Fluidized bed acrylonitrile reactor
By optimizing the reactant ratio and feed structure, and by using an external heat exchanger and fluidizing ring, the problems of catalyst breakage and wear were solved, the acrylonitrile yield and reactor life were improved, and the cost was reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2026-03-31
AI Technical Summary
In fluidized bed acrylonitrile reactors, catalyst particles are prone to breakage, pulverization, and loss, resulting in insufficient contact of reactants, which leads to catalyst wear on equipment, increases costs, and affects product yield and selectivity.
The reactant ratio and feed structure are optimized, and an external heat exchanger and upper and lower fluidizing rings are used to perform fluidization and heat extraction by compressed air. The internal complex components are reduced, and symmetrical and laterally symmetrical dendritic distributors are used to ensure uniform mixing of reactants.
It improves acrylonitrile yield, extends reactor life, reduces maintenance and replacement costs, and ensures production stability and product quality.
Smart Images
Figure CN224057330U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of acrylonitrile technology, specifically a fluidized bed acrylonitrile reactor. Background Technology
[0002] A fluidized bed acrylonitrile reactor is a key piece of equipment used in chemical production to prepare acrylonitrile. Its core function is to provide an efficient and stable reaction environment for the reaction between propylene, ammonia, and air (or oxygen). It utilizes gas flow to suspend and fluidize solid catalyst particles, allowing the reactants to fully contact and react, producing acrylonitrile, an important chemical raw material.
[0003] Existing fluidized bed acrylonitrile reactors suffer from several problems: In fluidized conditions, catalyst particles are prone to breakage and pulverization due to intense impact and friction with internal reactor components, generating a large number of fine particles that are carried out of the reactor by the gas flow, resulting in catalyst loss and requiring continuous replenishment, increasing costs. Simultaneously, the reactants pass through the bed in the gas phase, leading to insufficient gas-solid contact and a near-completely mixed bed flow, hindering acrylonitrile formation and reducing the yield of the target product. Furthermore, the high-speed movement of catalyst particles severely abrades internal components such as cooling pipes and inner walls, shortening equipment lifespan, increasing maintenance and replacement costs, and introducing production instability. While excessive air in the reaction has advantages, it increases reactor load and energy consumption, and may cause excessive exothermic reactions leading to temperatures exceeding the control range, affecting reaction selectivity and product quality. Utility Model Content
[0004] To address the aforementioned problems in the existing technology, this application provides a fluidized bed acrylonitrile reactor that optimizes the reactant ratio and feed structure, stabilizes the ratio of propylene and ammonia to compressed air, eliminates the complex internal heat exchange coils, and innovates the heat exchange method by using external heat exchangers with upper and lower fluidizing rings to achieve fluidized heat exchange with the help of compressed air.
[0005] To achieve the above objectives, this application adopts the following technical solution: a fluidized bed acrylonitrile reactor, comprising:
[0006] The reactor includes a gas collection chamber located at the top of the reactor, a secondary cyclone separator connected to the gas collection chamber, a primary cyclone separator connected to the secondary cyclone separator, a grid plate located in the middle of the reactor, a compressed air distributor located at the bottom of the reactor, a feed distributor located above the compressed air distributor, the compressed air distributor being connected to a compressed air pipeline, and propylene and ammonia feed pipelines being connected to both ends of the feed distributor, respectively.
[0007] The heat exchanger is connected to the reactor and has a lower fluidizing ring and an upper fluidizing ring inside. The lower fluidizing ring and the upper fluidizing ring are respectively connected to the compressed air pipeline.
[0008] The compressed air distributor is equipped with a fixed component, a main air pipe, and air branch pipes, and adopts a symmetrical tree-shaped distributor.
[0009] The feed distributor is equipped with a fixed component, a main feed pipe, and feed branch pipes, and adopts a side-symmetrical tree-shaped distributor.
[0010] The primary cyclone separator has one cyclone inlet, and the secondary cyclone separator has two cyclone outlets. The outlet of the primary cyclone separator is connected to the inlet of the secondary cyclone separator.
[0011] In this application, both the primary and secondary cyclone separators utilize wing valves for their material legs. The beneficial effects of this application are:
[0012] This application provides a fluidized bed acrylonitrile reactor. The reactor optimizes the reactant ratio and feed structure to ensure a stable ratio of propylene and ammonia feed to compressed air, providing favorable conditions for the reaction from the source and helping to improve the yield of the target product, acrylonitrile. A back-mixing external heat exchanger is used, which not only has a significant heat extraction effect but also a simple structure and convenient operation. By reducing complex internal components, it reduces the wear of catalyst particles on the equipment's internal structure, effectively improving the reactor's service life, reducing equipment maintenance and replacement costs, and ensuring the stability of the production process. The external heat exchanger uses upper and lower fluidizing rings, utilizing compressed air for fluidization and heat extraction. This effectively removes the heat generated by the reaction, precisely controls the reaction temperature, and appropriately replenishes the air in the reaction section, providing more favorable conditions for the reaction and driving the reaction towards the formation of acrylonitrile, thereby improving product yield. The bottom feeding method avoids wear on the feed line during catalyst fluidization in the reaction section, significantly improving the feed line's service life, reducing the risk of production interruption due to feed line damage, and lowering maintenance costs. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the fluidized bed acrylonitrile reactor of this application;
[0014] Figure 2 This is a top view schematic diagram of the compressed air distributor of the fluidized bed acrylonitrile reactor in this application;
[0015] Figure 3 This is a top view schematic diagram of the feed distributor of the fluidized bed acrylonitrile reactor in this application;
[0016] Figure 4 This is a top view schematic diagram of the grid plate of the fluidized bed acrylonitrile reactor of this application;
[0017] Figure 5 This is a top view schematic diagram of the cyclone separator of the fluidized bed acrylonitrile reactor in this application;
[0018] Figure 6This is a schematic diagram of the cyclone separator components of the fluidized bed acrylonitrile reactor in this application;
[0019] Figure 7 This is a top view of the lower fluidizing ring of the heat exchanger in the fluidized bed acrylonitrile reactor of this application;
[0020] Figure 8 This is a top view of the upper fluidizing ring of the heat exchanger in the fluidized bed acrylonitrile reactor of this application;
[0021] In the diagram, 1-reactor; 2-heat extractor; 101-compressed air distributor; 102-feed distributor; 103-grid plate; 104-first-stage cyclone separator; 105-second-stage cyclone separator; 106-gas collection chamber; 107-lower fluidizing ring; 108-upper fluidizing ring; 201-fixed component; 202-main air pipe; 203-air branch pipe; 204-main feed pipe; 205-feed branch pipe; 206-grid hole; 207-first cyclone inlet; 208-second cyclone outlet; 209-wing valve; 301-fluidizing hole. Detailed Implementation
[0022] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.
[0023] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0024] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 application.
[0025] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0026] like Figure 1 The fluidized bed acrylonitrile reactor shown includes a reactor 1 and a heat exchanger 2. The heat exchanger 2 is installed on the outside of the reactor 1 and connected to it. The lining at the bottom of the reactor 1 is thickened, which can effectively reduce the amount of catalyst stored at the bottom of the reactor 1 and prevent the catalyst from turning over at the bottom of the reactor 1 during the feeding process, which is conducive to the reaction proceeding towards the target product acrylonitrile. Propylene and ammonia, as well as compressed air pipelines, are all fed from the bottom of the reactor 1, which can effectively reduce the scouring of the pipelines by the catalyst in the reaction section of the reactor 1 and improve the service life of the pipelines.
[0027] Inside reactor 1, from bottom to top, are installed a compressed air distributor 101, a feed distributor 102, a grid plate 103, a primary cyclone separator 104, a secondary cyclone separator 105, and a gas collection chamber 106.
[0028] like Figure 2 As shown, the compressed air distributor 101 adopts a symmetrical dendritic distributor, and is equipped with a fixing member 201, an air main pipe 202, and an air branch pipe 203. One air main pipe 202 is provided. The fixing member 201 of the compressed air distributor 101 can be provided with at least 4 depending on the actual situation. There can be n air branch pipes 203. The compressed air feed nozzle is set on the air branch pipe 203. The compressed air distributor 101 is located at the bottom of the reactor 1 as much as possible. Combined with the thickening of the lining at the bottom of the reactor 1, when compressed air is introduced into the reactor 1, the catalyst at the bottom of the reactor 1 can be effectively prevented from turning over, thereby making better use of the reaction.
[0029] like Figure 3 As shown, the feed distributor 102 adopts a side-symmetrical dendritic distributor, which effectively improves the uniform mixing of propylene and ammonia with compressed air at the bottom of reactor 1, so that they can enter the reaction section for reaction, thereby improving the reaction conversion rate and yield. The feed distributor 102 is equipped with a fixing component 201, a main feed pipe 204, and feed branch pipes 205. There are two main feed pipes 204. The fixing component 201 of the feed distributor 102 can be set according to the actual situation. There can be n feed branch pipes 205. The propylene and ammonia feed nozzles are set on the feed branch pipes 205. The propylene and ammonia feed lines split from the main pipe into two lines and are respectively connected to the two ends of the feed distributor 102.
[0030] like Figure 4 As shown, a grid plate 103 is installed inside the reactor 1, and the grid plate 103 is provided with uniform grid holes 206, which effectively avoids irregular movement of the catalyst inside the reactor, thereby reducing the irregular collision between the catalyst and the reactor wall, reducing the force of catalyst damage, extending the service life of the catalyst, improving the utilization rate of the catalyst, and increasing the service life of the reactor 1, thereby reducing production and operating costs.
[0031] like Figure 5 , Figure 6 As shown, reactor 1 is equipped with a primary cyclone separator 104 and a secondary cyclone separator 105, and a gas collection chamber 106 is set at the top. The primary cyclone separator 104 is provided with a cyclone inlet 207, and the secondary cyclone separator 105 is provided with a cyclone outlet 208. The outlet of the primary cyclone separator 104 is connected to the inlet of the secondary cyclone separator 105. Both the primary cyclone separator 104 and the secondary cyclone separator 105 use wing valves 209, which can improve the recovery and utilization of catalyst, effectively reduce the catalyst carried by the reaction products, reduce the operating load of downstream, and improve the utilization rate of catalyst. The cyclone separators use wing valves, which have a good sealing effect and are flexible and easy to use. The gas collection chamber 106 set at the top of reactor 1 can effectively buffer the synchronous operation of each cyclone separator and improve the overall cyclone effect of the cyclone separator.
[0032] Reactor 1 is connected to propylene and ammonia feed lines, compressed air lines, and reaction product lines. The compressed air lines are also connected to heat exchanger 2. Heat exchanger 2 uses compressed air fluidization, and the compressed air volume can be appropriately matched to improve the conversion rate of propylene and help improve the selectivity of the reaction.
[0033] like Figure 7 , Figure 8 As shown, the heat exchanger 2 is equipped with a lower fluidizing ring 107 and an upper fluidizing ring 108, both of which have fluidizing holes 301. Using an external heat exchanger instead of an internal heat exchange coil avoids damage to the heat exchange tubes due to catalyst wear within the reactor. This design is simple and provides significant heat exchange efficiency. The lower fluidizing ring 107 has twice the number of fluidizing holes 301 as the upper fluidizing ring 108. The heat exchange efficiency is primarily adjusted through the fluidizing holes 301 in the lower fluidizing ring 107, allowing for effective heat extraction and matching the compressed air volume in the reaction section, thereby improving the propylene conversion rate and reaction selectivity.
[0034] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.
[0035] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0036] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A fluidized bed acrylonitrile reactor characterized by, The application relates to a reactor (1) and a heat-removing device (2) for preparing propylene amine. The reactor (1) comprises a gas collecting chamber (106) arranged at the top of the reactor (1), a secondary cyclone separator (105) connected with the gas collecting chamber (106), a primary cyclone separator (104) connected with the secondary cyclone separator (105), a grid plate (103) arranged in the middle of the reactor (1), a compressed air distributor (101) arranged at the bottom of the reactor (1), a feed distributor (102) arranged above the compressed air distributor (101), the compressed air distributor (101) being connected with a compressed air pipeline, and the feed distributor (102) being connected with propylene and ammonia feed pipelines respectively at two ends. The heat-removing device (2) is connected with the reactor (1) and internally arranged with a lower fluidizing ring (107) and an upper fluidizing ring (108), the lower fluidizing ring (107) and the upper fluidizing ring (108) being connected with the compressed air pipeline respectively.
2. The fluidized bed acrylonitrile reactor of claim 1 wherein, The compressed air distributor (101) is arranged with a fixing member (201), an air main pipe (202) and air branch pipes (203) and adopts a positive symmetry dendritic distributor.
3. The fluidized bed acrylonitrile reactor of claim 1 wherein, The feed distributor (102) is arranged with a fixing member (201), a feed main pipe (204) and feed branch pipes (205) and adopts a side symmetry dendritic distributor.
4. The fluidized bed acrylonitrile reactor of claim 1 wherein, The primary cyclone separator (104) is arranged with a primary cyclone inlet (207), the secondary cyclone separator (105) is arranged with a secondary cyclone outlet (208), and the outlet of the primary cyclone separator (104) is connected with the inlet of the secondary cyclone separator (105).
5. The fluidized bed acrylonitrile reactor of claim 1 wherein, Wing valves (209) are adopted for the material legs of the primary cyclone separator (104) and the secondary cyclone separator (105).