Treatment device for byproduct ammonium sulfate during caprolactam production

Abstract

The utility model relates to a treatment device for a byproduct ammonium sulfate during caprolactam production. Comprising a cyclohexanone-oxime storage tank and a sulfuric acid storage tank, the cyclohexanone-oxime storage tank and the sulfuric acid storage tank are respectively connected with a rearrangement device, an outlet of the rearrangement device and an outlet of a liquid ammonia storage tank are respectively connected with an inlet of an ammonium sulfate crystallization device, and a crude caprolactam outlet of the ammonium sulfate crystallization device is connected with an inlet of a caprolactam device. An ammonium sulfate outlet of the ammonium sulfate crystallization device and an outlet of the potassium chloride storage tank are respectively connected with an inlet of the potassium sulfate device reactor, an outlet of the potassium sulfate device reactor is connected with the settler, a crude potassium sulfate outlet of the settler is connected with the crude potassium scrubber, and an outlet of the crude potassium scrubber is connected with the potassium sulfate storage tank; the method has the characteristics that the yield of ammonium sulfate, potassium sulfate and ammonium chloride products can be flexibly adjusted according to market conditions while the defect of large amount of byproduct ammonium sulfate in caprolactam production is overcome, the elastic operation is good, the flexible adjustment capability is high, and the profitability of an enterprise is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of caprolactam production, and particularly relates to a processing device for by-product ammonium sulfate when producing caprolactam. Background Art

[0002] Caprolactam is prepared by Beckmann rearrangement of cyclohexanone oxime. Currently, there are two rearrangement process technologies: gas phase rearrangement and liquid phase rearrangement. The liquid phase rearrangement process is mature and stable, and the production capacity of a single unit is much greater than that of the gas phase method. However, the liquid phase Beckmann rearrangement process uses nicotinic acid as a catalyst, and ammonia neutralization treatment is required after the reaction, and a large amount of ammonium sulfate is produced as a by-product. According to statistics, 1.5-1.6 tons of ammonium sulfate are produced as a by-product per ton of caprolactam. The treatment of by-product ammonium sulfate has become a burden on existing caprolactam devices. When the inventory reaches a certain amount, the company takes load reduction or inspection and maintenance measures to deal with it. Therefore, the ammonium sulfate treatment method will also become the focus of enterprise discussion. Although patents CN102336708B and CN103012262B have announced the preparation method of caprolactam products, neither of them describes the treatment of by-product ammonium sulfate. Due to the above-mentioned large amount of by-product ammonium sulfate and the inability to process on a large scale, the cost of ammonium sulfate treatment of caprolactam production enterprises in my country is high, and even affects the industry's operating load capacity between 3 million and 5 million tons, which seriously affects the development of the industry and downstream industries. Utility Model Content

[0003] The utility model aims to overcome the defects in the prior art and provide a treatment device for by-product ammonium sulfate in the production of caprolactam.

[0004] The above technical objectives of the utility model are achieved through the following technical solutions:

[0005] A device for treating by-product ammonium sulfate when producing caprolactam, the device comprising a cyclohexanone oxime storage tank and a sulfuric acid storage tank, the cyclohexanone oxime storage tank and the sulfuric acid storage tank are respectively connected to a rearrangement device, the outlet of the rearrangement device and the outlet of the liquid ammonia storage tank are respectively connected to the inlet of an ammonium sulfate crystallization device, the crude caprolactam outlet of the ammonium sulfate crystallization device is connected to the inlet of the caprolactam device, the ammonium sulfate outlet of the ammonium sulfate crystallization device and the outlet of the potassium chloride storage tank are respectively connected to the inlet of a potassium sulfate device reactor, the outlet of the potassium sulfate device reactor is connected to a settler, the crude potassium sulfate outlet of the settler is connected to a crude potassium scrubber, and the outlet of the crude potassium scrubber is connected to the potassium sulfate storage tank.

[0006] The beneficial effects of the utility model are as follows: the utility model is based on the existing caprolactam production process, uses ammonium sulfate and potassium chloride produced as by-products of the above process as raw materials, and prepares potassium sulfate by double decomposition. The above process has the characteristics of no by-product hydrochloric acid, no high-temperature and high-pressure equipment and a high safety factor. At the same time, it can solve the defect that the by-product ammonium sulfate is large in amount and cannot be processed on a large scale, which affects the development of the industry and downstream industries.

[0007] Preferably, a vaporizer is provided between the outlet of the liquid ammonia storage tank and the inlet of the ammonium sulfate crystallization device.

[0008] Preferably, a first centrifugal separator is provided between the outlet of the crude potassium scrubber and the potassium sulfate storage tank.

[0009] Preferably, the crude ammonium chloride outlet of the settler is connected to a crystallizer, and the crystallizer is connected to an ammonium chloride storage tank.

[0010] Preferably, a second centrifugal separator is provided between the crystallizer and the ammonium chloride storage tank.

[0011] Preferably, a tee is provided between the ammonium sulfate outlet of the ammonium sulfate crystallization device and the inlet of the potassium sulfate device reactor, and the third end of the tee is connected to the ammonium sulfate storage tank through a third centrifugal separator.

[0012] Preferably, a first valve is provided between the tee and the inlet of the potassium sulfate device reactor, and a second valve is provided between the third end of the tee and the third centrifugal separator.

[0013] A device for treating ammonium sulfate produced as a by-product in the production of caprolactam is prepared according to the above technical scheme. The utility model is based on the existing caprolactam production process, uses ammonium sulfate and potassium chloride produced as by-products of the above process as raw materials, and prepares potassium sulfate by double decomposition. The above process has the characteristics of no by-product hydrochloric acid, no high-temperature and high-pressure equipment and high safety factor. Furthermore, the utility model gasifies the liquid ammonia in the liquid ammonia storage tank and then enters the ammonium sulfate crystallization device for neutralization to reduce the moisture in the raw material, thereby reducing the waste water in the system, and providing convenience for subsequent impurity removal and production of potassium sulfate and ammonium chloride; the utility model can be used to produce caprolactam, potassium sulfate, ammonium chloride and ammonium sulfate, so as to flexibly adjust the output of ammonium sulfate, potassium sulfate and ammonium chloride products according to market conditions, and has the characteristics of good elastic operation, strong flexible adjustment ability and improved enterprise profitability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 It is a structural schematic diagram of the utility model.

[0016] In the above picture:

[0017] 1. Cyclohexanone oxime storage tank 1; 2. Sulfuric acid storage tank; 3. Liquid ammonia storage tank; 4. Potassium chloride storage tank; 5. Rearrangement device; 6. Caprolactam device; 7. Vaporizer; 8. Ammonium sulfate crystallization device; 9. Potassium sulfate device reactor; 10. Settler; 11. Crystallizer; 12. Second centrifugal separator; 13. Ammonium chloride storage tank; 14. Crude potassium scrubber; 15. First centrifugal separator; 16. Potassium sulfate storage tank; 17. Third centrifugal separator; 18. Ammonium sulfate storage tank; 19. First valve; 20. Second valve. DETAILED DESCRIPTION

[0018] The technical solution of the utility model will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0019] Reference Figure 1 The utility model is a processing device for by-produced ammonium sulfate in the production of caprolactam, the processing device comprises a cyclohexanone oxime storage tank 1 and a sulfuric acid storage tank 2, the cyclohexanone oxime storage tank 1 and the sulfuric acid storage tank 2 are respectively connected to a rearrangement device 5, the outlet of the rearrangement device 5 and the outlet of the liquid ammonia storage tank 3 are respectively connected to the inlet of an ammonium sulfate crystallization device 8, the crude caprolactam outlet of the ammonium sulfate crystallization device 8 is connected to the inlet of a caprolactam device 6, the ammonium sulfate outlet of the ammonium sulfate crystallization device 8 and the outlet of a potassium chloride storage tank 4 are respectively connected to the inlet of a potassium sulfate device reactor 9, the outlet of the potassium sulfate device reactor 9 is connected to a settler 10, the crude potassium sulfate outlet of the settler 10 is connected to a crude potassium scrubber 14, and the outlet of the crude potassium scrubber 14 is connected to a potassium sulfate storage tank 16.

[0020] Furthermore, a vaporizer 7 is provided between the outlet of the liquid ammonia storage tank 3 and the inlet of the ammonium sulfate crystallization device 8. By providing the vaporizer 7, the liquid ammonia from the liquid ammonia storage tank 3 can be gasified so as to react in the ammonium sulfate crystallization device 8.

[0021] Furthermore, a first centrifugal separator 15 is provided between the outlet of the crude potassium scrubber 14 and the potassium sulfate storage tank 16. The first centrifugal separator 15 can be provided to separate the product potassium sulfate so as to achieve the purpose of selling it.

[0022] Furthermore, the crude ammonium chloride outlet of the settler 10 is connected to a crystallizer 11, and the crystallizer 11 is connected to an ammonium chloride storage tank 13. The crystallizer 11 can be provided to purify the crude ammonium chloride product and lay the foundation for the subsequent collection of ammonium chloride.

[0023] Furthermore, a second centrifugal separator 12 is provided between the crystallizer 11 and the ammonium chloride storage tank 13 .

[0024] Furthermore, a tee is provided between the ammonium sulfate outlet of the ammonium sulfate crystallization device 8 and the inlet of the potassium sulfate device reactor 9, and the third end of the tee is connected to the ammonium sulfate storage tank 18 through the third centrifugal separator 17.

[0025] Furthermore, a first valve 19 is provided between the tee and the inlet of the potassium sulfate device reactor 9 , and a second valve 20 is provided between the third end of the tee and the third centrifugal separator 17 .

[0026] The working principle of the utility model is as follows:

[0027] (1) Rearrangement reaction:

[0028] (2) Ammonium sulfate synthesis: 2NH3+H2SO4→(NH4)2SO4;

[0029] (3) Potassium sulfate synthesis: (NH4)2SO4+2KCl→K2SO4+2NH4Cl;

[0030] The specific process is as follows: the raw material cyclohexanone oxime from the cyclohexanone oxime storage tank 1 enters the rearrangement device 5, and the raw material sulfuric acid from the sulfuric acid storage tank 2 enters the rearrangement device 5 at the same time, and the rearranged liquid acid from the rearrangement device 5 enters the ammonium sulfate crystallization device 8 for crystallization treatment. The liquid ammonia from the liquid ammonia storage tank 3 is vaporized by the vaporizer 7 and then enters the ammonium sulfate crystallization device 8 to participate in the neutralization reaction to obtain a crude caprolactam product containing ammonium sulfate; after separation, the crude caprolactam enters the caprolactam device 6 for refining to obtain a caprolactam product; when it is necessary to produce the ammonium sulfate product, the second valve 20 is opened to allow the ammonium sulfate product to enter the third centrifugal separator 17 for centrifugal separation, and the separated ammonium sulfate product enters the ammonium sulfate storage tank 18 for sale; when it is necessary to produce ammonium chloride and / or potassium sulfate, the first valve 19 is opened, and the potassium chloride raw material from the potassium chloride warehouse 4 is mixed with the potassium chloride raw material from the ammonium sulfate device 8 in proportion. The ammonium sulfate product enters the potassium sulfate device reactor 9 together; it is converted into a potassium sulfate crude product and a crude ammonium chloride product through the potassium sulfate device reactor 9, and the above two enter the settler 10 for separation. The separated crude potassium sulfate crude product enters the crude potassium washer 14 for washing, and after washing, it preferably enters the first centrifugal separator 15 for centrifugal separation to obtain the product potassium sulfate, and enters the potassium sulfate storage tank 16 for sale; the separated crude ammonium chloride product enters the crystallizer 11 for crystallization, and after crystallization, it is centrifuged through the second centrifugal separator 12 to obtain the ammonium chloride product, and enters the ammonium chloride storage tank 13 for sale. The rearrangement device 5 described in the utility model mainly includes a rearrangement reactor and a condenser. The equipment is a conventional kettle reactor, and the operating temperature of the condenser is: 30-150°C, and the operating pressure is: 0.01-1.0MPa. The caprolactam device 6 mainly includes a caprolactam refining tower, and the distillation tower is a conventional plate tower, and the operating temperature is: 40-165°C, and the operating pressure is: 0.01-1.0MPa. The ammonium sulfate crystallization device 8 mainly includes a neutralization crystallization kettle, a thickener, and a mother liquor storage tank. The equipment is conventional equipment, and the operating temperature of the device is: 30-130°C, and the operating pressure is: 0.01-1.0MPa; the potassium sulfate device reactor 9 is a conventional reactor with a stirring function, and the operating temperature is: 30-120°C, and the operating pressure is: 0.01-0.6MPa, and the crude potassium scrubber 14 is a conventional washing device with a spraying function without a special structure. The above process has the characteristics of no by-product hydrochloric acid, no high-temperature and high-pressure equipment, and a high safety factor; at the same time, while solving the defect of a large amount of ammonium sulfate by-product in the production of caprolactam, it can realize the flexible adjustment of the output of ammonium sulfate, potassium sulfate, and ammonium chloride products according to market conditions, and has the characteristics of good elastic operation, strong flexible adjustment ability, and improved enterprise profitability.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for treating ammonium sulfate produced as a by-product during the production of caprolactam, the device comprising a cyclohexanone oxime storage tank (1) and a sulfuric acid storage tank (2), the cyclohexanone oxime storage tank (1) and the sulfuric acid storage tank (2) being connected to a rearrangement device (5) respectively, the outlet of the rearrangement device (5) and the outlet of the liquid ammonia storage tank (3) being connected to the inlet of an ammonium sulfate crystallization device (8) respectively, the crude caprolactam outlet of the ammonium sulfate crystallization device (8) being connected to the inlet of a caprolactam device (6), characterized in that: The ammonium sulfate outlet of the ammonium sulfate crystallization device (8) and the outlet of the potassium chloride storage tank (4) are respectively connected to the inlet of the potassium sulfate device reactor (9), the outlet of the potassium sulfate device reactor (9) is connected to the settler (10), the crude potassium sulfate outlet of the settler (10) is connected to the crude potassium scrubber (14), and the outlet of the crude potassium scrubber (14) is connected to the potassium sulfate storage tank (16).

2. The device for treating by-product ammonium sulfate in the production of caprolactam according to claim 1, characterized in that: A vaporizer (7) is provided between the outlet of the liquid ammonia storage tank (3) and the inlet of the ammonium sulfate crystallization device (8).

3. The device for treating by-product ammonium sulfate in the production of caprolactam according to claim 1, characterized in that: A first centrifugal separator (15) is provided between the outlet of the crude potassium scrubber (14) and the potassium sulfate storage tank (16).

4. The device for treating by-product ammonium sulfate in the production of caprolactam according to claim 1, characterized in that: The crude ammonium chloride outlet of the settler (10) is connected to a crystallizer (11), and the crystallizer (11) is connected to an ammonium chloride storage tank (13).

5. The device for treating by-product ammonium sulfate in the production of caprolactam according to claim 4, characterized in that: A second centrifugal separator (12) is provided between the crystallizer (11) and the ammonium chloride storage tank (13).

6. The device for treating by-product ammonium sulfate in the production of caprolactam according to claim 1, characterized in that: A tee is provided between the ammonium sulfate outlet of the ammonium sulfate crystallization device (8) and the inlet of the potassium sulfate device reactor (9), and the third end of the tee is connected to the ammonium sulfate storage tank (18) through a third centrifugal separator (17).

7. The device for treating by-product ammonium sulfate in the production of caprolactam according to claim 6, characterized in that: A first valve (19) is provided between the tee and the inlet of the potassium sulfate device reactor (9), and a second valve (20) is provided between the third end of the tee and the third centrifugal separator (17).

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