Apparatus and method for preparing t-butylamine by direct amination of isobutylene

Abstract

The application discloses a device and method for preparing tert-butylamine by directly ammoniating isobutene, which comprises sequentially connected raw material preparation unit, reaction separation unit, rectification separation unit and circulating recovery unit; the raw material preparation unit is used for storing, mixing and heating raw materials; the reaction separation unit is used for pressurizing reaction of the raw materials in the raw material preparation unit and gas-liquid separation of products; the rectification separation unit is used for rectification separation of liquid-phase products separated by the reaction separation unit and recovery of part of unreacted raw materials; and the circulating recovery unit is used for rectification recovery of part of raw materials of gas-phase products separated by the reaction separation unit. The application has the characteristics of low overall equipment investment, high energy utilization rate, simple product separation and purification, perfect overall device design and small environmental pollution.

Description

Technical Field

[0001] This invention belongs to the field of tert-butylamine preparation technology, specifically relating to an apparatus and method for preparing tert-butylamine by direct amination of isobutylene. Background Technology

[0002] tert-Butylamine, as an important organic chemical intermediate, has wide applications in pharmaceuticals, pesticides, rubber additives, and other fields. Among the methods for preparing tert-butylamine, the direct ammoniation of isobutylene has become the mainstream method for the industrial production of tert-butylamine due to the abundant source of isobutylene (often as a petrochemical byproduct) and its high atom economy (no water is generated as a byproduct).

[0003] Patent CN114736125A discloses "a method for the direct amination of isobutylene to prepare tert-butylamine at a relatively low temperature." This method also has its limitations. Firstly, while emphasizing the preparation of a highly efficient catalyst, it does not detail the specific composition of the catalyst or the quantitative relationship between key parameters and catalyst performance during preparation. This makes it difficult to flexibly adjust the catalyst preparation process to achieve optimal results under different production conditions in practical applications. Secondly, the long-term stable operation of the gas recovery device is uncertain. As operating time increases, problems such as corrosion and blockage may occur inside the device, affecting recovery efficiency and the continuity of the entire production system, while also increasing equipment maintenance costs and the risk of downtime.

[0004] Patent CN116082162A discloses a "production process for the direct catalytic amination of isobutylene to synthesize tert-butylamine." However, its drawbacks are also quite significant. In the catalyst preparation stage, a series of complex operations are required, including mixing ZSM-5 zeolite with an aqueous solution of a soluble metal salt and precisely adjusting the pH to 3-6, followed by reflux adsorption, washing, drying, and then uniformly mixing with a binder and nitric acid aqueous solution for crystallization. This places stringent demands on the professional skills of the operators and the stability of the production environment. During industrial scale-up, operational errors or environmental fluctuations can easily lead to catalyst performance deviations. Furthermore, the liquid-phase reaction system places high demands on the materials used in the reaction equipment, requiring excellent corrosion resistance, which undoubtedly increases equipment purchase costs. Simultaneously, the transportation, mixing, and product separation of liquid-phase materials are more complex than in gas-phase reactions, potentially resulting in higher energy consumption.

[0005] In summary, existing technologies still have certain shortcomings: First, the utilization and recovery of raw materials in the reaction process are not adequately considered, and there is uncertainty regarding the long-term stable operation of the gas recovery device. Furthermore, the recycling and recovery methods for unreacted isobutylene and ammonia are insufficiently considered. Second, production costs are high, and equipment maintenance is difficult. The liquid-phase reaction system places high demands on the materials used in the reaction equipment, increasing investment and maintenance costs. In addition, inadequate consideration of product separation increases energy consumption. Third, there is insufficient research on the overall continuous production process, and the methods for product distillation and purification are not comprehensively considered. Summary of the Invention

[0006] In order to overcome the defects of the existing technology, the purpose of this invention is to provide an apparatus and method for producing tert-butylamine by direct ammoniation of isobutylene. The apparatus and method have the characteristics of low overall equipment investment, high energy utilization rate, simple product separation and purification, well-designed overall apparatus and low environmental pollution.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An apparatus for producing tert-butylamine by direct ammoniation of isobutylene includes a raw material preparation unit 1, a reaction separation unit 2, a distillation separation unit 3, and a recycling unit 4 connected in sequence. The raw material preparation unit 1 is used for the storage, mixing and heating of raw materials; The reaction separation unit 2 is used to pressurize and react the raw materials in the raw material preparation unit 1 and to separate the product gas and liquid. The distillation separation unit 3 distills and separates the liquid phase product separated by the reaction separation unit 2, and recovers some of the unreacted raw materials; The recycling unit 4 recovers a portion of the raw materials from the gaseous products separated by the reaction separation unit 2 through distillation.

[0008] The raw material preparation unit 1 includes a low-pressure nitrogen storage tank 1-1, a nitrogen compressor 1-2, a high-pressure nitrogen storage tank 1-3, a nitrogen preheater 1-4, an isobutylene storage tank 1-5, an isobutylene pump 1-6, a liquid ammonia storage tank 1-7, a liquid ammonia pump 1-8, a raw material mixer 1-9, a raw material preheater 1-10, and a raw material superheater 1-11; The low-pressure nitrogen storage tank 1-1, nitrogen compressor 1-2, high-pressure nitrogen storage tank 1-3, nitrogen preheater 1-4, raw material mixer 1-9, raw material preheater 1-10, and raw material superheater 1-11 are connected in sequence by pipelines, and the inlet of the low-pressure nitrogen storage tank 1-1 is connected to the common nitrogen pipeline. The isobutylene storage tank 1-5 has a raw material isobutylene pipeline at its inlet and its outlet is connected to the inlet of the isobutylene pump 1-6. The liquid ammonia storage tank 1-7 has a raw material liquid ammonia pipeline at its inlet and its outlet is connected to the inlet of the liquid ammonia pump 1-8. The outlets of the nitrogen preheater 1-4, isobutylene pump 1-6, and liquid ammonia pump 1-8 are respectively connected to the pipelines of the raw material mixer 1-9. The cold material in the raw material preheater 1-10 is the raw material isobutylene and ammonia that have been fully mixed in the raw material mixer 1-9, and the hot material is the raw material from the reaction separation unit. The reaction products, cold and hot materials, exiting reactor 2-1 in unit 2 flow through the tube side and shell side of the raw material preheater 1-10, respectively, meaning the product (hot material) preheats the raw material (cold material). The raw material superheater 1-11 then performs a secondary superheating on the preheated raw material from the raw material preheater 1-10, ensuring the heated raw material temperature is higher than or equal to the operating temperature of reactor 2-1 in reaction separation unit 2. The heat source for the raw material superheater 1-11 is steam or electric heating. The reaction separation unit 2 includes a reactor 2-1, a product cooler 2-2, a high-pressure gas-liquid separator 2-3, a high-pressure gas phase valve 2-4, a high-pressure liquid phase valve 2-5, a low-pressure gas-liquid separator 2-6, a low-pressure gas phase valve 2-7, and a low-pressure liquid phase valve 2-8. The reactor 2-1 is a conventional high-pressure resistant fixed-bed reactor, which is filled with a number of molecular sieve catalysts (common catalysts for the direct ammoniation of isobutylene to produce tert-butylamine). The raw material inlet of reactor 2-1 is connected to the outlet pipe of the raw material superheater 1-11 in the raw material preparation unit 1, and the product outlet is sequentially connected to the raw material preheater 1-10, product cooler 2-2, and high-pressure gas-liquid separator 2-3 in the raw material preparation unit 1. The gas phase outlet of the high-pressure gas-liquid separator 2-3 is connected to the upper part of the low-pressure gas-liquid separator 2-6 via the high-pressure gas phase valve 2-4, and the liquid phase outlet is connected to the lower part of the low-pressure gas-liquid separator 2-6 via the high-pressure liquid phase valve 2-5. High-pressure nitrogen is introduced into the top of the high-pressure gas-liquid separator 2-3 and connected to the outlet nitrogen pipe of the high-pressure nitrogen storage tank 1-3. The gas phase outlet of the low-pressure gas-liquid separator 2-6 is connected to the middle part of the tail gas absorption tower 4-1 in the circulation recovery unit 4 via the low-pressure gas phase valve 2-7 and serves as the raw material for the tail gas absorption tower 4-1, and the liquid phase outlet is connected to the raw material inlet of the deammoniation tower 3-1 in the distillation separation unit 3 via the low-pressure liquid phase valve 2-8.

[0009] The distillation separation unit 3 includes a deammoniation tower 3-1, a deammoniation tower reboiler 3-2, a deammoniation tower condenser 3-3, a deammoniation tower reflux regulating valve 3-4, a deammoniation tower reflux tank 3-5, a deammoniation tower condensate pump 3-6, an isobutylene tower 3-7, an isobutylene tower reboiler 3-8, an isobutylene tower condenser 3-9, an isobutylene tower reflux regulating valve 3-10, an isobutylene tower reflux tank 3-11, an isobutylene tower condensate pump 3-12, a tert-butylamine tower 3-13, a tert-butylamine tower reboiler 3-14, a tert-butylamine tower condenser 3-15, a tert-butylamine tower reflux regulating valve 3-16, a tert-butylamine tower reflux tank 3-17, a tert-butylamine tower condensate pump 3-18, a tert-butylamine cooler 3-19, a tert-butylamine storage tank 3-20, a heavy component cooler 3-21, a heavy component pump 3-22, and a heavy component storage tank 3-23. A reboiler 3-2 is installed at the bottom of the ammonia removal tower 3-1. The reboiler 3-2 is used to heat the liquid feedstock in the ammonia removal tower 3-1. The gas phase outlet at the top of the ammonia removal tower 3-1 is sequentially connected to the ammonia removal tower condenser 3-3, the ammonia removal tower reflux regulating valve 3-4, and the ammonia removal tower reflux tank 3-5. The ammonia removal tower reflux regulating valve 3-4 refluxes part of the liquid ammonia condensed by the ammonia removal tower condenser 3-3 back to the top of the ammonia removal tower 3-1. The liquid phase outlet of the ammonia removal tower reflux tank 3-5 is connected to the inlet of the ammonia removal tower condensate pump 3-6, and the gas phase outlet is connected to the flare system. The outlet of the ammonia removal tower condensate pump 3-6 is connected in parallel to the feedstock inlet pipe of the isobutylene storage tank 1-5 in the feedstock preparation unit 1. The feed inlet of the isobutylene tower 3-7 is connected to the reboiler 3-2 of the deammoniation tower. A reboiler 3-8 is installed at the bottom of the isobutylene tower, used to heat the liquid feed in the tower. The top gaseous outlet of the isobutylene tower 3-7 is sequentially connected to the isobutylene tower condenser 3-9, the isobutylene tower reflux regulating valve 3-10, and the isobutylene tower reflux tank 3-11. The isobutylene tower reflux regulating valve 3-10 refluxes a portion of the liquid isobutylene condensed by the isobutylene tower condenser 3-9 back to the top of the isobutylene tower 3-7. The liquid outlet of the isobutylene tower reflux tank 3-11 is connected to the inlet of the isobutylene tower condensate pump 3-12, and the gaseous outlet is connected to the flare system. The outlet of the isobutylene tower condensate pump 3-12 is connected in parallel to the liquid ammonia pipeline at the inlet of the liquid ammonia storage tank 1-7 in the feed preparation unit 1. The raw material inlet of the tert-butylamine tower 3-13 is connected to the reboiler 3-8 of the isobutylene tower. A reboiler 3-14 of the tert-butylamine tower is installed at the bottom. The reboiler 3-14 of the tert-butylamine tower is used to heat the liquid raw material in the tower. The gas phase outlet of the top of the tert-butylamine tower 3-13 is connected in sequence to the condenser 3-15 of the tert-butylamine tower, the reflux regulating valve 3-16 of the tert-butylamine tower, and the reflux tank 3-17 of the tert-butylamine tower. The reflux regulating valve 3-16 of the tert-butylamine tower refluxes a portion of the liquid tert-butylamine condensed by the tert-butylamine tower condenser 3-15 back to the top of the tert-butylamine tower 3-13; the liquid phase outlet of the tert-butylamine tower reflux tank 3-17 is connected to the inlet of the tert-butylamine tower condensate pump 3-18, and the gas phase outlet is connected to the flare system; the outlet of the tert-butylamine tower condensate pump 3-18 is connected to the tert-butylamine storage tank 3-20 via the tert-butylamine cooler 3-19; the inlet of the heavy component cooler 3-21 is connected to the tert-butylamine tower reboiler 3-14, and the outlet is sequentially connected to the heavy component pump 3-22 and the heavy component storage tank 3-23, with one branch of the outlet of the heavy component pump 3-22 connected in parallel to the raw material inlet pipeline of the tert-butylamine tower 3-13.

[0010] The recycling unit 4 includes a tail gas absorption tower 4-1, an ammonia regeneration tower feed pump 4-2, an ammonia regeneration tower 4-3, an ammonia regeneration tower reboiler 4-4, a wastewater cooler 4-5, an ammonia regeneration tower condenser 4-6, an ammonia regeneration tower reflux regulating valve 4-7, an ammonia regeneration tower reflux tank 4-8, and an ammonia regeneration tower condensate pump 4-9. The tail gas absorption tower 4-1 is equipped with a safety valve at the top, which is connected to the flare gas system. The upper part of the tail gas absorption tower 4-1 is filled with common packing material, similar to that used in water washing towers. A demineralized water spraying device is installed above the packing material. The spraying device is connected to a demineralized water pipeline flange installed outside the tail gas absorption tower 4-1. The demineralized water is used to absorb ammonia gas entering the tail gas absorption tower 4-1. The demineralized water enters the tail gas absorption tower 4-1, is sprayed, and falls through the packing material to the bottom of the tail gas absorption tower 4-1. The inlet of the ammonia regeneration tower feed pump 4-2 is connected to the bottom outlet of the tail gas absorption tower 4-1, and the outlet is connected to the ammonia regeneration tower 4-3. A reboiler is installed at the bottom of the ammonia regeneration tower 4-3 to heat the liquid raw material inside the tower. The gas phase outlet at the top of the tower is sequentially connected to the ammonia regeneration tower condenser 4-6, the ammonia regeneration tower reflux regulating valve 4-7, and the ammonia regeneration tower reflux tank 4-8. The ammonia regeneration tower reflux regulating valve 4-7 refluxes a portion of the liquid ammonia condensed by the ammonia regeneration tower condenser 4-6 back to the top of the ammonia regeneration tower 4-3. The liquid phase outlet of the ammonia regeneration tower reflux tank 4-8 ​​is connected to the inlet of the ammonia regeneration tower condensate pump 4-9, and the gas phase outlet is connected to the flare system. The outlet of the ammonia regeneration tower condensate pump 4-9 is connected in parallel to the raw material liquid ammonia pipeline at the inlet of the liquid ammonia storage tank 1-7 in the raw material preparation unit 1. The inlet of the wastewater cooler 4-5 is connected to the ammonia regeneration tower reboiler 4-4, and one outlet is connected in parallel to the demineralized water pipeline at the top of the ammonia regeneration tower 4-3, and the other outlet is connected to the external wastewater treatment system.

[0011] A method for producing tert-butylamine by direct amination of isobutylene includes the following steps: Step 1. System inertization: Nitrogen gas at ambient temperature (0.1–0.7 MPa) from the public nitrogen pipeline enters and fills the low-pressure nitrogen storage tank 1-1. The nitrogen then passes through the nitrogen compressor 1-2 and the high-pressure nitrogen storage tank 1-3, with one path leading to the nitrogen preheater 1-4 and the other to the high-pressure gas-liquid separator 2-3. Following the process flow, it enters subsequent pipelines and equipment. The unit begins nitrogen inertization replacement. The system pressure is controlled by pressure regulating valves at the top of the ammonia removal tower reflux tank 3-5, isobutylene tower reflux tank 3-11, tert-butylamine tower reflux tank 3-17, and ammonia regeneration tower reflux tank 4-8, extending to the flare system, maintaining the unit pressure at 0.3–0.5 MPa. When the oxygen content in the gas before the ammonia regeneration tower condensate pump 4-9 is below 0.5%, the unit is considered inertized. All vent valves are then closed to maintain the inertized environment. Step 2. Reaction and Separation: Nitrogen preheater 1-4, raw material preheater 1-10, and raw material superheater 1-11 are put into operation, with heating temperatures set to 30-40℃, 130-140℃, and 260-280℃, respectively. Nitrogen compressor 1-2 is started, and compressed nitrogen enters high-pressure nitrogen storage tank 1-3. The load of nitrogen compressor 1-2 is gradually increased to bring its outlet pressure to 24-26MPa, and high-pressure nitrogen storage tank 1-3 is filled. High-pressure nitrogen exits from high-pressure nitrogen storage tank 1-3, passes through nitrogen preheater 1-4, enters raw material mixer 1-9, and then enters subsequent pipelines and equipment according to the process flow. The raw materials, isobutylene and liquid ammonia, are stored in isobutylene storage tank 1-5 and liquid ammonia storage tank 1-7, respectively. Isobutylene pump 1-6 and liquid ammonia pump 1-8 are started to bring the outlet pressure of both pumps to 24–26 MPa. Isobutylene and liquid ammonia at similar pressures simultaneously enter the raw material mixer 1-9, and then flow into reactor 2-1 at a pressure of 24–26 MPa and a temperature of 260–280 °C. The reaction product passes through the raw material preheater 1-10 and the product cooler 2-2, where the temperature is reduced to 40–60 °C and the pressure to 23–25 MPa, before entering the high-pressure gas-liquid separator. 2-3, where the gas and liquid phases are depressurized by high-pressure gas phase valve 2-4 and high-pressure liquid phase valve 2-5 respectively, and then enter the low-pressure gas-liquid separator 2-6, with a pressure of 13-15 MPa and a temperature of 50-70℃; then the gas phase enters the tail gas absorption tower 4-1 after the pressure is reduced to 1.3-1.5 MPa and the temperature to 30-50℃ by low-pressure gas phase valve 2-7, and the liquid phase enters the ammonia removal tower 3-1 through low-pressure liquid phase valve 2-8, with a pressure of 1.3-1.5 MPa and a temperature of 40-60℃; Step 3. Distillation and Separation: The product from the low-pressure liquid phase valve 2-8 enters the ammonia stripping tower 3-1. The temperature of the ammonia stripping tower 3-1 is 90-110℃ and the pressure is 1.3-1.5MPa. The reboiler 3-2 of the ammonia stripping tower is electrically heated or steam heated and provides a heat source for the ammonia stripping tower 3-1. Ammonia gas exits from the top of the ammonia stripping tower 3-1, is condensed into liquid by the ammonia stripping tower condenser 3-3, and then partially returns to the ammonia stripping tower 3-1 as reflux liquid to control the top temperature of the tower through the ammonia stripping tower reflux regulating valve 3-4. Part of it enters the ammonia stripping tower reflux tank 3-5, and is then sent to the liquid ammonia storage tank 1-7 by the ammonia stripping tower condensate pump 3-6. Part of the non-condensable gas exits from the top of the ammonia stripping tower reflux tank 3-5 through its back pressure valve to the flare system. The temperature of the ammonia stripping tower reflux tank 3-5 is 30-50℃ and the pressure is 1.3-1.5MPa. The liquid phase from the reboiler 3-2 of the deammoniation tower enters the isobutylene tower 3-7. The temperature of the isobutylene tower 3-7 is 95-115℃ and the pressure is 0.3-0.5MPa. The reboiler 3-8 of the isobutylene tower is electrically heated or steam heated and provides a heat source for the isobutylene tower 3-7. Isobutylene exits from the top of the isobutylene tower 3-7, is condensed into liquid by the isobutylene tower condenser 3-9, and then partially returns to the isobutylene tower 3-7 as reflux liquid to control the top temperature of the tower via the reflux regulating valve 3-10. Part of it enters the isobutylene tower reflux tank 3-11, and is then sent to the isobutylene storage tank 1-5 by the isobutylene tower condensate pump 3-12. Part of the non-condensable gas exits from the top of the isobutylene tower reflux tank 3-11 through its back pressure valve to the flare system. The temperature of the isobutylene tower reflux tank 3-11 is 25-45℃ and the pressure is 0.3-0.5MPa. The liquid phase from the isobutylene reboiler 3-8 enters the tert-butylamine tower 3-13. The temperature in the tert-butylamine tower 3-13 is 96–116℃, and the pressure is 0.1–0.3 MPa. The tert-butylamine tower reboiler 3-14 is electrically or steam heated, providing a heat source for the tert-butylamine tower 3-13. The tert-butylamine exits from the top of the tert-butylamine tower 3-13, is condensed into liquid by the tert-butylamine tower condenser 3-15, and then partially returns to the tert-butylamine tower 3-13 via the tert-butylamine tower reflux regulating valve 3-16. -13 is used as reflux liquid to control the top temperature of the column. Part of it enters the reflux tank 3-17 of the tert-butylamine column, and then is sent to the tert-butylamine storage tank 3-20 via the tert-butylamine column condensate pump 3-18 and the tert-butylamine cooler 3-19. Part of the non-condensable gas flows from the top of the tert-butylamine column reflux tank 3-17 through its back pressure valve to the flare system. The temperature of the tert-butylamine column reflux tank 3-17 is 33-56℃ and the pressure is 0.1-0.3MPa. The temperature of the tert-butylamine cooler 3-19 is 30-48℃. The heavy components at the bottom of the tert-butylamine column 3-13 are sent to the inlet feed pipeline of the tert-butylamine column 3-13 for re-distillation or directly to the heavy component storage tank 3-23 via the tert-butylamine column reboiler 3-14, the heavy component cooler 3-21, and the heavy component pump 3-22. The temperature of the heavy component cooler 3-21 is 38-50℃ and the pressure is 0.1-0.3MPa. Step 4. Ammonia regeneration: The gaseous product from the low-pressure gas phase valve 2-7 enters the tail gas absorption tower 4-1, mixes with and dissolves in the demineralized water from the top of the tower, and is then sent to the ammonia regeneration tower 4-3 via the ammonia regeneration tower feed pump 4-2. The tail gas absorption tower 4-1 has a temperature of 45-65℃ and a pressure of 0.1-0.5MPa, while the ammonia regeneration tower 4-3 has a temperature of 196-216℃ and a pressure of 1.3-1.5MPa. The ammonia regeneration tower reboiler 4-4 is electrically or steam-heated and provides a heat source for the ammonia regeneration tower 4-3. Ammonia exits from the top of the ammonia regeneration tower 4-3, is condensed into liquid by the ammonia regeneration tower condenser 4-6, and then passes through the ammonia regeneration tower reflux regulating valve. Part of the gas from 4-7 is returned to the ammonia regeneration tower 4-3 as reflux liquid to control the tower top temperature. Part of it enters the ammonia regeneration tower reflux tank 4-8, and is then sent to the liquid ammonia storage tank 1-7 via the ammonia regeneration tower condensate pump 4-9. Part of the non-condensable gas flows from the top of the ammonia regeneration tower reflux tank 4-8 ​​through its back pressure valve to the flare system. The temperature of the ammonia regeneration tower reflux tank 4-8 ​​is 38-58℃ and the pressure is 1.3-1.5MPa. The wastewater from the bottom of the ammonia regeneration tower 4-3 enters the wastewater cooler 4-5 via the ammonia regeneration tower reboiler 4-4, where it is cooled to no higher than 40℃, and then sent to the demineralized water inlet pipe at the top of the ammonia regeneration tower 4-3 or to an external wastewater treatment system.

[0012] The beneficial effects of this invention are: 1. The core high-pressure equipment of this invention consists only of a reactor, a product cooler, a high-pressure gas-liquid separator, and a low-pressure gas-liquid separator. The remaining equipment are all of common pressure levels in industrial production, so the overall equipment investment is low.

[0013] 2. This invention utilizes four core pieces of equipment: a deammoniation tower, an isobutylene tower, a tail gas absorption tower, and an ammonia regeneration tower. This enables multiple high-efficiency recovery of raw materials. Specifically, the deammoniation tower and the isobutylene tower separate and recover the unreacted raw materials, ammonia and isobutylene, from the product. The tail gas absorption tower and the ammonia regeneration tower recover the ammonia gas discharged from the low-pressure gas-liquid separator. Therefore, the recovery and utilization of raw materials, ammonia and isobutylene, are achieved, thereby improving energy efficiency. At the same time, the environmental pollution problem caused by the emission of unreacted raw material gas is also solved.

[0014] 3. This invention utilizes the synergistic distillation effect of the deammoniation tower, isobutylene tower, and tert-butylamine tower, and based on the distillation purification principle of the difference in volatility of each component in the mixture, it not only efficiently and accurately separates the raw materials and products and improves the purity of the target product, but also optimizes the separation and purification process, and realizes the practicality and operability of the separation and purification process.

[0015] 4. The reactor process conditions of this invention are high pressure (24-26 MPa) and low temperature (260-208°C). Within this temperature range, excessive pyrolysis and polymerization reactions of reactants and raw materials can be significantly suppressed from both thermodynamic and kinetic perspectives, almost avoiding carbonization and carbon buildup caused by high temperatures. Therefore, the active sites of the catalyst packed in the reactor remain exposed and maintain their original catalytic performance, effectively preventing deactivation caused by carbon covering the active sites or clogging the pores, extending the catalyst's lifespan, and reducing the cost of replacing the catalyst. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] The components include: 1-Raw material preparation unit; 2-Reaction separation unit; 3-Distillation separation unit; 4-Circulation and recovery unit; 1-1 Low-pressure nitrogen storage tank; 1-2 Nitrogen compressor; 1-3 High-pressure nitrogen storage tank; 1-4 Nitrogen preheater; 1-5 Isobutylene storage tank; 1-6 Isobutylene pump; 1-7 Liquid ammonia storage tank; 1-8 Liquid ammonia pump; 1-9 Raw material mixer; 1-10 Raw material preheater; 1-11 Raw material superheater; 2-1 Reactor; 2-2 Product cooler; 2-3 High-pressure gas-liquid separator; 2-4 High-pressure gas phase valve; 2-5 High-pressure liquid phase valve; 2-6 Low-pressure gas-liquid separator; 2-7 Low-pressure gas phase valve; 2-8 Low-pressure liquid phase valve; 3-1 Ammonia removal tower; 3-2 Ammonia removal tower reboiler; 3-3 Ammonia removal tower condenser; 3-4 Ammonia removal tower reflux regulating valve; 3-5 Ammonia removal tower reflux tank; 3-6 Ammonia removal tower condensate pump; 3-7 Isobutylene tower; 3-8 3-9 Isobutylene tower reboiler; 3-10 Isobutylene tower condenser; 3-11 Isobutylene tower reflux regulating valve; 3-12 Isobutylene tower reflux tank; 3-13 Isobutylene tower condensate pump; 3-14 tert-butylamine tower reboiler; 3-15 tert-butylamine tower condenser; 3-16 tert-butylamine tower reflux regulating valve; 3-17 tert-butylamine tower reflux tank; 3-18 tert-butylamine tower condensate pump; 3-19 tert-butylamine cooler; 3-20 Tert-Butylamine storage tank; 3-21 Heavy component cooler; 3-22 Heavy component pump; 3-23 Heavy component storage tank; 4-1 Tail gas absorption tower; 4-2 Ammonia regeneration tower feed pump; 4-3 Ammonia regeneration tower; 4-4 Ammonia regeneration tower reboiler; 4-5 Wastewater cooler; 4-6 Ammonia regeneration tower condenser; 4-7 Ammonia regeneration tower reflux regulating valve; 4-8 Ammonia regeneration tower reflux tank; 4-9 Ammonia regeneration tower condensate pump. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] like Figure 1As shown, an apparatus for producing tert-butylamine by direct ammoniation of isobutylene includes a raw material preparation unit 1, a reaction separation unit 2, a distillation separation unit 3, and a recycling unit 4 connected in sequence. The raw material preparation unit 1 is used for the storage, mixing and heating of raw materials; the reaction separation unit 2 is used for pressurizing and reacting the raw materials in the raw material preparation unit 1 and separating the product gas and liquid; the distillation separation unit 3 distills and separates the liquid phase product separated by the reaction separation unit 2 and recovers some unreacted raw materials; the recycling unit 4 distills and recovers some of the raw materials from the gas phase product separated by the reaction separation unit 2.

[0020] The raw material preparation unit 1 includes a low-pressure nitrogen storage tank 1-1, a nitrogen compressor 1-2, a high-pressure nitrogen storage tank 1-3, a nitrogen preheater 1-4, an isobutylene storage tank 1-5, an isobutylene pump 1-6, a liquid ammonia storage tank 1-7, a liquid ammonia pump 1-8, a raw material mixer 1-9, a raw material preheater 1-10, and a raw material superheater 1-11; The low-pressure nitrogen storage tank 1-1, nitrogen compressor 1-2, high-pressure nitrogen storage tank 1-3, nitrogen preheater 1-4, raw material mixer 1-9, raw material preheater 1-10, and raw material superheater 1-11 are connected in sequence by pipelines, and the inlet of the low-pressure nitrogen storage tank 1-1 is connected to the common nitrogen pipeline. The isobutylene storage tank 1-5 has a raw material isobutylene pipeline at its inlet and its outlet is connected to the inlet of the isobutylene pump 1-6. The liquid ammonia storage tank 1-7 has a raw material liquid ammonia pipeline at its inlet and its outlet is connected to the inlet of the liquid ammonia pump 1-8. The outlets of the nitrogen preheater 1-4, isobutylene pump 1-6, and liquid ammonia pump 1-8 are respectively connected to the pipelines of the raw material mixer 1-9. The cold material in the raw material preheater 1-10 is the raw material isobutylene and ammonia that have been fully mixed in the raw material mixer 1-9, and the hot material is the raw material from the reaction separation unit. In reactor 2-1 of unit 2, the reaction products, cold and hot materials, flow through the tube side and shell side of the raw material preheater 1-10, respectively, thus preheating the raw material (cold material) using the product (hot material). The raw material superheater 1-11 further superheats the preheated raw material, ensuring its temperature is higher than or equal to the operating temperature of reactor 2-1 in reaction separation unit 2. The heat source for the raw material superheater 1-11 is steam or electric heating. Reaction separation unit 2 includes reactor 2-1, product cooler 2-2, high-pressure gas-liquid separator 2-3, high-pressure gas phase valve 2-4, high-pressure liquid phase valve 2-5, low-pressure gas-liquid separator 2-6, low-pressure gas phase valve 2-7, and low-pressure liquid phase valve 2-8. The reactor 2-1 is a conventional high-pressure resistant fixed-bed reactor, which is filled with a number of molecular sieve catalysts (common catalysts for the direct ammoniation of isobutylene to produce tert-butylamine). The raw material inlet of reactor 2-1 is connected to the outlet pipe of the raw material superheater 1-11 in the raw material preparation unit 1, and the product outlet is sequentially connected to the raw material preheater 1-10, product cooler 2-2, and high-pressure gas-liquid separator 2-3 in the raw material preparation unit 1. The gas phase outlet of the high-pressure gas-liquid separator 2-3 is connected to the upper part of the low-pressure gas-liquid separator 2-6 via the high-pressure gas phase valve 2-4, and the liquid phase outlet is connected to the lower part of the low-pressure gas-liquid separator 2-6 via the high-pressure liquid phase valve 2-5. High-pressure nitrogen is introduced into the top of the high-pressure gas-liquid separator 2-3 and connected to the outlet nitrogen pipe of the high-pressure nitrogen storage tank 1-3. The gas phase outlet of the low-pressure gas-liquid separator 2-6 is connected to the middle part of the tail gas absorption tower 4-1 in the circulation recovery unit 4 via the low-pressure gas phase valve 2-7 and serves as the raw material for the tail gas absorption tower 4-1, and the liquid phase outlet is connected to the raw material inlet of the deammoniation tower 3-1 in the distillation separation unit 3 via the low-pressure liquid phase valve 2-8.

[0021] The distillation separation unit 3 includes a deammoniation tower 3-1, a deammoniation tower reboiler 3-2, a deammoniation tower condenser 3-3, a deammoniation tower reflux regulating valve 3-4, a deammoniation tower reflux tank 3-5, a deammoniation tower condensate pump 3-6, an isobutylene tower 3-7, an isobutylene tower reboiler 3-8, an isobutylene tower condenser 3-9, an isobutylene tower reflux regulating valve 3-10, an isobutylene tower reflux tank 3-11, an isobutylene tower condensate pump 3-12, a tert-butylamine tower 3-13, a tert-butylamine tower reboiler 3-14, a tert-butylamine tower condenser 3-15, a tert-butylamine tower reflux regulating valve 3-16, a tert-butylamine tower reflux tank 3-17, a tert-butylamine tower condensate pump 3-18, a tert-butylamine cooler 3-19, a tert-butylamine storage tank 3-20, a heavy component cooler 3-21, a heavy component pump 3-22, and a heavy component storage tank 3-23. A reboiler 3-2 is installed at the bottom of the ammonia removal tower 3-1. The reboiler 3-2 is used to heat the liquid feedstock in the ammonia removal tower 3-1. The gas phase outlet at the top of the ammonia removal tower 3-1 is sequentially connected to the ammonia removal tower condenser 3-3, the ammonia removal tower reflux regulating valve 3-4, and the ammonia removal tower reflux tank 3-5. The ammonia removal tower reflux regulating valve 3-4 refluxes part of the liquid ammonia condensed by the ammonia removal tower condenser 3-3 back to the top of the ammonia removal tower 3-1. The liquid phase outlet of the ammonia removal tower reflux tank 3-5 is connected to the inlet of the ammonia removal tower condensate pump 3-6, and the gas phase outlet is connected to the flare system. The outlet of the ammonia removal tower condensate pump 3-6 is connected in parallel to the feedstock inlet pipe of the isobutylene storage tank 1-5 in the feedstock preparation unit 1. The feed inlet of the isobutylene tower 3-7 is connected to the reboiler 3-2 of the deammoniation tower. A reboiler 3-8 is installed at the bottom of the isobutylene tower, used to heat the liquid feed in the tower. The top gaseous outlet of the isobutylene tower 3-7 is sequentially connected to the isobutylene tower condenser 3-9, the isobutylene tower reflux regulating valve 3-10, and the isobutylene tower reflux tank 3-11. The isobutylene tower reflux regulating valve 3-10 refluxes a portion of the liquid isobutylene condensed by the isobutylene tower condenser 3-9 back to the top of the isobutylene tower 3-7. The liquid outlet of the isobutylene tower reflux tank 3-11 is connected to the inlet of the isobutylene tower condensate pump 3-12, and the gaseous outlet is connected to the flare system. The outlet of the isobutylene tower condensate pump 3-12 is connected in parallel to the liquid ammonia pipeline at the inlet of the liquid ammonia storage tank 1-7 in the feed preparation unit 1. The raw material inlet of the tert-butylamine tower 3-13 is connected to the reboiler 3-8 of the isobutylene tower. A reboiler 3-14 of the tert-butylamine tower is installed at the bottom. The reboiler 3-14 of the tert-butylamine tower is used to heat the liquid raw material in the tower. The gas phase outlet of the top of the tert-butylamine tower 3-13 is connected in sequence to the condenser 3-15 of the tert-butylamine tower, the reflux regulating valve 3-16 of the tert-butylamine tower, and the reflux tank 3-17 of the tert-butylamine tower. The reflux regulating valve 3-16 of the tert-butylamine tower refluxes a portion of the liquid tert-butylamine condensed by the tert-butylamine tower condenser 3-15 back to the top of the tert-butylamine tower 3-13; the liquid phase outlet of the tert-butylamine tower reflux tank 3-17 is connected to the inlet of the tert-butylamine tower condensate pump 3-18, and the gas phase outlet is connected to the flare system; the outlet of the tert-butylamine tower condensate pump 3-18 is connected to the tert-butylamine storage tank 3-20 via the tert-butylamine cooler 3-19; the inlet of the heavy component cooler 3-21 is connected to the tert-butylamine tower reboiler 3-14, and the outlet is sequentially connected to the heavy component pump 3-22 and the heavy component storage tank 3-23, with one branch of the outlet of the heavy component pump 3-22 connected in parallel to the raw material inlet pipeline of the tert-butylamine tower 3-13.

[0022] The recycling unit 4 includes a tail gas absorption tower 4-1, an ammonia regeneration tower feed pump 4-2, an ammonia regeneration tower 4-3, an ammonia regeneration tower reboiler 4-4, a wastewater cooler 4-5, an ammonia regeneration tower condenser 4-6, an ammonia regeneration tower reflux regulating valve 4-7, an ammonia regeneration tower reflux tank 4-8, and an ammonia regeneration tower condensate pump 4-9. The tail gas absorption tower 4-1 is equipped with a safety valve at the top, which is connected to the flare gas system. The upper part of the tail gas absorption tower 4-1 is filled with common packing material, similar to that used in water washing towers. A demineralized water spraying device is installed above the packing material. The spraying device is connected to a demineralized water pipeline flange installed outside the tail gas absorption tower 4-1. The demineralized water is used to absorb ammonia gas entering the tail gas absorption tower 4-1. The demineralized water enters the tail gas absorption tower 4-1, is sprayed, and falls through the packing material to the bottom of the tail gas absorption tower 4-1. The inlet of the ammonia regeneration tower feed pump 4-2 is connected to the bottom outlet of the tail gas absorption tower 4-1, and the outlet is connected to the ammonia regeneration tower 4-3. A reboiler is installed at the bottom of the ammonia regeneration tower 4-3 to heat the liquid raw material inside the tower. The gas phase outlet at the top of the tower is sequentially connected to the ammonia regeneration tower condenser 4-6, the ammonia regeneration tower reflux regulating valve 4-7, and the ammonia regeneration tower reflux tank 4-8. The ammonia regeneration tower reflux regulating valve 4-7 refluxes a portion of the liquid ammonia condensed by the ammonia regeneration tower condenser 4-6 back to the top of the ammonia regeneration tower 4-3. The liquid phase outlet of the ammonia regeneration tower reflux tank 4-8 ​​is connected to the inlet of the ammonia regeneration tower condensate pump 4-9, and the gas phase outlet is connected to the flare system. The outlet of the ammonia regeneration tower condensate pump 4-9 is connected in parallel to the raw material liquid ammonia pipeline at the inlet of the liquid ammonia storage tank 1-7 in the raw material preparation unit 1. The inlet of the wastewater cooler 4-5 is connected to the ammonia regeneration tower reboiler 4-4, and one outlet is connected in parallel to the demineralized water pipeline at the top of the ammonia regeneration tower 4-3, and the other outlet is connected to the external wastewater treatment system.

[0023] A method for producing tert-butylamine by direct amination of isobutylene includes the following steps: Step 1. System inertization: Nitrogen gas at ambient temperature (0.1–0.7 MPa) from the public nitrogen pipeline enters and fills the low-pressure nitrogen storage tank 1-1. The nitrogen then passes through the nitrogen compressor 1-2 and the high-pressure nitrogen storage tank 1-3, with one path leading to the nitrogen preheater 1-4 and the other to the high-pressure gas-liquid separator 2-3. Following the process flow, it enters subsequent pipelines and equipment. The unit begins nitrogen inertization replacement. The system pressure is controlled by pressure regulating valves at the top of the ammonia removal tower reflux tank 3-5, isobutylene tower reflux tank 3-11, tert-butylamine tower reflux tank 3-17, and ammonia regeneration tower reflux tank 4-8, extending to the flare system, maintaining the unit pressure at 0.3–0.5 MPa. When the oxygen content in the gas before the ammonia regeneration tower condensate pump 4-9 is below 0.5%, the unit is considered inertized. All vent valves are then closed to maintain the inertized environment, preventing external gases from entering and disrupting the overall inertization environment. Step 2. Reaction and Separation: Nitrogen preheater 1-4, raw material preheater 1-10, and raw material superheater 1-11 are put into operation respectively, with heating temperatures set to 30-40℃, 130-140℃, and 260-280℃ respectively. The heating temperature of nitrogen preheater 1-4, raw material preheater 1-10, and raw material superheater 1-11 increases gradually, allowing the unit to heat up slowly. Nitrogen compressor 1-2 is started, and compressed nitrogen enters high-pressure nitrogen storage tank 1-3. The load of nitrogen compressor 1-2 is gradually increased to bring its outlet pressure to 24-26MPa, and high-pressure nitrogen storage tank 1-3 is filled. High-pressure nitrogen exits from high-pressure nitrogen storage tank 1-3, passes through nitrogen preheater 1-4, enters raw material mixer 1-9, and then enters subsequent pipelines and units according to the process flow. Raw materials isobutylene and liquid ammonia are stored in isobutylene storage tank 1-5 and liquid ammonia storage tank 1-7, respectively. Isobutylene pump 1-6 and liquid ammonia pump 1-8 are started to make the outlet pressure of both pumps 24-26 MPa. Isobutylene and liquid ammonia with similar pressures enter the raw material mixer 1-9 at the same time, and then enter the reactor 2-1 at a pressure of 24-26 MPa and a temperature of 260-280℃. The reaction product passes through the raw material preheater 1-10 and the product cooler 2-2 to reduce the temperature to 40-60℃ and the pressure to 23-25 ​​MPa, and then enters the high-pressure gas-liquid separator 2-3. The gas and liquid phases are depressurized by the high-pressure gas phase valve 2-4 and the high-pressure liquid phase valve 2-5, respectively, and then enter the low-pressure gas-liquid separator 2-6 at a pressure of 13-15 MPa and a temperature of 50-70℃. The gas phase is reduced to 1.3–1.5 MPa and 30–50°C via low-pressure gas phase valve 2-7 before entering tail gas absorption tower 4-1. The liquid phase enters deammoniation tower 3-1 via low-pressure liquid phase valve 2-8, with a pressure of 1.3–1.5 MPa and a temperature of 40–60°C. The temperature and pressure ranges set in reactor 2-1 allow for more complete reaction of materials under the corresponding temperature and pressure conditions. The pressure ranges set in high-pressure gas-liquid separator 2-3 and low-pressure gas-liquid separator 2-6 enable rapid depressurization of reaction products and effective connection with the downstream system. Furthermore, the sequential installation of the two depressurization stages not only achieves gas-liquid separation of reaction products but also increases the safety and operability of the depressurization system. Step 3. Distillation and Separation: The product from the low-pressure liquid phase valve 2-8 enters the ammonia removal tower 3-1. The temperature of the ammonia removal tower 3-1 is 90-110℃ and the pressure is 1.3-1.5MPa. This setup ensures that the ammonia in the ammonia removal tower 3-1 is always in a gaseous state. The reboiler 3-2 of the ammonia removal tower is electrically or steam-heated and provides a heat source for the ammonia removal tower 3-1. The ammonia gas exits from the top of the ammonia removal tower 3-1, is condensed into liquid by the ammonia removal tower condenser 3-3, and then passes through the ammonia removal tower reflux regulating valve 3. -4 A portion of the ammonia is returned to the deammoniation tower 3-1 as reflux liquid to control the tower top temperature. A portion enters the deammoniation tower reflux tank 3-5, and is then sent to the liquid ammonia storage tank 1-7 via the deammoniation tower condensate pump 3-6. A portion of the non-condensable gas flows from the top of the deammoniation tower reflux tank 3-5 through its back pressure valve to the flare system. The temperature of the deammoniation tower reflux tank 3-5 is 30-50℃, and the pressure is 1.3-1.5MPa. This configuration ensures that the ammonia in the deammoniation tower reflux tank 3-5 is always in a liquid state. The liquid phase from the reboiler 3-2 of the deammoniation tower enters the isobutylene tower 3-7. The temperature of the isobutylene tower 3-7 is 95-115℃ and the pressure is 0.3-0.5MPa, which ensures that the isobutylene in the isobutylene tower 3-7 is always in a gaseous state. The reboiler 3-8 of the isobutylene tower is electrically heated or steam heated, and provides a heat source for the isobutylene tower 3-7. Isobutylene exits from the top of isobutylene tower 3-7, is condensed into liquid by isobutylene tower condenser 3-9, and then partially returns to isobutylene tower 3-7 as reflux liquid to control the top temperature of the tower via isobutylene tower reflux regulating valve 3-10, while part of it enters isobutylene tower reflux tank 3-11, and is then sent to isobutylene storage tank 1-5 by isobutylene tower condensate pump 3-12. Part of the non-condensable gas exits from the top of isobutylene tower reflux tank 3-11 through its back pressure valve to the flare system. The temperature of isobutylene tower reflux tank 3-11 is 25-45℃ and the pressure is 0.3-0.5MPa, thus keeping the isobutylene in isobutylene tower reflux tank 3-11 in a liquid state. The liquid phase from the isobutylene reboiler 3-8 enters the tert-butylamine column 3-13. The temperature in the tert-butylamine column 3-13 is 96–116℃, and the pressure is 0.1–0.3 MPa, ensuring that the tert-butylamine in the column is in a gaseous state. The tert-butylamine column reboiler 3-14 is electrically or steam-heated, providing a heat source for the column. The tert-butylamine exits from the top of the column 3-13, is condensed into a liquid by the tert-butylamine column condenser 3-15, and then partially returns to the tert-butylamine column via the tert-butylamine column reflux regulating valve 3-16. 3-13 serves as the reflux liquid to control the top temperature of the tower. Part of it enters the tert-butylamine tower reflux tank 3-17, and then is sent to the tert-butylamine storage tank 3-20 via the tert-butylamine tower condensate pump 3-18 and the tert-butylamine cooler 3-19. Part of the non-condensable gas flows from the top of the tert-butylamine tower reflux tank 3-17 through its back pressure valve to the flare system. The temperature of the tert-butylamine tower reflux tank 3-17 is 33-56℃ and the pressure is 0.1-0.3MPa. The temperature of the tert-butylamine cooler 3-19 is 30-48℃, which ensures that the tert-butylamine in it is always in a liquid state. The heavy components at the bottom of the tert-butylamine tower 3-13 are sent to the inlet feed pipeline of the tert-butylamine tower 3-13 for further distillation or directly to the heavy component storage tank 3-23 via the reboiler 3-14, the heavy component cooler 3-21, and the heavy component pump 3-22. The temperature of the heavy component cooler 3-21 is 38-50℃ and the pressure is 0.1-0.3MPa, which ensures that the cooled heavy components are always in a liquid state. Step 4. Ammonia regeneration: The gaseous product from the low-pressure gas phase valve 2-7 enters the tail gas absorption tower 4-1, mixes with and dissolves in the demineralized water from the top of the tower, and is then sent to the ammonia regeneration tower 4-3 via the ammonia regeneration tower feed pump 4-2. The tail gas absorption tower 4-1 has a temperature of 45-65℃ and a pressure of 0.1-0.5MPa, which ensures that the ammonia is fully dissolved in the demineralized water. The ammonia regeneration tower 4-3 has a temperature of 196-216℃ and a pressure of 1.3-1.5MPa, ensuring that the ammonia in the ammonia regeneration tower 4-3 is in a gaseous state. The ammonia regeneration tower reboiler 4-4 is electrically or steam heated, providing a heat source for the ammonia regeneration tower 4-3. The ammonia exits from the top of the ammonia regeneration tower 4-3, is condensed into a liquid by the ammonia regeneration tower condenser 4-6, and then passes through the ammonia regeneration tower condenser. Part of the gas regeneration tower reflux regulating valve 4-7 returns a portion of the gas to the ammonia regeneration tower 4-3 as reflux liquid to control the tower top temperature, while a portion enters the ammonia regeneration tower reflux tank 4-8, and is then sent to the liquid ammonia storage tank 1-7 via the ammonia regeneration tower condensate pump 4-9. A portion of the non-condensable gas flows from the top of the ammonia regeneration tower reflux tank 4-8 ​​through its back pressure valve to the flare system. The temperature of the ammonia regeneration tower reflux tank 4-8 ​​is 38–58℃, and the pressure is 1.3–1.5 MPa, which keeps the ammonia in a liquid state. The wastewater at the bottom of the ammonia regeneration tower 4-3 enters the wastewater cooler 4-5 via the ammonia regeneration tower reboiler 4-4, where it is cooled to no higher than 40℃, and then sent to the demineralized water inlet pipe at the top of the ammonia regeneration tower 4-3 or to an external wastewater treatment system.

[0024] Example 1: A pilot-scale process for producing tert-butylamine using ammonia and isobutylene as raw materials.

[0025] 1. Nitrogen gas at 20℃ and 0.35MPa enters and fills the low-pressure nitrogen storage tank 1-1. The nitrogen gas then passes through the nitrogen compressor 1-2 and the high-pressure nitrogen storage tank 1-3, with one path leading to the nitrogen preheater 1-4 and the other to the high-pressure gas-liquid separator 2-3. Following the process flow, it enters subsequent pipelines and equipment. The unit begins nitrogen inertization replacement. The system pressure is controlled by the pressure regulating valves at the top of the ammonia removal tower reflux tank 3-5, the isobutylene tower reflux tank 3-11, the tert-butylamine tower reflux tank 3-17, and the ammonia regeneration tower reflux tank 4-8, extending to the flare system, and is maintained at 0.2MPa. If the oxygen content in the gas before the ammonia regeneration tower condensate pump 4-9 is 0.4% as detected online, the unit has passed inertization, and all vent valves are closed. 2. Nitrogen preheater 1-4, raw material preheater 1-10, and raw material superheater 1-11 are put into operation respectively, with heating temperatures set to 40℃, 130℃, and 260℃ respectively; nitrogen compressor 1-2 is started, so that compressed nitrogen enters high-pressure nitrogen storage tank 1-3, and the load of nitrogen compressor 1-2 is gradually increased to make its outlet pressure reach 25MPa, and the high-pressure nitrogen storage tank 1-3 is filled; high-pressure nitrogen exits from high-pressure nitrogen storage tank 1-3, enters raw material mixer 1-9 through nitrogen preheater 1-4, and then enters subsequent pipelines and equipment according to the process flow; The raw materials, isobutylene and liquid ammonia, are stored in isobutylene storage tank 1-5 and liquid ammonia storage tank 1-7, respectively. Isobutylene pump 1-6 and liquid ammonia pump 1-8 are started respectively, so that the outlet pressure of both pumps is 25MPa. Isobutylene and liquid ammonia with similar pressures enter the raw material mixer 1-9 at the same time, and then enter the reactor 2-1 at a pressure of 24MPa and a temperature of 260℃. The reaction product passes through the raw material preheater 1-10 and the product cooler 2-2, and the temperature is reduced to 40℃ and the pressure is reduced to 23MPa. Then it enters the high-pressure gas-liquid separator 2-3. The gas and liquid phases are depressurized by the high-pressure gas phase valve 2-4 and the high-pressure liquid phase valve 2-5 respectively, and then enter the low-pressure gas-liquid separator 2-6 at a pressure of 13MPa and a temperature of 50℃. Then the gas phase passes through the low-pressure gas phase valve 2-7, and the pressure is reduced to 1.3MPa and the temperature to 30℃, and enters the tail gas absorption tower 4-1. The liquid phase passes through the low-pressure liquid phase valve 2-8 and enters the deammoniation tower 3-1 at a pressure of 1.3MPa and a temperature of 40℃. 3. The product from the low-pressure liquid phase valve 2-8 enters the ammonia removal tower 3-1. The temperature of the ammonia removal tower 3-1 is 90℃ and the pressure is 1.3MPa. The reboiler 3-2 of the ammonia removal tower is heated by 0.5MPa saturated steam and provides a heat source for the ammonia removal tower 3-1. Ammonia gas exits from the top of the ammonia removal tower 3-1, is condensed into liquid by the ammonia removal tower condenser 3-3, and then partially returns to the ammonia removal tower 3-1 as reflux liquid to control the top temperature of the tower through the ammonia removal tower reflux regulating valve 3-4. Part of it enters the ammonia removal tower reflux tank 3-5, and is then sent to the liquid ammonia storage tank 1-7 by the ammonia removal tower condensate pump 3-6. Part of the non-condensable gas exits from the top of the ammonia removal tower reflux tank 3-5 through its back pressure valve to the flare system. The temperature of the ammonia removal tower reflux tank 3-5 is 30℃ and the pressure is 1.3MPa. The liquid phase from the reboiler 3-2 of the deammoniation tower enters the isobutylene tower 3-7, which has a temperature of 95℃ and a pressure of 0.3MPa. The reboiler 3-8 of the isobutylene tower is heated by saturated steam at 0.5MPa and provides a heat source for the isobutylene tower 3-7. Isobutylene exits from the top of the isobutylene tower 3-7, is condensed into liquid by the isobutylene tower condenser 3-9, and then partially returns to the isobutylene tower 3-7 as reflux liquid to control the top temperature of the tower via the reflux regulating valve 3-10. Part of it enters the isobutylene tower reflux tank 3-11, and is then sent to the isobutylene storage tank 1-5 by the isobutylene tower condensate pump 3-12. Part of the non-condensable gas exits from the top of the isobutylene tower reflux tank 3-11 through its back pressure valve to the flare system. The isobutylene tower reflux tank 3-11 has a temperature of 25℃ and a pressure of 0.3MPa. The liquid phase from the isobutylene reboiler 3-8 enters the tert-butylamine tower 3-13, where the temperature is 96℃ and the pressure is 0.1MPa. The tert-butylamine tower reboiler 3-14 is heated by 0.5MPa saturated steam, providing a heat source for the tert-butylamine tower 3-13. The tert-butylamine exits from the top of the tert-butylamine tower 3-13, is condensed into liquid by the tert-butylamine tower condenser 3-15, and then partially returns to the tert-butylamine tower via the tert-butylamine tower reflux regulating valve 3-16. The reflux liquid in amine tower 3-13 controls the top temperature of the tower. A portion of the reflux liquid enters the tert-butylamine tower reflux tank 3-17, and then is sent to the tert-butylamine storage tank 3-20 via the tert-butylamine tower condensate pump 3-18 and the tert-butylamine cooler 3-19. A portion of the non-condensable gas flows from the top of the tert-butylamine tower reflux tank 3-17 through its back pressure valve to the flare system. The temperature of the tert-butylamine tower reflux tank 3-17 is 33℃ and the pressure is 0.1MPa. The temperature of the tert-butylamine tower cooler 3-19 is 30℃. The heavy components at the bottom of the tert-butylamine tower 3-13 are sent to the tert-butylamine tower 3-13 inlet feed pipeline for further distillation via the tert-butylamine tower reboiler 3-14, the heavy component cooler 3-21, and the heavy component pump 3-22, or directly to the heavy component storage tank 3-23. The temperature of the heavy component cooler 3-21 is 38℃ and the pressure is 0.1MPa. 4. The gaseous product from the low-pressure gas phase valve 2-7 enters the tail gas absorption tower 4-1, mixes with and dissolves in the demineralized water from the top of the tower, and is then sent to the ammonia regeneration tower 4-3 via the ammonia regeneration tower feed pump 4-2. The tail gas absorption tower 4-1 has a temperature of 45℃ and a pressure of 0.1MPa, while the ammonia regeneration tower 4-3 has a temperature of 196℃ and a pressure of 1.3MPa. The ammonia regeneration tower reboiler 4-4 is electrically heated and provides a heat source for the ammonia regeneration tower 4-3. Ammonia gas exits from the top of the ammonia regeneration tower 4-3, is condensed into liquid by the ammonia regeneration tower condenser 4-6, and then passes through the ammonia regeneration tower reflux regulating valve 4-7. The reflux liquid returned to ammonia regeneration tower 4-3 is used to control the tower top temperature. Part of it enters ammonia regeneration tower reflux tank 4-8, and is then sent to liquid ammonia storage tank 1-7 via ammonia regeneration tower condensate pump 4-9. Part of the non-condensable gas flows from the top of ammonia regeneration tower reflux tank 4-8 ​​through its back pressure valve to the flare system. The temperature of ammonia regeneration tower reflux tank 4-8 ​​is 38℃ and the pressure is 1.3MPa. The wastewater at the bottom of ammonia regeneration tower 4-3 enters wastewater cooler 4-5 via ammonia regeneration tower reboiler 4-4, is cooled to 35℃, and then sent to the demineralized water inlet pipe at the top of ammonia regeneration tower 4-3 or to an external wastewater treatment system.

[0026] In this example, the isobutylene conversion rate can reach 20%, and the selectivity of the product tert-butylamine can reach 90%.

[0027] Example 2: A pilot-scale process for producing tert-butylamine using ammonia and isobutylene as raw materials.

[0028] 1. Nitrogen gas at 22℃ and 0.35MPa enters and fills the low-pressure nitrogen storage tank 1-1. The nitrogen gas then passes through the nitrogen compressor 1-2 and the high-pressure nitrogen storage tank 1-3, with one path leading to the nitrogen preheater 1-4 and the other to the high-pressure gas-liquid separator 2-3. Following the process flow, it enters subsequent pipelines and equipment. The unit begins nitrogen inertization replacement. The system pressure is controlled by the pressure regulating valves at the top of the ammonia removal tower reflux tank 3-5, the isobutylene tower reflux tank 3-11, the tert-butylamine tower reflux tank 3-17, and the ammonia regeneration tower reflux tank 4-8, extending to the flare system, maintaining the unit pressure at 0.2MPa. If the oxygen content in the gas before the ammonia regeneration tower condensate pump 4-9 is 0.4% as monitored online, the unit inertization is considered successful. All vent valves are then closed to maintain the inertized environment of the unit. 2. Nitrogen preheater 1-4, raw material preheater 1-10, and raw material superheater 1-11 are put into operation respectively, with heating temperatures set to 40℃, 140℃, and 280℃ respectively; nitrogen compressor 1-2 is started, so that compressed nitrogen enters high-pressure nitrogen storage tank 1-3, and the load of nitrogen compressor 1-2 is gradually increased to make its outlet pressure reach 26MPa, and the high-pressure nitrogen storage tank 1-3 is filled; high-pressure nitrogen exits from high-pressure nitrogen storage tank 1-3, enters raw material mixer 1-9 through nitrogen preheater 1-4, and then enters subsequent pipelines and equipment according to the process flow; The raw materials, isobutylene and liquid ammonia, are stored in isobutylene storage tank 1-5 and liquid ammonia storage tank 1-7, respectively. Isobutylene pump 1-6 and liquid ammonia pump 1-8 are started respectively, so that the outlet pressure of both pumps is 26MPa. Isobutylene and liquid ammonia with similar pressures enter the raw material mixer 1-9 at the same time, and then enter the reactor 2-1 at 26MPa and 280℃. The reaction product passes through the raw material preheater 1-10 and the product cooler 2-2, and the temperature is reduced to 60℃ and the pressure is reduced to 25MPa. Then it enters the high-pressure gas-liquid separator 2-3. The gas and liquid phases are depressurized by the high-pressure gas phase valve 2-4 and the high-pressure liquid phase valve 2-5 respectively, and then enter the low-pressure gas-liquid separator 2-6 at 15MPa and 70℃. Then the gas phase passes through the low-pressure gas phase valve 2-7, and the pressure is reduced to 1.5MPa and the temperature to 50℃, and enters the tail gas absorption tower 4-1. The liquid phase passes through the low-pressure liquid phase valve 2-8 and enters the deammoniation tower 3-1 at 1.5MPa and 60℃. 3. The product from the low-pressure liquid phase valve 2-8 enters the ammonia removal tower 3-1. The temperature of the ammonia removal tower 3-1 is 110℃ and the pressure is 1.5MPa. The reboiler 3-2 of the ammonia removal tower is electrically heated and provides a heat source for the ammonia removal tower 3-1. Ammonia gas exits from the top of the ammonia removal tower 3-1, is condensed into liquid by the ammonia removal tower condenser 3-3, and then partially returns to the ammonia removal tower 3-1 as reflux liquid to control the top temperature of the tower through the ammonia removal tower reflux regulating valve 3-4. Part of it enters the ammonia removal tower reflux tank 3-5, and is then sent to the liquid ammonia storage tank 1-7 by the ammonia removal tower condensate pump 3-6. Part of the non-condensable gas exits from the top of the ammonia removal tower reflux tank 3-5 through its back pressure valve to the flare system. The temperature of the ammonia removal tower reflux tank 3-5 is 50℃ and the pressure is 1.5MPa. The liquid phase from the reboiler 3-2 of the deammoniation tower enters the isobutylene tower 3-7, which has a temperature of 115℃ and a pressure of 0.5MPa. The reboiler 3-8 is electrically heated and provides a heat source for the isobutylene tower 3-7. Isobutylene exits from the top of the isobutylene tower 3-7, is condensed into liquid by the isobutylene tower condenser 3-9, and then partially returns to the isobutylene tower 3-7 as reflux liquid to control the top temperature of the tower via the reflux regulating valve 3-10. Part of it enters the isobutylene tower reflux tank 3-11, and is then sent to the isobutylene storage tank 1-5 by the isobutylene tower condensate pump 3-12. Part of the non-condensable gas exits from the top of the isobutylene tower reflux tank 3-11 through its back pressure valve to the flare system. The isobutylene tower reflux tank 3-11 has a temperature of 45℃ and a pressure of 0.5MPa. The liquid phase from the isobutylene reboiler 3-8 enters the tert-butylamine column 3-13. The temperature in the tert-butylamine column 3-13 is 116℃ and the pressure is 0.3MPa. The tert-butylamine column reboiler 3-14 is electrically heated and provides a heat source for the tert-butylamine column 3-13. The tert-butylamine exits from the top of the tert-butylamine column 3-13, is condensed into liquid by the tert-butylamine column condenser 3-15, and then partially returns to the tert-butylamine column 3-13 via the tert-butylamine column reflux regulating valve 3-16. 13, used as reflux liquid to control the top temperature of the column, partially enters the tert-butylamine column reflux tank 3-17, and then is sent to the tert-butylamine storage tank 3-20 via the tert-butylamine column condensate pump 3-18 and tert-butylamine cooler 3-19. Part of the non-condensable gas flows from the top of the tert-butylamine column reflux tank 3-17 through its back pressure valve to the flare system. The temperature of the tert-butylamine column reflux tank 3-17 is 56℃ and the pressure is 0.3MPa; the temperature of the tert-butylamine cooler 3-19 is 48℃. The heavy components at the bottom of the tert-butylamine column 3-13 are sent to the tert-butylamine column 3-13 inlet feed pipeline for further distillation or directly to the heavy component storage tank 3-23 via the tert-butylamine column reboiler 3-14, heavy component cooler 3-21, and heavy component pump 3-22. The temperature of the heavy component cooler 3-21 is 50℃ and the pressure is 0.3MPa. 4. The gaseous product from the low-pressure gas phase valve 2-7 enters the tail gas absorption tower 4-1, mixes with and dissolves in the demineralized water from the top of the tower, and is then sent to the ammonia regeneration tower 4-3 via the ammonia regeneration tower feed pump 4-2. The tail gas absorption tower 4-1 has a temperature of 65℃ and a pressure of 0.5MPa, while the ammonia regeneration tower 4-3 has a temperature of 216℃ and a pressure of 1.5MPa. The ammonia regeneration tower reboiler 4-4 is electrically heated and provides a heat source for the ammonia regeneration tower 4-3. Ammonia gas exits from the top of the ammonia regeneration tower 4-3, is condensed into liquid by the ammonia regeneration tower condenser 4-6, and then passes through the ammonia regeneration tower reflux regulating valve 4-7. The reflux liquid returned to ammonia regeneration tower 4-3 is used to control the tower top temperature. Part of it enters ammonia regeneration tower reflux tank 4-8, and is then sent to liquid ammonia storage tank 1-7 via ammonia regeneration tower condensate pump 4-9. Part of the non-condensable gas flows from the top of ammonia regeneration tower reflux tank 4-8 ​​through its back pressure valve to the flare system. The temperature of ammonia regeneration tower reflux tank 4-8 ​​is 58℃ and the pressure is 1.5MPa. The wastewater at the bottom of ammonia regeneration tower 4-3 enters wastewater cooler 4-5 via ammonia regeneration tower reboiler 4-4, is cooled to 38℃, and then sent to the demineralized water inlet pipe at the top of ammonia regeneration tower 4-3 or to an external wastewater treatment system.

[0029] In this example, the isobutylene conversion rate can reach 22%, and the selectivity of the product tert-butylamine can reach 93%.

Claims

1. An apparatus for producing tert-butylamine via direct ammoniation of isobutylene, characterized in that, It includes a raw material preparation unit (1), a reaction separation unit (2), a distillation separation unit (3), and a recycling unit (4) that are connected in sequence. The raw material preparation unit (1) is used for the storage, mixing and heating of raw materials; The reaction separation unit (2) is used to pressurize and react the raw materials in the raw material preparation unit (1) and to separate the product gas and liquid. The distillation separation unit (3) distills and separates the liquid phase product separated by the reaction separation unit (2) and recovers some unreacted raw materials; The recycling unit (4) distills and recovers a portion of the raw materials from the gaseous products separated by the reaction separation unit (2).

2. The apparatus for producing tert-butylamine from isobutylene by direct amination according to claim 1, characterized in that, The raw material preparation unit (1) includes a low-pressure nitrogen storage tank (1-1), a nitrogen compressor (1-2), a high-pressure nitrogen storage tank (1-3), a nitrogen preheater (1-4), a raw material mixer (1-9), a raw material preheater (1-10), and a raw material superheater (1-11) connected in sequence by pipelines, and the inlet of the low-pressure nitrogen storage tank (1-1) is connected to a common nitrogen pipeline; The isobutylene storage tank (1-5) has an inlet connected to a raw material isobutylene pipeline, and its outlet is connected to the inlet of the isobutylene pump (1-6). The liquid ammonia storage tank (1-7) has an inlet connected to a raw material liquid ammonia pipeline, and its outlet is connected to the inlet of the liquid ammonia pump (1-8). The outlets of the nitrogen preheater (1-4), isobutylene pump (1-6), and liquid ammonia pump (1-8) are respectively connected to the pipelines of the raw material mixer (1-9). The cold material in the raw material preheater (1-10) is the raw material isobutylene and ammonia that have been fully mixed in the raw material mixer (1-9), and the hot material is... The reaction product, cold material and hot material exiting the reactor (2-1) in the reaction separation unit (2) respectively flow through the tube side and shell side of the raw material preheater (1-10), that is, the product is used to preheat the raw material; the raw material superheater (1-11) performs secondary superheating on the raw material after preheating by the raw material preheater (1-10), so that the temperature of the heated raw material is higher than or equal to the working temperature of the reactor (2-1) in the reaction separation unit (2), and the heat source of the raw material superheater (1-11) is steam or electric heating.

3. The apparatus for producing tert-butylamine from isobutylene by direct amination according to claim 2, characterized in that, The reaction separation unit (2) includes a reactor (2-1). The raw material inlet of the reactor (2-1) is connected to the outlet pipe of the raw material superheater (1-11) in the raw material preparation unit (1), and the product outlet is connected in sequence to the raw material preheater (1-10), the product cooler (2-2), and the high-pressure gas-liquid separator (2-3) in the raw material preparation unit (1). The gas phase outlet of the high-pressure gas-liquid separator (2-3) is connected to the upper part of the low-pressure gas-liquid separator (2-6) via the high-pressure gas phase valve (2-4), and the liquid phase outlet is connected to the high-pressure liquid phase valve (2-6). -5) Connected to the lower part of the low-pressure gas-liquid separator (2-6); high-pressure nitrogen is introduced into the top of the high-pressure gas-liquid separator (2-3) and connected to the nitrogen pipeline at the outlet of the high-pressure nitrogen storage tank (1-3); the gas phase outlet of the low-pressure gas-liquid separator (2-6) is connected to the middle part of the tail gas absorption tower (4-1) in the circulation recovery unit (4) via the low-pressure gas phase valve (2-7) and serves as the raw material for the tail gas absorption tower (4-1); the liquid phase outlet is connected to the raw material inlet of the deammoniation tower (3-1) in the distillation separation unit (3) via the low-pressure liquid phase valve (2-8).

4. The apparatus for producing tert-butylamine by direct ammoniation of isobutylene according to claim 3, characterized in that, The reactor (2-1) is a common high-pressure resistant fixed-bed reactor, which is filled with molecular sieve catalyst. The molecular sieve catalyst is a common catalyst for the direct ammoniation of isobutylene to produce tert-butylamine.

5. The apparatus for producing tert-butylamine by direct ammoniation of isobutylene according to claim 3, characterized in that, The distillation separation unit (3) includes a deammoniation tower (3-1), with a deammoniation tower reboiler (3-2) installed at the bottom of the deammoniation tower (3-1). The deammoniation tower reboiler (3-2) is used to heat the liquid raw material in the deammoniation tower (3-1). The top gas phase outlet of the deammoniation tower (3-1) is sequentially connected to the deammoniation tower condenser (3-3), the deammoniation tower reflux regulating valve (3-4), and the deammoniation tower reflux tank (3-5). The deammoniation tower reflux regulating valve (3-4) refluxes part of the liquid ammonia generated by the condensation of the deammoniation tower condenser (3-3) back to the top of the deammoniation tower (3-1). The liquid phase outlet of the deammoniation tower reflux tank (3-5) is connected to the inlet of the deammoniation tower condensate pump (3-6), and the gas phase outlet is connected to the flare system. The outlet of the deammoniation tower condensate pump (3-6) is connected in parallel with the raw material inlet pipe of the isobutylene storage tank (1-5) in the raw material preparation unit (1). The feed inlet of the isobutylene tower (3-7) is connected to the reboiler (3-2) of the deammoniation tower. A reboiler (3-8) is installed at the bottom of the isobutylene tower. The reboiler (3-8) is used to heat the liquid feed in the tower. The top gas phase outlet of the isobutylene tower (3-7) is sequentially connected to the isobutylene tower condenser (3-9), the isobutylene tower reflux regulating valve (3-10), and the isobutylene tower reflux tank (3-11). 0) A portion of the liquid isobutylene produced by condensation in the isobutylene tower condenser (3-9) is returned to the top of the isobutylene tower (3-7); the liquid phase outlet of the isobutylene tower reflux tank (3-11) is connected to the inlet of the isobutylene tower condensate pump (3-12), and the gas phase outlet is connected to the flare system; the outlet of the isobutylene tower condensate pump (3-12) is connected in parallel to the raw material liquid ammonia pipeline at the inlet of the liquid ammonia storage tank (1-7) in the raw material preparation unit (1); The feed inlet of the tert-butylamine tower (3-13) is connected to the reboiler (3-8) of the isobutylene tower. A reboiler (3-14) of the tert-butylamine tower is installed at the bottom. The reboiler (3-14) of the tert-butylamine tower is used to heat the liquid phase feed in the tower. The gas phase outlet at the top of the tert-butylamine tower (3-13) is connected in sequence to the condenser (3-15) of the tert-butylamine tower, the reflux regulating valve (3-16) of the tert-butylamine tower, and the reflux tank (3-17) of the tert-butylamine tower. The reflux regulating valve (3-16) of the tert-butylamine tower refluxes a portion of the liquid tert-butylamine condensed by the tert-butylamine tower condenser (3-15) back to the top of the tert-butylamine tower (3-13); the liquid phase outlet of the tert-butylamine tower reflux tank (3-17) is connected to the inlet of the tert-butylamine tower condensate pump (3-18), and the gas phase outlet is connected to the flare system; the outlet of the tert-butylamine tower condensate pump (3-18) is connected to the tert-butylamine storage tank (3-20) via the tert-butylamine cooler (3-19); the inlet of the heavy component cooler (3-21) is connected to the tert-butylamine tower reboiler (3-14), and the outlet is sequentially connected to the heavy component pump (3-22) and the heavy component storage tank (3-23), and a branch of the outlet of the heavy component pump (3-22) is connected in parallel to the raw material inlet pipeline of the tert-butylamine tower (3-13).

6. The apparatus for producing tert-butylamine by direct amination of isobutylene according to claim 5, characterized in that, The recycling unit (4) includes a tail gas absorption tower (4-1), with a safety valve at the top and connected to the flare gas system. The upper part of the tail gas absorption tower (4-1) is filled with common packing material, which is commonly used in water washing towers. A demineralized water spraying device is installed on the upper part of the packing material. The spraying device is connected to the demineralized water pipeline flange installed outside the tail gas absorption tower (4-1). The demineralized water is used to absorb ammonia gas entering the tail gas absorption tower (4-1). The demineralized water enters the tail gas absorption tower (4-1), is sprayed, and falls through the packing material to the bottom of the tail gas absorption tower (4-1). The inlet of the ammonia regeneration tower feed pump (4-2) is connected to the bottom outlet of the tail gas absorption tower (4-1), and the outlet is connected to the ammonia regeneration tower (4-3). A reboiler is installed at the bottom of the ammonia regeneration tower (4-3) to heat the liquid feedstock inside the tower. The gas phase outlet at the top of the tower is sequentially connected to the ammonia regeneration tower condenser (4-6), the ammonia regeneration tower reflux regulating valve (4-7), and the ammonia regeneration tower reflux tank (4-8). The ammonia regeneration tower reflux regulating valve (4-7) refluxes a portion of the liquid ammonia condensed by the ammonia regeneration tower condenser (4-6) back to the top of the ammonia regeneration tower (4-3). The ammonia regeneration tower reflux tank (4-8)... -8) The liquid phase outlet is connected to the inlet of the ammonia regeneration tower condensate pump (4-9), and the gas phase outlet is connected to the flare system; the outlet of the ammonia regeneration tower condensate pump (4-9) is connected in parallel with the raw material liquid ammonia pipeline at the inlet of the liquid ammonia storage tank (1-7) in the raw material preparation unit (1); the inlet of the wastewater cooler (4-5) is connected to the ammonia regeneration tower reboiler (4-4), and one outlet is connected in parallel with the upper demineralized water pipeline of the ammonia regeneration tower (4-3), and the other outlet is connected to the external wastewater treatment system.

7. The method of using the apparatus for producing tert-butylamine by direct amination of isobutylene according to claim 6, characterized in that, Includes the following steps: Step 1: Nitrogen gas at ambient temperature (0.1–0.7 MPa) from the public nitrogen pipeline enters the low-pressure nitrogen storage tank (1-1) and fills the tank. The nitrogen gas then passes through the nitrogen compressor (1-2) and the high-pressure nitrogen storage tank (1-3), with one path leading to the nitrogen preheater (1-4) and the other to the high-pressure gas-liquid separator (2-3). Afterward, it enters the subsequent pipelines and equipment according to the process flow route. The unit begins nitrogen inertization replacement. The system pressure is controlled by the pressure regulating valves at the top of the deammonia removal tower reflux tank (3-5), isobutylene tower reflux tank (3-11), tert-butylamine tower reflux tank (3-17), and ammonia regeneration tower reflux tank (4-8) to the flare system, and the unit pressure is kept at 0.3–0.5 MPa. When the oxygen content in the gas before the ammonia regeneration tower condensate pump (4-9) is lower than 0.5%, the unit is considered inertized. All vent valves are closed to maintain the inertized environment of the unit. Step 2: Activate the nitrogen preheater (1-4), raw material preheater (1-10), and raw material superheater (1-11) respectively. Set the heating temperature of the nitrogen preheater (1-4) to 30-40℃, the heating temperature of the raw material preheater (1-10) to 130-140℃, and the heating temperature of the raw material superheater (1-11) to 260-280℃. Start the nitrogen compressor (1-2) to allow the compressed nitrogen to enter the high-pressure nitrogen storage tank (1-3). Gradually increase the load of the nitrogen compressor (1-2) to bring its outlet pressure to 24-26MPa and fill the high-pressure nitrogen storage tank (1-3). The high-pressure nitrogen exits from the high-pressure nitrogen storage tank (1-3), passes through the nitrogen preheater (1-4), enters the raw material mixer (1-9), and then enters the subsequent pipelines and equipment according to the process flow. Raw materials isobutylene and liquid ammonia are stored in isobutylene storage tank (1-5) and liquid ammonia storage tank (1-7), respectively. Isobutylene pump (1-6) and liquid ammonia pump (1-8) are started to bring the outlet pressure of both pumps to 24–26 MPa. Isobutylene and liquid ammonia at similar pressures simultaneously enter the raw material mixer (1-9), and then flow into reactor (2-1) at a pressure of 24–26 MPa and a temperature of 260–280 °C. The reaction product passes through a raw material preheater (1-10) and a product cooler (2-2), where the temperature is reduced to 40–60 °C and the pressure to 23–26 MPa. The pressure is 25 MPa, and then it enters the high-pressure gas-liquid separator (2-3). The gas and liquid phases are depressurized by the high-pressure gas phase valve (2-4) and the high-pressure liquid phase valve (2-5) respectively, and then enter the low-pressure gas-liquid separator (2-6) with a pressure of 13-15 MPa and a temperature of 50-70℃. Then the gas phase passes through the low-pressure gas phase valve (2-7) to reduce the pressure to 1.3-1.5 MPa and the temperature to 30-50℃ and enters the tail gas absorption tower (4-1). The liquid phase passes through the low-pressure liquid phase valve (2-8) and enters the deammoniation tower (3-1) with a pressure of 1.3-1.5 MPa and a temperature of 40-60℃. Step 3: The product from the low-pressure liquid phase valve (2-8) enters the ammonia stripping tower (3-1). The temperature of the ammonia stripping tower (3-1) is 90-110℃ and the pressure is 1.3-1.5MPa. The reboiler (3-2) of the ammonia stripping tower is electrically heated or steam heated and provides a heat source for the ammonia stripping tower (3-1). Ammonia gas exits from the top of the ammonia stripping tower (3-1), is condensed into liquid by the ammonia stripping tower condenser (3-3), and then partially returns to the ammonia stripping tower (3-1) as reflux liquid to control the top temperature of the tower through the ammonia stripping tower reflux regulating valve (3-4). Part of it enters the ammonia stripping tower reflux tank (3-5), and is then sent to the liquid ammonia storage tank (1-7) by the ammonia stripping tower condensate pump (3-6). Part of the non-condensable gas exits from the top of the ammonia stripping tower reflux tank (3-5) through its back pressure valve to the flare system. The temperature of the ammonia stripping tower reflux tank (3-5) is 30-50℃ and the pressure is 1.3-1.5MPa. The liquid phase from the reboiler (3-2) of the deammoniation tower enters the isobutylene tower (3-7). The temperature of the isobutylene tower (3-7) is 95-115℃ and the pressure is 0.3-0.5MPa. The reboiler (3-8) of the isobutylene tower is electrically heated or steam heated and provides a heat source for the isobutylene tower (3-7). Isobutylene exits from the top of the isobutylene tower (3-7), is condensed into liquid by the isobutylene tower condenser (3-9), and then passes through the isobutylene tower reflux regulating valve (…). 3-10) Part of the liquid is returned to the isobutylene tower (3-7) as reflux to control the top temperature of the tower, and part enters the isobutylene tower reflux tank (3-11), and is then sent to the isobutylene storage tank (1-5) by the isobutylene tower condensate pump (3-12). Part of the non-condensable gas is sent from the top of the isobutylene tower reflux tank (3-11) to the flare system through its back pressure valve. The temperature of the isobutylene tower reflux tank (3-11) is 25-45℃ and the pressure is 0.3-0.5MPa. The liquid phase from the isobutylene reboiler (3-8) enters the tert-butylamine column (3-13). The temperature of the tert-butylamine column (3-13) is 96-116℃ and the pressure is 0.1-0.3MPa. The tert-butylamine column reboiler (3-14) is electrically heated or steam heated and provides a heat source for the tert-butylamine column (3-13). The tert-butylamine exits from the top of the tert-butylamine column (3-13), is condensed into liquid by the tert-butylamine column condenser (3-15), and then partially returns to the tert-butylamine column (3-13) as reflux liquid to control the top temperature of the column through the tert-butylamine column reflux regulating valve (3-16). Part of it enters the tert-butylamine column reflux tank (3-17), and then passes through the tert-butylamine column condensate pump (3-18) and the tert-butylamine cooler (3-19). The non-condensable gas is fed into the tert-butylamine storage tank (3-20). Some of the non-condensable gas flows from the top of the tert-butylamine tower reflux tank (3-17) through its back pressure valve to the flare system. The temperature of the tert-butylamine tower reflux tank (3-17) is 33-56℃ and the pressure is 0.1-0.3MPa. The temperature of the tert-butylamine cooler (3-19) is 30-48℃. The heavy components at the bottom of the tert-butylamine tower (3-13) are sent to the tert-butylamine tower (3-13) inlet feed pipeline for re-distillation or directly to the heavy components storage tank (3-23) via the tert-butylamine tower reboiler (3-14), heavy components cooler (3-21), and heavy components pump (3-22). The temperature of the heavy components cooler (3-21) is 38-50℃ and the pressure is 0.1-0.3MPa. Step 4: The gaseous product from the low-pressure gas phase valve (2-7) enters the tail gas absorption tower (4-1), mixes with and dissolves in the demineralized water from the top of the tower, and is then sent to the ammonia regeneration tower (4-3) via the ammonia regeneration tower feed pump (4-2). The tail gas absorption tower (4-1) has a temperature of 45-65℃ and a pressure of 0.1-0.5MPa, while the ammonia regeneration tower (4-3) has a temperature of 196-216℃ and a pressure of 1.3-1.5MPa. The ammonia regeneration tower reboiler (4-4) is electrically heated or steam heated and provides a heat source for the ammonia regeneration tower (4-3). Ammonia exits from the top of the ammonia regeneration tower (4-3), is condensed into liquid by the ammonia regeneration tower condenser (4-6), and then refluxed through the ammonia regeneration tower. Valve (4-7) partially returns to the ammonia regeneration tower (4-3) as reflux liquid to control the tower top temperature, and partially enters the ammonia regeneration tower reflux tank (4-8), and is then sent to the liquid ammonia storage tank (1-7) via the ammonia regeneration tower condensate pump (4-9). Part of the non-condensable gas flows from the top of the ammonia regeneration tower reflux tank (4-8) through its back pressure valve to the flare system. The temperature of the ammonia regeneration tower reflux tank (4-8) is 38-58℃ and the pressure is 1.3-1.5MPa. The wastewater at the bottom of the ammonia regeneration tower (4-3) enters the wastewater cooler (4-5) via the ammonia regeneration tower reboiler (4-4) and is cooled to no higher than 40℃, and then sent to the demineralized water inlet pipe at the top of the ammonia regeneration tower (4-3) or the external wastewater treatment system.

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