Production equipment and production method of 1, 1, 1, 2, 3-pentachloropropane

Abstract

The invention relates to production equipment and a production method of 1, 1, 1, 2, 3-pentachloropropane, and belongs to the technical field of preparation of chemical intermediates. According to the invention, 1, 1, 1, 3-tetrachloropropane is adopted as an initial raw material, 1, 1, 1, 2, 3-pentachloropropane is produced through dehydrochlorination and chlorination in the serial tower reactor, and compared with a traditional two-step synthesis process of 1, 1, 1, 2, 3-pentachloropropane, after dehydrochlorination of 1, 1, 1, 3-tetrachloropropane and a 1, 1, 3-trichloropropene chlorination system are coupled, the process flow is shortened; compared with the existing one-pot synthesis process, the reaction is easier to control; a fixed bed catalyst system is adopted, the problems that traditional anhydrous ferric chloride catalyst powder is not easy to add, poor in dispersity and frequent to add are solved, saponification salt-containing wastewater is not discharged, the process is green and environmentally friendly, and the application prospect is wide.

Description

Technical Field

[0001] The present invention relates to production equipment and a production method of 1,1,1,2,3-pentachloropropane, belonging to the technical field of chemical intermediate preparation. Background Art

[0002] At present, 1,1,1,2,3-pentachloropropane is a colorless liquid at room temperature and pressure with a density of 1.598g / cm 3 , with a boiling point of 196°C. It is an important raw material for the preparation of 1,1,2,3-tetrachloropropene, which is an important raw material for the preparation of the chemical herbicide maltose, and is also an intermediate for the synthesis of the new environmentally friendly refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf).

[0003] According to the different raw materials for preparing 1,1,1,2,3-pentachloropropane, there are mainly three routes: (1) CN119191939B discloses a method for synthesizing 1,1,1,2,3-pentachloropropane by isomerization using 1,1,1,3,3-pentachloropropane as raw material. In this method, the raw materials 1,1,1,3,3-pentachloropropane and the catalyst are expensive, 1,1,1,3,3-pentachloropropane is easy to decompose, the output of three wastes is large, and the yield of the target product is low; (2) CN107001190A uses 1,1,1,3-tetrachloropropane as raw material and first dehydrochlorinates in the gas phase to synthesize 1,1,3-trichloropropene. The trichloropropene is separated and then photochlorinated to synthesize 1,1,1,2,3-pentachloropropane. This method has a long process and trichloropropene is unstable and difficult to store. In addition, there are documents that use 1,1,1,3-tetrachloropropane to react with alkali to synthesize the intermediate trichloropropane. This method produces a lot of salt-containing wastewater and puts a lot of pressure on the environmental protection process. (3) CN104130100A uses 1,1,1,3-tetrachloropropane and chlorine as raw materials and directly obtains 1,1,1,2,3-pentachloropropane through FeCl3 catalysis. This method is difficult to add catalyst and easy to deactivate, the reaction control is difficult, the product selectivity is low, the amount of "three wastes" is large, and it is not conducive to large-scale production. CN104163750A also uses 1,1,1,3-tetrachloropropane as a precursor. Under the action of oxychlorination catalyst (main active ingredient CuCl2), oxygen and HCl are introduced to produce 1,1,1,2,3-pentachloropropane. This method has low reaction selectivity and a short catalyst life.

[0004] The traditional 1,1,1,2,3-pentachloropropane synthesis process uses 1,1,1,3-tetrachloropropane for dehydrochlorination. Chlorine is then added to the reaction after the dehydrochlorination reaction is complete or has reached a certain level. The inconsistent reaction temperatures (the dehydrochlorination temperature must be higher than the chlorination temperature) make it difficult to control in practice. Furthermore, the solid anhydrous ferric chloride powder catalyst used in the reaction easily absorbs moisture and agglomerates, making it difficult to add and dispersible. The trichloropropylene produced during the reaction easily polymerizes on the catalyst surface to produce high-boiling products, which deactivates the Lewis acid catalyst, reduces product yield, and complicates subsequent separation and purification, hindering industrial production and operation.

[0005] In view of the above-mentioned drawbacks, the present invention aims to create a 1,1,1,2,3-pentachloropropane production device and a production method thereof, so as to make them more valuable for industrial utilization. Summary of the Invention

[0006] In order to solve the above technical problems, the purpose of the present invention is to provide a production device and a production method of 1,1,1,2,3-pentachloropropane.

[0007] The present invention provides a 1,1,1,2,3-pentachloropropane production device, comprising a hydrogen chloride washing tower and a dehydrochlorination reactor, wherein the bottom of the hydrogen chloride washing tower is connected to the upper end of the side wall of the dehydrochlorination reactor through a pipeline, the top of the dehydrochlorination reactor is connected to the bottom of the hydrogen chloride washing tower through a dehydrochlorination reactor condenser, the bottom of the dehydrochlorination reactor condenser is connected to the dehydrochlorination reactor body, the bottom of the dehydrochlorination reactor is connected to the body and multiple chlorination reaction systems in series through a dehydrochlorination reactor circulation pump, each of the chlorination reaction systems comprises a chlorination reactor, and the top of the chlorination reactor is connected through a chlorination reactor. The reactor condenser is connected to the bottom of the hydrogen chloride washing tower, the bottom of the chlorination reactor condenser is connected to the chlorination reactor body, the bottom of the chlorination reactor of each chlorination reaction system is connected to the body through the chlorination reactor circulation pump, the bottom of the last-stage chlorination reactor is connected to the deepening reactor through the chlorination reactor circulation pump, the top of the deepening reactor is connected to the bottom of the hydrogen chloride washing tower through the deepening reactor condenser, the bottom of the deepening reactor condenser is connected to the deepening reactor body, the bottom of the deepening reactor is connected to the body through the deepening reactor circulation pump, and the outlet of the deepening reactor circulation pump goes to the reaction liquid post-processing device.

[0008] Furthermore, a tetrachloropropane inlet and a hydrogen chloride outlet are provided at the top of the hydrogen chloride scrubbing tower, and the hydrogen chloride outlet is connected to a hydrogen chloride post-processing device.

[0009] Furthermore, an online detector is installed at the bottom of the dehydrochlorination reactor for online analysis of the composition of the dehydrochlorination reaction liquid.

[0010] Furthermore, an online detector is installed at the bottom of the chlorination reactor for online analysis of the composition of the chlorination reaction liquid.

[0011] Furthermore, an online detector is installed at the bottom of the deepening reactor for online analysis of the composition of the reaction liquid.

[0012] A method for producing 1,1,1,2,3-pentachloropropane using 1,1,1,2,3-pentachloropropane production equipment, the specific production steps are:

[0013] (1) First, 1,1,1,3-tetrachloropropane is added to a dehydrochlorination reactor through a hydrogen chloride washing tower, heating and material circulation are started, and a dehydrochlorination reaction of 1,1,1,3-tetrachloropropane is carried out at 80-130° C.;

[0014] (2) When the 1,1,3-trichloropropene content in the dehydrochlorination reactor reaches 2-30%, the dehydrochlorination reactor circulation pump bypass is opened to transfer the reaction liquid into the chlorination reaction system, and chlorine gas is introduced into the chlorination reaction system to carry out the chlorination reaction at 60-130° C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 2-15%;

[0015] (3) When the tetrachloropropane conversion rate in the nth chlorination reaction system is greater than 95%, the chlorination reaction liquid is transferred to a further reactor and the reaction is continued at 80-130°C;

[0016] (4) when the tetrachloropropane conversion rate in the deepening reactor is greater than 98% and the 1,1,3-trichloropropene content is less than 1%, the chlorinated liquid is continuously discharged to the post-treatment system to obtain 1,1,1,2,3-pentachloropropane product;

[0017] (5) The raw material tetrachloropropane is continuously added to the dehydrochlorination reactor through the hydrogen chloride scrubber;

[0018] (6) The tail gases of each reactor are cooled and then combined to go to the hydrogen chloride scrubber. After the free chlorine carried by the tail gas is removed by absorption with 1,1,1,3-tetrachloropropane, the by-product hydrogen chloride is sent to the post-treatment system.

[0019] Furthermore, the water content of the 1,1,1,3-tetrachloropropane in step (1) is 30-150 ppm.

[0020] Furthermore, the hydrogen chloride washing tower, the dehydrochlorination reactor and the deepening reactor in step (1) and step (3) are filled with fillers, and the filler material is iron.

[0021] Furthermore, the number of the chlorination reaction systems in step (2) is 2 to 3, and the chlorination reactor is filled with fillers, and the filler material is one or more of ceramics, nickel, and iron.

[0022] By means of the above solution, the present invention has at least the following advantages:

[0023] The present invention uses 1,1,1,3-tetrachloropropane as a starting material to produce 1,1,1,2,3-pentachloropropane via dehydrochlorination and chlorination in a series of tower reactors. Compared with the traditional two-step synthesis process for 1,1,1,2,3-pentachloropropane, the process flow is shortened by coupling the dehydrochlorination of 1,1,1,3-tetrachloropropane with the chlorination system of 1,1,3-trichloropropene. A fixed bed of stacked iron rings, etc., is used as the reactor filler, continuously generating catalytically active Lewis acids in situ during the heating reaction. This solves the problems of traditional anhydrous ferric chloride catalyst powder, such as difficulty in addition, poor dispersibility, and frequent dosing. Furthermore, the fixed-bed catalyst system process does not discharge saponified salt-containing wastewater, making the process environmentally friendly and promising for broad application prospects. Compared with the existing one-step synthesis process, the method adopts the form of separating the dehydrochlorination reaction of 1,1,1,3-tetrachloropropane and the chlorination reaction of 1,1,3-trichloropropene and then reacting them in series, which can avoid the mismatch problem of the chlorination and dehydrochlorination reaction rates caused by the strong exothermic acceleration of the dehydrochlorination of 1,1,1,3-tetrachloropropane in the "one-pot method", making the reaction easier to control and easy to achieve continuous automated production.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate a certain embodiment of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic structural diagram of a 1,1,1,2,3-pentachloropropane production device according to the present invention;

[0027] Among them, in the figure:

[0028] 1. Hydrogen chloride scrubber, 2. Dehydrochlorination reactor, 3. Dehydrochlorination reactor packing, 4. Dehydrochlorination reactor circulation pump, 5. Dehydrochlorination reactor heater, 6. Dehydrochlorination reactor condenser, 7. Dehydrochlorination reactor online detector, 8. Chlorination reactor, 9. Chlorination reactor packing, 10. Chlorination reactor circulation pump, 11. Chlorination reactor cooler, 12. Chlorination reactor condenser, 13. Chlorination reactor online detector, 14. Deepening reactor, 15. Deepening reactor packing, 16. Deepening reactor circulation pump, 17. Deepening reactor cooler, 18. Deepening reactor condenser, 19. Deepening reactor online detector. DETAILED DESCRIPTION

[0029] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0030] See also Figure 1, a device for producing 1,1,1,2,3-pentachloropropane according to a preferred embodiment of the present invention comprises a hydrogen chloride washing tower 1 and a dehydrochlorination reactor 2, wherein the top of the hydrogen chloride washing tower 1 is provided with a tetrachloropropane inlet and a hydrogen chloride outlet, the hydrogen chloride outlet is connected to a hydrogen chloride post-processing device, the bottom of the hydrogen chloride washing tower 1 is connected to the upper end of the side wall of the dehydrochlorination reactor 2 through a pipeline, the top of the dehydrochlorination reactor 2 is connected to the bottom of the hydrogen chloride washing tower 1 through a dehydrochlorination reactor condenser 6, the bottom of the dehydrochlorination reactor condenser 6 is connected to the body of the dehydrochlorination reactor 2, an online detector 7 is installed at the bottom of the dehydrochlorination reactor 2 for online analysis of the composition of the dehydrochlorination reaction liquid, the bottom of the dehydrochlorination reactor 2 is connected to the body and multiple chlorination reaction systems in series through a dehydrochlorination reactor circulation pump 4, the number of the chlorination reaction systems is 2 to 3, each of the chlorination reaction systems comprises a chlorination reactor 8, the chlorination The top of the reactor 8 is connected to the bottom of the hydrogen chloride washing tower 1 through the chlorination reactor condenser 12, and the bottom of the chlorination reactor condenser 12 is connected to the body of the chlorination reactor 8. An online detector 13 is installed at the bottom of the chlorination reactor 8 for online analysis of the composition of the chlorination reaction liquid. The bottom of the chlorination reactor 8 of each chlorination reaction system is connected to the body through the chlorination reactor circulation pump 10. The bottom of the last-stage chlorination reactor is connected to the deepening reactor 14 through the chlorination reactor circulation pump 10. The top of the deepening reactor 14 is connected to the bottom of the hydrogen chloride washing tower 1 through the deepening reactor condenser 18. The bottom of the deepening reactor condenser 18 is connected to the body of the deepening reactor 14. An online detector 19 is installed at the bottom of the deepening reactor 14 for online analysis of the composition of the reaction liquid. The bottom of the deepening reactor 14 is connected to the body through the deepening reactor circulation pump 16. The outlet of the deepening reactor circulation pump 16 goes to the reaction liquid post-processing device.

[0031] The working principle of the present invention is as follows:

[0032] In actual use:

[0033] (1) First, 1,1,1,3-tetrachloropropane is added to the dehydrochlorination reactor 2 through the hydrogen chloride washing tower 1, and the heating and material circulation are turned on to carry out the dehydrochlorination reaction of 1,1,1,3-tetrachloropropane at 80-130° C.;

[0034] (2) When the 1,1,3-trichloropropene content in the dehydrochlorination reactor 2 reaches 2 to 30%, the dehydrochlorination reactor circulation pump 4 is bypassed to transfer the reaction liquid into the chlorination reaction system, and chlorine gas is introduced into the chlorination reaction system to carry out the chlorination reaction at 60 to 130° C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 2 to 15%;

[0035] (3) When the tetrachloropropane conversion rate in the nth chlorination reaction system is greater than 95%, the chlorination reaction liquid is transferred to the deepening reactor 14 and the reaction is continued at 80-130° C.;

[0036] (4) when the tetrachloropropane conversion rate in the deepening reactor 14 is greater than 98% and the 1,1,3-trichloropropene content is less than 1%, the chlorinated liquid is continuously discharged to the post-treatment system to obtain a 1,1,1,2,3-pentachloropropane product;

[0037] (5) The raw material tetrachloropropane is continuously added to the dehydrochlorination reactor 2 through the hydrogen chloride washing tower 1;

[0038] (6) The tail gases of each reactor are cooled and then combined to go to hydrogen chloride scrubber 1. After the free chlorine carried by the tail gas is removed by absorption with 1,1,1,3-tetrachloropropane, the by-product hydrogen chloride is sent to the post-treatment system.

[0039] Example

[0040] Example 1

[0041] (1) 6.8 kg of 1,1,1,3-tetrachloropropane with a water content of 30 ppm (wt) was added to a dehydrochlorination reactor 2 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside) through a hydrogen chloride washing tower 1 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside), and heating and material circulation were started to carry out a 1,1,1,3-tetrachloropropane dehydrochlorination reaction at 80°C;

[0042] (2) When the 1,1,3-trichloropropene content in the dehydrochlorination reactor 2 reaches 5.1%, the dehydrochlorination reactor circulation pump 4 is opened to bypass and the reaction liquid is transferred to the first chlorination reactor 8 (with a size of φ100×1000 mm and an iron pipe with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 173.9 L / h, and the chlorination reaction is carried out at 60°C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 5-10%;

[0043] (3) When the conversion rate of tetrachloropropane in the first chlorination reactor 8 reaches 12.5%, the bypass of the circulation pump 10 of the first chlorination reactor is opened, and the reaction liquid is transferred to the second chlorination reactor 8 (with a size of φ100×1000 mm and an iron pipe with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 159.9 L / h, and the chlorination reaction is carried out at 60°C. During the chlorination reaction, the content of 1,1,3-trichloropropene is controlled to be 5-10%;

[0044] (4) When the tetrachloropropane conversion rate in the second chlorination reactor 8 is greater than 95%, the second chlorination reactor circulation pump 10 is opened to bypass and the chlorination reaction liquid is transferred to the deepening reactor 14 (with dimensions of φ80×800 mm and filled with an iron pipe with dimensions of φ15×30 mm), chlorine gas is introduced at a flow rate of 42.8 L / h, and the reaction is continued at 80°C;

[0045] (5) When the conversion rate of tetrachloropropane in the deepening reactor 14 is greater than 98% and the content of 1,1,3-trichloropropene is less than 1%, the chlorinated liquid is continuously discharged to the post-treatment system at a flow rate of 5.48 kg / h, and the high boiling point produced is 0.6%. The purity of the obtained 1,1,1,2,3-pentachloropropane is 99.9%, and the yield is 95.9%;

[0046] (6) Fresh tetrachloropropane is continuously added to the dehydrochlorination reactor 2 through the hydrogen chloride scrubber 1 at a flow rate of 4.62 kg / h;

[0047] (7) The tail gases of each reactor are cooled and then combined to go to the hydrogen chloride scrubber 1. After the free chlorine carried by the tail gas is removed by absorption with 1,1,1,3-tetrachloropropane, the by-product hydrogen chloride is sent to the post-treatment system.

[0048]

[0049] Note: Equipment number 8-1 represents the first chlorination reactor 8, and 8-2 represents the second chlorination reactor 8.

[0050] Example 2

[0051] (1) 6.8 kg of 1,1,1,3-tetrachloropropane with a water content of 90 ppm (wt) was added to a dehydrochlorination reactor 2 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside) through a hydrogen chloride washing tower 1 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside), and heating and material circulation were started to carry out a dehydrochlorination reaction of 1,1,1,3-tetrachloropropane at 105°C;

[0052] (2) When the 1,1,3-trichloropropene content in the dehydrochlorination reactor 2 reaches 29.1%, the dehydrochlorination reactor circulation pump 4 is opened to bypass and the reaction liquid is transferred to the first chlorination reactor 8 (with a size of φ100×1000 mm and a nickel tube with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 85.1 L / h, and the chlorination reaction is carried out at 95°C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 10-15%;

[0053] (3) When the tetrachloropropane conversion rate in the first chlorination reactor 8 reaches 37.5%, the circulation pump 10 of the first chlorination reactor is opened to bypass and the reaction liquid is transferred to the second chlorination reactor 8 (with a size of φ100×1000 mm and a nickel tube with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 101.2 L / h, and the chlorination reaction is carried out at 95°C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 10-15%;

[0054] (4) When the tetrachloropropane conversion rate in the second chlorination reactor 8 reaches 60.1%, the bypass of the circulation pump 10 of the second chlorination reactor is opened, and the reaction liquid is transferred to the third chlorination reactor 8 (with a size of φ100×1000 mm and a ceramic ring with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 133.4 L / h, and the chlorination reaction is carried out at 95°C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 10-15%;

[0055] (5) When the conversion rate of tetrachloropropane in the third chlorination reactor 8 is greater than 95%, the bypass of the circulation pump 10 of the third chlorination reactor is opened, and the chlorination reaction liquid is transferred to the deepening reactor 14 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside), and chlorine gas is introduced at a flow rate of 55.3 L / h, and the reaction is continued at 105°C;

[0056] (6) When the conversion rate of tetrachloropropane in the deepening reactor 14 is greater than 98% and the content of 1,1,3-trichloropropene is less than 1%, the chlorinated liquid is continuously discharged to the post-treatment system at a flow rate of 5.48 kg / h, and the final high boiling point produced is 1%. The purity of the obtained 1,1,1,2,3-pentachloropropane is 99.9%, and the yield is 95.4%;

[0057] (7) Fresh tetrachloropropane is continuously added to the dehydrochlorination reactor 2 through the hydrogen chloride scrubber 1 at a flow rate of 4.62 kg / h;

[0058] (8) The tail gases of each reactor are cooled and then combined to go to the hydrogen chloride scrubber 1. After the free chlorine carried by the tail gas is removed by absorption with 1,1,1,3-tetrachloropropane, the by-product hydrogen chloride is sent to the post-treatment system.

[0059]

[0060]

[0061] Note: The equipment number 8-1 represents the first chlorination reactor 8, 8-2 represents the second chlorination reactor 8, and 8-3 represents the third chlorination reactor 8.

[0062] Example 3

[0063] (1) 6.8 kg of 1,1,1,3-tetrachloropropane with a water content of 150 ppm (wt) was added to a dehydrochlorination reactor 2 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside) through a hydrogen chloride washing tower 1 (with a size of φ80×800 mm and an iron pipe with a size of φ15×30 mm inside), and heating and material circulation were started to carry out a 1,1,1,3-tetrachloropropane dehydrochlorination reaction at 130° C.;

[0064] (2) When the 1,1,3-trichloropropene content in the dehydrochlorination reactor 2 reaches 2.1%, the dehydrochlorination reactor circulation pump 4 is bypassed and the reaction liquid is transferred to the first chlorination reactor 8 (with a size of φ100×1000 mm and a ceramic ring with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 35.7 L / h, and the chlorination reaction is carried out at 130°C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 2-5%;

[0065] (3) When the conversion rate of tetrachloropropane in the first chlorination reactor 8 reaches 12.5%, the circulation pump 10 of the first chlorination reactor is opened to bypass and the reaction liquid is transferred to the second chlorination reactor 8 (with a size of φ100×1000 mm and a ceramic ring with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 161.8 L / h, and the chlorination reaction is carried out at 130° C. During the chlorination reaction, the content of 1,1,3-trichloropropene is controlled to be 2-5%;

[0066] (4) When the conversion rate of tetrachloropropane in the second chlorination reactor 8 reaches 57.3%, the circulation pump 10 of the second chlorination reactor is opened to bypass and the reaction liquid is transferred to the third chlorination reactor 8 (with a size of φ100×1000 mm and a ceramic ring with a size of φ15×30 mm filled inside), chlorine gas is introduced at a flow rate of 151.7 L / h, and the chlorination reaction is carried out at 130° C. During the chlorination reaction, the content of 1,1,3-trichloropropene is controlled to be 2-5%;

[0067] (5) When the conversion rate of tetrachloropropane in the third chlorination reactor 8 is greater than 95%, the circulation pump 10 of the third chlorination reactor is opened to bypass and the chlorination reaction liquid is transferred to the deepening reactor 14 (with dimensions of φ80×800 mm and filled with an iron pipe with dimensions of φ15×30 mm), chlorine gas is introduced at a flow rate of 22.6 L / h, and the reaction is continued at 130°C;

[0068] (6) When the conversion rate of tetrachloropropane in the deepening reactor 14 is greater than 98% and the content of 1,1,3-trichloropropene is less than 1%, the chlorinated liquid is continuously discharged to the post-treatment system at a flow rate of 5.47 kg / h, and the final high boiling point produced is 0.5%, and the purity of the obtained 1,1,1,2,3-pentachloropropane is 99.9%, and the yield is 94.7%;

[0069] (7) Fresh tetrachloropropane is continuously added to the dehydrochlorination reactor 2 through the hydrogen chloride scrubber 1 at a flow rate of 4.62 kg / h;

[0070] (8) The tail gases of each reactor are cooled and then combined to go to the hydrogen chloride scrubber 1. After the free chlorine carried by the tail gas is removed by absorption with 1,1,1,3-tetrachloropropane, the by-product hydrogen chloride is sent to the post-treatment system.

[0071]

[0072] Note: The equipment number 8-1 represents the first chlorination reactor 8, 8-2 represents the second chlorination reactor 8, and 8-3 represents the third chlorination reactor 8.

[0073] Comparative Example 1

[0074] This comparative example differs from Example 2 in that 0.3% ferric chloride powder was added to the tetrachloropropane feedstock as a catalyst, and the dehydrochlorination of the tetrachloropropane and the chlorination of the trichloropropene were carried out simultaneously in a chlorination tower filled with inert ceramic rings (packing size: φ15×30 mm). After the reaction, the conversion of the tetrachloropropane was 87%, the final high boiling point product was 5.6%, and the purity of the obtained pentachloropropane was 99.9%, with a yield of 81%. The high boiling point product in this comparative example was significantly higher than that in Example 2. This is because the temperature required for the dehydrochlorination of the tetrachloropropane was relatively high in the early stages of the reaction, and the generated trichloropropene released a large amount of heat during chlorination at high temperatures, which resulted in an increase in the reaction temperature and intensified the dehydrochlorination and chlorination reactions. In the later stages of the reaction, the reaction rate slowed due to the decrease in the tetrachloropropane concentration. If a one-pot reaction (dehydrochlorination and chlorination reactions were carried out entirely in a single reactor) were used, the reaction parameters would need to be constantly adjusted during the process, making it difficult to smoothly control the reaction and achieve continuous operation. In addition, the ferric chloride powder has poor dispersibility during the reaction, and the catalyst is prone to coking, which is not conducive to the full reaction of the raw materials and is prone to high boiling.

[0075] Comparative Example 2

[0076] The difference between this comparative example and Example 2 is that the trichloropropene content during the chlorination reaction is greater than 15%, the tetrachloropropane conversion rate after the reaction is 94%, the final high boiling point product is 3.6%, the purity of the obtained pentachloropropane is 99.9%, and the yield is 90%. Finally, the high boiling point product of this comparative example is also significantly higher than that of Example 2. This is because high-concentration trichloropropene is easily polymerized on the catalyst surface during the reaction, causing catalyst deactivation, which is not conducive to the full reaction of the raw materials and easily produces high boiling points.

[0077] Comparative Example 3

[0078] This comparative example differs from Example 1 in that scrubber 1 and each reactor were filled with inert ceramic ring packing (packing size: φ15×30 mm). After the reaction at 130°C, the raw material tetrachloropropane was substantially unconverted. This is because the reaction requires a Lewis acid catalyst. In Example 1, metal packing was used in the reactor. Under high temperature and the presence of trace amounts of water, the metal packing corroded, generating an in situ catalytically active Lewis acid catalyst, thus catalyzing the reaction. Replacing the packing with ceramic rings failed to generate a sufficient concentration of catalyst, resulting in the substantial non-reaction of the raw material tetrachloropropane.

[0079] Comparison of the above examples and control examples demonstrates that the present invention utilizes 1,1,1,3-tetrachloropropane as a starting material to produce 1,1,1,2,3-pentachloropropane via dehydrochlorination and chlorination in a series of tower reactors. Compared to the conventional two-step synthesis of 1,1,1,2,3-pentachloropropane, the coupling of the 1,1,1,3-tetrachloropropane dehydrochlorination and 1,1,3-trichloropropene chlorination systems shortens the process flow. Using a fixed bed of stacked iron rings or the like as reactor filler, catalytically active Lewis acid can be continuously generated in situ during the heating reaction, resolving the issues of conventional anhydrous ferric chloride catalyst powder, such as difficulty in addition, poor dispersibility, and frequent dosing. Furthermore, the fixed-bed catalyst system process eliminates the discharge of saponified, salty wastewater, resulting in a green and environmentally friendly process with broad application prospects. Compared with the existing one-step synthesis process, the method adopts the form of separating the dehydrochlorination reaction of 1,1,1,3-tetrachloropropane and the chlorination reaction of 1,1,3-trichloropropene and then reacting them in series, which can avoid the mismatch problem of the chlorination and dehydrochlorination reaction rates caused by the strong exothermic acceleration of the dehydrochlorination of 1,1,1,3-tetrachloropropane in the "one-pot method", making the reaction easier to control and easy to achieve continuous automated production.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A 1,1,1,2,3-pentachloropropane production plant, characterized by: The invention comprises a hydrogen chloride washing tower and a dehydrochlorination reactor, wherein the bottom of the hydrogen chloride washing tower is connected to the upper end of the side wall of the dehydrochlorination reactor through a pipeline, the top of the dehydrochlorination reactor is connected to the bottom of the hydrogen chloride washing tower through a dehydrochlorination reactor condenser, the bottom of the dehydrochlorination reactor condenser is connected to the dehydrochlorination reactor body, the bottom of the dehydrochlorination reactor is connected to the body of the dehydrochlorination reactor, and the bottom of the dehydrochlorination reactor is connected to the body and multiple chlorination reaction systems connected in series through a dehydrochlorination reactor circulation pump. Each chlorination reaction system comprises a chlorination reactor, the top of the chlorination reactor is connected to the bottom of the hydrogen chloride washing tower through a chlorination reactor condenser, the bottom of the chlorination reactor condenser is connected to the chlorination reactor body, the bottom of the chlorination reactor of each chlorination reaction system is connected to the body through a chlorination reactor circulation pump, the bottom of the last-stage chlorination reactor is connected to a deepening reactor through a chlorination reactor circulation pump, the top of the deepening reactor is connected to the bottom of the hydrogen chloride washing tower through a deepening reactor condenser, the bottom of the deepening reactor condenser is connected to the deepening reactor body, the bottom of the deepening reactor is connected to the body through a deepening reactor circulation pump, and the outlet of the deepening reactor circulation pump is connected to a reaction liquid post-processing device.

2. The production equipment for 1,1,1,2,3-pentachloropropane according to claim 1, characterized in that: A tetrachloropropane inlet and a hydrogen chloride outlet are provided on the top of the hydrogen chloride scrubbing tower, and the hydrogen chloride outlet is connected to a hydrogen chloride post-processing device.

3. The production equipment for 1,1,1,2,3-pentachloropropane according to claim 1, characterized in that: An online detector is installed at the bottom of the dehydrochlorination reactor for online analysis of the composition of the dehydrochlorination reaction liquid.

4. The production equipment for 1,1,1,2,3-pentachloropropane according to claim 1, characterized in that: An online detector is installed at the bottom of the chlorination reactor for online analysis of the composition of the chlorination reaction liquid.

5. The production equipment for 1,1,1,2,3-pentachloropropane according to claim 1, characterized in that: An online detector is installed at the bottom of the deepening reactor for online analysis of the composition of the reaction liquid.

6. A method for producing 1,1,1,2,3-pentachloropropane using the 1,1,1,2,3-pentachloropropane production equipment according to claim 1, characterized in that: The specific production steps are: (1) First, 1,1,1,3-tetrachloropropane is added to a dehydrochlorination reactor through a hydrogen chloride washing tower, heating and material circulation are started, and a dehydrochlorination reaction of 1,1,1,3-tetrachloropropane is carried out at 80-130° C.; (2) When the 1,1,3-trichloropropene content in the dehydrochlorination reactor reaches 2-30%, the dehydrochlorination reactor circulation pump bypass is opened to transfer the reaction liquid into the chlorination reaction system, and chlorine gas is introduced into the chlorination reaction system to carry out the chlorination reaction at 60-130° C. During the chlorination reaction, the 1,1,3-trichloropropene content is controlled to be 2-15%; (3) When the tetrachloropropane conversion rate in the nth chlorination reaction system is greater than 95%, the chlorination reaction liquid is transferred to a further reactor and the reaction is continued at 80-130°C; (4) when the tetrachloropropane conversion rate in the deepening reactor is greater than 98% and the 1,1,3-trichloropropene content is less than 1%, the chlorinated liquid is continuously discharged to the post-treatment system to obtain 1,1,1,2,3-pentachloropropane product; (5) The raw material tetrachloropropane is continuously added to the dehydrochlorination reactor through the hydrogen chloride scrubber; (6) The tail gases of each reactor are cooled and then combined to go to the hydrogen chloride scrubber. After the free chlorine carried by the tail gas is removed by absorption with 1,1,1,3-tetrachloropropane, the by-product hydrogen chloride is sent to the post-treatment system.

7. The method for producing 1,1,1,2,3-pentachloropropane using a 1,1,1,2,3-pentachloropropane production device according to claim 6, characterized in that: The water content of 1,1,1,3-tetrachloropropane described in step (1) is 30 to 150 ppm.

8. The method for producing 1,1,1,2,3-pentachloropropane using a 1,1,1,2,3-pentachloropropane production device according to claim 6, characterized in that: The hydrogen chloride washing tower, dehydrochlorination reactor and deepening reactor in step (1) and step (3) are filled with fillers, and the filler material is iron.

9. The method for producing 1,1,1,2,3-pentachloropropane using a 1,1,1,2,3-pentachloropropane production device according to claim 6, characterized in that: The number of the chlorination reaction systems in step (2) is 2 to 3, and the chlorination reactor is filled with fillers, and the filler material is one or more of ceramics, nickel, and iron.

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