High-efficiency production process and production device of chipton crystal

Abstract

The present application relates to the technical field of B01D7 / 02, in particular to a high-efficiency production process and production device of chlorothalonil transformation crystal, at least comprising the following steps: (1) gas-phase chlorothalonil product is transferred to the transformation kettle through the gas-phase chlorothalonil feeding port, and the alpha crystal form chlorothalonil seed is transported into the transformation kettle from the nitrogen gas feeding port through the nitrogen gas feeding pipe by the gas blowing method, the gas-phase chlorothalonil product contacts with the alpha crystal form chlorothalonil seed to form a transformation crystal mixing area for transformation crystal; (2) after the transformation crystal ends, the alpha-type chlorothalonil product falls to the bottom of the transformation kettle, the alpha-type chlorothalonil product is continuously extracted from the alpha-type chlorothalonil product discharge port through the screw discharge machine, and the tail gas generated in the reaction process is transferred to the spray tower for spray treatment through the tail gas outlet, the gas-solid transformation crystal is realized based on the optimized process by using a specific device, is directly converted into alpha type, the alpha-type chlorothalonil continuous rapid and stable transformation is realized, and the production transformation efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the technical field of B01D7 / 02, specifically to a highly efficient process and apparatus for producing chlorothalonil crystals. Background Technology

[0002] Chlorothalonil is a broad-spectrum organochlorine fungicide. Currently, my country's chlorothalonil production technology is basically complete, and its application has gradually expanded from agriculture to pharmaceuticals, building materials, light industry, and electrical manufacturing plants. The main raw material for chlorothalonil is m-xylene, which undergoes an ammonia oxidation catalytic reaction to obtain the intermediate isophthalonitrile, followed by high-temperature chlorination to obtain chlorothalonil. Different crystal forms of chlorothalonil technical material are obtained during preparation, resulting in different applications in the formulation field, mainly α-type and β-type. In terms of biological activity, the α-type is several times higher than the β-type. Therefore, the prepared chlorothalonil technical material needs further transformation to obtain the highly biologically active α-type product. For example, Chinese patent application (authorization announcement number CN216764759U) discloses a chlorothalonil lattice transformation device, which requires first partially transforming the chlorothalonil raw material through a primary transformation device, and then completing the lattice transformation through a secondary transformation device. However, this transformation device is prone to agglomeration during the uniform preheating and temperature rise transformation process, resulting in incomplete transformation. Chinese patent application (authorization announcement number CN207576415U) discloses a device for converting chlorothalonil technical material into crystal form, but it still cannot effectively solve the problems of easy agglomeration and incomplete conversion during the conversion process. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a highly efficient chlorothalonil crystallization production process and apparatus. Utilizing a specific device and optimized process, it achieves gas-solid crystallization directly into the α-type, eliminating the need for prior conversion to the β-type. This enables continuous, rapid, and stable conversion of α-type chlorothalonil, significantly improving production efficiency and effectively resolving the problems of agglomeration and incomplete conversion in traditional solid-solid crystallization processes. It has immense industrial application value.

[0004] This invention provides an efficient process for producing chlorothalonil crystals, comprising at least the following steps:

[0005] (1) The gas phase chlorothalonil product is transferred to the crystallization reactor through the gas phase chlorothalonil inlet. At the same time, the α-crystal chlorothalonil seed crystals are transported to the crystallization reactor through the nitrogen inlet via the nitrogen inlet using a gas blowing method. The gas phase chlorothalonil product and the α-crystal chlorothalonil seed crystals come into contact to form a crystallization mixing zone for crystallization.

[0006] (2) After the crystallization is completed, the α-type chlorothalonil product falls to the bottom of the crystallization kettle. The α-type chlorothalonil product is continuously extracted from the α-type chlorothalonil product outlet through the screw discharge machine. The tail gas generated during the reaction is transferred to the spray tower for spraying treatment through the tail gas outlet.

[0007] As a preferred technical solution, the purity of the α-crystal chlorothalonil seed crystals is ≥98.5%, and the particle size is 5-10μm.

[0008] As a preferred technical solution, the gas blowing is specifically nitrogen reverse blowing.

[0009] As a preferred technical solution, the pressure of the nitrogen reverse blowing is 0.05-0.3MPa, preferably 0.1-0.3MPa.

[0010] As a preferred technical solution, the temperature of the gas-phase chlorothalonil product is 200-280℃, which is measured through the first temperature measuring port.

[0011] As a preferred technical solution, the temperature in the region below the crystal mixing zone in the crystal transfer vessel is <100℃, which is measured through the third temperature measuring port.

[0012] As a preferred technical solution, the weight ratio of the gaseous chlorothalonil product to the α-crystalline chlorothalonil seed crystals is 100:(40-60).

[0013] As a preferred technical solution, the height of the crystal-mixing zone is 2-5m, preferably 3-5m.

[0014] As a preferred technical solution, the temperature of the crystal mixing zone in the crystal transfer vessel is 100-150℃, which is measured through the second temperature measuring port.

[0015] The chlorothalonil crystallization production process provided by this invention uses α-crystalline chlorothalonil seed crystals with a purity ≥98.5% and a particle size of 5-10 μm to achieve rapid crystallization of the gas-phase chlorothalonil product. The resulting α-type chlorothalonil crystal particles are large (5-30 μm) and have high purity. The inventors believe the reason may be that the introduction of α-crystalline chlorothalonil seed crystals serves as the crystallization nucleus for the gas-phase chlorothalonil product. After contact with the α-crystalline chlorothalonil seed crystals, the gas-phase chlorothalonil product rapidly crystallizes to form large-particle, high-purity α-type chlorothalonil finished product.

[0016] In particular, the reverse nitrogen blowing method is used to transport α-crystalline chlorothalonil seed crystals from the bottom to the top of the crystallization reactor, providing the necessary reaction power for crystallization transformation. At the same time, the gaseous chlorothalonil product enters the crystallization reactor from the gaseous chlorothalonil inlet and is transported from the top to the bottom. After the α-crystalline chlorothalonil seed crystals transported from bottom to top come into contact with the gaseous chlorothalonil product transported from top to bottom, a crystallization mixing zone with a temperature of 100-150℃ is formed at a depth of 3-5m. This effectively ensures that the α-crystalline chlorothalonil seed crystals (5-10μm) are in contact with the surface of the gaseous chlorothalonil product during the crystallization process, and quickly reduces the temperature of the gaseous chlorothalonil product to the transformation temperature to achieve transformation. In continuous production, rapid cooling crystallization can be achieved, with high conversion rate, high output, and short transformation time. Moreover, no heating or cooling system is required, reducing the loss of gaseous chlorothalonil product during the crystallization process. This process has great economic value in industry.

[0017] In this invention, by controlling the weight ratio of gaseous chlorothalonil product to α-crystalline chlorothalonil seed crystals to be 100:(40-60), the temperature of the 3-5m crystallization mixing zone formed in the crystallization reactor is 100-150℃, which ensures a shortened transformation time and results in α-crystalline chlorothalonil finished product with large crystal particles and high purity.

[0018] Another aspect of the present invention provides a chlorothalonil crystallization production apparatus, comprising a nitrogen storage tank, an α-crystalline chlorothalonil seed storage tank, a crystallization reactor, a gaseous chlorothalonil inlet, a tail gas outlet, a nitrogen inlet, a first temperature measuring port, a second temperature measuring port, a third temperature measuring port, a screw discharger, and an α-crystalline chlorothalonil finished product outlet. The crystallization reactor is provided with a gaseous chlorothalonil inlet, a tail gas outlet, a nitrogen inlet, a first temperature measuring port, a second temperature measuring port, and a third temperature measuring port. The nitrogen storage tank and the α-crystalline chlorothalonil seed storage tank are connected by a nitrogen inlet pipe, which is connected to the nitrogen inlet of the crystallization reactor. The crystallization reactor is connected to the screw discharger, which is provided with an α-crystalline chlorothalonil finished product outlet.

[0019] The chlorothalonil crystallization production device provided by this invention can realize the continuous production and transformation of chlorothalonil products without the need for additional turning and stirring devices. It also has low equipment investment, high processing capacity, convenient operation, simple structure and equipment, and is easy to promote and apply on a large scale.

[0020] Beneficial effects

[0021] 1. This invention provides a highly efficient chlorothalonil crystallization production process and its production apparatus. It uses a specific device based on an optimized process to achieve gas-solid crystallization, directly converting to α-type without first converting to β-type and then to α-type. This enables continuous, rapid and stable conversion of α-type chlorothalonil, greatly improving the production conversion efficiency and effectively solving the problems of easy agglomeration and incomplete conversion in the traditional conversion process (solid-solid crystallization). It has great value for industrial application.

[0022] 2. The chlorothalonil crystallization production process provided by this invention uses α-crystal chlorothalonil seed crystals with a purity ≥98.5% and a particle size of 5-10μm to achieve rapid crystallization of chlorothalonil products in the gas phase. The α-crystal chlorothalonil crystal particles obtained after crystallization are large (5-30μm) and have high purity.

[0023] 3. The efficient chlorothalonil crystallization production process provided by this invention adopts a nitrogen reverse blowing method, which effectively ensures that the α-crystal chlorothalonil seed crystals (5-10μm) are in contact with the surface of the gaseous chlorothalonil product during the crystallization process, and quickly reduces the temperature of the gaseous chlorothalonil product to the transformation temperature to achieve transformation. In continuous production, rapid cooling crystallization can be achieved, with high conversion rate, high output, and short transformation time. Moreover, no heating or cooling system is required, which reduces the loss of gaseous chlorothalonil product during the crystallization process. This process has great economic value in industry.

[0024] 4. In this invention, by controlling the weight ratio of gaseous chlorothalonil product to α-crystalline chlorothalonil seed crystals to be 100:(40-60), the temperature of the 3-5m crystallization mixing zone formed in the crystallization reactor is 100-150℃, which ensures that the transformation time is shortened and the resulting α-crystalline chlorothalonil product has large crystal particles and high purity.

[0025] 5. The chlorothalonil crystallization production device provided by the present invention can realize the continuous production and transformation of chlorothalonil products without the need for additional turning and stirring devices. It has low equipment investment, high processing capacity, convenient operation, simple structure and equipment, and is easy to promote and apply on a large scale. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the chlorothalonil crystallization production device in Embodiment 1 of the present invention. The diagram includes a nitrogen storage tank 1, an α-crystal chlorothalonil seed storage tank 2, a crystallization kettle 3, a gas phase chlorothalonil inlet 3.1, a tail gas outlet 3.2, a nitrogen inlet 3.3, a first temperature measuring port 3.4, a second temperature measuring port 3.5, a third temperature measuring port 3.6, a screw feeder 4, and an α-type chlorothalonil finished product outlet 5.

[0027] Figure 2 This is the XRD test report for the α-type chlorothalonil product prepared using the process and apparatus provided in Example 1. Detailed Implementation

[0028] Example 1

[0029] Embodiment 1 of the present invention provides an efficient process for producing chlorothalonil crystals, comprising the following steps:

[0030] (1) The gas phase chlorothalonil product (100 parts by weight) is transferred to the crystallization reactor through the gas phase chlorothalonil inlet. At the same time, the α-crystal chlorothalonil seed crystals are transported to the crystallization reactor through the nitrogen inlet via the nitrogen inlet pipe by gas blowing. The gas phase chlorothalonil product and the α-crystal chlorothalonil seed crystals come into contact to form a crystallization mixing zone for crystallization.

[0031] (2) After the crystallization is completed, a total of 150 parts by weight of α-type chlorothalonil product is obtained. The α-type chlorothalonil product falls to the bottom of the crystallization kettle. The α-type chlorothalonil product is continuously extracted from the α-type chlorothalonil product outlet through the screw discharge machine. The tail gas generated during the reaction is transferred to the spray tower for spraying treatment through the tail gas outlet.

[0032] The purity of the α-crystal chlorothalonil seed crystals is 98.5%, and the particle size is 5-10 μm.

[0033] The gas blowing is specifically a reverse blowing of nitrogen.

[0034] The pressure of the nitrogen reverse blowing is 0.2 MPa.

[0035] The temperature of the gas-phase chlorothalonil product is 250±2℃, which is measured through the first temperature measuring port.

[0036] The weight ratio of the vapor-phase chlorothalonil product to the α-crystalline chlorothalonil seed crystals is 100:50.

[0037] The height of the crystallization mixing zone is 4m.

[0038] The temperature of the crystal mixing zone in the crystal transfer vessel is 120±2℃, which is measured through the second temperature measuring port.

[0039] The temperature in the region below the crystal mixing zone in the crystal transfer vessel is 80±2℃, which is measured through the third temperature measuring port.

[0040] See Figure 1In another aspect, Embodiment 1 of the present invention provides a chlorothalonil crystallization production apparatus, including a nitrogen storage tank 1, an α-crystal chlorothalonil seed storage tank 2, a crystallization reactor 3, a chlorothalonil gas inlet 3.1, a tail gas outlet 3.2, a nitrogen inlet 3.3, a first temperature measuring port 3.4, a second temperature measuring port 3.5, a third temperature measuring port 3.6, a screw feeder 4, and an α-crystal chlorothalonil finished product outlet 5. The crystallization reactor 3 is equipped with a chlorothalonil gas inlet 3.1, a tail gas outlet 3.2, a nitrogen inlet 3.3, a first temperature measuring port 3.4, a second temperature measuring port 3.5, and a third temperature measuring port 3.6. The chlorothalonil gas inlet 3.1 and the tail gas outlet 3.2 are located at the top of the crystallization reactor. The first temperature measuring port 3.4, the second temperature measuring port 3.5, and the third temperature measuring port 3.6 are located at the top of the crystallization reactor. Temperature port 3.5 and the third temperature measuring port 3.6 are both located on the same side of the crystallization reactor. The second temperature measuring port 3.5 is located in the crystallization mixing zone formed in the crystallization reactor 3. The first temperature measuring port 3.4 is located in the area above the crystallization mixing zone formed in the crystallization reactor 3. The third temperature measuring port 3.6 is located in the area below the mixing zone formed in the crystallization reactor 3. The nitrogen storage tank 1 and the α-crystal chlorothalonil seed storage tank 2 are connected by a nitrogen feed pipe. The nitrogen feed pipe is connected to the nitrogen inlet 3.3 of the crystallization reactor 3. The nitrogen inlet 3.3 is located at the bottom of the crystallization reactor 3 on the opposite side from the first temperature measuring port 3.4, the second temperature measuring port 3.5, and the third temperature measuring port 3.6. The crystallization reactor 3 is connected to the screw discharge machine 4. The screw discharge machine 4 is equipped with an α-type chlorothalonil finished product discharge port 5.

[0041] Example 2

[0042] Embodiment 2 of the present invention provides an efficient chlorothalonil crystallization production process and its production apparatus. The specific implementation method is the same as that of Embodiment 1, except that the weight ratio of the gaseous chlorothalonil product to the α-crystalline chlorothalonil seed crystals is 100:60, the pressure of the nitrogen reverse blowing is 0.3MPa, the height of the crystallization mixing zone is 5m, and the temperature of the crystallization mixing zone in the crystallization kettle is 100±2℃, resulting in a total of 160 parts by weight of α-type chlorothalonil finished product.

[0043] Example 3

[0044] Embodiment 3 of the present invention provides an efficient chlorothalonil crystallization production process and its production apparatus. The specific implementation method is the same as that of Embodiment 1, except that the weight ratio of the gaseous chlorothalonil product to the α-crystalline chlorothalonil seed crystal is 100:40, the pressure of the nitrogen reverse blowing is 0.1 MPa, the height of the crystallization mixing zone is 3 m, and the temperature of the crystallization mixing zone in the crystallization kettle is 150±2℃, resulting in a total of 140 parts by weight of α-type chlorothalonil finished product.

[0045] Comparative Example 1

[0046] Embodiment 3 of the present invention provides an efficient chlorothalonil crystallization production process and its production apparatus. The specific implementation method is the same as that of Embodiment 1, except that the weight ratio of the gaseous chlorothalonil product to the α-crystalline chlorothalonil seed crystals is 100:30, the pressure of the nitrogen reverse blowing is 0.05MPa, the height of the crystallization mixing zone is 2m, and the temperature of the crystallization mixing zone in the crystallization kettle is 160℃, resulting in a total of 130 parts by weight of α-type chlorothalonil finished product.

[0047] Comparative Example 2

[0048] Embodiment 3 of the present invention provides an efficient chlorothalonil crystallization production process and its production apparatus. The specific implementation method is the same as that of Embodiment 1, except that the weight ratio of the gaseous chlorothalonil product to the α-crystalline chlorothalonil seed crystals is 100:70, the pressure of the nitrogen reverse blowing is 0.1 MPa, the height of the crystallization mixing zone is 3 m, and the temperature of the crystallization mixing zone in the crystallization kettle is 80±2℃, resulting in a total of 170 parts by weight of α-type chlorothalonil finished product.

[0049] Performance testing

[0050] 1. XRD tests were performed on the α-type chlorothalonil product prepared using the process and apparatus provided in Example 1. The test report can be found here. Figure 2 .

[0051] 2. The particle size of the α-type chlorothalonil product prepared using the processes and apparatus provided in the examples and comparative examples was tested. The test results are shown in Table 1.

[0052] 3. Conversion rate: The conversion rate of 100 parts by weight of gaseous chlorothalonil product to α-type chlorothalonil product in the process and apparatus provided in the examples and comparative examples was calculated. Conversion rate = weight of α-type chlorothalonil product in the α-type chlorothalonil finished product / weight of gaseous chlorothalonil product × 100%. The test results are shown in Table 1.

[0053] Table 1

[0054]

Claims

1. A highly efficient process for producing chlorothalonil crystals, characterized in that, At least the following steps are included: (1) The gas phase chlorothalonil product is transferred to the crystallization reactor through the gas phase chlorothalonil inlet. At the same time, the α-crystal chlorothalonil seed crystals are transported to the crystallization reactor through the nitrogen inlet via the nitrogen inlet pipe by gas blowing. The gas phase chlorothalonil product and the α-crystal chlorothalonil seed crystals come into contact to form a crystallization mixing zone for crystallization. (2) After the crystallization is completed, the α-type chlorothalonil product falls to the bottom of the crystallization reactor. The α-type chlorothalonil product is continuously discharged from the α-type chlorothalonil product outlet through the screw discharge machine. The tail gas generated during the reaction is transferred to the spray tower for spray treatment through the tail gas outlet. The height of the crystallization mixing zone is 3-5m. The temperature of the gas phase chlorothalonil product is 200-280℃, which is measured by the first temperature measuring port. The temperature of the crystallization mixing zone in the crystallization reactor is 100-150℃, which is measured by the second temperature measuring port. The temperature of the area below the crystallization mixing zone in the crystallization reactor is <100℃, which is measured by the third temperature measuring port. The weight ratio of the gas phase chlorothalonil product to the α-type chlorothalonil seed crystal is 100:(40-60).

2. The efficient chlorothalonil crystallization production process according to claim 1, characterized in that, The α-crystal chlorothalonil seed crystals have a purity of ≥98.5% and a particle size of 5-10 μm.

3. The efficient chlorothalonil crystallization production process according to claim 2, characterized in that, The gas blowing is specifically a reverse blowing of nitrogen.

4. The efficient chlorothalonil crystallization production process according to claim 3, characterized in that, The pressure of the nitrogen reverse blowing is 0.05-0.3 MPa.

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