A tube-in-tube type uniform temperature hydrogenation reactor with heat pipe

Abstract

The utility model discloses a kind of tubular reactor of even temperature hydrogenation with heat pipe, from top to bottom comprising: upper head, reaction section and lower head;The reaction section includes more than one tubular reactor, and heat pipe is arranged in the tubular in the tube pass of the tubular reactor and is filled with catalyst, and heat pipe is buried in catalyst;The bottom and side part of lower head are respectively provided with raw material inlet, and the bottom and side part of upper head are respectively provided with reactant gas outlet and liquid outlet;The middle of the tubular reactor is provided with intermediate distribution plate;The heat pipe is divided into lower evaporation section and upper condensation section, and heat pipe moves the heat generated by reaction from evaporation section to condensation section.The reactor of the utility model can effectively curb the problem of local temperature of hydrogenation reaction too high, improve reaction efficiency;Efficiently and quickly make reactant and heat transfer of heat conduction medium;React more completely simultaneously, effectively reduce the occurrence of side reaction.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment, and specifically relates to a tubular isothermal hydrogenation reactor with heat pipes that can perform 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 two-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.

[0006] 4. The reactor does not have an integrated gas-liquid separation unit. Gas-liquid separation must be completed by a separate gas-liquid separator, which increases the equipment investment cost.

[0007] 5. The product flow direction of the reactor is singular and cannot be adjusted to achieve optimal operating conditions. Utility Model Content

[0008] The purpose of this invention is to address the shortcomings of existing technologies by providing a tubular isothermal hydrogenation reactor with heat pipes.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a tubular isothermal hydrogenation reactor with heat pipes, comprising, from top to bottom: an upper head, a reaction section, and a lower head;

[0010] The reaction section includes one or more tube reactors, and the tubes in the tube side of the tube reactor are equipped with heat pipes and filled with catalyst, with the heat pipes embedded in the catalyst.

[0011] The bottom and side of the lower head are respectively provided with raw material inlets, and the bottom and side of the upper head are respectively provided with reactant gas outlets and liquid outlets;

[0012] An intermediate distribution plate is provided in the middle of the tubular reactor;

[0013] The heat pipe is divided into a lower evaporation section and an upper condensation section, and the heat pipe moves the heat generated by the reaction from the evaporation section to the condensation section.

[0014] Furthermore, the length ratio of the evaporation section to the condensation section is 1:(1~3).

[0015] Furthermore, a wire mesh demister is installed inside the upper end cap.

[0016] Furthermore, a gas-liquid mixer is installed at the raw material inlet of the lower head.

[0017] Furthermore, the ratio of the tube diameter to the heat pipe diameter in the tubular reactor is 2~5:1.

[0018] Furthermore, the heat pipe is fixed to the center of the tube by fixing brackets set at both ends of the tube.

[0019] Furthermore, upper tube sheets and lower tube sheets are distributed at both ends of the reaction section. Trays are installed at the upper end of the upper tube sheet and the lower end of the lower tube sheet. The trays are provided with small holes and fix the catalyst inside the tubes.

[0020] Furthermore, the parts of the upper and lower tube sheets that come into contact with raw materials or reactants are made of corrosion-resistant materials, which are overlaid or coated onto the tube sheets.

[0021] Furthermore, ceramic ball pads are filled at both ends of the tube.

[0022] Furthermore, the shell side of the reaction section is provided with an inlet and an outlet for the heat transfer medium, located below and above the reaction section, respectively.

[0023] This invention employs a tubular isothermal hydrogenation reactor with heat pipes. Heat pipes are added inside the tubular structure, utilizing the phase change process of the medium evaporating at the hot end and condensing at the cold end (i.e., utilizing the latent heat of vaporization and condensation of the liquid) to facilitate rapid heat transfer. A typical heat pipe consists of a shell, a wick, and end caps. The inside of the heat pipe is evacuated to a negative pressure state and filled with a suitable liquid with a low boiling point and high volatility. The tube wall has a wick made of a capillary porous material. One end of the heat pipe is the evaporation end, and the other end is the condensation end. When one end of the heat pipe is heated, the liquid in the capillary rapidly vaporizes. The vapor flows to the other end under the force of thermal diffusion and condenses at the cold end, releasing 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 (at which point thermal diffusion of the vapor stops). Simultaneously controlling the temperature of the jacketed heat transfer medium maintains the entire catalyst bed within the tube at its optimal operating temperature, effectively controlling side reactions, extending catalyst life, and resulting in more stable and higher yields. Furthermore, this reactor integrates the reaction process and gas-liquid separation process into a single unit, eliminating the need for a separate gas-liquid separator compared to traditional reactors, thus reducing equipment investment, floor space, and piping connections. Additionally, this reactor allows for flexible selection of material flow direction to achieve optimal operating conditions under different reaction states.

[0024] Compared with the prior art, the advantages of this utility model are as follows:

[0025] (1) The organic hydrogen storage material is fed from the bottom. This allows the raw materials to be evenly distributed in each tube, ensuring uniform reaction. It also extends the residence time of the raw materials in the bed, making the reaction complete, effectively improving the reaction efficiency and extending the catalyst life.

[0026] (2) The upper head is equipped with a gas-liquid separation section, which can complete the reaction and gas-liquid separation simultaneously in the reactor, eliminating the need for a separate gas-liquid separator, saving equipment investment and reducing the on-site installation area.

[0027] (3) The tube sheet is welded or coated with anti-corrosion and clean materials on a material with high hardness, which greatly saves the amount of anti-corrosion and clean materials used, reduces the investment in reactor equipment, and reduces the equipment volume while using a high-strength base material.

[0028] (4) A gas-liquid mixer is installed at the feed inlet, which can make hydrogen and raw materials mix well to form a hydrogen-rich emulsion. Compared with direct feeding, the raw materials can be pressurized and dissolved after being mixed by the gas-liquid mixer, generate free radicals, enhance mass transfer efficiency, accelerate the reaction rate, and reduce the occurrence of side reactions.

[0029] (5) Each tube is fitted with a heat pipe, which is fixed by a support bracket. The heat pipe is surrounded by catalyst. After the reaction begins in the lower part of the tube, the heat pipe transfers excess heat to the upper part of the tube, ensuring a uniform temperature throughout the reaction section. An intermediate distribution plate is designed between the condensation and evaporation sections above the heat pipe, allowing the separated hydrogen and raw materials to re-aggregate and mix evenly, reducing wall flow effects and facilitating entry into the next stage of the reaction. This reduces problems such as accelerated hydrogen-liquid separation, decreased gas solubility, reduced reaction rate, and decreased catalyst utilization in the later stages of the reaction.

[0030] (6) Multistage tubular reactors can be filled with catalysts of different properties or heights according to reaction requirements, maximizing reactor utilization. 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 bottom reaction evaporation section can be filled with a catalyst with good tolerance and strong adsorption to partially treat the impurities with hydrogenation. The reaction is relatively rapid and the temperature rise is large, but excessive temperature rise can easily trigger side reactions. The heat pipe promptly moves the heat to the upper condensation section. The condensation section can be divided into two stages. The second stage 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. In the later stage of the reaction, there are only a small amount of raw materials and the bond energy is large, making hydrogenation difficult. At this time, the third stage at the top can be filled with a catalyst with a high loading to increase the reaction rate and make all raw materials react completely.

[0031] (7) 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

[0032] Figure 1 This is a schematic diagram of the structure of the tubular isothermal hydrogenation reactor with heat pipes in the embodiment.

[0033] Figure 2 This is a schematic diagram of the structure of a single tube in the reactor of the embodiment.

[0034] Figure reference numerals: a, upper head; n, reaction section; b, lower head; 1, heat pipe; 2, tube sheet; 3, ceramic ball pad; 4, catalyst; 5, lower tube sheet; 6, upper tube sheet; 7, heat exchange medium inlet; 8, heat exchange medium outlet; N1, top outlet of upper head; N2, side outlet of upper head; N3, bottom inlet of lower head; N4, side inlet of lower head; L1, heat pipe evaporation section; L2, heat pipe condensation section; 9, intermediate distribution plate; 10, heat pipe fixing bracket. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] A tubular isothermal hydrogenation reactor with heat pipes includes the following components: an upper head, which is elliptical or circular, detachable, and connected to the reaction section via a flange and secured with bolts; a feed or discharge pipeline is installed on the upper head, and a wire mesh demister is installed inside the upper head. A gas-liquid separation section is also installed inside the upper head, and a level gauge is installed outside the upper head to monitor the liquid level in the separation section. The liquid level in the separation section is maintained by controlling the liquid discharge rate.

[0038] The reactor section with heat pipes employs a shell-and-tube reactor, consisting of an upper tube sheet, tubes, heat pipes, a lower tube sheet, a shell, and baffles. The tubes are evenly distributed throughout the reaction section and rigidly connected to the upper and lower tube sheets, which are welded to the outer shell. The tubes themselves (tube side) are fitted with heat pipe supports and heat pipes, and filled with a catalyst or a mixture of catalyst and diluent. Outside the tubes, inside the shell, is a circulating heat transfer medium. The heat required for the reaction inside the tubes is controlled and transferred by the heat transfer medium outside the tubes and the evaporation and condensation of the medium inside the heat pipes. This ensures uniform temperature at the center and wall of the tubes. The tube sheets are fixed and sealed to the reaction tubes using strength welding and expansion. All materials in contact with the material are corrosion-resistant and clean, covered by welding or coating on carbon steel or other high-strength materials. Multi-stage baffles are used in the shell side to increase the flow rate of the heat transfer medium during circulation, increasing the rate and efficiency of heat exchange between the inside and outside of the reaction tubes, and more effectively controlling the reaction temperature inside the tubes.

[0039] The lower head is elliptical or circular, detachable, and connected to the reaction section via a flange and secured with bolts. Inlet or outlet pipelines are installed on the lower head. A gas-liquid separation section is located inside the lower head, and a level gauge is installed outside the head to monitor the liquid level in the separation section. The liquid level in the separation section is maintained by controlling the liquid discharge rate.

[0040] Example

[0041] like Figure 1 The image shows a tubular isothermal hydrogenation reactor with heat pipes, mainly composed of an upper head (a), a reaction section (n), and a lower head (b). The upper and lower heads are connected and fixed with bolts, and sealed with a gasket in between.

[0042] The raw materials and hydrogen are mixed in the lower gas-liquid mixer. The gas-liquid mixer can generate ultra-microbubbles in the gas, which dissolve in the raw materials before entering the lower head b. After the lower head b is filled, it enters the reaction section n. The tube side of the reaction section is filled with heat pipes and catalyst as needed, and the shell side is filled with circulating heat transfer medium. The heat transfer medium enters from the heat transfer agent inlet 7 at the lower end of the reaction section b and exits from the heat transfer agent outlet 8 at the upper end. After external heat is replenished or released, it is circulated. The heat pipes inside transfer the heat from the lower evaporation section L1 to the condensation section L2. A tray is installed at the lower end of the lower tube sheet 5. The tray has multiple small holes. The liquid and gas participating in the reaction can pass through the small holes, but the catalyst in the reaction tube 2 cannot pass through. The upper tube sheet 6 is also fixed with a perforated tray at the upper end, so that the catalyst is fixed in the tube side of the reaction section.

[0043] After the reaction is complete, the product and excess hydrogen enter the upper head a together. There is an exhaust port N1 on the top and a liquid drain port N2 on the side. The amount of liquid drained is controlled by monitoring the liquid level in the lower head a to maintain the liquid level in the upper head a, so as to achieve the purpose of gas-liquid separation.

[0044] 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.

[0045] Figure 2 This is a detailed diagram of a single heat pipe. Heat pipe retainers are installed above and below the heat pipe to keep the heat pipe in the middle of the heat pipe. An intermediate distribution plate is installed in the middle of the heat pipe to allow the gas and liquid to mix evenly again before entering the subsequent reaction.

[0046] This device can maintain a uniform temperature inside the tubular gas-liquid hydrogenation reaction tube, minimizing side reactions caused by overheating and maximizing energy utilization efficiency.

[0047] 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 tubular isothermal hydrogenation reactor with heat pipes, characterized in that: From top to bottom, it includes: upper head, reaction section, and lower head; The reaction section includes one or more tube reactors, and the tubes in the tube side of the tube reactor are equipped with heat pipes and filled with catalyst, with the heat pipes embedded in the catalyst. The bottom and side of the lower head are respectively provided with raw material inlets, and the bottom and side of the upper head are respectively provided with reactant gas outlets and liquid outlets; An intermediate distribution plate is provided in the middle of the tubular reactor; The heat pipe is divided into a lower evaporation section and an upper condensation section, and the heat pipe moves the heat generated by the reaction from the evaporation section to the condensation section.

2. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: The length ratio of the evaporation section to the condensation section is 1:(1~3).

3. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: A wire mesh demister is installed inside the upper end cap.

4. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: A gas-liquid mixer is installed at the raw material inlet of the lower end cap.

5. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: The ratio of the diameter of the tubular reactor tubes to the diameter of the heat pipes is (2~5):

1.

6. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: The heat pipe is fixed to the center of the tube by fixed brackets set at both ends of the tube.

7. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: The reaction section is provided with an upper tube sheet and a lower tube sheet at both ends. A tray is installed at the upper end of the upper tube sheet and the lower end of the lower tube sheet. The tray has small holes and fixes the catalyst inside the tube.

8. The tubular isothermal hydrogenation reactor with heat pipes according to claim 7, characterized in that: The parts of the upper and lower tube sheets that come into contact with the raw materials or reactants are made of corrosion-resistant materials, which are overlaid or coated onto the tube sheets.

9. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: The two ends of the tube are respectively filled with ceramic ball pads.

10. The tubular isothermal hydrogenation reactor with heat pipes according to claim 1, characterized in that: The shell side of the reaction section is provided with an inlet and an outlet for the heat-conducting medium, located below and above the reaction section, respectively.

Images