阅读说明：本技术 一种氨肟化法制备环己酮肟的精制系统 (Refining system for preparing cyclohexanone oxime by ammoximation method ) 是由 李本斌 李晓星 禹保卫 许永锋 胡红勤 彭伟 张恒超 潘娇阳 王付军 于 2021-10-20 设计创作，主要内容包括：本发明涉及一种氨肟化法制备环己酮肟的精制系统。该精制系统包括提浓以及精制塔,提浓塔上设有提浓塔进液管、提浓塔出液管以及提浓塔出气管,提浓塔的两侧分别连接有第一提浓塔再沸器以及第二提浓塔再沸器,精制塔上设有精制塔进液管、精制塔出液管以及精制塔出气管,提浓塔出液管通过第一连接管与精制塔进液管连接,第一连接管上设有第一输送泵,精制塔出气管通过第二连接管与第二提浓塔再沸器的进气口连接,第二提浓塔再沸器的冷凝液出口通过第三连接管与肟水稀液收集罐连接,肟水稀液收集罐通过第四连接管与提浓塔进液管连接,第四连接管上设有第二输送泵。本发明通过物理手段对环己酮肟进行精制提纯,使得环己酮肟精制更加环保、节能、安全。(The invention relates to a refining system for preparing cyclohexanone oxime by an ammoximation method. The refining system comprises a concentration tower and a refining tower, wherein a concentration tower liquid inlet pipe is arranged on the concentration tower, a concentration tower liquid outlet pipe and a concentration tower gas outlet pipe are arranged on the concentration tower, a first concentration tower reboiler and a second concentration tower reboiler are respectively connected to two sides of the concentration tower, a refining tower liquid inlet pipe is arranged on the refining tower, a refining tower liquid outlet pipe and a refining tower gas outlet pipe are arranged on the refining tower, the concentration tower liquid outlet pipe is connected with the refining tower liquid inlet pipe through a first connecting pipe, a first conveying pump is arranged on the first connecting pipe, the refining tower gas outlet pipe is connected with a gas inlet of the second concentration tower reboiler through a second connecting pipe, a condensate outlet of the second concentration tower reboiler is connected with an oxime water dilute liquid collecting tank through a third connecting pipe, the oxime water dilute liquid collecting tank is connected with the concentration tower liquid inlet pipe through a fourth connecting pipe, and a second conveying pump is arranged on the fourth connecting pipe. The invention refines and purifies the cyclohexanone oxime by a physical means, so that the refining of the cyclohexanone oxime is more environment-friendly, energy-saving and safe.)

1. A refining system for preparing cyclohexanone oxime by an ammoximation method is characterized by comprising a concentration tower and a refining tower, wherein a concentration tower liquid inlet pipe, a concentration tower liquid outlet pipe and a concentration tower gas outlet pipe are arranged on the concentration tower, a first concentration tower reboiler and a second concentration tower reboiler are respectively connected with two sides of the concentration tower, a refining tower liquid inlet pipe, a refining tower liquid outlet pipe and a refining tower gas outlet pipe are arranged on the refining tower, the concentration tower liquid outlet pipe is connected with the refining tower liquid inlet pipe through a first connecting pipe, a first conveying pump is arranged on the first connecting pipe, the refining tower gas outlet pipe is connected with a gas inlet of the second concentration tower reboiler through a second connecting pipe, a condensate outlet of the second concentration tower is connected with an oxime water dilute liquid collecting tank through a third connecting pipe, and the oxime water dilute liquid collecting tank is connected with the concentration tower liquid inlet pipe through a fourth connecting pipe, and a second delivery pump is arranged on the fourth connecting pipe.

2. The refining system for preparing cyclohexanone oxime by an ammoximation process according to claim 1, wherein a vacuum device for forming a negative pressure in the refining tower is connected to the oxime water dilute liquid collecting tank.

3. The refining system for preparing cyclohexanone oxime by an ammoximation method according to claim 1, wherein a liquid outlet pipe of the refining tower is connected with a cyclohexanone oxime collecting tank through a fifth connecting pipe, and a third conveying pump is arranged on the liquid outlet pipe of the cyclohexanone oxime.

4. The refining system for producing cyclohexanone oxime by an ammoximation process according to claim 1, wherein an inlet pipe of the reboiler of the first concentration tower is connected to an external steam pipe.

5. The refining system for producing cyclohexanone oxime by the ammoximation process according to claim 1, wherein a refining column reboiler is connected to an outer side of the refining column, and an inlet pipe of the refining column reboiler is connected to an external steam pipe.

6. The refining system for producing cyclohexanone oxime by an ammoximation process according to claim 1, wherein an outlet pipe of the concentration tower is connected to a heat source utilization device, a condensate pipe of the heat source utilization device is connected to a wastewater collection tank, and a water outlet pipe of the wastewater collection tank is provided with a fourth delivery pump.

Technical Field

The invention relates to the technical field of cyclohexanone oxime production, in particular to a refining system for preparing cyclohexanone oxime by an ammoximation method.

Background

Caprolactam is an important chemical raw material, and cyclohexanone oxime is an intermediate in the production process of caprolactam. At present, the production process of cyclohexanone oxime is mainly an ammoximation process, which was first discovered by Enichem company, italy, in the 80 s of the 20 th century, and was rapidly developed to replace the popular hydroxylamine process for preparing cyclohexanone oxime. The preparation of cyclohexanone oxime by an ammoximation method is characterized in that a titanium-silicon molecular sieve is used as a catalyst, cyclohexanone, hydrogen peroxide and ammonia are used as raw materials, a solvent is selected to create a homogeneous reaction environment (generally tert-butyl alcohol) for the raw materials, after ammoximation reaction, the solvent is recovered to form an oxime aqueous solution, then an extractant (generally toluene) is used for extracting cyclohexanone oxime, and the extractant is recovered by a rectification means to obtain cyclohexanone oxime with higher purity; and the raffinate phase is water and a small amount of cyclohexanone-oxime solution (generally about 2 percent), and is sent out after being treated by waste water.

Compared with the traditional hydroxylamine method for producing cyclohexanone oxime, the ammoximation method for preparing cyclohexanone oxime has no ammonium sulfate by-product, thereby greatly shortening the production flow. However, the ammoximation method for preparing cyclohexanone oxime still has the problems, most notably the generated waste water is difficult to treat; secondly, the solvent (tert-butanol) and the extractant (toluene) which are introduced in sequence in the reaction and refining processes are dangerous. Although the technology of the process for preparing cyclohexanone oxime by ammoximation is continuously improved in recent years, the two difficulties are not improved.

Disclosure of Invention

In order to solve the technical problems, the invention provides a refining system for preparing cyclohexanone oxime by an ammoximation method, which is used for refining and purifying cyclohexanone oxime by a physical means, so that the cyclohexanone oxime is more environment-friendly, energy-saving and safe to refine.

The invention relates to a refining system for preparing cyclohexanone oxime by an ammoximation method, which adopts the technical scheme that:

a refining system for preparing cyclohexanone oxime by an ammoximation method comprises a concentration tower and a refining tower, wherein a concentration tower liquid inlet pipe, a concentration tower liquid outlet pipe and a concentration tower gas outlet pipe are arranged on the concentration tower, a first concentration tower reboiler and a second concentration tower reboiler are respectively connected with two sides of the concentration tower, a refining tower liquid inlet pipe, a refining tower liquid outlet pipe and a refining tower gas outlet pipe are arranged on the refining tower, the concentration tower liquid outlet pipe is connected with the refining tower liquid inlet pipe through a first connecting pipe, a first conveying pump is arranged on the first connecting pipe, the refining tower gas outlet pipe is connected with a gas inlet of the second concentration tower reboiler through a second connecting pipe, a condensate outlet of the second concentration tower reboiler is connected with an oxime water dilute liquid collecting tank through a third connecting pipe, and the oxime water dilute liquid collecting tank is connected with the concentration tower liquid inlet pipe through a fourth connecting pipe, and a second delivery pump is arranged on the fourth connecting pipe.

As a further improvement of the first technical solution, a vacuum device for forming negative pressure in the refining tower is connected to the oxime and water dilute liquid collecting tank.

As a further improvement of the above technical solution, a liquid outlet pipe of the refining tower is connected with a cyclohexanone oxime collection tank through a fifth connecting pipe, and a third delivery pump is arranged on the liquid outlet pipe of the cyclohexanone oxime.

As a further improvement of the above technical solution, an air inlet pipe of the reboiler of the first concentrating tower is connected to an external steam pipe.

As a further improvement of the above technical means, a refining column reboiler is connected to an outside of the refining column, and an air inlet pipe of the refining column reboiler is connected to an outside steam pipe.

As a further improvement of the above technical solution, the outlet duct of the concentration tower is connected to a heat source utilization device, a condensate pipe of the heat source utilization device is connected to a wastewater collection tank, and a water outlet pipe of the wastewater collection tank is provided with a fourth delivery pump.

The invention provides a refining system for preparing cyclohexanone oxime by an ammoximation method, which has the following advantages compared with the prior art:

when the refining system for preparing cyclohexanone oxime by an ammoximation method is used, oxime aqueous solution fed from the previous process enters a concentration tower, a reboiler of the first concentration tower uses steam as a heat source for concentration, the concentration tower mainly has the main function of primarily concentrating the oxime aqueous solution, the operating conditions of the tower are controlled, the tower top components mainly comprise water vapor (containing trace cyclohexanol and cyclohexanone), and after the tower top steam is used as the heat source and heat energy is recovered by heat source utilization equipment, condensate enters a wastewater collection tank and is sent out by a fourth conveying pump. The concentrated oxime water solution after concentration at the tower bottom enters a refining tower through a first delivery pump, and the refining tower realizes negative pressure rectification by using vacuum equipment. Steam is used as a heat source in a reboiler of the refining tower, and the cyclohexanone oxime product at the bottom of the tower enters a cyclohexanone oxime collection tank and is pumped to the subsequent process through a ring third conveying pump. In order to ensure the purity of the cyclohexanone-oxime at the bottom of the tower, the gas phase at the top of the tower contains a certain amount of cyclohexanone-oxime, the main components are water and cyclohexanone-oxime, the condensed liquid enters a oxime water dilute liquid collecting tank after entering a first concentration tower reboiler to recover heat, and the condensed liquid returns to the concentration tower through a second conveying pump. Compared with the prior art, the refining system for preparing cyclohexanone oxime by an ammoximation method has the advantages that the wastewater index is greatly improved in the production process of cyclohexanone oxime, the content of cyclohexanone oxime in wastewater is reduced, and the environment-friendly aim is fulfilled. The refining system for preparing cyclohexanone oxime by the ammoximation method ensures the quality index of cyclohexanone oxime, effectively recovers heat and reduces the refining cost of cyclohexanone oxime. The refining system for preparing the cyclohexanone oxime by the ammoximation method does not introduce an extracting agent, and improves the safety of the process for preparing the cyclohexanone oxime by the ammoximation method. The refining system for preparing cyclohexanone oxime by the ammoximation method does not need the processes of extraction, wastewater treatment and the like, and shortens the production flow of cyclohexanone oxime.

Drawings

FIG. 1 is a schematic diagram of a refining system for producing cyclohexanone oxime by an ammoximation process of the present invention;

reference numbers in the figures: 1. a concentration tower; 2. a refining tower; 3. an oxime water dilute liquid collecting tank; 4. a wastewater collection tank; 5. a cyclohexanone oxime collection tank; 6. a first concentrating column reboiler; 7. a second concentration tower reboiler; 8. a refining column reboiler; 9. a heat source utilization device; 10. a second delivery pump; 11. a vacuum device; 12. a first delivery pump; 13. a fourth delivery pump; 14. and a third delivery pump.

Detailed Description

The invention is described in further detail below with reference to the following figures and detailed description:

the specific embodiment of the refining system for preparing cyclohexanone oxime by an ammoximation method comprises a concentration tower 1, wherein the concentration tower 1 is provided with a liquid inlet pipe of the concentration tower 1, a liquid outlet pipe of the concentration tower 1 and a gas outlet pipe of the concentration tower 1, the liquid inlet pipe of the concentration tower 1 is connected to the upper end of the side surface of the concentration tower 1, the liquid outlet pipe of the concentration tower 1 is connected to the bottom of the concentration tower 1, and the gas outlet pipe of the concentration tower 1 is connected to the top of the concentration tower 1, as shown in fig. 1.

In this embodiment, both sides of the concentrating tower 1 are connected with a first concentrating tower reboiler 6 and a second concentrating tower reboiler 7 respectively, an air inlet of the first concentrating tower reboiler 6 is connected with an external steam pipe, and a condensate pipe of the first concentrating tower reboiler 6 is connected with external condensate collecting equipment. An air outlet pipe of the concentration tower 1 is connected with external heat source utilization equipment 9 through a sixth connecting pipe, a condensing pipe of the heat source utilization equipment 9 is connected with a wastewater collection tank 4 through a seventh connecting pipe, a fourth conveying pump 13 is installed on an water outlet pipe of the wastewater collection tank 4, and the fourth conveying pump 13 is used for discharging wastewater in the wastewater collection tank 4.

In this embodiment, the refining tower 2 is provided with a refining tower 2 liquid inlet pipe, a refining tower 2 liquid outlet pipe and a refining tower 2 gas outlet pipe, wherein the refining tower 2 liquid inlet pipe is located at the upper end of the side surface of the refining tower 2, the refining tower 2 liquid outlet pipe is located at the bottom of the refining tower 2, and the refining tower 2 gas outlet pipe is located at the top of the refining tower 2. The side of the refining tower 2 is connected with a refining tower reboiler 8, the air inlet of the refining tower reboiler 8 is connected with an external steam pipe, and external high-temperature high-pressure steam provides heat for the refining tower reboiler 8. The liquid inlet pipe of the refining tower 2 is connected with the liquid outlet pipe of the concentration tower 1 through a first connecting pipe, a first delivery pump 12 is installed on the first connecting pipe, and the first delivery pump 12 is used for delivering the oxime water solution concentrated at the bottom of the concentration tower 1 into the refining tower 2. An air outlet pipe of the refining tower 2 is connected with an air inlet of a second concentration tower reboiler 7 through a second connecting pipe, a condensate outlet of the second concentration tower reboiler 7 is connected with an oxime water and dilute liquid collecting tank 3 through a third connecting pipe, and the oxime water and dilute liquid collecting tank 3 is connected with a vacuum device 11 used for enabling negative pressure to be formed in the refining tower 2. The oxime water dilute liquid collecting tank 3 is connected with a liquid inlet pipe of the concentration tower 1 through a fourth connecting pipe, a second delivery pump 10 is arranged on the fourth connecting pipe, and the second delivery pump 10 is used for delivering the oxime water in the oxime water dilute liquid collecting tank 3 into the concentration tower 1.

In this embodiment, a liquid outlet pipe of the refining tower 2 is connected with a cyclohexanone oxime collection tank 5 through a fifth connecting pipe, and a third delivery pump 14 is arranged on the liquid outlet pipe of the cyclohexanone oxime.

When the refining system for preparing cyclohexanone oxime by an ammoximation method is used, oxime aqueous solution sent from the previous process enters the concentration tower 1, the first concentration tower reboiler 6 uses steam as a heat source for concentration, the concentration tower 1 mainly has the main function of primarily concentrating the oxime aqueous solution, the operation conditions of the tower are controlled, the tower top components mainly comprise water vapor (containing trace cyclohexanol and cyclohexanone), the heat energy is recovered by the tower top steam as the heat source through the heat source utilization equipment 9, and then condensate enters a wastewater collection tank and is sent out through the fourth conveying pump 13. The concentrated oxime water solution after concentration at the tower bottom enters a refining tower 2 through a first conveying pump 12, and the refining tower 2 realizes negative pressure rectification by using a vacuum device 11. The reboiler 8 of the refining tower uses steam as a heat source, and the cyclohexanone oxime as a bottom product enters the cyclohexanone oxime collecting tank 5 and is sent to the subsequent process by the ring third conveying pump 14. In order to ensure the purity of the cyclohexanone-oxime at the bottom of the tower, the gas phase at the top of the tower contains a certain amount of cyclohexanone-oxime, the main components are water and cyclohexanone-oxime, the condensed liquid enters a oxime water dilute liquid collecting tank 3 after entering a first concentration tower reboiler 6 to recover heat, and the condensed liquid returns to the concentration tower 1 through a second conveying pump 10. Compared with the prior art, the refining system for preparing cyclohexanone oxime by an ammoximation method has the advantages that the wastewater index is greatly improved in the production process of cyclohexanone oxime, the content of cyclohexanone oxime in wastewater is reduced, and the environment-friendly aim is fulfilled. The refining system for preparing cyclohexanone oxime by the ammoximation method ensures the quality index of cyclohexanone oxime, effectively recovers heat and reduces the refining cost of cyclohexanone oxime. The refining system for preparing the cyclohexanone oxime by the ammoximation method does not introduce an extracting agent, and improves the safety of the process for preparing the cyclohexanone oxime by the ammoximation method. The refining system for preparing cyclohexanone oxime by the ammoximation method does not need the processes of extraction, wastewater treatment and the like, and shortens the production flow of cyclohexanone oxime.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.