Production system of 7-chloro-8-methylquinoline

Abstract

The utility model belongs to the technical field of pesticide intermediate production, and particularly discloses a 7-chloro-8-methylquinoline production system which comprises a reaction kettle, a neutralization kettle and a reduced pressure distillation kettle, the lower end of the reaction kettle is connected with the upper end of the neutralization kettle through a first delivery pump, and the upper end of the neutralization kettle is connected with a liquid caustic soda storage tank and a water storage tank. The lower end of the neutralization kettle is respectively connected with a wastewater storage tank and a second delivery pump, the output end of the second delivery pump is connected with the upper end of a reduced pressure distillation kettle, the upper end of the reduced pressure distillation kettle is connected with a first condenser, and the lower end of the first condenser is connected with a product collection tank. According to the utility model, the reduced pressure distillation kettle is arranged to separate product components to replace the process of adding petroleum ether to dissolve, extract and separate the product components, so that the use of petroleum ether is avoided, and the problems of harm to the health of personnel and pollution to the ambient atmosphere caused by careless leakage of petroleum ether steam due to the use of petroleum ether as a solvent are solved; and the environmental protection and the safety of the system for producing the 7-chloro-8-methylquinoline are improved.

Description

Technical Field

[0001] This utility model belongs to the field of pesticide intermediate production technology, specifically a production system for 7-chloro-8-methylquinoline. Background Technology

[0002] 7-Chloro-8-methylquinoline is a precursor in the synthesis of the pesticide intermediate 3,7-dichloro-8-dichloromethylquinoline. Currently, industrial production of 7-chloro-8-methylquinoline primarily employs the Skraup synthesis method, where 3-chloro-2-methylaniline and glycerol are reacted as starting materials, undergoing a cyclization reaction in the presence of sulfuric acid and an oxidizing agent to generate the target product. The product is then dissolved and separated in a reactor using petroleum ether, neutralized with an alkaline solution, filtered, and separated. The organic phase is then subjected to solvent removal, and the solvent is recycled to obtain the final product. While petroleum ether can be used as a solvent to dissolve and separate the 7-chloro-8-methylquinoline product, it is flammable and explosive, requires stringent storage conditions, and its vapors are irritating to the eyes, mucous membranes, and respiratory tract, and are also environmentally hazardous. Therefore, a production system for 7-chloro-8-methylquinoline that does not use petroleum ether as a solvent is needed. Utility Model Content

[0003] To address the above technical problems, this utility model provides a production system for 7-chloro-8-methylquinoline that can replace petroleum ether for the separation and purification of the product. This solves the problem that in the existing 7-chloro-8-methylquinoline production process, when petroleum ether is used as a solvent, the accidental leakage of petroleum ether vapor can cause harm to human health and pollution to the environment.

[0004] To solve the above technical problems, the technical solution of this utility model is as follows: a production system for 7-chloro-8-methylquinoline, comprising a reaction vessel, a neutralization vessel, and a vacuum distillation vessel. The upper end of the reaction vessel is connected to a feed pipe and an outlet pipe, respectively. The other end of the outlet pipe is connected to a waste gas absorption tank. The lower end of the reaction vessel is connected to the upper end of the neutralization vessel via a first conveying pump. The upper end of the neutralization vessel is connected to a liquid alkali storage tank and a water storage tank via a pipe. The lower end of the neutralization vessel is connected to a wastewater storage tank and a second conveying pump via a tee. The output end of the second conveying pump is connected to the upper end of the vacuum distillation vessel via a pipe. The upper end of the vacuum distillation vessel is connected to a first condenser via a pipe. The other end of the first condenser is connected to a vacuum pump via a pipe. The lower end of the first condenser is connected to a product collection tank via a pipe.

[0005] Furthermore, a second condenser is installed on the gas outlet pipeline, and a recovery liquid storage tank is connected to the liquid outlet at the lower end of the second condenser via a pipeline. The lower end of the recovery liquid storage tank is connected to the feed pipeline via a pipeline.

[0006] Furthermore, the reaction vessel, neutralization vessel, and vacuum distillation vessel are all lined with enamel.

[0007] This utility model has the following advantages compared with the prior art:

[0008] 1. This utility model replaces the process of adding petroleum ether to dissolve and extract the product components by setting up a vacuum distillation kettle to separate the product components. This avoids the use of petroleum ether and prevents the problem of accidental leakage of petroleum ether vapor caused by the use of petroleum ether as a solvent, which may cause harm to human health and pollution to the environment. This improves the environmental protection and safety of the system for the production of 7-chloro-8-methylquinoline.

[0009] 2. This utility model, by adding a second condenser to the outlet pipe through which the waste gas passes through the reactor, can condense the acrolein vapor mixed in the waste gas and recycle it back into the reactor to participate in the reaction, thereby increasing the utilization rate of raw materials and reducing the waste of reaction raw materials. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of the production system of this utility model.

[0011] In the diagram: 1. Reactor, 2. Neutralization vessel, 3. Vacuum distillation vessel, 4. Feed pipeline, 5. Gas outlet pipeline, 6. Waste gas absorption tank, 7. First transfer pump, 8. Liquid alkali storage tank, 9. Water storage tank, 10. Wastewater storage tank, 11. Second transfer pump, 12. First condenser, 13. Vacuum pump, 14. Product collection tank, 15. Second condenser, 16. Recovered liquid storage tank. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings.

[0013] like Figure 1 The system shown is for the production of 7-chloro-8-methylquinoline, including a reaction vessel 1, a neutralization vessel 2, and a vacuum distillation vessel 3. The upper end of the reaction vessel 1 is connected to a feed pipe 4 and an outlet pipe 5, respectively. The other end of the outlet pipe 5 is connected to a waste gas absorption tank 6. The lower end of the reaction vessel 1 is connected to the upper end of the neutralization vessel 2 via a first transfer pump 7. The upper end of the neutralization vessel 2 is connected to a liquid alkali storage tank 8 and a water storage tank 9 via pipes. Both the liquid alkali storage tank 8 and the water storage tank 9 are located at a higher position than the neutralization vessel 2. The lower end of the neutralization vessel 2 is connected to a wastewater storage tank 10 and a second transfer pump 11 via a tee. The output end of the second transfer pump 11 is connected to the upper end of the vacuum distillation vessel 3 via a pipe. The upper end of the vacuum distillation vessel 3 is connected to a first condenser 12 via a pipe. The other end of the first condenser 12 is connected to a vacuum pump 13 via a pipe. The lower end of the first condenser 12 is connected to a product collection tank 14 via a pipe.

[0014] It should be noted that in this embodiment, both the first delivery pump 7 and the second delivery pump 11 are chemical corrosion-resistant centrifugal pumps, and valves are installed on all pipelines.

[0015] To recover the acrolein gas that evaporates and is discharged from the reactor 1 along with the sulfur dioxide waste gas, a second condenser 15 is installed on the gas outlet pipe 5. The liquid outlet at the lower end of the second condenser 15 is connected to a recovery liquid storage tank 16 via a pipe. The lower end of the recovery liquid storage tank 16 is connected to the feed pipe 4 via a pipe. After the acrolein gas passes through the second condenser 15 for heat exchange, it condenses into liquid and flows back to the recovery liquid storage tank 16. Then, it re-enters the reactor 1 through the feed pipe 4 to participate in the reaction.

[0016] To enhance the corrosion resistance of each vessel, reaction vessel 1, neutralization vessel 2, and vacuum distillation vessel 3 are all lined with enamel.

[0017] The specific working process of this utility model is as follows:

[0018] The raw materials 3-chloro-2-methylaniline and glycerol are added to the reactor 1 through the feed pipe 4. 80% sulfuric acid is continuously added dropwise to the reactor. The heating and stirring functions of the reactor are started. The raw materials complete cyclization in the reactor 1 to obtain crude product. During this period, the sulfur dioxide gas generated is discharged from the outlet pipe 5 and enters the waste gas absorption tank 6 for harmless treatment. The evaporated acrolein vapor is separated when passing through the second condenser 15 and re-enters the reactor 1 to participate in the reaction. After the reaction is completed, the first transfer pump 7 is started to pump the material in the reactor 1 to the neutralization tank 2.

[0019] The material enters the neutralization vessel 2 for cooling. The valves on the pipelines of liquid alkali storage tank 8 and water storage tank 9 are opened, and liquid alkali and water enter the neutralization vessel 2 to neutralize the acid. After neutralization, the valves on the pipelines of liquid alkali storage tank 8 and water storage tank 9 are closed, and the mixture is allowed to stand to allow the organic phase and aqueous phase to separate. After separation, the valve at the lower outlet of the neutralization vessel is opened to discharge the aqueous phase into the wastewater storage tank 10. After collection, the wastewater is treated accordingly. The organic phase is then pumped to the vacuum distillation vessel 3 through the second transfer pump 11.

[0020] Turn on the heating and stirring functions of the vacuum distillation vessel 3, and start the vacuum pump 13. Under the operation of the vacuum pump 13, the gas pressure inside the vacuum distillation vessel 3 continuously decreases until it reaches and is maintained within the pressure range of high vacuum distillation (i.e., the operating pressure inside the vacuum distillation vessel 3 is between 1 Pa and 100 Pa). The temperature inside the vacuum distillation vessel 3 is controlled by heating, and different components in the organic phase inside the vacuum distillation vessel 3 are distilled and separated in sequence. When the product is distilled and separated, the final condensed product is collected from the outlet at the lower end of the first condenser 12 into the product collection tank 14.

Claims

1. A production system for 7-chloro-8-methylquinoline, characterized in that: The reactor includes a reaction vessel (1), a neutralization vessel (2), and a vacuum distillation vessel (3). The upper end of the reaction vessel (1) is connected to a feed pipe (4) and an outlet pipe (5). The other end of the outlet pipe (5) is connected to a waste gas absorption tank (6). The lower outlet of the reaction vessel (1) is connected to the upper inlet of the neutralization vessel (2) via a first conveying pump (7). The upper end of the neutralization vessel (2) is connected to a liquid alkali storage tank (8) and a water storage tank (9) via pipes. 2) The lower outlet is connected to a wastewater storage tank (10) and a second delivery pump (11) via a tee. The output end of the second delivery pump (11) is connected to the upper inlet of the vacuum distillation vessel (3) via a pipeline. The upper end of the vacuum distillation vessel (3) is connected to a first condenser (12) via a pipeline. The other end of the first condenser (12) is connected to a vacuum pump (13) via a pipeline. The lower end of the first condenser (12) is connected to a product collection tank (14) via a pipeline.

2. The production system for 7-chloro-8-methylquinoline according to claim 1, characterized in that: A second condenser (15) is installed on the gas outlet pipe (5). The liquid outlet at the lower end of the second condenser (15) is connected to a recovery liquid storage tank (16) via a pipe. The lower end of the recovery liquid storage tank (16) is connected to the feed pipe (4) via a pipe.

3. The production system for 7-chloro-8-methylquinoline according to claim 1, characterized in that: The reaction vessel (1), neutralization vessel (2), and vacuum distillation vessel (3) are all lined with enamel.

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