Production system for preparing carboxylic acid through continuous flow oxidation

Abstract

The utility model discloses a production system for preparing carboxylic acid through continuous flow oxidation. The production system comprises a feeding unit, a tubular reactor, a cooling unit, a crystallization unit and a self-discharging continuous centrifugal machine, the feeding unit comprises a first feeding unit and a second feeding unit which are connected in parallel; the cooling unit comprises a cooler, a back pressure valve and an exhaust valve which are connected in sequence; the crystallization unit comprises a first crystallization kettle and a second crystallization kettle which are connected in series; a feed port of the first crystallization kettle is connected with a discharge port of the tubular reactor through the cooling unit; a discharge port of the first crystallization kettle is connected with a feed port of the second crystallization kettle; and a discharge port of the second crystallization kettle is connected with a feed port of the self-discharging continuous centrifugal machine. According to the production system disclosed by the utility model, carboxylic acid can be prepared by continuous flow oxidation, the automation level and the safety standard of production are greatly improved, the stable quality of a product is ensured, and the market competitiveness of the product is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of production system for preparing carboxylic acid by continuous flow oxidation. BACKGROUND

[0002] Continuous flow reaction technology is a technology that pumps reactants or their solutions into a pipe or microreactor of a specified size, mixes quickly in the pipe or microchannel, and then undergoes a chemical reaction in continuous flow mode. Although the application of continuous flow reaction technology in the petroleum industry has a history of nearly a hundred years, there is still great development space in the traditional fine chemical industry. With the development of green chemistry in recent years, the trend of continuous production in the fine chemical industry is becoming more and more obvious. Compared with traditional tank production, the promotion of continuous flow reaction technology undoubtedly plays a core role in promoting the transition from batch processing to continuous flow processing. This technology has the advantages of small reaction volume, fast mixing speed, good mass and heat transfer, etc., which can improve reaction performance and safety, and more accurately control reaction variables. In addition, the production process is carried out in a continuous manner, thereby avoiding separation and purification in the reaction, which has significant advantages in reducing costs, improving reaction speed, and enhancing process safety, etc. Therefore, the innovation and application of continuous flow production are crucial to the future development of fine chemicals.

[0003] Carboxylic acid has a wide range of applications in many fields, including the food industry, soap manufacturing, rubber production, drug synthesis, and the textile industry. In fine chemicals, the traditional method of preparing carboxylic acid is to add substrates (methyl substances, alcohols, etc.), solvents, and catalysts to a reaction kettle, heat it to a certain temperature, and then add an oxidizing agent to produce carboxylic acid. The amount of material for online reaction is large, the risk coefficient is high, the intermittent operation has high labor intensity, the production capacity is low, and the quality is unstable. UTILITY MODEL CONTENT

[0004] The utility model aims to solve the above problems and provides a production system for preparing carboxylic acid by continuous flow oxidation.

[0005] The technical scheme for realizing the purpose of the utility model is: a production system for preparing carboxylic acid through continuous flow oxidation, comprising a feeding unit, a tubular reactor, a cooling unit, a crystallization unit and a self-unloading continuous centrifuge; the feeding unit comprises first and second feeding units connected in parallel; the first feeding unit comprises first batching kettles, first metering pumps and a first preheater connected in sequence; the second feeding unit comprises second batching kettles, second metering pumps and a second preheater connected in sequence; the feeding ports of the tubular reactor are connected with the discharge ports of the first and second preheaters respectively; the cooling unit comprises a cooler, a back pressure valve and an exhaust valve connected in sequence; the crystallization unit comprises first and second crystallization kettles connected in series; the feeding port of the first crystallization kettle is connected with the discharge port of the tubular reactor through the cooling unit; the discharge port of the first crystallization kettle is connected with the feeding port of the second crystallization kettle; and the discharge port of the second crystallization kettle is connected with the feeding port of the self-unloading continuous centrifuge.

[0006] An on-line detector is further arranged between the tubular reactor and the cooling unit.

[0007] A mother liquor refiner is further arranged between the liquid discharge port of the self-unloading continuous centrifuge and the feeding port of the second batching kettle.

[0008] The cooling unit is arranged vertically with the material flowing from high to low.

[0009] The agitators of the first and second crystallization kettles are both propeller agitators.

[0010] A rinsing device is further arranged in the self-unloading continuous centrifuge.

[0011] The utility model has the following advantages:

[0012] (1) The production system can realize continuous flow oxidation for preparing carboxylic acid, greatly improves the automation level and safety standard of production, ensures the stable quality of products, improves the market competitiveness of products, and especially can reduce the discharge of three wastes, which is beneficial to environmental protection.

[0013] (2) The cooling unit is arranged vertically with the material flowing from high to low, so that the small amount of material precipitated in the preliminary cooling can be prevented from accumulating in the cooler to block the pipeline, and the long-term stable operation of the cooler is facilitated.

[0014] (3) The agitators of the two crystallization kettles are both propeller agitators, so that the back mixing of the material can be avoided, and the quality and production efficiency of the products are ensured.

[0015] (4) The utility model discloses adopt on -line detector real -time monitoring the progress of oxidation reaction, and according to the reaction situation, the running speed of two metering pumps in the feeding unit is adjusted in real time, thereby guaranteeing the smooth progress of entire continuous flow reaction and reaction efficiency.

[0016] (5) The utility model discloses adopt mother liquor refiner to the centrifugal mother liquor and carry out refining purification, to remove the colored impurity and gelatinous insoluble substance in centrifugal mother liquor, not only avoid the enrichment of impurity in the reaction system, guarantee the product quality and the stable operation of system, and realize the recycling of centrifugal mother liquor, greatly reduce the discharge of three wastes. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the structural diagram of the production system of the continuous flow oxidation preparation carboxylic acid of the utility model. DETAILED DESCRIPTION

[0018] (Example 1)

[0019] Referring to Figure 1 , the continuous flow oxidation preparation carboxylic acid production system of the embodiment includes a feeding unit 100, a tubular reactor 200, a cooling unit 300, a crystallization unit 400, a self-discharging continuous centrifuge 500, an on-line detector 600, and a mother liquor refiner 700.

[0020] The feeding unit 100 includes a first feeding unit 110 and a second feeding unit 120 connected in parallel.

[0021] The first feeding unit 110 includes a first batching kettle 111, a first metering pump 112, and a first preheater 113 connected in sequence. The first batching kettle 111 is provided with a feeding port 111-1 and a discharging port 111-2. The first preheater 113 is provided with a feeding port 113-1 and a discharging port 113-2. The discharging port 111-2 of the first batching kettle 111 is connected to the feeding port 113-1 of the second preheater 113 through the first metering pump 112.

[0022] The second feeding unit 120 includes a second batching kettle 121, a second metering pump 122, and a second preheater 123 connected in sequence. The second batching kettle 121 is provided with a feeding port 121-1 and a discharging port 121-2. The second preheater 113 is provided with a feeding port 123-1 and a discharging port 123-2. The discharging port 121-2 of the second batching kettle 121 is connected to the feeding port 123-1 of the second preheater 123 through the second metering pump 122.

[0023] The tubular reactor 200 is provided with a feeding port 201 and a discharging port 202. The feeding port 201 of the tubular reactor 200 is connected to the discharging port 113-2 of the first preheater 113 and the discharging port 123-2 of the second preheater 123, respectively.

[0024] The cooling unit 300 comprises a cooler 301, a back pressure valve 302 and an exhaust valve 303 connected in sequence; wherein the cooler 301 is arranged vertically with the material flowing from high to low. The online detector 600 is arranged between the tubular reactor 200 and the cooling unit 300.

[0025] The crystallization unit 400 comprises a first crystallization kettle 410 and a second crystallization kettle 420 connected in series.

[0026] The first crystallization kettle 410 is provided with a feed inlet 411, a discharge outlet 412 and a first agitator 413; the second crystallization kettle 420 is provided with a feed inlet 421, a discharge outlet 422 and a second agitator 423; the first agitator 413 and the second agitator 423 are both push-type agitators.

[0027] The feed inlet 411 of the first crystallization kettle 410 is connected with the discharge outlet 202 of the tubular reactor 200 through the cooling unit 300; the discharge outlet 412 of the first crystallization kettle 410 is connected with the feed inlet 421 of the second crystallization kettle 420.

[0028] The self-discharging continuous centrifuge 500 is provided with a feed inlet 501, a liquid discharge outlet 502 and a solid discharge outlet 503, and is further provided with a spray washing device 504. The feed inlet 501 of the self-discharging continuous centrifuge is connected with the discharge outlet 422 of the second crystallization kettle 420; the mother liquor refiner 700 is arranged between the liquid discharge outlet 502 of the self-discharging continuous centrifuge and the feed inlet 121-1 of the second batching kettle 121.

[0029] The production system for continuously preparing carboxylic acid by oxidation according to the utility model has the advantages that the production system is simple in structure, high in efficiency, low in cost, and capable of realizing continuous production.

[0030] The main raw material (for example, p-chlorotoluene) is added into the first batching kettle 111, and the oxidant (for example, 30% nitric acid) is added into the second batching kettle 121; the discharge outlet 111-2 of the first batching kettle 111 and the discharge outlet 121-2 of the second batching kettle 121 are opened respectively, and the first metering pump 112 and the second metering pump 122 are started at the same time; the main raw material and the oxidant are heated through the first preheater 113 and the second preheater 123, and then are combined into the tubular reactor 200 according to the set raw material ratio to perform oxidation reaction (the online detector 600 monitors the reaction completely online); the reacted material is cooled in the cooling unit 300, and then is introduced into the crystallization unit 400; the material is crystallized and separated out through the first crystallization kettle 410 and the second crystallization kettle 420 connected in series; finally, the solid is introduced into a drying system through the solid discharge outlet 503 to be dried to obtain the target product; and the centrifugal mother liquor can be refined through the mother liquor refiner 700, and then is returned to the second batching kettle 121 to be reused.

Claims

1. A production system for the continuous flow oxidation production of carboxylic acids, characterized in that The application relates to a continuous production device for preparing a lithium ion battery cathode material. The device comprises a feeding unit (100), a tubular reactor (200), a cooling unit (300), a crystallization unit (400) and a self-unloading continuous centrifuge (500). The feeding unit (100) comprises a first feeding unit (110) and a second feeding unit (120) connected in parallel; the first feeding unit (110) comprises a first batching kettle (111), a first metering pump (112) and a first preheater (113) connected in sequence; the second feeding unit (120) comprises a second batching kettle (121), a second metering pump (122) and a second preheater (123) connected in sequence. The feeding port of the tubular reactor (200) is connected with the discharge port of the first preheater (113) and the discharge port of the second preheater (123) respectively. The cooling unit (300) comprises a cooler (301), a back pressure valve (302) and an exhaust valve (303) connected in sequence. The crystallization unit (400) comprises a first crystallization kettle (410) and a second crystallization kettle (420) connected in series; the feeding port of the first crystallization kettle (410) is connected with the discharge port of the tubular reactor (200) through the cooling unit (300); the discharge port of the first crystallization kettle (410) is connected with the feeding port of the second crystallization kettle (420); the discharge port of the second crystallization kettle (420) is connected with the feeding port of the self-unloading continuous centrifuge (500).

2. The production system for the continuous flow oxidation production of carboxylic acids according to claim 1, characterized in that: An online detector (600) is arranged between the tubular reactor (200) and the cooling unit (300).

3. The continuous flow production system for the oxidation preparation of carboxylic acids according to claim 1, characterized in that: A mother liquor refiner (700) is arranged between the liquid discharge port of the self-unloading continuous centrifuge (500) and the feeding port of the second batching kettle (121).

4. The continuous flow production system for the oxidation preparation of carboxylic acids according to claim 1, characterized in that: The cooling unit (300) is arranged in a vertical direction so that the material flows from high to low.

5. The continuous flow production system for the oxidation preparation of carboxylic acids according to claim 1, characterized in that: The stirrers of the first crystallization kettle (410) and the second crystallization kettle (420) are both propeller stirrers.

6. The continuous flow production system for the oxidation preparation of carboxylic acids according to claim 1, characterized in that: A rinsing device (504) is arranged in the self-unloading continuous centrifuge (500).

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