Fixed bed hydrogenation reactor with heat pipe equalizer

Abstract

The utility model discloses a fixed bed hydrogenation reactor with heat pipe temperature equalizer from top to bottom includes: upper head, reaction section and lower head, reaction section adopts fixed bed reactor, and the inside of reactor is filled with catalyst, and is evenly distributed with two or more than two heat pipe bundle layers, and the heat pipe in each heat pipe bundle is fixed through distribution board, and the periphery of heat pipe is filled with catalyst, and upper head and lower head are provided with material inlet and outlet respectively, and reaction raw material can enter from upper head or lower head, and after hydrogenation reaction in reaction section, reaction product is discharged from lower head or upper head, and heat pipe bundle layer transfers the heat generated by reaction from one end to another end, and realizes the temperature equalization of whole reaction section, the fixed bed hydrogenation reactor of the utility model can effectively curb the problem that hydrogenation reaction local temperature is too high, improves reaction efficiency, and makes the heat transfer of reaction product and heat conducting medium high -efficient and fast, and makes the reaction more complete simultaneously, and effectively reduces the occurrence of side reaction.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment, and specifically relates to a fixed-bed hydrogenation reactor with a heat pipe isotherm that allows for segmented reaction and segmented control of gas-liquid two-phase products. Background Technology

[0002] Tubular reactors are crucial equipment in laboratory and industrial applications, serving both gas-phase and liquid-phase hydrogenation. They are suitable for hydrogenation of novel organic hydrogen storage materials, primarily used in chemical production and experimental processes with significant reaction heat. Currently, gas-liquid-solid three-phase hydrogenation reactors face the following challenges:

[0003] 1. The reactor has a small heat exchange area, and the reaction process is closer to an adiabatic reaction. This results in insufficient heat exchange, leading to situations where the temperature is either too high or too low in certain areas within the reactor.

[0004] 2. Uneven local temperature within the reactor causes the catalyst to deviate from its optimal catalytic temperature and operating conditions, significantly impacting its lifespan and resulting in lower catalytic efficiency.

[0005] 3. Uneven reaction temperature leads to reaction instability, side reactions cannot be effectively controlled, and reaction yield is unstable. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a fixed-bed hydrogenation reactor with a heat pipe isotherm.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a fixed-bed hydrogenation reactor with a heat pipe thermostat, comprising, from top to bottom: an upper head, a reaction section, and a lower head;

[0008] The reaction section adopts a fixed-bed reactor, which is filled with catalyst and has two or more layers of heat pipe bundles evenly distributed inside. The heat pipes in each heat pipe bundle are fixed by a distribution plate, and the catalyst is filled around the heat pipes.

[0009] The upper and lower heads are respectively equipped with material inlets and outlets. The reaction raw materials can enter from the upper head or the lower head. After the hydrogenation reaction is carried out in the reaction section, the reactants are discharged from the lower head or the upper head.

[0010] Each heat pipe bundle layer consists of several heat pipes arranged vertically and evenly in the reactor using a distribution plate. The heat pipe bundle layer transfers the heat generated by the reaction from one end to the other, achieving uniform temperature throughout the entire reaction section.

[0011] Furthermore, the number of heat pipe bundle layers is 2 to 5.

[0012] Furthermore, the heat pipe includes a shell, a wick, and end caps; the wick is disposed inside the shell, and end caps are provided at both ends of the shell. The inside of the heat pipe is evacuated to a negative pressure state and filled with a low-boiling-point volatile liquid; the wick is made of a fine porous material.

[0013] Furthermore, heat pipes are welded to a distribution plate, which is evenly provided with small holes.

[0014] Furthermore, the distance between the small holes and the edge of the heat pipe is 1 to 5 mm, and each heat pipe is surrounded by 3 to 8 small holes with a diameter of 0.1 to 0.5 times the diameter of the heat pipe.

[0015] Furthermore, the heat pipe includes a lower evaporation section and an upper condensation section, with the heat generated by the reaction moving from the evaporation section to the condensation section.

[0016] Furthermore, the length ratio of the evaporation section to the condensation section is 1:(1~3).

[0017] Furthermore, the heat pipes are distributed in a triangular or square pattern on the distribution plate, with the center-to-center distance between adjacent heat pipes being 1.5 to 3 times the heat pipe diameter.

[0018] Compared with the prior art, the advantages of this utility model are as follows:

[0019] (1) The reaction section is equipped with multiple layers of heat pipes, which are welded to a distribution plate. The catalyst is filled around the heat pipes. After the reaction begins in the lower part of the reaction section, the heat pipes transfer excess heat to the upper part of the heat pipes, so that the entire reaction section achieves uniform temperature. An intermediate distribution plate is designed between the condensation section and the evaporation section in the upper part of the heat pipes, which can make the separated hydrogen and raw materials gather and mix evenly again, reduce the wall flow effect, and enter the upper reaction stage. This can reduce problems such as accelerated hydrogen gas-liquid separation, reduced gas solubility, decreased reaction rate, and reduced catalyst utilization in the later stage of the reaction.

[0020] (2) Multi-stage heat pipe beds can be filled with catalysts of different properties or heights according to reaction requirements, so as to maximize the utilization of the reactor. Taking the hydrogenation of organic liquid hydrogen storage materials with a large hydrogenation ratio as an example, the reaction raw materials are recycled from the outside. During the external use, some impurities that are detrimental to the catalysts of subsequent reactions may be introduced. At this time, the first stage of the reaction evaporation section at the bottom can be filled with a catalyst with good tolerance and strong adsorption, and part of the impurities are treated by hydrogenation. The reaction is relatively fast and the temperature rise is large, but the excessive temperature rise is easy to trigger side reactions. The heat pipe promptly moves the heat to the upper condensation section. The condensation section can be filled with a catalyst with a low loading or the catalyst can be diluted to reduce the reaction rate and make the bed temperature rise operate under ideal conditions. The second stage heat pipe is in the later stage of the reaction with only a small amount of raw materials and large bond energy, which is difficult to hydrogenate. It can be filled with a catalyst with a high loading to increase the reaction rate and make all raw materials react completely. If the reaction is particularly sensitive to the hydrogenation temperature, a third and fourth stage heat pipe can be designed for multi-stage step-by-step reaction, so that the raw materials can react completely under mild conditions.

[0021] (3) The number of bed stages can be freely adjusted according to the reaction conditions. It is easy to disassemble and different stages can be set for different raw materials. It can cope with hydrogenation of various raw materials with different hydrogenation rates, reducing the equipment investment cost of early-stage experiments and later-stage scale-up. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the fixed-bed hydrogenation reactor with a heat pipe isotherm in the embodiment;

[0023] Figure descriptions: a) Upper head, n) Reaction section, b) Lower head, 1) Heat pipe, 2) Distribution plate, 3) Support grid, 4) Compactor grid, N1) Top outlet of lower head, N2) Top outlet of upper head, L1) Heat pipe evaporation section, L2) Heat pipe condensation section.

[0024] Figure 2 This is a diagram showing the heat pipe and perforation layout of the distribution plate. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0027] like Figure 1 The image shows a fixed-bed hydrogenation reactor with a heat pipe isotherm, mainly composed of an upper head a, a reaction section n, and a lower head b. The upper and lower heads are welded to the reactor body.

[0028] The reaction section employs a fixed-bed reactor, filled with catalyst and containing two or more uniformly distributed layers of heat pipe bundles. Each heat pipe bundle is fixed by a distribution plate, and the heat pipes are surrounded by catalyst. This embodiment uses two layers of heat pipe bundles. Each layer of heat pipe bundles has several heat pipes arranged vertically and evenly within the reactor using a distribution plate.

[0029] The wick is housed inside the heat pipe shell, which has end caps at both ends. The inside of the heat pipe is evacuated to a negative pressure and filled with a low-boiling-point volatile liquid. The wick is made of a fine porous material. One end of the heat pipe is the evaporation end, and the other end is the condensation end. When the evaporation end is heated, the liquid in the wick rapidly vaporizes. The vapor flows to the condensation end under the force of thermal diffusion, where it condenses and releases heat. The liquid then flows back to the evaporation end along the porous material by capillary action. This cycle continues until the temperatures at both ends of the heat pipe are equal.

[0030] The heat pipes are welded to a distribution plate, which has evenly spaced small holes to allow the reactant gases and liquids to be mixed uniformly before entering the subsequent reaction. The distribution plate divides the heat pipes into an upper evaporation section and a lower condensation section, and the heat generated by the reaction is transferred from the evaporation section to the condensation section. The length ratio of the evaporation section to the condensation section is 1:(1~3).

[0031] The raw materials and hydrogen are mixed and heated to the reaction temperature in the lower gas-liquid mixer before entering the lower head b. Once the lower head b is full, it enters the reaction section n. Heat pipes and catalyst are loaded into the reaction section as needed. After the materials contact the catalyst and begin to react, the heat pipes transfer heat from the lower evaporation section L1 to the condensation section L2, ensuring the reaction is maintained at a uniform temperature. A tray with multiple small holes is installed at the lower end of the catalyst support grid 3. The reacting liquids and gases can pass through these holes, but the catalyst cannot. A perforated tray is also fixed to the upper end of the pressure grid 4, securing the catalyst within the reaction section tubes.

[0032] After the reaction is complete, the product and excess hydrogen enter the upper head a together, and are discharged by N1 to separate into gas and liquid products or enter the next reactor for further reaction.

[0033] After the above process, the organic hydrogen storage liquid and hydrogen gas react in the reactor and are then discharged separately after gas-liquid separation, achieving the goal of high efficiency, stability and controllability of the reaction.

[0034] like Figure 2 This diagram shows the arrangement of heat pipes and openings on a distribution plate. The heat pipes are welded to the distribution plate, and small holes are made around the heat pipes on the middle distribution plate to allow the gas and liquid to mix evenly again before entering the subsequent reaction.

[0035] The small holes around the heat pipe serve to redistribute gas and liquid, allowing the second gas and liquid to exit through these holes, thus increasing heat transfer. The distance from the edge of the hole to the edge of the heat pipe is typically 1-5 mm, with 3-8 holes in total. The diameter of the holes is typically 0.1-0.5 times the diameter of the heat pipe, and the center-to-center distance of the heat pipe is typically 1.5-3 times the diameter of the heat pipe.

[0036] This device can maintain a uniform temperature inside the fixed-bed reactor, minimizing side reactions caused by overheating and maximizing energy utilization efficiency.

[0037] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A fixed-bed hydrogenation reactor with a heat pipe isotherm, characterized in that: From top to bottom, it includes: upper head, reaction section, and lower head; The reaction section adopts a fixed-bed reactor, which is filled with catalyst and has two or more layers of heat pipe bundles evenly distributed inside. The heat pipes in each heat pipe bundle are fixed by a distribution plate, and the catalyst is filled around the heat pipes. The upper and lower heads are respectively equipped with material inlets and outlets. The reaction raw materials can enter from the upper head or the lower head. After the hydrogenation reaction is carried out in the reaction section, the reactants are discharged from the lower head or the upper head. Each heat pipe bundle layer consists of several heat pipes arranged vertically and evenly in the reactor using a distribution plate. The heat pipe bundle layer transfers the heat generated by the reaction from one end to the other, achieving uniform temperature throughout the entire reaction section.

2. The fixed-bed hydrogenation reactor with heat pipe homogenizer according to claim 1, characterized in that: The number of heat pipe bundle layers is 2 to 5.

3. The fixed-bed hydrogenation reactor with heat pipe homogenizer according to claim 1, characterized in that: The heat pipe includes a shell, a wick, and end caps; the wick is disposed inside the shell, and end caps are provided at both ends of the shell. The inside of the heat pipe is evacuated to a negative pressure state and filled with a low-boiling-point volatile liquid; the wick is made of a fine porous material.

4. The fixed-bed hydrogenation reactor with heat pipe homogenizer according to claim 1, characterized in that: The heat pipe is welded to a distribution plate, which has small holes evenly distributed on it.

5. The fixed-bed hydrogenation reactor with heat pipe homogenizer according to claim 4, characterized in that: The distance between the small hole and the edge of the heat pipe is 1 to 5 mm. Each heat pipe is surrounded by 3 to 8 small holes, and the diameter of the small holes is 0.1 to 0.5 times the diameter of the heat pipe.

6. The fixed-bed hydrogenation reactor with heat pipe isotherm according to claim 4, characterized in that: The heat pipe includes a lower evaporation section and an upper condensation section, and the heat generated by the reaction is transferred from the evaporation section to the condensation section.

7. The fixed-bed hydrogenation reactor with heat pipe homogenizer according to claim 6, characterized in that: The length ratio of the evaporation section to the condensation section is 1:(1~3).

8. The fixed-bed hydrogenation reactor with heat pipe homogenizer according to claim 1, characterized in that: The heat pipes are distributed in a triangular or square pattern on the distribution plate, with the center-to-center distance between adjacent heat pipes being 1.5 to 3 times the heat pipe diameter.

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