Caprolactam gasification device and method

Abstract

The invention discloses a caprolactam gasification device and method. The caprolactam gasification device comprises a gasifier (1), a nozzle (2) extending into the gasifier (1), a gas-liquid separator (3) and a scraper jet recycling reactor (4). The caprolactam gasification method comprises the following steps: (1) introducing ammonia gas into a gasifier, spraying a caprolactam raw material from a nozzle extending into the gasifier, mixing the caprolactam raw material with the ammonia gas, gasifying, enabling the gasified material to enter a gas-liquid separator, enabling the gas to enter an ammoniation reactor, and enabling the generated polymer impurity liquid to enter a scraper jet recycling reactor; and (2) carrying out membrane scraping on the polymer impurity liquid in a scraper jet recycling reactor, reacting the polymer impurity liquid with the sprayed ammonia gas on the inner wall loaded with the catalyst, decomposing the polymer impurity liquid into a raw material caprolactam, enabling the raw material caprolactam and the ammonia gas to upwards enter a reaction system through a gas-liquid separator, and discharging tar from an outlet below.

Description

Technical Field

[0001] This invention relates to a vaporization apparatus and method, and particularly to a vaporization apparatus and method for caprolactam. Background Technology

[0002] 6-Aminohexanonitrile (6-ACN) is a key chemical intermediate in the synthesis of hexamethylenediamine (HDA), which is crucial industrially. HDA is primarily used in the production of high-performance materials such as nylon 66 (one of the most important polyamide categories, along with nylon 6), nylon 610, and nylon 612, and is widely applied in polyurethane resins, ion exchange resins, diisocyanates, epoxy resin curing agents, organic crosslinking agents, adhesives, stabilizers, bleaching agents, and corrosion inhibitors. Therefore, the efficient synthesis of 6-aminohexanonitrile has significant economic and industrial value.

[0003] Currently, the synthesis of 6-aminohexanonitrile mainly uses caprolactam as a raw material, achieved through a catalytic amination and dehydration reaction. This process route is mainly divided into two categories:

[0004] Liquid phase method: This process usually involves complex reaction steps and a long process flow, and it is easy to generate a lot of by-products and wastewater, which poses challenges to environmental protection and large-scale industrial production, and has been gradually phased out.

[0005] Gas-phase method: Compared to the liquid-phase method, the operation steps of the gas-phase method can be significantly simplified, which has potential process advantages. However, in order to fully realize the potential of the gas-phase method and achieve its industrial application, it is still necessary to optimize and improve the operating conditions according to the characteristics of gas-phase reactions.

[0006] Therefore, developing a more efficient and environmentally friendly technology for the amination and dehydration of caprolactam to produce 6-aminohexanonitrile, especially one that meets the requirements of gas-phase reactions, is an important research direction in this field.

[0007] Several studies have reported on the gas-phase preparation of 6-aminohexanonitrile. Patent CN107602416A discloses a method of mixing caprolactam vapor with excess hot ammonia and carrying out an ammoniation and dehydration reaction in the presence of a specific catalyst (such as alkaline earth metal / transition metal oxides, silica, activated alumina, or combinations thereof), with the product being separated and purified to obtain 6-aminohexanonitrile. Although the conversion rate of this method can reach over 96%, it has significant drawbacks: (1) the gasification process is unclear and risky. Given the thermosensitive nature of caprolactam, simple heating and gasification can easily lead to polymerization side reactions, affecting the stability of subsequent reactions; (2) the ammonia consumption is too high, resulting in a significant increase in production costs. It is difficult to meet the requirements of industrial production.

[0008] Patent CN 111004148A describes a method that involves metering caprolactam and ammonia gas, preheating them separately at a molar ratio of 1:3 to 1:20, mixing them, and then further heating to obtain a mixture. This mixture is then fed into a reactor for ammoniation and dehydration in the presence of a catalyst to obtain an ammoniation product. The catalyst is composed of alkaline earth metal salts or transition metal salts as active components, and titanium dioxide or ZSM-5 molecular sieves as a support. Finally, the product, 6-aminohexanonitrile, is obtained through separation and purification. However, this method primarily focuses on reaction and purification steps and does not address how to preheat and vaporize the caprolactam feedstock, nor does it specify the necessary equipment.

[0009] In summary, the existing technology for preparing 6-aminohexanonitrile has several drawbacks, including uneven mixing of caprolactam raw materials, excessively long gasification time, incomplete gasification, easy polymerization, and low gasification equilibrium rate. Further improvements are needed in the gasification equipment and process to prevent caprolactam polymerization during preheating, ensure uniform mixing of raw materials, improve the conversion rate of reactants, and enhance the stability of the reaction apparatus. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the present invention aims to provide a caprolactam vaporization device and method. By atomizing and spirally spraying caprolactam, and then strongly mixing it with ammonia gas flowing in the opposite spiral direction, instantaneous vaporization is achieved, increasing the vaporization rate, shortening the vaporization time, and reducing high-temperature polymerization. Simultaneously, the vaporization method incorporates a simple and efficient resource recovery method to depolymerize the generated polymeric impurities without the need for water or solvents. This resource recovery further improves the vaporization equilibrium rate.

[0011] The first aspect of this application provides a caprolactam vaporization device, the device comprising a vaporizer 1, a nozzle 2 extending into the vaporizer 1, a gas-liquid separator 3, and a scraped jet-type resource recovery reactor 4.

[0012] This application also provides a method for vaporizing caprolactam using the above-described apparatus, the method comprising the following steps:

[0013] (1) Ammonia is introduced into the gasifier, and caprolactam raw material is injected from the nozzle that extends into the gasifier. It is mixed with ammonia and gasified. The gasified material enters the gas-liquid separator, the gas goes to the ammonia reactor, and the generated polymer impurity liquid enters the scraped jet resource recovery reactor.

[0014] (2) The polymer impurity liquid is scraped in a scraped jet-type resource recovery reactor and reacts with the sprayed ammonia gas on the inner wall loaded with catalyst to decompose the polymer impurity liquid into the raw material caprolactam. The caprolactam and ammonia gas are then introduced upward into the reaction system through a gas-liquid separator, and the tar is discharged through the lower outlet.

[0015] The advantages of this invention are:

[0016] (1) The present invention provides a caprolactam vaporization device and method, which achieves a vaporization rate of over 99.9%.

[0017] (2) The present invention uses the oblique cut air inlet of the vaporizer, the spiral flow stabilizing component and the conical flow guiding component of the nozzle to make the gas and atomized micro-droplets spirally sprayed out with opposite spiral directions, forming collision and shear forced mixing, instantaneous heat transfer and vaporization, which greatly shortens the vaporization time and minimizes the amount of polymer impurities generated.

[0018] (3) The present invention continuously separates polymeric impurity liquid from gasified materials through a rotary separator, thereby improving production separation efficiency and solving the defects of easy entrainment and difficult separation of liquid in high-speed, high-temperature compound gases.

[0019] (4) By coupling double-helix strong mixing gasification and resource utilization, the operation process is simplified while improving the gasification rate of caprolactam.

[0020] (5) This application uses a resource-based catalyst that does not require water or other solvents and directly depolymerizes polymer impurities in the presence of ammonia, greatly reducing the difficulty of subsequent water or solvent separation and improving the economic benefits of resource utilization. Simultaneously, the catalyst is cleverly loaded onto the inner wall of the scraped-film jet-type resource-based reactor through in-situ generation, eliminating the problem of catalyst separation from the reaction liquid. Furthermore, the use of a scraped film and rotating shaft jet method improves heat transfer at the reaction interface and enhances the reaction effect. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a caprolactam gasification device, wherein: 1-gasifier, 1-1-ammonia inlet, 2-nozzle, 3-gas-liquid separator, 3-1-separator cone, 3-2-demister, 4-scraper jet-type resource recovery reactor, 4-1-gas-liquid diversion cap, 4-2-inner wall catalyst membrane, 4-3-scraper, 4-4-jet-type rotating shaft, 4-5-vent, 4-6-discharge port, 4-7-inlet, 4-8-motor.

[0022] Figure 2 This is an enlarged view of nozzle 2, where 2-1-feed rod, 2-2-conical guide assembly, 2-3-nozzle orifice, and 2-4-insulation jacket.

[0023] Figure 3 This is an enlarged view of the conical drainage component 2-2, where 2-2-1 is the fluid impact head and 2-2-2 is the arc-shaped drainage plate.

[0024] Figure 4This is a top view of a caprolactam vaporization device, where 1-vaporizer, 1-1-ammonia inlet, 1-2-spiral flow stabilizer, 2-nozzle, and 3-gas-liquid separator. Detailed Implementation

[0025] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0026] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0027] The "range" disclosed herein is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0028] Unless otherwise specified in this application, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0029] Unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0030] In this application, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0031] In this application, unless otherwise specified, the terms "comprising" and "including" as used herein are open-ended or closed-ended. For example, "comprising" and "including" may mean that other components not listed may also be included, or that only the listed components may be included.

[0032] In the description of this article, it should be noted that, unless otherwise stated, "above" and "below" include the number itself, and "several" in "one or more" means two or more.

[0033] In this description, unless otherwise stated, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0034] Unless otherwise specified, percentages (%) or parts refer to weight percentages or parts relative to the composition.

[0035] Unless otherwise stated herein, the sum of the contents of the components in the composition is 100%.

[0036] Unless otherwise stated herein, the sum of the parts of each component in the composition may be 100 parts by weight.

[0037] In this document, unless otherwise stated, “combination of” means a multi-component mixture of the elements, such as two, three, four, and up to the maximum possible multi-component mixture.

[0038] Unless otherwise specified, the term "a" as used in this specification means "at least one".

[0039] This application provides a caprolactam vaporization device, which includes a vaporizer 1, a nozzle 2 extending into the vaporizer 1, a gas-liquid separator 3, and a scraped jet-type resource recovery reactor 4.

[0040] vaporizer

[0041] The vaporizer, such as Figure 1 , 4 The diagram shows a reducing pipe with a tapering section, consisting of a large-diameter section, a tapering section, and a small-diameter section in sequence from the air inlet direction. The large-diameter section has an ammonia inlet, which is tangent to the cylindrical surface of the large-diameter section. The angle between the ammonia inlet and the horizontal line is θ1 (also called the incident angle), which can be 20–80°, 30–70°, or 40–60°. Preferably, a spiral flow stabilizer is also provided inside the reducing pipe (preferably inside the small-diameter section). Under the combined action of the inlet and the flow stabilizer, the ammonia is transported forward in a spiral pattern.

[0042] nozzle

[0043] The nozzle is as follows Figure 2 The diagram shows a spindle-shaped structure that is narrow at both ends and thick in the middle, located at the end of the vaporizer near the air inlet.

[0044] The nozzle has a flow-guiding assembly inside, preferably a conical flow-guiding assembly. The left end of the flow-guiding assembly has a fluid impact head, preferably spherical, and arc-shaped flow-guiding plates are distributed on the outer surface of the flow-guiding assembly. The number of arc-shaped flow-guiding plates is 3–9, 4–8, or 5–7. When the flow-guiding assembly is conical, the angle between the arc-shaped flow-guiding plate and the bottom circle of the cone is θ2, where θ2 is 20–80°, 30–70°, or 40–60°. Preferably, the nozzle may be provided with a heat-insulating jacket.

[0045] like Figure 2 and Figure 3 As shown, nozzle 2 includes a feed rod 2-1 and a nozzle orifice 2-3. Nozzle orifice 2-3 includes a flow guiding assembly 2-2, preferably a conical flow guiding assembly. The flow guiding assembly 2-2 includes a fluid impact head 2-2-1 and an arc-shaped flow guiding plate 2-2-2. The fluid impact head 2-2-1 is preferably spherical. The arc-shaped flow guiding plates 2-2-2 are distributed on the outer surface of the flow guiding assembly 2-2 (e.g., on the conical surface of the conical flow guiding assembly). The number of arc-shaped flow guiding plates 2-2-2 is 3 to 9, 4 to 8, or 5 to 7. When the flow guiding assembly is a conical flow guiding assembly 2-2, the angle between the arc-shaped flow guiding plate 2-2-2 and the bottom circle of the cone is θ2, which is 20 to 80°, 30 to 70°, or 40 to 60°. Preferably, a heat-insulating jacket 2-4 may be provided on the outside of nozzle 2.

[0046] The liquid enters the feed rod of the nozzle through a high-pressure pump, collides with the fluid impact head of the diversion component and breaks up, and under the action of the diversion plate, it moves spirally in the nozzle cavity and is quickly spirally sprayed out. Under the action of the nozzle, the liquid is atomized into extremely small droplets.

[0047] gas-liquid separator

[0048] The gas-liquid separator is as follows Figure 1 The shape shown is a cone, wider at the top and narrower at the bottom.

[0049] The gas-liquid separator 3 is connected to the gasifier 1 and the scraper jet-type resource recovery reactor 4, respectively.

[0050] The tail end of the gasifier 1 is connected to the middle of the gas-liquid separator 3. The gasified material enters tangentially, the gas outlet is located at the upper part of the gas-liquid separator 3, and the liquid outlet is located at the lower part of the gas-liquid separator 3.

[0051] The gas-liquid separator 3 includes a separator cone 3-1, and optionally a demister 3-2 is provided at the top of the gas-liquid separator 3.

[0052] The gasified material enters the gas-liquid separator tangentially from the middle, forming a rotating airflow. Under the action of centrifugal force, the gas flows upward along the center of the vortex, while the liquid flows downward along the separator wall.

[0053] Scraped jet reactor

[0054] The scraper jet reactor is a reaction device that uses a scraper to form a thin liquid film of polymerized impurity liquid on the inner wall, which reacts with ammonia gas sprayed from the rotating shaft on the inner wall of the catalyst-supported reactor to realize the resource recovery of waste.

[0055] The scraper jet-type resource recovery reactor 4, as described above Figure 1 As shown, the top of the scraper jet reactor 4 is connected to the lower end of the gas-liquid separator 3. The scraper jet reactor 4 consists of a gas-liquid diversion cap 4-1, a resource-based catalyst membrane 4-2 loaded on the inner wall of the scraper jet reactor, a rotating scraper 4-3, a jet shaft 4-4, and a discharge port 4-6. The jet shaft 4-4 has air holes 4-5. Preferably, the bottom of the scraper jet reactor is also provided with a fresh ammonia inlet 4-7 and a motor 4-8.

[0056] The gas-liquid separator cap is a cone-shaped funnel, wider at the bottom and narrower at the top. Liquid flows down the outer edge of the separator cap, while gas flows upward through the inner opening. After entering, the liquid is scraped onto the inner wall by a rotating scraper. The rotating scraper's shaft has an air jet function, and gas is evenly injected onto the liquid film on the inner wall through vents on the shaft. Simultaneously, the resource-based catalyst is evenly loaded onto the inner wall.

[0057] The catalyst is tri[bis(triC)]1-6 [alkylsilyl)amino]-Ln, preferably tri[bis(triethylsilyl)amino]-Ln, wherein Ln is one of the rare earth elements scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), europium (Eu), dysprosium (Dy), and lutetium (Lu).

[0058] The catalyst is loaded onto the inner wall of the scraped jet reactor via in-situ precipitation. With this catalyst, water is not required for depolymerization, reducing subsequent water separation. The resulting caprolactam and ammonia directly enter the subsequent ammoniation reaction system through a gas-liquid separator.

[0059] The tail end of the gasifier 1 is connected to the middle part of the gas-liquid separator 3, and the lower end of the gas-liquid separator 3 is connected to the upper end of the scraper jet-type resource recovery reactor 4.

[0060] Ammonia and caprolactam liquid are vaporized in the vaporizer and then enter the gas-liquid separator from the tail end of the vaporizer to form a rotating airflow. Under the action of centrifugal force, the gas flows upward along the center of the vortex, and the liquid flows downward along the separator wall and enters the scraped jet resource recovery reactor for a scraped membrane reaction.

[0061] On the other hand, this application also provides a method for vaporizing caprolactam using the above-described apparatus, the method comprising the following steps:

[0062] (1) Ammonia is introduced into the gasifier, and caprolactam raw material is injected from the nozzle that extends into the gasifier. It is mixed with ammonia and gasified. The gasified material enters the gas-liquid separator, the gas goes to the ammonia reactor, and the generated polymer impurity liquid enters the scraped jet resource recovery reactor.

[0063] (2) The polymer impurity liquid is scraped in a scraped jet-type resource recovery reactor and reacts with the sprayed ammonia gas on the inner wall loaded with catalyst to decompose the polymer impurity liquid into the raw material caprolactam. The caprolactam and ammonia gas are then introduced upward into the reaction system through a gas-liquid separator, and the tar is discharged through the lower outlet.

[0064] In step (1), the temperature at which the ammonia gas is introduced is 240–500°C, or 250–400°C, or 280–350°C, or 290–310°C.

[0065] In step (1), the inlet flow rate of ammonia is 5-18 m / s, or 8-15 m / s, or 10-13 m / s.

[0066] In step (1), caprolactam is sprayed in liquid atomized form at a spraying temperature of 69–220°C, 80–215°C, 120–210°C, 150–205°C, or 180–200°C.

[0067] In step (1), the molar ratio of ammonia to caprolactam is (3-50):1, or (5-40):1, or (10-30):1, or (15-25):1.

[0068] In step (1), caprolactam is ejected in a spiral manner through the nozzle's guiding component, with the spiral direction opposite to that of ammonia. Specifically, under the combined action of the oblique tangential air inlet and the spiral flow stabilizer, ammonia is conveyed forward in a spiral shape, and caprolactam is injected in liquid atomized form at an injection temperature of 69–220°C. The caprolactam is ejected in a spiral manner through the conical guiding component of the nozzle, with the spiral direction opposite to that of ammonia, forming impact and collision, enhancing the shear force of ammonia on the droplets, greatly enhancing mass and heat transfer, and rapidly transferring heat to the droplets to achieve efficient vaporization and minimize the heating time of caprolactam.

[0069] In step (1), the gasified material is effectively separated in a gas-liquid separator, reducing the polymer impurities carried in the gas to below 100 ppm. The polymer impurities are polycaprolactam (PA6) and deammoniation impurities, etc. During the gasification process, due to the influence of high temperature and a small amount of moisture, caprolactam will inevitably undergo ring-opening condensation to form impurities, which greatly affects the gasification rate of caprolactam.

[0070] In step (2), the resource recovery temperature is 280-600℃, or 290-500℃, or 300-400℃, or 310-330℃.

[0071] In step (2), the polymer impurity liquid and ammonia gas are depolymerized into caprolactam monomers under the action of a catalyst supported on the inner wall.

[0072] In step (2), the catalyst is tri[bis(triC)] 1-6 [alkylsilyl)amino]-Ln, preferably tri[bis(triethylsilyl)amino]-Ln, wherein Ln is one of the rare earth elements scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), europium (Eu), dysprosium (Dy), and lutetium (Lu).

[0073] In step (2), the catalyst is loaded onto the inner wall of the scraped jet reactor via in-situ precipitation. With this catalyst, water is not required for depolymerization, reducing subsequent water separation. The resulting caprolactam and ammonia directly enter the subsequent ammoniation reaction system through a gas-liquid separator.

[0074] In step (2), the inlet gas (ammonia) flow rate is 2-10 m / s, or 2.5-8 m / s, or 3-5 m / s.

[0075] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0076] Example

[0077] A. Source of raw materials:

[0078] Caprolactam (purity > 99.9%, purchased from Aladdin)

[0079] Ammonia (purity > 99.9%, purchased from Wuhan Jixin Yibang)

[0080] B. Testing or analysis methods

[0081] Resource recovery rate = (mass of caprolactam generated in the gas phase at the top of the resource recovery reactor / mass of polymerized impurity liquid) × 100.

[0082] Caprolactam vaporization rate = (mass of gaseous caprolactam entering the reaction system / total mass of liquid caprolactam entering the vaporizer) × 100%

[0083] Caprolactam was quantitatively measured by gas chromatography.

[0084] Device Example 1

[0085] The flow structure of the caprolactam vaporization device in Example 1 is as follows: Figure 1 As shown, the device includes the following units: a vaporizer 1, a nozzle 2, a gas-liquid separator 3, and a scraped jet-type resource recovery reactor 4. The vaporizer 1 includes an ammonia inlet 1-1 and a spiral flow stabilizer 1-2 (see...). Figure 3 The vaporizer is as follows: Figure 1 , 4The diagram shows a tapered section of a tube, with the sections arranged sequentially from the air inlet direction: a large diameter section, a tapered section, and a small diameter section. The large diameter section has an ammonia inlet, which is tangent to the cylindrical surface of the large diameter section, and the angle between the ammonia inlet and the horizontal line is θ1. The nozzle 2 extends into the narrow tube of the vaporizer 1 near the air inlet. The nozzle 2 has a heat-insulating jacket 2-4 and includes a feed rod 2-1 and a nozzle orifice 2-3. The nozzle orifice 2-3 includes a conical guide assembly 2-2, which includes a fluid impact head 2-2-1 and an arc-shaped guide plate 2-2-2. The gas-liquid separator 3 has a conical structure with a larger upper section and a smaller lower section. The middle of the gas-liquid separator 3 is tangentially connected to the tail end of the vaporizer 1, with the upper part being the gas phase outlet and the lower part being the liquid outlet. The gas-liquid separator 3 includes a separator cone 3-1, and a demister 3-2 is also provided at the top of the gas-liquid separator 3. The upper feed inlet of the scraper jet-type resource recovery reactor 4 is connected to the lower discharge outlet of the gas-liquid separator 3. The resource recovery reactor 4 includes an upper gas-liquid diversion cap 4-1, a resource recovery catalyst film 4-2 loaded on the inner wall of the scraper jet-type resource recovery reactor, a rotating scraper 4-3, a jet-type rotating shaft 4-4, a vent 4-5 on the rotating shaft, a discharge port 4-6, a bottom fresh ammonia gas inlet 4-7, and a motor 4-8.

[0086] In the vaporizer 1, the angle θ1 between the ammonia inlet 1-1 and the horizontal line is 30°, and the angle θ2 between the arc-shaped guide plate of the nozzle 2 and the bottom circle of the cone is 20°.

[0087] The inlet gas flow rate in the source reactor 4 is 3 m / s, and the catalyst supported on the inner wall is tris[bis(triethylsilyl)amino]-La.

[0088] Device Example 2

[0089] The process structure of the caprolactam vaporization device in Example 2 is as follows: Figure 1 As shown, the device includes the following units: a vaporizer 1, a nozzle 2, a gas-liquid separator 3, and a scraped jet-type resource recovery reactor 4. The vaporizer 1 includes an ammonia inlet 1-1 and a spiral flow stabilizer 1-2 (see...). Figure 3 The vaporizer is as follows: Figure 1 , 4The diagram shows a tapered section of a tube, with the sections arranged sequentially from the air inlet direction: a large diameter section, a tapered section, and a small diameter section. The large diameter section has an ammonia inlet, which is tangent to the cylindrical surface of the large diameter section, and the angle between the ammonia inlet and the horizontal line is θ1. The nozzle 2 extends into the narrow tube of the vaporizer 1 near the air inlet. The nozzle 2 has a heat-insulating jacket 2-4 and includes a feed rod 2-1 and a nozzle orifice 2-3. The nozzle orifice 2-3 includes a conical guide assembly 2-2, which includes a fluid impact head 2-2-1 and an arc-shaped guide plate 2-2-2. The gas-liquid separator 3 has a conical structure with a larger upper section and a smaller lower section. The middle of the gas-liquid separator 3 is tangentially connected to the tail end of the vaporizer 1, with the upper part being the gas phase outlet and the lower part being the liquid outlet. The gas-liquid separator 3 includes a separator cone 3-1, and a demister 3-2 is also provided at the top of the gas-liquid separator 3. The upper feed inlet of the scraper jet-type resource recovery reactor 4 is connected to the lower discharge outlet of the gas-liquid separator 3. The resource recovery reactor 4 includes an upper gas-liquid diversion cap 4-1, a resource recovery catalyst film 4-2 loaded on the inner wall of the scraper jet-type resource recovery reactor, a rotating scraper 4-3, a jet-type rotating shaft 4-4, a vent 4-5 on the rotating shaft, a discharge port 4-6, a bottom fresh ammonia gas inlet 4-7, and a motor 4-8.

[0090] In the vaporizer 1, the angle θ1 between the ammonia inlet 1-1 and the horizontal line is 45°, and the angle θ2 between the arc-shaped guide plate of the nozzle 2 and the bottom circle of the cone is 30°.

[0091] The inlet gas flow rate in the source reactor 4 is 5 m / s, and the catalyst supported on the inner wall is tris[bis(triethylsilyl)amino]-Nd.

[0092] Device Example 3

[0093] The flow structure of the caprolactam vaporization device in Example 3 is as follows: Figure 1 As shown, the device includes the following units: a vaporizer 1, a nozzle 2, a gas-liquid separator 3, and a scraped jet-type resource recovery reactor 4. The vaporizer 1 includes an ammonia inlet 1-1 and a spiral flow stabilizer 1-2 (see...). Figure 3 The vaporizer is as follows: Figure 1 , 4The diagram shows a tapered section of a tube, with the sections arranged sequentially from the air inlet direction: a large diameter section, a tapered section, and a small diameter section. The large diameter section has an ammonia inlet, which is tangent to the cylindrical surface of the large diameter section, and the angle between the ammonia inlet and the horizontal line is θ1. The nozzle 2 extends into the narrow tube of the vaporizer 1 near the air inlet. The nozzle 2 has a heat-insulating jacket 2-4 and includes a feed rod 2-1 and a nozzle orifice 2-3. The nozzle orifice 2-3 includes a conical guide assembly 2-2, which includes a fluid impact head 2-2-1 and an arc-shaped guide plate 2-2-2. The gas-liquid separator 3 has a conical structure with a larger upper section and a smaller lower section. The middle of the gas-liquid separator 3 is tangentially connected to the tail end of the vaporizer 1, with the upper part being the gas phase outlet and the lower part being the liquid outlet. The gas-liquid separator 3 includes a separator cone 3-1, and a demister 3-2 is also provided at the top of the gas-liquid separator 3. The upper feed inlet of the scraper jet-type resource recovery reactor 4 is connected to the lower discharge outlet of the gas-liquid separator 3. The resource recovery reactor 4 includes an upper gas-liquid diversion cap 4-1, a resource recovery catalyst film 4-2 loaded on the inner wall of the scraper jet-type resource recovery reactor, a rotating scraper 4-3, a jet-type rotating shaft 4-4, a vent 4-5 on the rotating shaft, a discharge port 4-6, a bottom fresh ammonia gas inlet 4-7, and a motor 4-8.

[0094] In the vaporizer 1, the angle θ1 between the ammonia inlet 1-1 and the horizontal line is 60°, and the angle θ2 between the arc-shaped guide plate of the nozzle 2 and the bottom circle of the cone is 45°.

[0095] The inlet gas flow rate in the source reactor 4 is 5 m / s, and the catalyst supported on the inner wall is tris[bis(triethylsilyl)amino]-Lu.

[0096] Method Example 4

[0097] The caprolactam gasification method in Example 4 uses the apparatus described in Example 1. Ammonia gas is introduced into the gasifier through inlet 1-1 at a feed rate of 10 m / s and an inlet temperature of 300°C. Caprolactam raw material is injected in liquid form from nozzle 2 at an injection temperature of 200°C. The molar ratio of ammonia to caprolactam is 15:1. The ammonia and caprolactam are strongly mixed and gasified. The gas passes through gas-liquid separator 3 to the ammonification reactor, and the resulting polymer impurity liquid enters the scraped jet-type resource recovery reactor 4. In the scraped jet-type resource recovery reactor, the liquid reacts with the sprayed ammonia gas on the catalyst-loaded inner wall. The resource recovery temperature is 320°C, and the ammonia gas inlet flow rate is 3 m / s. The generated caprolactam and ammonia gas rise upwards through the gas-liquid separator into the reaction system, while the tar is discharged through the lower outlet. The resource recovery rate is 99.0%, and the gasification rate of caprolactam before entering the reactor reaches 99.995%.

[0098] Method Example 5

[0099] The caprolactam gasification method in Example 5 uses the apparatus described in Example 2. Ammonia gas is introduced into the gasifier through inlet 1-1 at a feed rate of 10 m / s and an inlet temperature of 300°C. Caprolactam raw material is injected in liquid form from nozzle 2 at an injection temperature of 200°C. The molar ratio of ammonia to caprolactam is 15:1. The ammonia and caprolactam are strongly mixed and gasified. The gas passes through gas-liquid separator 3 to the ammonification reactor, and the resulting polymer impurity liquid enters the scraped-plate jet-type resource recovery reactor 4. In the scraped-plate jet-type resource recovery reactor, the liquid reacts with the sprayed ammonia gas on the catalyst-loaded inner wall. The resource recovery temperature is 320°C, and the ammonia gas inlet flow rate is 5 m / s. The generated caprolactam and ammonia gas rise upwards through the gas-liquid separator into the reaction system, while the tar is discharged through the lower outlet. The resource recovery rate is 98.6%, and the gasification rate of caprolactam before entering the reactor reaches 99.985%.

[0100] Method Example 6

[0101] The caprolactam gasification method in Example 6 uses the apparatus described in Example 3. Ammonia gas is introduced into the gasifier through inlet 1-1 at a feed rate of 13 m / s and an inlet temperature of 300°C. Caprolactam raw material is injected in liquid form from nozzle 2 at an injection temperature of 200°C. The molar ratio of ammonia to caprolactam is 20:1. The ammonia and caprolactam are strongly mixed and gasified. The gas passes through gas-liquid separator 3 to the ammonification reactor, and the resulting polymer impurity liquid enters the scraped jet-type resource recovery reactor 4. In the scraped jet-type resource recovery reactor, the liquid reacts with the sprayed ammonia gas on the catalyst-loaded inner wall. The resource recovery temperature is 320°C, and the ammonia inlet flow rate is 5 m / s. The generated caprolactam and ammonia gas rise upwards through the gas-liquid separator into the reaction system, while the tar is discharged through the lower outlet. The resource recovery rate is 98.0%, and the gasification rate of caprolactam before entering the reactor reaches 99.968%.

[0102] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of the substantive technical content of this disclosure. The substantive technical content of this disclosure is broadly defined within the scope of the claims of this application. Any technical entity or method completed by others that is completely identical to or an equivalent modification of the claims of this application shall be deemed to be covered within the scope of the claims.

[0103] All documents mentioned in this disclosure are incorporated herein by reference as if each document were individually incorporated herein by reference. Furthermore, it should be understood that after reading the foregoing contents of this disclosure, those skilled in the art can make various alterations or modifications to this disclosure, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A caprolactam vaporization device, the device comprising a vaporizer (1), a nozzle (2) extending into the vaporizer (1), a gas-liquid separator (3), and a scraped jet-type resource recovery reactor (4).

2. The device as described in claim 1, wherein the vaporizer (1) is a tapered section with a large diameter section, a tapered section and a small diameter section in sequence from the air inlet direction. Preferably, the large diameter section is provided with an ammonia inlet, the ammonia inlet is tangent to the cylindrical surface of the large diameter section, and the ammonia inlet makes an angle of θ1 with the horizontal line, where θ1 is 20 to 80°.

3. The apparatus of claim 1, wherein the nozzle (2) is a spindle-shaped structure that is narrow at both ends and thick in the middle, located at the end of the vaporizer near the air inlet; and / or The nozzle (2) has a flow guiding assembly (2-2) inside, the flow guiding assembly (2-2) has a fluid impact head at its left end, and arc-shaped flow guiding plates are distributed on the outer surface of the flow guiding assembly; and / or The nozzle (2) is provided with an insulation jacket (2-4) on the outside.

4. The device as claimed in claim 3, wherein the drainage component (2-2) is a conical drainage component, preferably, the angle between the arc-shaped drainage plate (2-2-2) and the bottom circle of the cone is θ2, and θ2 is 20 to 80°.

5. The apparatus of claim 1, wherein the gas-liquid separator (3) is a conical shape, wider at the top and narrower at the bottom; and / or The gas-liquid separator (3) is connected to the gasifier (1) and the scraped jet reactor (4) respectively; and / or The tail end of the gasifier (1) is connected to the middle of the gas-liquid separator (3). The gasified material enters tangentially. The gas outlet is located at the upper part of the gas-liquid separator (3), and the liquid outlet is located at the lower part of the gas-liquid separator (3), and / or The gas-liquid separator (3) includes a separator cone (3-1), and optionally a demister (3-2) is provided at the top of the gas-liquid separator 3.

6. The apparatus of claim 1, wherein the top of the scraper jet reactor (4) is connected to the lower end of the gas-liquid separator (3); and / or The scraper jet-type resource recovery reactor (4) consists of a gas-liquid split cap (4-1), a resource recovery catalyst film (4-2) loaded on the inner wall of the scraper jet-type resource recovery reactor, a rotating scraper (4-3), a jet-type rotating shaft (4-4), and a discharge port (4-6). The jet-type rotating shaft (4-4) has air holes (4-5).

7. The apparatus of claim 6, wherein the catalyst is tri[bis(triC)] 1-6 [alkylsilyl)amino]-Ln, wherein Ln is one of the rare earth elements scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), europium (Eu), dysprosium (Dy), and lutetium (Lu).

8. A method for vaporizing caprolactam using the apparatus according to any one of claims 1-7, the method comprising the following steps: (1) Ammonia is introduced into the gasifier, and caprolactam raw material is injected from the nozzle that extends into the gasifier. It is mixed with ammonia and gasified. The gasified material enters the gas-liquid separator, the gas goes to the ammonia reactor, and the generated polymer impurity liquid enters the scraped jet resource recovery reactor. (2) The polymer impurity liquid is scraped in a scraped jet-type resource recovery reactor and reacts with the sprayed ammonia gas on the inner wall loaded with catalyst to decompose the polymer impurity liquid into the raw material caprolactam. The caprolactam and ammonia gas are then introduced upward into the reaction system through a gas-liquid separator, and the tar is discharged through the lower outlet.

9. The method of claim 8, wherein in step (1), caprolactam is ejected in a spiral manner through the nozzle's guiding assembly, the spiral direction being opposite to that of ammonia; and / or In step (1), the ammonia gas is introduced at a temperature of 240–500°C; and / or In step (1), the inlet flow rate of ammonia is 5–18 m / s; and / or In step (1), caprolactam is sprayed in liquid atomized form at a spraying temperature of 69–220°C; and / or In step (1), the molar ratio of ammonia to caprolactam is (3-50):

1.

10. The method of claim 8, wherein in step (2), the resource recovery temperature is 280–600°C, and / or In step (2), the catalyst is tri[bis(triC)] 1-6 [alkylsilyl)amino]-Ln, wherein Ln is one of the rare earth elements scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), europium (Eu), dysprosium (Dy), and lutetium (Lu).

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