the reaction layer 121 and the hydrogen permeation layer 122 arranged sequentially along the dehydrogenation path, the reaction layer 121 is filled with a dehydrogenation catalyst bed to promote the dehydrogenation reaction, and the hydrogen permeation layer 122 is made of a material with high selectivity for hydrogen to allow selective hydrogen permeation.

[0044] Hydrogen gas produced by the dehydrogenation reaction enters the permeation chamber 111 through the hydrogen permeation membrane under the drive of partial pressure difference. The oxygen-containing gas undergoes a redox reaction with the metallic nickel on the porous nickel layer. Before the separated hydrogen is combined into hydrogen gas, it undergoes a redox reaction with the porous nickel oxide on the permeation layer (i.e., the hydrogen permeation layer 122) during the permeation process, releasing heat and directly providing heat to the hydrogen permeation layer 122. The heat is then transferred to the reaction layer 121 through the metal membrane structure, providing thermal energy for the continuous endothermic dehydrogenation reaction.

[0045] Simultaneously, heat is transferred to the permeation chamber 111 via infrared radiation to heat the oxygen-containing gas, providing self-heating for the dehydrogenation reaction. This solves the technical problem of high energy consumption and low efficiency caused by the need for an external heat source in traditional dehydrogenation reactions.

[0046] Meanwhile, oxygen reacts with hydrogen on the permeation side, producing water as a byproduct. This reduces the hydrogen pressure on the permeation side, increasing the pressure difference between the reaction side and the permeation side, which is beneficial for the smooth progress of the entire dehydrogenation reaction. It also solves the problems caused by oxygen being located on the reaction side, such as uncontrollable exothermic reactions between oxygen and the dehydrogenation feedstock, and the potential for unsaturated products like olefins and styrene, leading to oxidation side reactions. Furthermore, it addresses the issues of localized high temperatures or temperature fluctuations during the exothermic oxidation process, which exacerbate side reactions such as cracking, isomerization, and catalyst coking in the feedstock and products. The generated water vapor can also damage the dehydrogenation catalyst structure or deactivate active components. Moreover, this embodiment eliminates the need for additional separation processes to treat CO. Byproducts such as these reduce separation costs and energy consumption.

[0047] Based on the above embodiments, a feasible implementation method is proposed, characterized in that the hydrogen permeable layer 122 further includes a palladium alloy film, a palladium-yttrium alloy film, a palladium-silver alloy film, and a porous nickel layer disposed between the reaction layer 121 and the porous nickel layer. The membrane is a composite ceramic membrane, an iron-based alloy hollow fiber membrane, or a SAPO-34 molecular sieve membrane. With this configuration, the present application achieves high selectivity and permeability for hydrogen through the aforementioned materials, allowing only hydrogen to permeate efficiently during the dehydrogenation reaction. This ensures that the hydrogen passing through is in a free state and first undergoes a redox reaction with the nickel oxide on the porous nickel layer. This helps to solve the technical problems of poor selectivity in ordinary membrane materials leading to the permeation of other gases, and the existing hydrogen permeation membranes and oxygen permeation membranes only forming a redox reaction between hydrogen and oxygen. Furthermore, the aforementioned metallic membrane structure can conduct heat, directly transferring the heat generated during the hydrogen-oxygen reduction reaction on the membrane body to the reaction layer 121 through the aforementioned metallic membrane, heating the reaction layer 121 and providing the necessary heat for the reaction in the dehydrogenation reaction chamber 110.

[0048] In addition to the feasible implementation methods described above, to ensure a smoother reaction process in the entire self-heating device, in a more preferred embodiment, the dehydrogenation reaction self-heating device based on the hydrogen permeation membrane reactor also includes a temperature control system. The temperature control system includes a temperature sensor, a flow regulating valve, and a controller. The temperature sensor is located in the dehydrogenation reaction chamber 110 and the permeation chamber 111. The flow regulating valve is connected to the oxygen-containing gas inlet. The controller is communicatively connected to the temperature sensor and the flow regulating valve to adjust the feed flow rate of the oxygen-containing gas based on real-time feedback of the temperature in the dehydrogenation reaction chamber 110, thereby controlling the exothermic rate of the hydrogen-oxygen reduction reaction. In this embodiment, the temperature sensor can monitor the reaction temperature in real time, and the controller can adjust the flow regulating valve to control the feed flow rate of the oxygen-containing gas based on the temperature data feedback, thereby precisely controlling the exothermic rate of the hydrogen-oxygen reduction reaction and achieving stable control of the reaction temperature. This maintains the reaction within the optimal temperature range, avoids temperature fluctuations that could lead to decreased reaction efficiency or catalyst deactivation, and solves the technical problem that the dehydrogenation reaction is sensitive to temperature and that traditional control methods struggle to adjust the heat supply in real time.

[0049] Based on the above embodiments, a feasible implementation method is proposed. The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor further includes an auxiliary heating system. The auxiliary heating system consists of heating wires embedded in the reactor wall, electromagnetic induction coils wound around the outside of the reactor, or a start-up burner connected to the outside of the reactor. This system provides supplementary heat during device start-up, load fluctuations, or insufficient heating from the hydrogen permeation membrane side. In practical implementation, this structure ensures that the reactor quickly reaches its operating temperature or maintains stable operation, achieving rapid reactor start-up and adaptation to load changes. This improves the reliability and operational flexibility of the device, effectively addressing the technical problem of insufficient heat during start-up or load fluctuations, leading to reaction interruption or reduced efficiency.

[0050] Based on the above embodiments, a feasible implementation method is proposed, wherein the dehydrogenation catalyst of the dehydrogenation reaction chamber 110 is a supported Pt-Sn catalyst. catalyst or This is one type of catalyst; the permeation chamber 111 is filled with a hydrogen oxidation catalyst, which is a supported platinum or palladium catalyst. The catalysts in the adjacent chambers work together, with the dehydrogenation catalyst efficiently catalyzing the dehydrogenation reaction to produce hydrogen and olefins or aromatics, and the hydrogen oxidation catalyst promoting the rapid exothermic oxidation of hydrogen and oxygen in the permeation chamber 111. This achieves the synergistic effect of dehydrogenation and redox reactions, improving the reaction rate and heat generation efficiency, and achieving the technical effect of optimizing reaction kinetics and energy utilization.

[0051] Based on the same inventive concept, another objective of this application is to propose a self-heating method for dehydrogenation reactions, employing a self-heating device for dehydrogenation reactions based on a hydrogen permeation membrane reactor as described above, comprising the following steps:

[0052] S1. Preheat the entire reactor to above the dehydrogenation reaction initiation temperature;

[0053] S2. An alkane or aromatic derivative raw material is introduced into the dehydrogenation reaction chamber 110, so that it undergoes a dehydrogenation reaction under the action of a dehydrogenation catalyst to generate a mixture containing olefin or aromatic products and hydrogen.

[0054] S3. Hydrogen generated in dehydrogenation reaction chamber 110 selectively permeates through hydrogen permeation membrane into permeation chamber 111 under the drive of partial pressure difference;

[0055] S4. Introduce oxygen-containing gas into the permeation chamber 111. Hydrogen and oxygen groups undergo an exothermic redox reaction in the porous nickel layer. The hydrogen permeation component 12 and the reactor wall transfer the heat to the dehydrogenation reaction chamber 110, providing thermal energy for the continuous endothermic dehydrogenation reaction.

[0056] S5. Collect the product mixture rich in olefins or aromatics from the dehydrogenation product outlet of the dehydrogenation reaction chamber 110; discharge the tail gas, mainly composed of water vapor, from the tail gas outlet of the permeation chamber 111.

[0057] Compared to existing technologies, the above embodiment preheats the entire reactor to above the dehydrogenation reaction initiation temperature. Alkane or aromatic derivative feedstock is introduced into the dehydrogenation reaction chamber 110 for dehydrogenation. Driven by the partial pressure difference, hydrogen selectively permeates through the hydrogen permeation membrane into the permeation chamber 111, where it undergoes an exothermic redox reaction with the introduced oxygen-containing gas based on the porous nickel layer. The heat is transferred back to the dehydrogenation reaction chamber 110 and heats the oxygen-containing gas in the permeation chamber 111. By combining the separation effect of the hydrogen permeation membrane and the exothermic characteristics of the redox reaction, a self-heating cycle for the dehydrogenation reaction and a pressure reduction process on the hydrogen permeation side are achieved, eliminating the need for an external heat source, reducing energy consumption, and simplifying operation. Furthermore, in the specific implementation process, the reaction of oxygen and hydrogen to form water reduces the hydrogen pressure on the permeation side, which is beneficial for the smooth progress of the entire dehydrogenation reaction. It also solves the problems caused by oxygen being located on the reaction side, such as uncontrollable exothermic reactions between oxygen and the dehydrogenation feedstock and the easy generation of unsaturated products such as olefins and styrene, leading to oxidation side reactions. Furthermore, since the reaction between traditional oxygen and dehydrogenation feedstocks has poor controllability, in this application, oxygen only reacts with hydrogen. This also solves the problem that the exothermic oxidation process easily leads to local high temperatures or temperature fluctuations, exacerbating side reactions such as cracking, isomerization, and catalyst coking of feedstocks and products, and generating water vapor and... It also avoids problems such as damaging the dehydrogenation catalyst structure or causing deactivation of active components, eliminating the need for additional separation processes to treat CO. Byproducts such as these reduce separation costs and energy consumption.

[0058] Based on the above embodiments, a feasible implementation method is proposed. Specifically, step S4 above further includes the following steps: S401, real-time monitoring of the temperature of the dehydrogenation reaction chamber 110, and precise control of the exothermic rate of the permeation chamber 111 by adjusting the feed flow rate of oxygen-containing gas, so that the operating temperature of the dehydrogenation reaction chamber 110 is stably maintained between 500℃ and 650℃. Of course, according to the specific dehydrogenation requirements, the reaction temperature is stabilized in the target range of 500-800℃, and the temperature fluctuation is controlled within ±5℃. Compared with the local overheating problem of electric heating and the uneven temperature of open flame heating, the hydrogen-oxygen reduction reaction of this application avoids side reactions such as olefin oxidation, raw material cracking and catalyst carbonization caused by abnormal temperature, and the selectivity of the target product is improved by 5%-10%; the water vapor or carbon dioxide generated on the permeation side can be directly discharged as clean emissions and will not enter the dehydrogenation reaction side, protecting the structure of the reaction layer 121 and extending the service life of the catalyst.

[0059] Based on the above embodiments, a feasible implementation method is proposed, wherein the hydrogen partial pressure difference across the hydrogen permeation component 12 is maintained at 0.1 MPa to 0.5 MPa to ensure an economically feasible hydrogen permeation rate. In conjunction with controlling reaction conditions such as feed pressure and composition, efficient hydrogen permeation is driven, resulting in a more economically viable permeation rate and ensuring the continuous operation of the self-heating cycle.

[0060] Based on the above embodiments, a feasible implementation method is proposed, wherein the oxygen-containing gas is air, oxygen-enriched air, or pure oxygen; the molar ratio of the amount of oxygen introduced into the permeation chamber 111 to the amount of hydrogen permeated is ( / The concentration of oxygen in the oxygen-containing gas is kept between 0.5 and 1.2 to ensure sufficient hydrogen reaction and avoid potential oxidative damage to the membrane material from excessive oxygen. By selecting appropriate oxygen-containing gases and proportions, the hydrogen is ensured to fully combust and generate water vapor or condensate, while avoiding oxidative damage to the membrane material from excessive oxygen. This achieves efficient and safe redox reactions, improves heat generation efficiency, and protects the membrane material.

[0061] Based on the above embodiments, a feasible implementation method is proposed, which is applicable to any one of the following: dehydrogenation of ethylbenzene to styrene, dehydrogenation of propane to propylene, and dehydrogenation of isobutane to isobutene.

[0062] With the above setup, combined with the versatility of the self-heating device and method, heat energy is provided for various dehydrogenation reactions through hydrogen permeation membrane separation and the exothermic mechanism of redox reaction. Based on the above solid-phase reaction, energy-saving and high-efficiency production of various dehydrogenation reactions is achieved, thereby broadening the application scope and improving industrial applicability, and solving the technical problems that different dehydrogenation reactions require specific heating conditions and that traditional methods have low energy efficiency.

[0063] It should be noted that in constructing transmembrane hydrogen pressure differentials, it is usually necessary to increase the feed-side pressure or decrease the permeate-side pressure to enhance the driving force. On the permeate side, common methods for reducing pressure include vacuuming and introducing purge gas, but both methods have significant drawbacks: vacuuming consumes a lot of energy, and the hydrogen carried out by the purge gas is difficult to recover and reuse, resulting in resource waste.

[0064] To address the aforementioned issues, the proposed solution involves introducing air into the permeation side, allowing the permeated hydrogen to undergo a solid-phase redox reaction with oxygen in metallic nickel. This approach effectively utilizes the heat released from the hydrogen-oxygen reduction reaction for heating, while also rapidly removing hydrogen from the permeation side, thereby maintaining a significant hydrogen partial pressure differential and enhancing the separation driving force.

[0065] In summary, compared to other existing reaction coupling technologies, the dehydrogenation reaction in this application allows oxygen introduced from the heating device to react with the porous nickel layer of the membrane to generate nickel oxide. During this reaction, oxygen first oxidizes the porous nickel on the membrane surface to nickel oxide, and then the permeated hydrogen atoms directly reduce the nickel oxide to metallic nickel during diffusion in the metal phase. Compared to existing methods where hydrogen permeates through the membrane (dissociating into hydrogen atoms on the reaction side, diffusing within the metal lattice to the permeation side, and then recombine to form hydrogen molecules), in this embodiment, the permeated hydrogen atoms directly reduce nickel oxide to metallic nickel during diffusion in the metal phase. Hydrogen and oxygen do not react in a purely gaseous state, but rather through a solid-phase reaction pathway. That is, hydrogen atoms in the metal phase undergo a reduction reaction with nickel oxide. This reaction mechanism eliminates the step of hydrogen atoms recombinating into hydrogen molecules, and the solid-phase reaction, due to its high density and fast reaction rate, is superior to the gas-phase reaction, thus significantly improving the separation and reaction efficiency of the entire reactor.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor, characterized in that, include: The reactor body (1) includes a reaction shell (11) and a hydrogen permeation assembly (12) disposed inside the reaction shell (11). The interior of the reaction shell (11) is separated by the hydrogen permeation assembly (12) to form a dehydrogenation reaction chamber (110) and a permeation chamber (111) that are physically isolated from each other. The reaction shell (11) has a dehydrogenation feedstock inlet, a dehydrogenation product outlet, an oxygen-containing gas inlet, and a permeation chamber (111) tail gas outlet. The dehydrogenation feedstock inlet and the dehydrogenation product outlet are connected to the dehydrogenation reaction chamber (110), and the oxygen-containing gas inlet and the permeation chamber (111) tail gas outlet are connected to the permeation chamber (111). The hydrogen permeation assembly (12) includes a reaction layer (121) and a hydrogen permeation layer (122) arranged sequentially along the dehydrogenation path. The reaction layer (121) is filled with a dehydrogenation catalyst bed. The hydrogen permeation layer (122) is a membrane structure with a porous metal layer. As the dehydrogenation reaction proceeds, oxygen oxidizes with the porous nickel on the hydrogen permeation layer (122) to generate nickel oxide. Hydrogen permeating through the hydrogen permeation layer (122) undergoes a reduction reaction with the nickel oxide. The solid-phase redox reaction of hydrogen and oxygen with the porous nickel provides the heat required for the dehydrogenation reaction chamber (110).

2. The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor according to claim 1, characterized in that, The hydrogen permeable layer (122) further includes a palladium alloy film, a palladium-yttrium alloy film, a palladium-silver alloy film, and a porous nickel layer disposed between the reaction layer (121) and the porous nickel layer. One of composite ceramic membranes, iron-based alloy hollow fiber membranes, or SAPO-34 molecular sieve membranes.

3. The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor according to claim 1, characterized in that, The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor further includes a temperature control system, which includes: Temperature sensors are disposed in the dehydrogenation reaction chamber (110) and the permeation chamber (111). A flow regulating valve is connected to the oxygen-containing gas inlet; The controller is communicatively connected to the temperature sensor and the flow regulating valve to adjust the feed flow rate of oxygen-containing gas in real time according to the temperature feedback of the dehydrogenation reaction chamber (110) in order to control the exothermic rate of the hydrogen-oxygen reduction reaction.

4. The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor according to claim 3, characterized in that, The self-heating device for dehydrogenation reaction based on hydrogen permeation membrane reactor also includes an auxiliary heating system. The auxiliary heating system is an electric heating wire embedded in the reactor wall, an electromagnetic induction coil wound around the outside of the reactor, or a start-up burner connected to the outside of the reactor. It is used to provide supplementary heat when the device is started up, when the load fluctuates, or when the heat supply on the hydrogen permeation membrane side is insufficient.

5. The self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor according to claim 1, characterized in that, The dehydrogenation catalyst in the dehydrogenation reaction chamber (110) is a supported Pt-Sn catalyst. catalyst or It is one of the catalysts; the permeation chamber (111) is filled with a hydrogen oxidation catalyst, which is a supported platinum or palladium catalyst.

6. A self-heating method for dehydrogenation reaction, employing the self-heating device for dehydrogenation reaction based on a hydrogen permeation membrane reactor as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Preheat the entire reactor to above the dehydrogenation reaction initiation temperature; S2. Introduce alkane or aromatic derivative raw materials into the dehydrogenation reaction chamber (110) so that they undergo a dehydrogenation reaction under the action of a dehydrogenation catalyst to generate a mixture containing olefin or aromatic products and hydrogen. S3. Hydrogen generated in the dehydrogenation reaction chamber (110) selectively permeates through the hydrogen permeation membrane into the permeation chamber (111) under the drive of the partial pressure difference. S4. Introduce oxygen-containing gas into the permeation chamber (111). Hydrogen and oxygen groups undergo an exothermic redox reaction in the porous nickel layer. The hydrogen permeation component (12) and the reactor wall transfer heat to the dehydrogenation reaction chamber (110), providing thermal energy for the continuous endothermic dehydrogenation reaction. S5. Collect the product mixture rich in olefins or aromatics from the dehydrogenation product outlet of the dehydrogenation reaction chamber (110); discharge the tail gas, mainly water vapor, from the tail gas outlet of the permeation chamber (111).

7. The self-heating method for dehydrogenation reaction according to claim 6, characterized in that, Step S4 also includes the following steps: S401. Real-time monitoring of the temperature of the dehydrogenation reaction chamber (110) and precise control of the exothermic rate of the hydrogen-oxygen reduction reaction by adjusting the feed flow rate of oxygen-containing gas, so that the operating temperature of the dehydrogenation reaction chamber (110) is stably maintained between 500°C and 650°C.

8. The self-heating method for dehydrogenation reaction according to claim 7, characterized in that, The hydrogen partial pressure difference across the hydrogen permeation component (12) is maintained at 0.1 MPa to 0.5 MPa to ensure that hydrogen has an economically feasible permeation rate.

9. The self-heating method for dehydrogenation reaction according to claim 6, characterized in that, The oxygen-containing gas is air, oxygen-enriched air, or pure oxygen; the molar ratio of the amount of oxygen introduced into the permeation chamber (111) to the amount of hydrogen permeated is ( / The concentration should be between 0.5 and 1.2 to ensure complete combustion of hydrogen and avoid potential oxidative damage to the membrane material from excessive oxygen.

10. The self-heating method for dehydrogenation reaction according to claim 6, characterized in that, The self-heating method for the dehydrogenation reaction is applicable to any one of the following: ethylbenzene dehydrogenation to styrene, propane dehydrogenation to propylene, and isobutane dehydrogenation to isobutene.

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