Reaction device for preparing 6-aminocapronitrile through pressurization method and gas phase method
The reaction device for 6-aminocapronitrile was prepared by gas-phase method by pressurized method. The integrated design solved the problems of catalyst coking and water polymerization, achieved efficient material mixing and separation, extended the catalyst life, reduced costs, and supported the large-scale production of the device.
Patent Information
- Application Number
- CN202422588144.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-08-26
- Estimated Expiration
- 2034-10-25
AI Technical Summary
In the prior art, during the preparation of 6-aminocapronitrile, the polymer coke adheres to the catalyst surface, reducing the catalyst activity and service life, and generating water promotes caprolactam polymerization to increase costs, and the micro-positive pressure operation leads to difficulty in large-scale equipment.
The reaction device for preparing 6-aminocapronitrile by gas-phase method is adopted to prepare 6-aminocapronitrile, including gas ammonia preheater, temperature control reactor, crude product tower, low-temperature separation tower and circulation fan. It integrates evaporation gasification, deweighting, heating, reaction, heat recovery and other functions, optimizes the material mixing and separation process, reduces oligomer generation, and improves conversion and selectivity.
Effectively extend the life of the catalyst, reduce production costs, realize the large-scale equipment, improve the reaction conversion rate and selectivity, ensure production safety and stability, and reduce investment costs.
Smart Images
Figure CN223263810U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of reaction devices, in particular to a reaction device for preparing 6-aminocapronitrile by a pressurized gas phase method. Background Art
[0002] Nylon 66 is a high-grade thermoplastic resin and an excellent polymer material for manufacturing chemical fibers and engineering plastics. Hexamethylenediamine is the key raw material for producing nylon 66 salt, while 6-aminocapronitrile is the key intermediate raw material in the preparation of hexamethylenediamine.
[0003] The current mainstream process for the preparation of 6-aminocapronitrile is: high-temperature caprolactam vapor and hot ammonia are mixed in a certain proportion; the mixed gas reacts in the presence of a catalyst to produce 6-aminocapronitrile, and the pressure is controlled at a slightly positive pressure.
[0004] Liquid caprolactam evaporates at high temperatures and easily produces oligomers. The polymers will coke and adhere to the catalyst surface, reducing the catalyst activity and service life; water is generated during the reaction, and high temperature promotes the polymerization of caprolactam in water, increasing the product refining cost and the risk of product refining operation; the system operates at a slightly positive pressure, and the equipment and pipelines in the system are large in size, resulting in a small load on the single series device and not utilizing large-scale production of the device. Utility Model Content
[0005] The utility model aims to provide a reaction device for preparing 6-aminocapronitrile by a pressurized gas phase process, which solves the problems in the prior art that polymers coke and adhere to the catalyst surface, thereby reducing the activity and service life of the catalyst; water is generated during the reaction process, and caprolactam polymerization is promoted in the water at high temperature, which increases the product refining cost and the risk of product refining operation; and the device and pipeline in the system are relatively large in size due to micro-positive pressure operation, resulting in a small load on a single-series device and not utilizing large-scale production of the device.
[0006] To achieve the above-mentioned objectives, the present invention provides a reaction device for preparing 6-aminocapronitrile by a pressurized gas phase process, comprising a gas ammonia preheater, a temperature-controlled reactor, a circulating fan and a caprolactam preheater, wherein the caprolactam preheater is fixedly connected to one end of the temperature-controlled reactor, the two ends of the gas ammonia preheater are respectively fixedly connected to the two ends of the temperature-controlled reactor, and one end of the circulating fan is fixedly connected to the temperature-controlled reactor.
[0007] The reaction device for preparing 6-aminocapronitrile by the pressurized gas phase method further includes a crude product tower and a low-temperature separation tower. The other end of the circulating fan is fixedly connected to the low-temperature separation tower, one end of the low-temperature separation tower is fixedly connected to the crude product tower, and one end of the temperature-controlled reactor is fixedly connected to the crude product tower.
[0008] The crude product tower comprises a shell-and-tube water-cooled separation section and a distillation and stripping section, and one end of the water-cooled separation section is fixedly connected to one end of the distillation and stripping section.
[0009] The utility model discloses a reaction device for preparing 6-aminocapronitrile by a pressurized gas phase process. The temperature-controlled reactor integrates evaporation and gasification, weight removal, heating, reaction, and heat recovery, thereby effectively ensuring uniform mixing of reaction materials, removing heavy components, improving reaction conversion rate and selectivity, and extending catalyst life. The crude product tower integrates cooling separation and ammonia recovery, thereby effectively reducing the generation of oligomers and lowering energy consumption in product refining. The low-temperature separation tower integrates deep-cold separation, liquid ammonia gasification, and cold recovery, thereby effectively achieving the addition of fresh raw gas while improving separation efficiency, optimizing the operating conditions of a circulating fan, and extending the practical life of the circulating fan. The device has a simple and optimized process design, high equipment integration, and a large single-series load. It breaks through the existing mainstream process route, can more efficiently utilize raw materials, fundamentally blocks the generation path of low-molecular-weight polymers, improves reactor conversion rate and selectivity, ensures continuous, safe, and stable operation of the production device, reduces production costs and investment costs, and is conducive to large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.
[0011] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0012] 1-gas ammonia preheater, 2-temperature control reactor, 3-crude product tower, 4-low-temperature separation tower, 5-circulating fan, 6-caprolactam preheater, 7-shell-and-tube water-cooled separation section, 8-distillation and stripping section. DETAILED DESCRIPTION
[0013] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention.
[0014] See also Figure 1 , Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0015] The utility model provides a reaction device for preparing 6-aminocapronitrile by a pressurized gas phase process, comprising a gas ammonia preheater 1, a temperature-controlled reactor 2, a crude product tower 3, a low-temperature separation tower 4, a circulating fan 5 and a caprolactam preheater 6, wherein the caprolactam preheater 6 is fixedly connected to one end of the temperature-controlled reactor 2, two ends of the gas ammonia preheater 1 are respectively fixedly connected to two ends of the temperature-controlled reactor 2, one end of the circulating fan 5 is fixedly connected to the temperature-controlled reactor 2, the other end of the circulating fan 5 is fixedly connected to the low-temperature separation tower 4, one end of the low-temperature separation tower 4 is fixedly connected to the crude product tower 3, and one end of the temperature-controlled reactor 2 is fixedly connected to the crude product tower 3.
[0016] In this embodiment, the temperature-controlled reactor 2 is an equipment integrating evaporation and gasification, deweighting, heating, reaction and heat recovery, which can effectively ensure uniform mixing of reaction materials, remove heavy components, improve reaction conversion rate and selectivity, and extend catalyst life; the crude product tower 3 is an equipment integrating cooling separation and ammonia recovery, which can effectively reduce the production of oligomers and reduce product refining energy consumption; the low-temperature separation tower 4 is an equipment integrating deep cold separation, liquid ammonia gasification and cold recovery, which can effectively realize the addition of fresh raw gas while improving separation efficiency, optimizing the operating conditions of the circulating fan 5, and extending the practical life of the circulating fan 5; the device has a simple and optimized process design, high equipment integration, large single series load, breaks through the existing mainstream process route, can utilize raw materials more efficiently, fundamentally blocks the generation path of low molecular weight polymers, improves reactor conversion rate and selectivity, ensures continuous, safe and stable operation of the production device, reduces production cost and investment cost, and is conducive to large-scale industrial production. After the gas-ammonia preheater 1, the high-temperature process gas and liquid caprolactam enter the temperature-controlled reactor 2 respectively. After the materials are fully gasified and mixed, the temperature is raised again and they enter the reaction section to react. After the reaction, the process gas is heat exchanged again and sent out of the temperature-controlled reactor 2; the resulting material is then sent to the crude product tower 3, and after the first gas-liquid separation, a second cooling gas-liquid separation is performed again; the separated process gas is then sent to the low-temperature separation tower 4, and a third cooling gas-liquid separation is performed; the separated process gas is then pressurized by the circulating fan 5, sent to the temperature-controlled reactor 2 for preheating, and then enters the gas-ammonia preheater 1 again for temperature increase.
[0017] Furthermore, the crude product tower 3 includes a shell-and-tube water-cooled separation section 7 and a distillation and stripping section 8 , and one end of the water-cooled separation section is fixedly connected to one end of the distillation and stripping section 8 .
[0018] In this embodiment, the crude product tower 3 is a device that integrates cooling separation and ammonia recovery. The process gas after the reaction enters the bottom of the crude product tower 3. After gas-liquid separation, the process gas ascends and contacts the cooled circulating crude product liquid. While gas-liquid mass transfer occurs in the packing section, ammonia in the crude product liquid is captured into the process gas, and the process gas temperature is further reduced; the cooled process gas enters the shell-and-tube water-cooled separation section 7 from the top of the crude product tower 3, and after heat exchange with the circulating water, the gas and liquid are separated, and the liquid phase enters the packing section at the bottom of the crude product tower 3, and the process gas is sent out.
[0019] When using the reaction device of the utility model for preparing 6-aminocapronitrile by the pressurized gas phase method, the mass percentage concentration of liquid caprolactam is 90% to 99%, and the molar ratio of caprolactam to ammonia is 1:(10 to 100); further, in step 1, the temperature of the liquid caprolactam is 80 to 200°C, and the preheating temperature of the gaseous ammonia is 200 to 400°C; further, in step 2, when the reaction is carried out in the temperature-controlled reactor 2, the reaction pressure is 0.1 MPag to 2.0 MPag, and the reactor temperature is 200 to 400°C; further, in step 3, the temperature of the process gas after cooling in the crude product tower 3 is 30 to 70°C; further, in step 4, the temperature of the material process gas after cooling in the low-temperature separation tower 4 is -10 to 20°C; further, the process gas after pressurization by the circulating fan 5 is sent to step 1 to continue the reaction.
[0020] The above disclosure is merely one or more preferred embodiments of the present application and is not intended to limit the scope of the present application. A person skilled in the art will understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present application are still within the scope of the present application.
Claims
1. A reaction device for preparing 6-aminocapronitrile by a pressurized gas phase process, characterized in that: It includes ammonia gas preheater, temperature control reactor, circulating fan and caprolactam preheater; The caprolactam preheater is fixedly connected to one end of the temperature-controlled reactor, the two ends of the gas ammonia preheater are respectively fixedly connected to the two ends of the temperature-controlled reactor, and one end of the circulating fan is fixedly connected to the temperature-controlled reactor.
2. The reaction device for preparing 6-aminocapronitrile by a pressurized gas phase method according to claim 1, wherein The reaction device for preparing 6-aminocapronitrile by the pressurized gas phase method also includes a crude product tower and a low-temperature separation tower. The other end of the circulating fan is fixedly connected to the low-temperature separation tower, one end of the low-temperature separation tower is fixedly connected to the crude product tower, and one end of the temperature-controlled reactor is fixedly connected to the crude product tower.
3. The reaction unit for preparing 6-aminocapronitrile by a pressurized gas phase method as claimed in claim 2, wherein The crude product tower comprises a shell-and-tube water-cooling separation section and a distillation and stripping section, and one end of the water-cooling separation section is fixedly connected to one end of the distillation and stripping section.