Chlorination apparatus

Abstract

The application provides a chlorination reaction device. The reaction substrate and chlorine are continuously input through the pipeline reactor, the continuous reaction is realized, a gas-liquid separator is arranged to separate the reaction liquid and the gas generated in the reaction process, the separated gas is treated to recover the chlorine therein, the separated reaction liquid is transported to a water washing kettle to recover the solvent and is water washed to obtain a crude product, and the crude product is input into a post-treatment device for treatment. Through the cooperation of the above-mentioned devices, the continuous synthesis of 2-amino-5-chloro-N, 3-dimethylbenzamide is realized, and the problem of low production efficiency caused by the intermittent input of chlorine in the traditional synthesis reaction is overcome.

Description

Technical Field

[0001] This application relates to the field of organic synthesis technology, and in particular to a chlorination reaction apparatus. Background Technology

[0002] Chlorantraniliprole is a ryanodine receptor inhibitor insecticide with advantages such as high efficiency, broad spectrum, low toxicity, long residual effect and environmental friendliness. It can effectively control a variety of agricultural pests, such as lepidopteran pests and some coleopteran, dipteran, hemiptera and isoptera pests; it still has high insecticidal activity at very low mass concentrations.

[0003] 2-Amino-5-chloro-N,3-dimethylbenzamide is the main intermediate in the preparation of chlorantraniliprole. There are three main methods for synthesizing 2-amino-5-chloro-N,3-dimethylbenzamide: the route using methyl 2-nitro-3-methylbenzoate as a starting material, the route using 2-ethoxyformamido-3-methylbenzoic acid as a starting material, and the route using methyl 2-nitro-3-methylbenzoate as a starting material. Among these, the route using methyl 2-nitro-3-methylbenzoate as a starting material is more commonly used industrially due to its simplicity. This method involves a three-step reaction of methyl 2-nitro-3-methylbenzoate, namely methylation, iron powder reduction, and chlorination, to obtain the final product. The chlorination reaction is the key step in the reaction. The existing chlorination method uses thionyl chloride as the chlorinating agent, but thionyl chloride is expensive and requires strict storage conditions. Therefore, industrial production mostly uses chlorine gas as the chlorinating agent. However, the existing chlorination method using chlorine gas involves intermittent chlorination, which greatly restricts production efficiency. Utility Model Content

[0004] This application provides a chlorination reaction apparatus to solve the problem of low production efficiency caused by intermittent chlorination using chlorine gas as a chlorinating reagent in the synthesis of 2-amino-5-chloro-N,3-dimethylbenzamide.

[0005] This application provides a chlorination reaction apparatus, including at least one pipeline reactor, which is connected in series with a gas-liquid separator, a water washing tank and a post-treatment device.

[0006] The gas-liquid separator is also connected in sequence to a gas processing unit and a pipeline reactor;

[0007] The inlet of the pipeline reactor is also connected to a chlorine supply pipeline and a substrate solution storage tank, respectively.

[0008] A transfer pump is installed between the substrate solution storage tank and the inlet of the pipeline reactor.

[0009] Optionally, multiple pipeline reactors are provided, and the multiple pipeline reactors are connected in series.

[0010] Optionally, the gas processing unit includes a cryostat, a liquid chlorine storage tank, and a liquid chlorine vaporizer connected in series.

[0011] The cryogenic cooler is also connected to the exhaust gas treatment device;

[0012] The liquid chlorine vaporizer is also connected to the inlet of the pipeline reactor.

[0013] Optionally, the exhaust gas treatment device includes a water scrubbing tower, an alkaline scrubbing tower, and an adsorption tower connected in series.

[0014] The water washing tower is also connected to the hydrochloric acid storage tank.

[0015] Optionally, the post-treatment device includes a filter, a filtrate storage tank, a distillation column, an extraction vessel, and a recovery tank connected in series.

[0016] The filter is also connected to the crude product storage tank, and the extraction vessel is also connected to the wastewater treatment section.

[0017] The distillation column is also connected to a solvent storage tank.

[0018] Optionally, a demister is provided at the top of the gas-liquid separator.

[0019] Alternatively, the demister can be a baffle demister, a cyclone demister, or a wire mesh demister.

[0020] This application provides a chlorination reaction apparatus. A pipeline reactor is used to continuously input the reaction substrate and chlorine gas, enabling continuous reaction. A gas-liquid separator is simultaneously installed to separate the reaction liquid from the gases generated during the reaction. The separated gas is treated to recover the chlorine gas, and the separated reaction liquid is sent to a washing tank to recover the solvent and is washed with water to obtain a crude product. The crude product is then sent to a post-processing unit for further processing. Through the combined use of the above equipment, this apparatus achieves the continuous synthesis of 2-amino-5-chloro-N,3-dimethylbenzamide, overcoming the drawback of low production efficiency caused by intermittent chlorination using chlorine gas as the chlorinating agent in traditional synthesis reactions. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a chlorination reaction apparatus provided in one embodiment of this application;

[0023] Figure 2A schematic diagram of a chlorination reaction apparatus provided in another embodiment of this application;

[0024] Figure 3 This is a schematic diagram of a gas processing apparatus provided in one embodiment of this application;

[0025] Figure 4 A schematic diagram of a post-processing apparatus provided in an embodiment of this application;

[0026] Figure 5 This is a schematic diagram of the structure of a gas-liquid separator provided in one embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Pipeline reactor; 2. Gas-liquid separator; 3. Washing tank; 4. Post-treatment device; 5. Gas treatment device; 6. Substrate solution storage tank; 10. Chlorine supply pipeline; 20. Equipped with a transfer pump; 21. Demister; 41. Filter; 42. Filtrate storage tank; 43. Distillation column; 44. Extraction vessel; 45. Recovery tank; 46. Crude product storage silo; 47. Wastewater treatment section; 48. Solvent storage tank; 51. Cryogenic cooler; 52. Liquid chlorine storage tank; 53. Liquid chlorine vaporizer; 54. Tail gas treatment device; 541. Washing tower; 542. Alkali washing tower; 543. Adsorption tower; 544. Hydrochloric acid storage tank. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0030] like Figure 1 As shown, this application provides a chlorination reaction apparatus, including at least one pipeline reactor 1, which is connected in series with a gas-liquid separator 2, a water washing tank 3 and a post-treatment device 4.

[0031] The gas-liquid separator 2 is also connected in sequence to the gas processing device 5 and the pipeline reactor 1;

[0032] The input end of the pipeline reactor 1 is also connected to the chlorine supply pipeline 10 and the substrate solution storage tank 6, respectively.

[0033] A transfer pump 20 is installed between the substrate solution storage tank 6 and the input end of the pipeline reactor 1.

[0034] In this application, the pipeline reactor 1 includes a shell, and a reaction tube is disposed inside the shell. The inlet end of the reaction tube passes through the lower side of the shell and extends out of the shell, and the outlet end of the reaction tube passes through the upper side of the shell and extends out of the shell.

[0035] The reaction tube is coiled and folded into multiple layers inside the shell.

[0036] In use, the substrate solution storage tank 6 contains a certain concentration of acetonitrile solution of 2-amino-N,3-dimethylbenzamide (hereinafter referred to as the substrate solution), and a catalyst (aluminum chloride or ferric chloride, which is a suspension in the substrate solution because it is insoluble in organic solvents) is also added. The substrate solution is pumped into the reaction tube of the pipeline reactor 1 by the transfer pump 20. At the same time, chlorine gas supply pipeline 10 and chlorine gas recovered from liquid gas treatment device 5 are also transferred into the pipeline reactor 1 in a certain proportion (the amount of chlorine gas added is excess, and the molar ratio of chlorine gas to substrate is 1.2~1.5∶1), mixed with the substrate solution and reacted in the pipeline reactor 1. At the same time, circulating water is introduced into the shell of the pipeline reactor 1 to maintain the temperature of the reaction system in the range of 35~45℃. The substrate and chlorine gas undergo the following chlorination reaction in the reactor:

[0037]

[0038] In the reaction, chlorine is in a gaseous state, and the chlorine produced is also in a gaseous state. Therefore, after the reaction is completed, there will be a mixture of gases, mainly hydrogen chloride (and a small amount of unreacted chlorine). Thus, the gas-liquid mixture is output from the reactor.

[0039] The gas-liquid mixture that flows out after the reaction in the tubular reactor 1 enters the gas-liquid separator 2 for gas-liquid separation. The reaction liquid falls to the bottom of the separator 2, while the gas overflows from the reaction liquid system, passes through the top of the gas-liquid separator 2, and enters the gas processing device 5 for processing. The chlorine gas in the device is recovered and combined with the chlorine gas supplied by the chlorine gas supply pipeline 10, and then supplied to the tubular reactor 1 for further reaction.

[0040] The reaction liquid separated in the gas-liquid separator 2 is transferred to the water washing tank 3. The solvent in the reaction liquid is first concentrated by heating until the volume of the reaction liquid is 20-25% of the original volume. The distilled solvent is then recovered to the corresponding recovery tank. Water is then added to the concentrated reaction liquid until no more solids precipitate. At this point, the reaction products, which are insoluble in water, will precipitate, forming a solid-liquid mixture. This solid-liquid mixture is then transferred to the post-processing device 4 for post-processing.

[0041] The chlorination reactor provided in this application continuously inputs the reaction substrate and chlorine gas into a pipeline reactor 1, enabling continuous reaction. Simultaneously, a gas-liquid separator 2 separates the reaction liquid from the gas generated during the reaction. The separated gas is treated to recover the chlorine gas, while the separated reaction liquid is sent to a washing tank 3 to recover the solvent and is washed with water to obtain a crude product. The crude product is then fed into a post-processing unit 4 for further processing. Through the combined use of the above equipment, this apparatus achieves the continuous synthesis of 2-amino-5-chloro-N,3-dimethylbenzamide, overcoming the drawback of low production efficiency caused by intermittent chlorination using chlorine gas as the chlorinating agent in traditional synthesis reactions.

[0042] Optionally, multiple pipeline reactors 1 are provided, and the multiple pipeline reactors 1 are connected in series.

[0043] In this application, setting up multiple pipeline reactors 1 can extend the path of the reaction tube, thereby extending the reaction time and helping to improve the reaction conversion rate.

[0044] like Figure 2 As shown, optionally, the gas processing device 5 includes a cryocooler 51, a liquid chlorine storage tank 52 and a liquid chlorine vaporizer 53 connected in series.

[0045] The cryogenic cooler 51 is also connected to the exhaust gas treatment device 54;

[0046] The liquid chlorine vaporizer 53 is also connected to the input end of the pipeline reactor 1.

[0047] In this application, during use, the gas-liquid mixture flowing out after the reaction in the pipeline reactor 1 enters the gas-liquid separator 2 for gas-liquid separation. The reaction liquid falls to the bottom of the separator 2, while the gas overflowing from the reaction liquid system passes through the demister 21 installed at the top of the gas-liquid separator 2 for demisting and separation, and is output from the top of the gas-liquid separator 2 into the cryogenic cooler 51 for cooling (the temperature of the cooling medium is -40℃). This causes the chlorine gas in the gas to condense into a liquid state and be recovered into the liquid chlorine storage tank 52. After being vaporized by the liquid chlorine vaporizer 53, it is combined with the chlorine supplied by the chlorine supply pipeline 10 and fed into the tubular reactor 1 for reaction. The gas that is not condensed in the cryogenic cooler 51 (mainly hydrogen chloride) enters the tail gas treatment device 54 for treatment.

[0048] like Figure 3 As shown, optionally, the exhaust gas treatment device 54 includes a water washing tower 541, an alkaline washing tower 542 and an adsorption tower 543 connected in series.

[0049] The water washing tower 541 is also connected to the hydrochloric acid storage tank 544.

[0050] The gas that is not condensed in the cryogenic cooler 51 (mainly hydrogen chloride) enters the water scrubbing tower 541 in the tail gas treatment device 54. Water absorbs the hydrogen chloride gas to form hydrochloric acid, thus removing the hydrogen chloride from the gas. After water scrubbing removes most of the hydrogen chloride, the remaining gases and a small amount of residual hydrogen chloride enter the alkaline scrubbing tower 542. Alkaline solution absorbs and removes the acidic gases. The alkaline-washed gas then enters the adsorption tower 543, where absorbent packing materials such as activated carbon adsorb and remove the remaining gases. The gas treated by the adsorption tower 543 meets emission standards and can be discharged or collected in the emission pipeline to be discharged together with the gases treated in other parts of the factory. The hydrochloric acid obtained from the water scrubbing tower 541 is transferred to the hydrochloric acid storage tank 544. Since the gas still contains a small amount of free chlorine, it needs to be refined before use or sale.

[0051] like Figure 4 As shown, optionally, the post-treatment device 4 includes a filter 41, a filtrate storage tank 42, a distillation column 43, an extraction vessel 44, and a recovery tank 45 connected in series.

[0052] Filter 41 is also connected to crude product storage tank 46, and extraction vessel 44 is also connected to wastewater treatment section 47;

[0053] The distillation column 43 is also connected to the solvent storage tank 48.

[0054] The reaction liquid separated in the gas-liquid separator 2 is transferred to the water washing tank 3. The solvent in the reaction liquid is first concentrated by heating until the volume of the reaction liquid is 20-25% of the original volume. The distilled solvent is then recovered to the corresponding recovery tank. Water is then added to the concentrated reaction liquid until no more solids precipitate. At this point, the reaction product, being insoluble in water, will precipitate, forming a solid-liquid mixture. This solid-liquid mixture is then transferred to the filter 41 for filtration. The filter cake, which is the crude product, is transferred to the crude product storage silo 46 for further purification.

[0055] The filtrate filtered in filter 41 is transferred to filtrate storage tank 42, and then fed into distillation column 43 to distill the organic solvent in the filtrate. The collected organic solvent is transferred to solvent storage tank 48 for reuse. The residue after distillation, i.e., water, also contains a small amount of high-boiling-point raw materials and byproducts. The residue is transferred to extraction vessel 44, where an organic solvent immiscible with water is used for extraction. The high-boiling-point substances are extracted and recovered to recovery tank 45 for further processing. The raffinate after extraction is sent to wastewater treatment section 47 for harmless treatment.

[0056] like Figure 5As shown, optionally, a demister 21 is provided at the top of the gas-liquid separator 2.

[0057] In this application, a small amount of liquid droplets will be output with the gas during the gas-liquid separation process, that is, mist entrainment. Therefore, the demister 21 can remove the small amount of liquid droplets mixed in.

[0058] Optionally, the demister 21 is a baffle demister, a swirl demister, or a wire mesh demister.

[0059] A chlorination reaction apparatus, the working process of which is as follows:

[0060] In use, the substrate solution storage tank 6 contains a certain concentration of acetonitrile solution of 2-amino-N,3-dimethylbenzamide (hereinafter referred to as the substrate solution), which also contains a catalyst (aluminum chloride or ferric chloride; since the catalyst is insoluble in organic solvents, it is a suspension in the substrate solution). The substrate solution is pumped into the reaction tube of the pipeline reactor 1 by the transfer pump 20. At the same time, the chlorine gas supply pipeline 10 and the chlorine gas vaporized by the liquid chlorine vaporizer 53 are also transferred into the pipeline reactor 1 in a certain proportion (the amount of chlorine gas added is excess, and the molar ratio of chlorine gas to substrate is 1.2~1.5∶1), mixed with the substrate solution, and reacted in the pipeline reactor 1. At the same time, circulating water is introduced into the shell of the pipeline reactor 1 to maintain the temperature of the reaction system in the range of 35~45℃. The substrate and chlorine gas undergo the following chlorination reaction in the reactor:

[0061]

[0062] In the reaction, chlorine is in a gaseous state, and the chlorine produced is also in a gaseous state. Therefore, after the reaction is completed, there will be a mixture of gases, mainly hydrogen chloride (and a small amount of unreacted chlorine). Thus, the gas-liquid mixture is output from the reactor.

[0063] The gas-liquid mixture that flows out after the reaction in the tubular reactor 1 enters the gas-liquid separator 2 for gas-liquid separation. The reaction liquid falls to the bottom of the separator 2, while the gas overflows from the reaction liquid system and passes through the demister 21 set at the top of the gas-liquid separator 2 for demisting and separation. It then exits from the top of the gas-liquid separator 2 and enters the cryogenic cooler 51 for cooling (the temperature of the cooling medium is -40℃). This causes the chlorine in the gas to condense into liquid and be recovered into the liquid chlorine storage tank 52. After being vaporized by the liquid chlorine vaporizer 53, it is combined with the chlorine supplied by the chlorine supply pipeline 10 and fed into the tubular reactor 1 for reaction. The gas that is not condensed in the cryogenic cooler 51 (mainly hydrogen chloride) enters the water scrubbing tower 541 in the tail gas treatment device 54. Water absorbs the hydrogen chloride gas to form hydrochloric acid, thus removing the hydrogen chloride from the gas. After water scrubbing removes most of the hydrogen chloride, the remaining gases and a small amount of residual hydrogen chloride enter the alkaline scrubbing tower 542. Alkaline solution removes the acidic gases. The alkaline-washed gas then enters the adsorption tower 543, where absorbent packing materials such as activated carbon adsorb and remove gases. The gas treated by the adsorption tower 543 meets emission standards and can be discharged or collected in the emission pipeline to be discharged together with the gases treated in other parts of the factory. The hydrochloric acid obtained from the water scrubbing tower 541 is transferred to the hydrochloric acid storage tank 544. Since the gas still contains a small amount of free chlorine, it needs to be refined before use or sale.

[0064] The reaction liquid separated in the gas-liquid separator 2 is transferred to the water washing tank 3. The solvent in the reaction liquid is first concentrated by heating until the volume of the reaction liquid is 20-25% of the original volume. The distilled solvent is then recovered to the corresponding recovery tank. Water is then added to the concentrated reaction liquid until no more solids precipitate. At this point, the reaction product, being insoluble in water, will precipitate, forming a solid-liquid mixture. This solid-liquid mixture is then transferred to the filter 41 for filtration. The filter cake, which is the crude product, is transferred to the crude product storage silo 46 for further purification.

[0065] The filtrate filtered in filter 41 is transferred to filtrate storage tank 42, and then fed into distillation column 43 to distill the organic solvent in the filtrate. The collected organic solvent is transferred to solvent storage tank 48 for reuse. The residue after distillation, i.e., water, also contains a small amount of high-boiling-point raw materials and byproducts. The residue is transferred to extraction vessel 44, where an organic solvent immiscible with water is used for extraction. The high-boiling-point substances are extracted and recovered to recovery tank 45 for further processing. The raffinate after extraction is sent to wastewater treatment section 47 for harmless treatment.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A chlorination reaction apparatus, characterized in that, It includes at least one pipeline reactor (1), which is connected in series with a gas-liquid separator (2), a water washing tank (3) and a post-treatment device (4); The gas-liquid separator (2) is also connected in sequence to the gas processing device (5) and the pipeline reactor (1); The input end of the pipeline reactor (1) is also connected to the chlorine supply pipeline (10) and the substrate solution storage tank (6), respectively; A transfer pump (20) is provided between the substrate solution storage tank (6) and the input end of the pipeline reactor (1).

2. The chlorination reaction apparatus according to claim 1, characterized in that, Multiple pipeline reactors (1) are provided, and the multiple pipeline reactors (1) are connected in series.

3. The chlorination reaction apparatus according to claim 1, characterized in that, The gas processing device (5) includes a cryostat (51), a liquid chlorine storage tank (52) and a liquid chlorine vaporizer (53) connected in series. The cryogenic device (51) is also connected to the exhaust gas treatment device (54); The liquid chlorine vaporizer (53) is also connected to the input end of the pipeline reactor (1).

4. The chlorination reaction apparatus according to claim 3, characterized in that, The exhaust gas treatment device (54) includes a water washing tower (541), an alkaline washing tower (542), and an adsorption tower (543) connected in series. The water washing tower (541) is also connected to the hydrochloric acid storage tank (544).

5. The chlorination reaction apparatus according to claim 1, characterized in that, The post-processing device (4) includes a filter (41), a filtrate storage tank (42), a distillation column (43), an extraction vessel (44), and a recovery tank (45) connected in series. The filter (41) is also connected to the crude product storage tank (46), and the extraction vessel (44) is also connected to the wastewater treatment section (47); The distillation column (43) is also connected to the solvent storage tank (48).

6. The chlorination reaction apparatus according to claim 1, characterized in that, A demister (21) is provided at the top of the gas-liquid separator (2).

7. The chlorination reaction apparatus according to claim 6, characterized in that, The demister (21) is a baffle demister, a cyclone demister, or a wire mesh demister.

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