Supergravity adiponitrile production system and method

Abstract

The invention relates to a supergravity adiponitrile production system and method, the system comprises a supergravity nitrile reactor, a separation tower, a semi-nitrile evaporator and a refining device, the middle part of the supergravity nitrile reactor is communicated with the lower part of the separation tower through a main pipeline, and the top of the supergravity nitrile reactor is communicated with a main ammonia gas pipeline; the top of the separation tower is respectively communicated with an ammonia recovery pipeline and a water recovery pipeline, and the upper part of the separation tower is communicated with the refining device through a pipeline; and the top of the semi-nitrile evaporator is respectively communicated with the bottom of the separation tower, the main pipeline and the main ammonia gas pipeline through pipelines. The reactor has the beneficial effects that the characteristics of structure, technology and the like of the supergravity reactor are utilized, the reverse concentration gradient of ammonia gas and molten adipic acid is formed in the radial direction of the rotor from inside to outside, the gas-liquid contact specific area is increased, the mass transfer driving force is increased, the reaction rate is increased, reaction products are separated out in the reaction process, and the reaction is accelerated and pushed.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, and particularly relates to a supergravity adiponitrile production system and method. Background Art

[0002] One of the methods for producing adiponitrile is that an excessive amount of ammonia reacts with molten adipic acid in the liquid phase under the condition of using phosphoric acid as a catalyst. The theoretical reaction pressure is 0.03 - 0.045 MPag, and the theoretical reaction temperature ranges from 250 to 290 °C.

[0003] In industrial production of adiponitrile by the liquid phase method, a shell-and-tube nitrilation reactor is used. The outside of the tube bundle is heated by a heat carrier steam. During the production cycle, the temperature gradually increases from 307 °C to 340 °C, with an average temperature higher than the theoretical reaction temperature by 50 °C. In the nitrilation reactor in the existing process technology route, due to the small reaction interface, long reaction residence time, the interface temperature far exceeds the theoretical temperature, and it is easy to form coke. Especially at the end stage, usually the reaction temperature is much higher than the theoretical temperature, especially the temperature gradient on the inner wall of the reactor is higher, and the coking is serious, resulting in an increase in side reactions and high energy consumption for subsequent separation.

[0004] The article "Discussion on the Reaction Mechanism of Adiponitrile" mentions that during the ammoniation process of adipic acid, a large number of side reactions occur simultaneously. Adipic acid starts to decompose in large amounts above 220 °C, and the decomposition rate increases with the increase of temperature; the dimer of adiponitrile is also produced under long-term heating or local overheating conditions. To minimize the impurities in the crude adiponitrile obtained by the liquid phase method, the ammoniation time must be shortened, and adiponitrile must be removed from the reaction zone as soon as possible. Summary of the Invention

[0005] The present invention provides a supergravity adiponitrile production system and method, aiming to solve the problems in the existing technology.

[0006] The technical solution for the present invention to solve the above technical problems is as follows:

[0007] A supergravity adiponitrile production system includes a supergravity nitrilation reactor, a separation tower, a semi-nitrile evaporator, and a refining device. The middle part of the supergravity nitrilation reactor is connected to the lower part of the separation tower through a main pipeline, and its top is connected to a main ammonia pipeline; the top of the separation tower is respectively connected to an ammonia recovery pipeline and a water recovery pipeline, and its upper part is connected to the refining device through a pipeline; the top of the semi-nitrile evaporator is respectively connected to the bottom of the separation tower, the main pipeline, and the main ammonia pipeline through pipelines.

[0008] The beneficial effects of the present invention are as follows: During the production process, molten adipic acid is mixed with a catalyst and then sent into a rotating packed bed nitrilation reactor to contact and react with ammonia in a reverse concentration gradient. The product obtained from the rotating packed bed nitrilation reactor enters a separation column. The separation column separates ammonia, water, crude adiponitrile, and semi-adiponitrile from top to bottom. Ammonia and water are sent to other systems for treatment and recovery. The crude adiponitrile enters a refining system for treatment to obtain an adiponitrile product;

[0009] The semi-adiponitrile is sent to a falling film semi-adiponitrile evaporator heated by a heat carrier steam and equipped with stirring, and ammonia gas is introduced. The countercurrent ammonia can further convert the semi-adiponitrile into adiponitrile, and the adiponitrile and volatile products are separated and recovered from the residue and catalyst through the separation column.

[0010] The present invention utilizes the characteristics of the structure and technology of the rotating packed bed reactor. From the inside to the outside in the radial direction of the rotor, a reverse concentration gradient of ammonia and molten adipic acid is formed, increasing the gas-liquid contact specific area, enhancing the mass transfer driving force, accelerating the reaction rate, and separating the reaction products during the reaction process, thus accelerating the progress of the reaction.

[0011] Based on the above technical solutions, the present invention can be further improved as follows.

[0012] Further, the refining device includes a crude adiponitrile water washing tank, a decanter, a dehydrator, a topping column, and a tailing column connected in sequence through pipelines. The top of the crude adiponitrile water washing tank is connected to the upper part of the separation column through a pipeline.

[0013] The beneficial effect of adopting the above further solution is that during the production process, the crude adiponitrile enters the crude adiponitrile water washing tank for washing to remove some intermediate products, and then the light phase of pre-distilled adiponitrile is obtained through the decanter; the ammonia water dissolved in the pre-distilled adiponitrile is removed through the crude adiponitrile dehydrator and recycled after condensation and treatment; the dehydrated adiponitrile removes the light components in the topping column under vacuum operation, and the adiponitrile after topping removes the heavy components in the tailing column under vacuum operation, and the adiponitrile product is obtained after refining.

[0014] Further, the top of the topping column is connected to the lower part of the tailing column through pipeline 1, and the top of the tailing column is connected to a product pipeline; buffer tanks are fixedly installed on pipeline 1 and the product pipeline respectively.

[0015] The beneficial effect of adopting the above further solution is that the structure is simple and the design is reasonable. By setting buffer tanks to buffer the corresponding substances, the subsequent production can be carried out smoothly.

[0016] Furthermore, condensers are respectively and fixedly installed on the first pipeline and the product pipeline. The two condensers are respectively located at the part of the first pipeline between the topping column and one of the buffer tanks, and at the part of the product pipeline between the tailing column and the other buffer tank. The tops of the two condensers are respectively communicated with vacuum pipelines.

[0017] The beneficial effect of adopting the above further scheme is that the structure is simple and the design is reasonable. The substances coming out of the topping column and the tailing column are cooled by two coolers to recover the corresponding heat and save energy consumption.

[0018] Furthermore, the refining device further includes a refined adiponitrile storage tank, and the refined adiponitrile storage tank is communicated with the product pipeline.

[0019] The beneficial effect of adopting the above further scheme is that the structure is simple and the design is reasonable. The adiponitrile product prepared is collected by the refined adiponitrile storage tank, which is convenient for collection.

[0020] Furthermore, reboilers are respectively connected in parallel at the lower parts of the topping column and the tailing column.

[0021] The beneficial effect of adopting the above further scheme is that the structure is simple and the design is reasonable. The liquids in the topping column and the tailing column are vaporized again by two reboilers to ensure the normal progress of production operations.

[0022] Furthermore, the bottom of the dehydrator is communicated with the middle part of the topping column through the second pipeline, and a topping column feed tank is fixedly installed on the second pipeline; the bottom of the crude nitrile water washing tank is communicated with the top of the decanter through the third pipeline, and a filter is fixedly installed on the third pipeline.

[0023] The beneficial effect of adopting the above further scheme is that the structure is simple and the design is reasonable. The substances separated from the crude nitrile dehydrator are sent to the topping column through the topping column feed tank to ensure the normal progress of production.

[0024] Furthermore, a premixing tank is further included, and the premixing tank is communicated with the bottom of the rotating packed bed nitrilation reactor through a pipeline.

[0025] The beneficial effect of adopting the above further scheme is that the structure is simple and the design is reasonable. The molten adipic acid and the catalyst phosphoric acid are premixed by the premixing tank to send the mixed solution into the rotating packed bed nitrilation reactor for subsequent processing.

[0026] Furthermore, a heater is further included. The top and bottom of the heater are respectively communicated with the two ends of a heating pipeline, and the heating pipeline penetrates through the rotating packed bed nitrilation reactor.

[0027] The beneficial effects of adopting the above further scheme are that the structure is simple and the design is reasonable. By heating the high-gravity cyanidation reactor with a heater, the normal progress of the separation operation is ensured.

[0028] The present invention also relates to a method for producing adiponitrile by high gravity, which is realized by using the high-gravity adiponitrile production system as described above, and includes the following specific steps:

[0029] The molten adipic acid is mixed with a catalyst and then sent into the high-gravity cyanidation reactor to contact and react with ammonia in a reverse concentration gradient. The obtained product enters the separation tower. The separation tower separates ammonia, water, crude nitrile and semi-nitrile from top to bottom. The ammonia and water are sent to other systems for treatment and recovery, and the crude nitrile enters the refining system for treatment to obtain the adiponitrile product;

[0030] The semi-nitrile is sent to a falling film semi-nitrile evaporator, and ammonia is introduced. The countercurrent ammonia can further convert the semi-nitrile into adiponitrile, and the adiponitrile and volatile products are sent back to the separation tower again.

[0031] The beneficial effects of adopting the above further scheme are that the present invention also provides a method for producing adiponitrile by high gravity. This method utilizes the structural and technical characteristics of the high-gravity reactor. From the inside to the outside in the radial direction of the rotor, a reverse concentration gradient of ammonia and molten adipic acid is formed, increasing the gas-liquid contact specific area, increasing the mass transfer driving force, accelerating the reaction rate, separating the reaction products during the reaction process, and accelerating the promotion of the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 is a schematic diagram of a partial structure of the present invention;

[0034] Figure 3 is a schematic diagram of the structure of the refining device in the present invention.

[0035] In the drawings, the list of components represented by each reference numeral is as follows:

[0036] 1. Premixing tank; 2. High-gravity cyanidation reactor; 3. Heater; 4. Separation tower; 5. Condenser; 6. Semi-nitrile evaporator; 7. Crude nitrile water washing tank; 8. Filter; 9. Decanter; 10. Dehydrator; 11. Stripping tower feed tank; 12. Stripping tower; 13. Reboiler; 14. Buffer tank; 15. Refined adiponitrile storage tank; 16. Tail-cutting tower. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0040] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0041] Embodiment 1

[0042] As Figures 1 to 3 shown, this embodiment provides a supergravity adiponitrile production system, including a supergravity nitrilation reactor 2, a separation tower 4, a semi-nitrile evaporator 6 and a refining device. The middle part of the supergravity nitrilation reactor 2 is communicated with the lower part of the separation tower 4 through a main pipeline, and its top is communicated with a main ammonia pipeline; the top of the separation tower 4 is respectively communicated with an ammonia recovery pipeline and a water recovery pipeline, and its upper part is communicated with the refining device through a pipeline; the top of the semi-nitrile evaporator 6 is respectively communicated with the bottom of the separation tower 4, the main pipeline and the main ammonia pipeline through pipelines.

[0043] During the production process, molten adipic acid is mixed with a catalyst and then sent into the supergravity nitrilation reactor 2 to contact and react with ammonia in a reverse concentration gradient. The product obtained from the supergravity nitrilation reactor 2 enters the separation tower 4. The separation tower 4 separates ammonia, water, crude nitrile and semi-nitrile from top to bottom. Ammonia and water are sent to other systems for treatment and recovery, and the crude nitrile enters the refining device for treatment to obtain adiponitrile products.

[0044] The heminitrile is sent to a stirred falling film heminitrile evaporator 6 heated by a hot carrier steam, and ammonia gas is introduced. The countercurrent ammonia can further convert the heminitrile into adiponitrile, and the adiponitrile and volatile products are separated and recovered from the residues and catalysts through the separation column 4.

[0045] Preferably, in this embodiment, one end of the main ammonia pipeline is connected to the top of the gravity nitrilation reactor 2, and the other end is used to connect to an ammonia supply device.

[0046] Based on the above solution, a condenser 5 is fixedly installed on the ammonia recovery pipeline, and the bottom of the condenser 5 is connected to the top of the high-gravity nitrilation reactor 2 through a pipeline.

[0047] It should be noted that the above high-gravity nitrilation reactor 2, separation column 4, and heminitrile evaporator 6 respectively adopt existing technologies, and their specific structures and principles will not be elaborated here.

[0048] This embodiment utilizes the structural and technical characteristics of the high-gravity reactor. From the inside to the outside in the radial direction of the rotor, a reverse concentration gradient of ammonia gas and molten adipic acid is formed, increasing the gas-liquid contact specific area, increasing the mass transfer driving force, accelerating the reaction rate, separating the reaction products during the reaction process, and accelerating the promotion of the reaction.

[0049] Example 2

[0050] On the basis of Example 1, in this embodiment, the refining device includes a crude nitrile water washing tank 7, a decanter 9, a dehydrator 10, a topping column 12, and a tailing column 16 connected in sequence through pipelines. The top of the crude nitrile water washing tank 7 is connected to the upper part of the separation column 4 through a pipeline.

[0051] During the production process, the crude nitrile enters the crude nitrile water washing tank 7 for washing to remove some intermediate products, and then the light phase of pre-distilled adiponitrile is obtained through the decanter 9; the ammonia water dissolved in the pre-distilled adiponitrile is removed through the crude nitrile dehydrator and recycled after condensation and treatment; the dehydrated adiponitrile removes the light components in the topping column 12 under vacuum operation, and the adiponitrile after topping removes the heavy components in the tailing column 16 under vacuum operation, and the adiponitrile product is obtained after refining.

[0052] It should be noted that the above crude nitrile water washing tank 7, decanter 9, dehydrator 10, topping column 12, and tailing column 16 respectively adopt existing technologies, and their specific structures and principles will not be elaborated here.

[0053] Example 3

[0054] On the basis of Embodiment 2, in this embodiment, the top of the topping column 12 is communicated with the lower part of the tailing column 16 through Pipeline 1, and the top of the tailing column 16 is communicated with a product pipeline; buffer tanks 14 are fixedly installed on Pipeline 1 and the product pipeline respectively.

[0055] This solution has a simple structure and reasonable design. By arranging the buffer tank 14 to buffer the corresponding substances, the subsequent production can be carried out.

[0056] It should be noted that the above buffer tank 14 adopts the existing technology, and its specific structure and principle will not be elaborated here.

[0057] Embodiment 4

[0058] On the basis of Embodiment 3, in this embodiment, condensers 5 are also fixedly installed on Pipeline 1 and the product pipeline respectively. The two condensers 5 are respectively located at the part of Pipeline 1 corresponding to the position between the topping column 12 and one of the buffer tanks 14 and at the part of the product pipeline corresponding to the position between the tailing column 16 and the other buffer tank 14, and the tops of the two condensers 5 are respectively communicated with vacuum pipelines.

[0059] This solution has a simple structure and reasonable design. By cooling the substances coming out of the topping column and the tailing column through the two coolers 5, the corresponding heat is recovered, and the energy consumption is saved.

[0060] It should be noted that the above condenser 5 adopts the existing technology, and its specific structure and principle will not be elaborated here.

[0061] Embodiment 5

[0062] On the basis of any one of Embodiments 3 to 4, in this embodiment, the refining device further includes an adiponitrile storage tank 15, and the adiponitrile storage tank 15 is communicated with the product pipeline.

[0063] This solution has a simple structure and reasonable design. The prepared adiponitrile product is collected through the adiponitrile storage tank 15, which is convenient for collection.

[0064] Preferably, in this embodiment, a nitrogen pipe is communicated with the top of the above adiponitrile storage tank 15, and nitrogen is introduced into the adiponitrile storage tank 15 through the nitrogen pipe to isolate the product in the adiponitrile storage tank 15 from the air and protect the product.

[0065] Based on the above solution, the two ends of the product pipeline are respectively communicated with the top of the adiponitrile storage tank 15 and the top of the tailing column 16.

[0066] Embodiment 6

[0067] Based on any one of Embodiments 3 to 5, in this embodiment, reboilers 13 are respectively connected in parallel to the lower part of the topping column 12 and the lower part of the tailing column 16.

[0068] This solution has a simple structure and reasonable design. The two reboilers 13 vaporize the liquid in the topping column 12 and the tailing column 16 again to ensure the normal progress of production operations.

[0069] It should be noted that the above-mentioned reboilers 13 adopt existing technologies, and their specific structures and principles will not be elaborated here.

[0070] Embodiment 7

[0071] Based on any one of Embodiments 3 to 6, in this embodiment, the bottom of the dehydrator 10 is connected to the middle part of the topping column 12 through Pipeline 2, and a topping column feed tank 11 is fixedly installed on Pipeline 2; the bottom of the crude acrylonitrile water washing tank 7 is connected to the top of the decanter 9 through Pipeline 3, and a filter 8 is fixedly installed on Pipeline 3.

[0072] This solution has a simple structure and reasonable design. The material discharged from the crude acrylonitrile dehydrator is sent to the topping column 12 through the topping column feed tank 11 to ensure the normal progress of production.

[0073] It should be noted that the above-mentioned topping column feed tank 11 adopts existing technologies, and their specific structures and principles will not be elaborated here.

[0074] Embodiment 8

[0075] Based on the above embodiments, this embodiment further includes a premixing tank 1, and the premixing tank 1 is connected to the bottom of the rotating packed bed acrylonitrile reactor 2 through a pipeline.

[0076] This solution has a simple structure and reasonable design. The molten adipic acid and the catalyst phosphoric acid are premixed through the premixing tank 1, so as to send the mixed solution into the rotating packed bed acrylonitrile reactor 2 for subsequent processing.

[0077] Preferably, in this embodiment, a nitrogen pipe is connected to the top of the above-mentioned premixing tank 1, and nitrogen is introduced into the premixing tank 1 through the nitrogen pipe to isolate the raw materials in the premixing tank 1 from the air and protect the raw materials.

[0078] Alternatively, the molten adipic acid and the catalyst phosphoric acid can also be manually premixed first, and then pumped into the rotating packed bed acrylonitrile reactor 2.

[0079] Based on the above solution, the lower ends of the two nitrogen pipes are respectively connected to the top of the premixing tank 1 and the top of the adiponitrile storage tank 15, and the other ends are respectively used to connect to a nitrogen gas tank.

[0080] Embodiment 9

[0081] Based on the above embodiments, this embodiment further includes a heater 3. The top and bottom of the heater 3 are respectively communicated with both ends of the heating pipeline, and the heating pipeline penetrates through the supergravity nitrile reactor 2.

[0082] This solution has a simple structure and reasonable design. By heating the supergravity nitrile reactor 2 with the heater 3, the normal progress of the separation operation is ensured.

[0083] It should be noted that the above heater 3 adopts the prior art, and its specific structure and principle will not be elaborated herein.

[0084] Example 10

[0085] Based on the above embodiments, this embodiment further provides a method for producing supergravity adiponitrile, which is realized by using the supergravity adiponitrile production system as described above, and includes the following specific steps:

[0086] The molten adipic acid is mixed with the catalyst and then sent into the supergravity nitrile reactor 2 to contact and react with ammonia in a reverse concentration gradient. The product obtained from the supergravity nitrile reactor 2 enters the separation tower 4. The separation tower 4 separates ammonia, water, crude nitrile and semi-nitrile from top to bottom. The ammonia and water are sent to other systems for treatment and recovery, and the crude nitrile enters the refining system for treatment to obtain the adiponitrile product;

[0087] The semi-nitrile is sent to a falling film semi-nitrile evaporator 6 heated by a heat carrier steam and equipped with stirring, and ammonia is introduced. The countercurrent ammonia can further convert the semi-nitrile into adiponitrile, and the adiponitrile and volatile products are separated and recovered from the residue and catalyst through the separation tower 4.

[0088] This embodiment further provides a method for producing supergravity adiponitrile. This method utilizes the structural and technical characteristics of the supergravity reactor. From the inside to the outside in the radial direction of the rotor, a reverse concentration gradient of ammonia and molten adipic acid is formed, increasing the gas-liquid contact specific area, increasing the mass transfer driving force, accelerating the reaction rate, separating the reaction products during the reaction process, and accelerating the progress of the reaction.

[0089] The production process of the present invention is as follows:

[0090] The molten adipic acid and the catalyst phosphoric acid are premixed in the premixing tank 1 and then sent into the supergravity nitrile reactor 2 to contact and react with ammonia in a reverse concentration gradient. The heat required for the reaction is provided by the heater 3;

[0091] The product obtained from the high-gravity cyanidation reactor 2 enters the separation column 4, where ammonia, water, crude adiponitrile and semi-adiponitrile are separated from top to bottom. The ammonia and water are sent to other systems for treatment and recovery; the crude adiponitrile enters the refining system; the semi-adiponitrile is sent to a falling film semi-adiponitrile evaporator 6 heated by a heat carrier steam and equipped with stirring, and ammonia gas is introduced. The countercurrent ammonia can further convert the semi-adiponitrile into adiponitrile, and the adiponitrile and volatile products are separated and recovered from the residue and catalyst;

[0092] The crude adiponitrile enters the crude adiponitrile water washing tank 7 for washing to remove some intermediate products. After cooling and passing through the filter 8, a two-phase liquid mixture is obtained, and then the light phase of pre-distilled adiponitrile is obtained through the decanter 9. The ammonia water dissolved in the pre-distilled adiponitrile is removed through the crude adiponitrile dehydrator 10, and after condensation, it is processed for recycling;

[0093] The dehydrated adiponitrile removes the light components in the topping column 12 under vacuum operation;

[0094] The adiponitrile after topping removes the heavy components in the tailing column 16 under vacuum operation, and the refined adiponitrile product is sent to the refined adiponitrile storage tank 15.

[0095] Compared with the prior art, the present invention has the following advantages:

[0096] 1. Strengthen the mass transfer effect between molten adipic acid and ammonia gas.

[0097] 2. Shorten the reaction time, reduce the reaction temperature, reduce the occurrence of side reactions, improve the product conversion rate, and save the energy consumption during product refining.

[0098] 3. Reduce the coking tendency of the cyanidation reactor and extend the stable operation time of the device.

[0099] The purpose of the present invention is to provide a process system for producing and subsequent separating and refining adiponitrile by the high-gravity method. By utilizing the structure and technology characteristics of the high-gravity reactor, a reverse concentration gradient of ammonia gas and molten adipic acid is formed from the inside to the outside in the radial direction of the rotor, increasing the gas-liquid contact specific area, increasing the mass transfer driving force, accelerating the reaction rate, and separating the reaction products during the reaction process, thus accelerating the progress of the reaction. It can solve the problems of coking in the cyanidation reactor, increased side reactions, low reaction conversion rate, and high production cost in the existing process route.

[0100] It should be noted that all the electronic components involved in the present invention adopt the prior art, and the above-mentioned components are electrically connected to the controller, and the control circuit between the controller and each component is the prior art.

[0101] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0102] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0103] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A supergravity adiponitrile production system, characterized in that: It includes a supergravity cyanidation reactor (2), a separation column (4), a semi-nitrile evaporator (6) and a refining device. The middle part of the supergravity cyanidation reactor (2) is connected to the lower part of the separation column (4) through a main pipeline, and its top is connected to a main ammonia pipeline; the top of the separation column (4) is respectively connected to an ammonia recovery pipeline and a water recovery pipeline, and its upper part is connected to the refining device through a pipeline; the top of the semi-nitrile evaporator (6) is respectively connected to the bottom of the separation column (4), the main pipeline and the main ammonia pipeline through pipelines.

2. The supergravity adiponitrile production system according to claim 1, characterized in that: The refining device includes a crude adiponitrile water washing tank (7), a decanter (9), a dehydrator (10), a topping column (12) and a tailing column (16) connected in sequence through pipelines. The top of the crude adiponitrile water washing tank (7) is connected to the upper part of the separation column (4) through a pipeline.

3. The supergravity adiponitrile production system according to claim 2, wherein: The top of the topping column (12) is connected to the lower part of the tailing column (16) through pipeline one, and the top of the tailing column (16) is connected to a product pipeline; buffer tanks (14) are fixedly installed on pipeline one and the product pipeline respectively.

4. The supergravity adiponitrile production system according to claim 3, characterized in that: Condensers (5) are also fixedly installed on pipeline one and the product pipeline respectively. The two condensers (5) are respectively located at the part of pipeline one corresponding to between the topping column (12) and one of the buffer tanks (14) and the part of the product pipeline corresponding to between the tailing column (16) and the other buffer tank (14), and the tops of the two condensers (5) are respectively connected to a vacuum pipeline.

5. The supergravity adiponitrile production system according to claim 3, wherein: The refining device also includes a refined adiponitrile storage tank (15), and the refined adiponitrile storage tank (15) is connected to the product pipeline.

6. The supergravity adiponitrile production system according to claim 3, wherein: Reboilers (13) are connected in parallel to the lower parts of the topping column (12) and the tailing column (16) respectively.

7. The supergravity adiponitrile production system according to claim 3, wherein: The bottom of the dehydrator (10) is connected to the middle part of the topping column (12) through pipeline two, and a topping column feed tank (11) is fixedly installed on pipeline two; the bottom of the crude adiponitrile water washing tank (7) is connected to the top of the decanter (9) through pipeline three, and a filter (8) is fixedly installed on pipeline three.

8. The supergravity adiponitrile production system according to any one of claims 1-7, characterized in that: It also includes a premixing tank (1), and the premixing tank (1) is connected to the bottom of the supergravity cyanidation reactor (2) through a pipeline.

9. The supergravity adiponitrile production system according to any one of claims 1-7, characterized in that: It also includes a heater (3). The top and bottom of the heater (3) are respectively connected to the two ends of a heating pipeline, and the heating pipeline passes through the supergravity cyanidation reactor (2).

10. A method for producing adiponitrile by using high gravity, characterized in that: It is realized by using the supergravity adiponitrile production system according to any one of claims 1-9, and includes the following specific steps: The molten adipic acid is mixed with a catalyst and then sent into the supergravity cyanidation reactor (2) to contact and react with ammonia in a reverse concentration gradient. The obtained product enters the separation column (4). The separation column (4) separates ammonia, water, crude adiponitrile and semi-nitrile from top to bottom. The ammonia and water are sent to other systems for treatment and recovery, and the crude adiponitrile enters the refining system for treatment to obtain an adiponitrile product; The semi-nitrile is sent to a falling film semi-nitrile evaporator (6), and ammonia is introduced. The countercurrent ammonia can further convert the semi-nitrile into adiponitrile, and the adiponitrile and volatile products are sent back to the separation column (4) again.

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