Fixed bed catalytic filler structure suitable for perhydrobenzyltoluene dehydrogenation reaction

Abstract

The utility model relates to a fixed bed catalytic filler structure suitable for a perhydrobenzyltoluene dehydrogenation reaction, which comprises catalytic filler particles stacked in a fixed bed reactor shell, the catalytic filler particles are cylindrical, and a plurality of axial through holes penetrating through two end surfaces of the catalytic filler particles are arranged in the catalytic filler particles. The fixed bed catalytic filler suitable for the perhydrobenzyltoluene dehydrogenation reaction is reasonable in structural design and novel in structure, the contact area of fluid and a catalyst is increased by forming the axial through holes with specific structures in the catalytic filler particles, so that the heat transfer behavior and the utilization efficiency of the catalyst are enhanced, and the catalytic filler is suitable for the perhydrobenzyltoluene dehydrogenation reaction. The catalytic filler structure can obviously reduce the pressure drop of a reactor bed, so that the temperature distribution in the reactor is more uniform, the utilization efficiency of the catalyst is improved, the dehydrogenation reaction process of perhydrobenzyltoluene (H12-BT) is enhanced, and the problems of non-uniform temperature distribution in the reactor and low catalyst utilization rate are solved.

Description

Technical Field

[0001] This utility model relates to the field of dehydrogenation reaction technology, and in particular to a fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene. Background Technology

[0002] Climate change has become a common challenge that all of humanity urgently needs to overcome, and its negative impacts on the ecological environment and socio-economic development are constantly intensifying. Against this severe backdrop, energy transition is imminent. Hydrogen energy, as a clean and efficient secondary energy source, is gradually moving to the center of the global energy stage. Its utilization does not involve carbon dioxide emissions and can be produced on an industrial scale without relying on the environment. However, the storage and transportation of hydrogen severely hinders the widespread development of the hydrogen energy industry chain. Organic liquid hydrogen storage technology is considered a novel way to break through the bottleneck of hydrogen storage and transportation. Among many liquid organic hydrogen carriers, the benzyltoluene / perhydrobenzyltoluene system is considered promising. However, research on this system as a LOHC is limited, making the development of dehydrogenation reactors an important research direction. Several novel reactors have shown excellent performance in theoretical and laboratory studies, but from a practical application perspective, they still face many challenges in industrial operation beyond the laboratory scale and have not yet reached a mature stage. Fixed-bed reactors have a simpler structure and are easier to control in operation. Parameters such as temperature, pressure, and flow rate are relatively stable, and scaling up from laboratory to industrial production is relatively easy. As long as similar hydrodynamic conditions and heat and mass transfer characteristics are maintained, similar reaction effects to small-scale tests can be achieved in large-scale production, facilitating industrial application. However, dehydrogenation reactions in fixed-bed reactors also present certain challenges.

[0003] Dehydrogenation is inherently a strongly endothermic reaction, requiring a rapid and continuous supply of heat to the active sites of the catalyst. Therefore, an efficient heat transfer and supply system is crucial for continuous dehydrogenation reactions. Fixed-bed reactors offer a larger reaction space compared to stirred-tank reactors. The continuous inflow of all-hydrogen reactants into the fixed-bed reactor creates complex fluid flow and heat / mass transfer processes within the reactor. This can easily lead to uneven temperature distribution within the fixed-bed reactor, resulting in significant inhomogeneity in the chemical reaction. Furthermore, an overly dense catalyst packing structure can also lead to low catalyst utilization. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyl toluene, which can significantly reduce the pressure drop of the reactor bed, make the temperature distribution in the reactor more uniform, and improve the catalyst utilization efficiency.

[0005] This utility model is achieved by the following scheme: a fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene, comprising catalytic packing particles stacked in the shell of a fixed-bed reactor, wherein the catalytic packing particles are cylindrical and have multiple axial through holes penetrating both ends of the catalytic packing particles inside.

[0006] Furthermore, the ratio of the diameter of the axial through hole to the diameter of the catalyst packing particles is 1:4.

[0007] Furthermore, the number of axial through holes is 5, and they are distributed in a cross shape on the catalytic packing particles.

[0008] Furthermore, one of the axial through holes is located at the center of the catalyst packing particle, and the other four axial through holes are evenly distributed around the axial through hole at the center.

[0009] Furthermore, the diameter of the axial through hole is 1.6 mm, and the center distance between the central axial through hole and the other four axial through holes is 2.0 mm.

[0010] Furthermore, the diameter of the catalytic packing particles is 6.4 mm and the height is 6.4 mm.

[0011] Furthermore, the shell of the fixed-bed reactor is cylindrical.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The fixed-bed catalytic packing structure of the present invention, applicable to the dehydrogenation reaction of perhydrobenzyl toluene, is reasonably designed and has a novel structure. By opening axial through holes with a specific structure on the catalytic packing particles, the contact area between the fluid and the catalyst is increased to enhance heat transfer behavior and catalyst utilization efficiency. The catalytic packing structure can significantly reduce the pressure drop of the reactor bed, make the temperature distribution in the reactor more uniform, improve the catalyst utilization efficiency, strengthen the dehydrogenation reaction process of perhydrobenzyl toluene (H12-BT), and improve the problems of uneven temperature distribution and low catalyst utilization in the reactor.

[0013] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below through specific embodiments and related drawings. Attached Figure Description

[0014] Figure 1 This is an overall perspective view of an embodiment of the present utility model;

[0015] Figure 2 This is a three-dimensional view of the catalytic packing particles according to an embodiment of the present invention;

[0016] Figure 3 This is a top view of the catalytic packing particles according to an embodiment of the present invention;

[0017] The labels in the diagram are as follows: 100 - fixed bed reactor shell, 200 - catalytic packing particles, 210 - axial through hole. Detailed Implementation

[0018] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] like Figures 1-3 As shown, a fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene (H12-BT) includes catalytic packing particles 200 stacked in a fixed-bed reactor shell 100. The catalytic packing particles are cylindrical, and each particle has multiple axial through-holes 210 penetrating both ends. This fixed-bed catalytic packing structure is mainly used to solve problems such as uneven temperature distribution and low catalyst utilization in fixed-bed reactors during the dehydrogenation of perhydrobenzyltoluene (H12-BT). The catalytic packing is composed of multiple cylindrical catalytic packing particles with axial through-holes. Compared to traditional catalytic packing particles, this invention increases the contact area between the fluid and the catalyst by opening holes in the cylindrical catalytic packing particles, thereby enhancing heat transfer and catalyst utilization efficiency. The catalytic packing structure can significantly reduce the pressure drop in the reactor bed, making the temperature distribution within the reactor more uniform, improving catalyst utilization efficiency, strengthening the dehydrogenation reaction process of perhydrobenzyltoluene (H12-BT), and improving the problems of uneven temperature distribution and low catalyst utilization within the reactor.

[0021] The manufacturing process of catalytic packing particles: Alumina powder, water, binder, and pore-forming agent are mixed, shaped, dried, and calcined to obtain a cylindrical carrier with multiple axial through holes; then, the reactive sites are loaded onto the cylindrical carrier by impregnation to obtain catalytic packing particles, thus completing the preparation of catalytic packing particles.

[0022] In this embodiment, the ratio of the diameter of the axial through hole to the diameter of the catalytic packing particles is 1:4.

[0023] In this embodiment, the number of axial through holes is 5, and they are distributed in a cross shape on the catalyst packing particles.

[0024] In this embodiment, one axial through hole is located at the center of the catalyst packing particle, and the other four axial through holes are evenly distributed around the axial through hole at the center.

[0025] In this embodiment, the diameter of the axial through hole is 1.6 mm, and the center distance between the central axial through hole and the other four axial through holes is 2.0 mm.

[0026] In this embodiment, the diameter of the catalytic packing particles is 6.4 mm and the height is 6.4 mm.

[0027] In this embodiment, the shell of the fixed-bed reactor is cylindrical.

[0028] This invention increases fluid flow channels by creating axially oriented through-holes with a specific structure on the catalytic packing particles, reducing "dead zones" and "flow deviations" caused by dense packing within the reactor, and significantly lowering bed pressure drop. In terms of heat transfer, the increased flow channels enlarge the contact area between the fluid and the catalytic packing particles, correspondingly increasing the effective heat transfer area. This allows for more efficient heat exchange with the fluid during the reaction. Regarding mass transfer, the presence of through-holes shortens the diffusion path of the fluid within the catalytic packing particles, allowing reactants to diffuse out of the particles more quickly after the reaction, enabling reactive sites to participate in new reactions and increasing their utilization rate. Furthermore, the larger two-phase contact area facilitates easier diffusion of the fluid into the particle interior for further reaction.

[0029] The dehydrogenation reaction is carried out in a fixed-bed reactor with bottom-up feeding, at a temperature of 265 °C and a pressure of atmospheric pressure. Since the reactor can accommodate a fixed number of catalytic packing particles, but these particles vary in size and shape, the packing density is used to represent the amount of catalytic packing particles used, and the degree of dehydrogenation is used to evaluate the extent of the reaction.

[0030] The novel catalytic packing structure reduces bed pressure drop by 22% compared to traditional catalytic packing, resulting in more uniform fluid velocity within the reactor and preventing reaction inhomogeneity. While maintaining the same degree of dehydrogenation, the reactor using this novel catalytic packing structure achieves a 26% reduction in catalyst packing density, indicating a significant improvement in catalyst utilization.

[0031] Unless otherwise stated, if any of the technical solutions disclosed in this utility model discloses a numerical range, then the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this utility model discloses only some numerical values ​​to illustrate the technical solutions of this utility model. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this utility model.

[0032] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured by integral molding using a casting process) (except where it is obviously impossible to use an integral molding process).

[0033] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this utility model to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0034] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0035] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from its technical solution shall still fall within the protection scope of this utility model.

Claims

1. A fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene, characterized in that: It includes catalytic packing particles stacked in the shell of a fixed-bed reactor. The catalytic packing particles are cylindrical and have multiple axial through holes penetrating both ends of the catalytic packing particles.

2. The fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene according to claim 1, characterized in that: The diameter of the axial through hole is 1:4 compared to the diameter of the catalytic packing particles.

3. The fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene according to claim 1, characterized in that: The number of axial through holes is 5, and they are distributed in a cross shape on the catalyst packing particles.

4. The fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene according to claim 3, characterized in that: One of the axial through holes is located at the center of the catalyst packing particle, and the other four axial through holes are evenly distributed around the axial through hole at the center.

5. The fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene according to claim 4, characterized in that: The diameter of the axial through hole is 1.6 mm, and the center distance between the central axial through hole and the other four axial through holes is 2.0 mm.

6. The fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene according to claim 1, characterized in that: The catalytic packing particles have a diameter of 6.4 mm and a height of 6.4 mm.

7. The fixed-bed catalytic packing structure suitable for the dehydrogenation reaction of perhydrobenzyltoluene according to claim 1, characterized in that: The shell of the fixed-bed reactor is cylindrical.

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