Production system for producing dichloropropanol through glycerol chlorination

Abstract

The utility model relates to the technical field of preparation of dichloropropanol from glycerol, in particular to a production system for producing dichloropropanol through glycerol chlorination. The device comprises an adipaldehyde mixing tank for mixing adipaldehyde and pure water, a gas-liquid reaction kettle for absorbing chlorine in crude hydrogen chloride, a first microporous filter for filtering out a catalyst, a cooler for cooling crystals and a second microporous filter for removing crystals. The method has the effects of improving the problem of side reaction caused by chlorine impurities in crude hydrogen chloride and increasing the conversion rate of glycerol.

Description

Technical Field

[0001] This application relates to the technical field of preparing dichloropropanol from glycerol, and in particular to a production system for producing dichloropropanol by chlorination of glycerol. Background Technology

[0002] The chlorination of glycerol to produce dichloropropanol is a key intermediate step in the preparation of epichlorohydrin (ECH), and its conversion efficiency directly affects the product quality and production cost of ECH.

[0003] In related technologies, domestic ECH (Extractable Chloride) plants using the glycerol process generally utilize HCl, a byproduct of chlor-alkali industry or organochlorination production, which typically contains 1-2% Cl2 and other organic impurities. Existing processes pretreat HCl using simple methods such as adsorption and condensation to remove some impurities, but lack efficient purification measures for Cl2. The strong oxidizing properties of Cl2 lead to non-selective oxidation reactions with glycerol, generating chlorinated byproducts (such as dichloropropanol isomers), increasing glycerol consumption by 5-10% and reducing the yield and purity of the target product. Furthermore, traditional processes do not fully utilize side reaction resources, resulting in low catalytic system efficiency and failure to recover reaction heat, leading to energy waste.

[0004] The current process suffers from several shortcomings regarding the aforementioned technologies: First, Cl2 impurities trigger side reactions, increasing glycerol consumption and product complexity, requiring additional purification costs. Second, the resource utilization of impurities is not achieved; Cl2 is simply discarded as a harmful component and fails to be converted into high-value chemicals or catalysts. Third, the process has high energy consumption and lacks the recovery and utilization of reaction heat, leading to increased overall costs. These problems make it difficult for existing equipment to meet the demands of a green circular economy. Therefore, there is an urgent need to provide a new production system that integrates purification, catalysis, and energy synergy optimization to overcome the conversion rate bottleneck and improve resource utilization. Utility Model Content

[0005] In order to improve the problem of side reactions caused by chlorine impurities in crude hydrogen chloride and increase the conversion rate of glycerol, this application provides a production system for producing dichloropropanol by chlorination of glycerol.

[0006] The production system for producing dichloropropanol by glycerol chlorination provided in this application adopts the following technical solution:

[0007] A production system for producing dichloropropanol by chlorination of glycerol includes an adipaldehyde mixing tank for mixing adipaldehyde and pure water, a gas-liquid reaction vessel for absorbing chlorine gas from crude hydrogen chloride, a first microporous filter for filtering out the catalyst, a cooler for cooling crystallization, and a second microporous filter for removing crystals.

[0008] The adipaldehyde mixing tank is equipped with an adipaldehyde feed pipe, a pure water feed pipe and an adipaldehyde aqueous solution delivery pipe connected to the interior, and the adipaldehyde mixing tank is connected to the gas-liquid reaction vessel. The adipaldehyde mixing tank is provided with a catalyst inlet and the adipaldehyde aqueous solution delivery pipe is equipped with a first centrifugal pump.

[0009] The gas-liquid reactor is equipped with a crude hydrogen chloride input pipe connected to the interior, a mixed liquid conveying pipe for outputting the liquid phase, and a hydrogen chloride exhaust pipe for outputting the gas phase. The end of the mixed liquid conveying pipe away from the gas-liquid reactor is connected to the first microporous filter. A second centrifugal pump is provided on the mixed liquid conveying pipe, and a first recovery port for recovering the catalyst is opened on the first microporous filter.

[0010] The cooler is connected between the first microporous filter and the second microporous filter, and a third centrifugal pump is provided between the cooler and the first microporous filter;

[0011] The second microporous filter has a second recovery port for recovering crystals.

[0012] By adopting the above technical solution, an aqueous solution of adipaldehyde is prepared using a mixing tank and then transported to a gas-liquid reactor. It reacts with crude hydrogen chloride containing chlorine impurities to absorb chlorine, avoiding side reactions between chlorine and glycerol, reducing glycerol loss, and improving product selectivity, thereby increasing the conversion rate of glycerol chlorination to dichloropropanol. A cooler is placed between the first and second microporous filters. A third centrifugal pump transports the material, allowing it to first be filtered to remove the catalyst, then cooled to crystallize, and finally filtered to remove the crystals. The entire process is rational and improves production efficiency. The reacted mixture passes through the first microporous filter, where the catalyst can be recovered through the first recovery port, allowing for catalyst recycling and reducing production costs. The second microporous filter recovers the crystals through the second recovery port, achieving effective separation and recovery of the product and improving resource utilization.

[0013] Furthermore, the gas-liquid reactor has a jacketed temperature control layer, and a temperature-regulating water cooling mechanism for connecting the jacketed temperature control layer is provided outside the gas-liquid reactor.

[0014] By adopting the above technical solution, the appropriate temperature is crucial for the reaction rate and selectivity in the reaction process between adipic aldehyde aqueous solution and crude hydrogen chloride. The jacketed temperature-regulating layer of the gas-liquid reactor is connected to the temperature-regulating water cooling mechanism, enabling precise control of the reaction temperature within the reactor and ensuring that the reaction remains within the optimal temperature range. The redox reaction between adipic aldehyde and chlorine is exothermic; the temperature-regulating water cooling mechanism collects this heat of reaction while cooling the reactor. The collected heat can be used to preheat glycerol and other processes requiring heat energy, achieving energy recovery and utilization, reducing the overall energy consumption of the production system, and improving energy efficiency.

[0015] Furthermore, the gas-liquid reactor is equipped with a stirring paddle inside.

[0016] By adopting the above technical solution, the stirring paddle prevents sedimentation and stratification of materials during the reaction process, ensuring that catalysts and other substances are uniformly dispersed in the solution, guaranteeing the homogeneity of the entire reaction system, fully utilizing the catalyst's role, and improving reaction efficiency. Continuous stirring by the paddle breaks down the mass transfer resistance at the gas-liquid interface, allowing crude hydrogen chloride gas to be uniformly dispersed in the hexamethylenetetramine aqueous solution, increasing the contact area and collision probability between the two. This accelerates the reaction rate, making the reaction more complete, improving the absorption efficiency of chlorine gas, and thus reducing the residual amount of chlorine gas in the tail gas. The reaction process generates heat; the operation of the stirring paddle ensures a uniform temperature distribution within the reactor, preventing localized overheating or overcooling, and avoiding abnormal reactions due to temperature differences. Combined with the jacketed temperature control layer and temperature-controlled water cooling mechanism, it better maintains a suitable reaction temperature, ensuring the stability and consistency of the reaction.

[0017] Furthermore, the adipaldehyde feed pipe and the pure water feed pipe are equipped with circulating pumps for fully circulating and dissolving adipaldehyde and pure water.

[0018] By adopting the above technical solution, the circulating pump enables continuous circulation of adipic aldehyde and pure water within the pipeline, increasing the contact frequency and mixing degree between the two. This accelerates the dissolution rate of adipic aldehyde in pure water, allowing for the preparation of a uniform adipic aldehyde aqueous solution in a shorter time compared to natural dissolution or simple stirring, thus improving the efficiency of the production preparation stage. Continuous circulation also prevents uneven concentrations of adipic aldehyde and pure water during mixing, ensuring consistent concentration throughout the prepared adipic aldehyde aqueous solution. This provides a stable and uniform reactant for the subsequent reaction in the gas-liquid reactor, contributing to the stability and consistency of the reaction effect and improving product quality stability.

[0019] Furthermore, the end of the crude hydrogen chloride input pipe that is furthest from the gas-liquid reactor is connected to a chlorinated paraffin mechanism and a hydrogen chloride compressor.

[0020] By adopting the above technical solution and connecting it to the chlorinated paraffin mechanism, a stable source of crude hydrogen chloride is ensured. The hydrogen chloride compressor increases the pressure of the crude hydrogen chloride, overcomes pipeline resistance, and allows it to be delivered to the gas-liquid reactor more efficiently. Higher pressure increases the diffusion rate and reactivity of the gas within the reactor, accelerating the reaction rate between hexamethylenetetramine aqueous solution and crude hydrogen chloride, thereby improving overall production efficiency. The crude hydrogen chloride, a byproduct generated during chlorinated paraffin production, is utilized rationally, achieving resource recycling, reducing the raw material procurement cost for the glycerol chlorination to dichloropropanol production, and also reducing the emission treatment cost of crude hydrogen chloride during chlorinated paraffin production.

[0021] Furthermore, the number of the first microporous filters is several and each of the first microporous filters is arranged in parallel, and the mixture liquid conveying pipe and the second centrifugal pump are respectively arranged in one-to-one correspondence with each of the first microporous filters.

[0022] By adopting the above technical solution, when one or more of the first microporous filters need cleaning, maintenance, or malfunction, the other filters can still operate normally without affecting the overall production process. By closing the delivery pipe valve of the corresponding faulty filter, individual treatment of that filter can be achieved, ensuring the continuity and stability of production.

[0023] Furthermore, the number of the second microporous filters is several, and each of the second microporous filters is arranged in parallel.

[0024] By adopting the above technical solution, when one of the second microporous filters becomes clogged, malfunctions, or requires regular maintenance, the other parallel filters can still work normally, ensuring continuous filtration of the feed liquid and recovery of adipic acid crystals, maintaining stable production operation, avoiding production interruptions due to equipment problems, and reducing the negative impact on the entire production process.

[0025] Furthermore, the cooler is connected to a chilled water circulation pipe.

[0026] By adopting the above technical solution, chilled water, with its lower temperature, circulates through the cooling pipes in the cooler, rapidly removing heat from the substances requiring cooling. This results in a better cooling effect than ordinary cooling water, allowing materials containing adipic acid crystals, such as liquids, to reach the required low temperature in a shorter time, thus improving cooling efficiency. The chilled water circulation pipes provide a stable low-temperature environment, which helps control the growth rate and morphology of adipic acid crystals, ensuring the stability and consistency of product quality.

[0027] Furthermore, the second microporous filter is connected to a glycerol mixing tank at the second recovery port location.

[0028] By adopting the above technical solution, adipaldehyde absorbs chlorine from crude hydrogen chloride and is oxidized to adipic acid. The adipic acid crystals recovered through the second microporous filter are transported to the glycerol mixing tank, where they dissolve with glycerol to form a catalyst for the chlorination of glycerol to produce dichloropropanol. This process realizes the resource recycling of impurities into key catalysts, avoids the disposal of adipic acid as waste, significantly improves the material utilization rate of the entire production system, and reduces dependence on external catalysts and procurement costs.

[0029] Furthermore, the side of the second microporous filter away from the cooler is connected to a recovery tank for recovering the liquid phase.

[0030] By adopting the above technical solution, in the entire process of glycerol chlorination to produce dichloropropanol, after the adipic acid crystals are removed by the second microporous filter, the remaining liquid phase still contains a variety of usable substances, such as unreacted hexamethylenetetramine and small amounts of other soluble substances. These liquid phases are recycled to a recovery tank and reused to dissolve hexamethylenetetramine, achieving material recycling, improving resource utilization, and reducing raw material waste.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. Adipical solution is prepared by mixing adipical solution in a mixing tank to absorb chlorine gas from crude hydrogen chloride, avoiding side reactions between chlorine and glycerol, reducing glycerol loss, and improving product selectivity and conversion rate. The stirring paddle in the gas-liquid reactor promotes gas-liquid mixing and uniform temperature distribution, ensuring stable reaction, accelerating reaction rate and chlorine absorption efficiency. The cooler, in conjunction with the chilled water circulation pipe, provides a stable low temperature, controls crystal growth, and ensures stable product quality.

[0033] 2. Multiple first and second microporous filters are set up in parallel to serve as backup, ensuring production continuity and reducing production stoppage losses caused by equipment failure or maintenance. The first microporous filter recovers the catalyst for recycling, and the second microporous filter recovers adipic acid crystals and converts them into catalyst, reducing dependence on external catalysts and procurement costs. It is connected to the chlorinated paraffin mechanism to obtain a stable source of crude hydrogen chloride, realizing resource recycling and reducing raw material procurement costs.

[0034] 3. The liquid phase filtered by the second microporous filter is recovered and used to dissolve hexamethylenetetramine, realizing material recycling and reducing raw material waste. The temperature control layer of the gas-liquid reactor jacket recovers the reaction heat and uses it to preheat glycerin, etc., realizing energy recovery and utilization and reducing the energy consumption of the production system. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the production system for producing dichloropropanol by chlorination of glycerol in Example 1 of this application.

[0036] Figure 2 This is a schematic diagram of the structure of the adipaldehyde mixing tank and its upstream and downstream pipelines in Embodiment 1 of this application.

[0037] Figure 3 This is a schematic diagram of the gas-liquid reactor and its upstream and downstream pipelines in Embodiment 1 of this application.

[0038] Figure 4 This is a schematic diagram of the gas-liquid reactor and the first microporous filter in Embodiment 1 of this application.

[0039] Figure 5 This is a schematic diagram of the structure of the first microporous filter and cooler in Embodiment 1 of this application.

[0040] Figure 6 This is a schematic diagram of the structure of the cooler, the second microporous filter, and the glycerin mixing tank in Embodiment 1 of this application.

[0041] Figure 7 This is a schematic diagram of the overall structure of the production system for producing dichloropropanol by chlorination of glycerol in Example 2 of this application.

[0042] Figure 8 This is a schematic diagram of the structure of the cooler, the second microporous filter, the glycerol mixing tank and the recovery tank in Embodiment 2 of this application.

[0043] Explanation of reference numerals in the attached drawings: 1. Glyoxal mixing tank; 11. Glyoxal feed pipe; 12. Pure water feed pipe; 13. Circulation pump; 14. Catalyst inlet; 15. Glyoxal aqueous solution delivery pipe; 16. First centrifugal pump; 2. Gas-liquid reactor; 21. Crude hydrogen chloride input pipe; 211. Chlorinated paraffin mechanism; 212. Hydrogen chloride compressor; 22. Mixed material liquid delivery pipe; 23. Second centrifugal pump; 24. Hydrogen chloride exhaust pipe; 25. Glycerol chlorination to dichloropropanol synthesis working section; 26. Jacketed temperature control layer; 261. Temperature control water cooling mechanism; 27. Stirring paddle; 3. First microporous filter; 31. First recovery port; 32. Third centrifugal pump; 4. Cooler; 41. Chilled water circulation pipe; 5. Second microporous filter; 51. Second recovery port; 6. Glycerol mixing tank; 7. Recovery tank. Detailed Implementation

[0044] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figure 1-8 Examples 1 and 2 will be used to further describe this application in detail.

[0045] Example 1

[0046] This application discloses a production system for producing dichloropropanol by chlorinating glycerol. (Refer to...) Figure 1The production system for producing dichloropropanol from glycerol by chlorination includes a hexamethylenedialdehyde mixing tank 1, a gas-liquid reaction vessel 2, a first microporous filter 3, a cooler 4, and a second microporous filter 5. The hexamethylenedialdehyde mixing tank 1 is used to mix hexamethylenedialdehyde and pure water; the gas-liquid reaction vessel 2 is used to absorb chlorine gas from crude hydrogen chloride; the first microporous filter 3 is used to filter out catalyst particles; the cooler 4 is used to cool and crystallize the liquid phase output from the first microporous filter 3; and the second microporous filter 5 is used to remove crystals.

[0047] Reference Figure 1 and Figure 2 The adipaldehyde mixing tank 1 is connected to one side by an adipaldehyde inlet pipe 11 for inputting adipaldehyde liquid and a pure water inlet pipe 12 for inputting pure water. Both the adipaldehyde inlet pipe 11 and the pure water inlet pipe 12 are connected to the interior of the adipaldehyde mixing tank 1. In this embodiment, a circulation pump 13 is installed on the adipaldehyde inlet pipe 11 and the pure water inlet pipe 12. In actual operation, adipaldehyde is added to pure water at 80°C, and the circulation pump 13 is used to continuously circulate adipaldehyde and pure water in the pipeline, thereby fully circulating and dissolving them to prepare a 20wt% aqueous solution. The operating pressure is controlled at 5-10 kPaG. This accelerates the dissolution rate of adipaldehyde in pure water, prepares a uniform adipaldehyde aqueous solution, improves the efficiency of the production preparation stage, and ensures that the concentration of the prepared adipaldehyde aqueous solution is consistent throughout, providing a stable and uniform reactant for subsequent reactions.

[0048] The adipaldehyde mixing tank 1 has a catalyst inlet 14 on its top side. After the adipaldehyde aqueous solution is mixed evenly, 3%-6% tungsten phosphate is added from the top of the mixing tank as a catalyst. The adipaldehyde mixing tank 1 has an adipaldehyde aqueous solution delivery pipe 15 on the side away from the adipaldehyde feed pipe 11 and the pure water feed pipe 12 for connecting to the gas-liquid reactor 2. The adipaldehyde aqueous solution delivery pipe 15 is equipped with a first centrifugal pump 16, which delivers the prepared adipaldehyde aqueous solution with added catalyst to the gas-liquid reactor 2.

[0049] Reference Figure 2 and Figure 3 The gas-liquid reactor 2 has a crude hydrogen chloride input pipe 21 connected to the interior on its lower side. A mixture feed pipe 22 for outputting the liquid phase is located on the side of the gas-liquid reactor 2 away from the hexamethylenetetramine mixing tank 1. The end of the mixture feed pipe 22 away from the gas-liquid reactor 2 is connected to a first microporous filter 3, and a second centrifugal pump 23 is installed on the mixture feed pipe 22. A hydrogen chloride exhaust pipe 24 for outputting the gas phase is located on the top side of the gas-liquid reactor 2. The end of the hydrogen chloride exhaust pipe 24 away from the gas-liquid reactor 2 is connected to the glycerol chlorination to dichloropropanol synthesis working section 25.

[0050] In this embodiment, the end of the crude hydrogen chloride input pipe 21 furthest from the gas-liquid reactor 2 is connected to the chlorination paraffin mechanism 211 and the hydrogen chloride compressor 212. During operation, the hydrogen chloride compressor 212 delivers the crude hydrogen chloride generated by the chlorination paraffin mechanism to the gas-liquid reactor 2. This ensures a stable source of crude hydrogen chloride and increases its pressure, allowing for more efficient delivery to the gas-liquid reactor 2, accelerating the reaction rate, achieving resource recycling, and reducing costs.

[0051] The gas-liquid reactor 2 has a jacketed temperature-regulating layer 26 inside, and a temperature-regulating water cooling mechanism 261 connected to the outside of the gas-liquid reactor 2 for connecting the jacketed temperature-regulating layer 26. Adipicalgaldehyde aqueous solution reacts with crude hydrogen chloride inside the gas-liquid reactor 2 under reaction conditions of 90-100℃ and a pressure of 0.4 mPaG. This reaction is exothermic. During the reaction, the jacketed temperature-regulating layer 26 and the temperature-regulating water cooling mechanism 261 work together to precisely control the reaction temperature inside the reactor, keeping the temperature-regulating water at 70-80℃. While cooling the reactor, this heat of reaction is collected and used to preheat glycerol to 60℃, achieving energy recovery and utilization, and reducing energy consumption.

[0052] The gas-liquid reactor 2 is equipped with a stirring paddle 27 inside. During the reaction process, the stirring paddle 27 can prevent the material from settling and separating, so that the catalyst and other substances are evenly dispersed in the solution, ensuring the homogeneity of the entire reaction system, giving full play to the role of the catalyst, and improving the reaction efficiency.

[0053] After the reaction, the purity of hydrogen chloride in the gas phase can increase from 99% to 99.8%, and then the gas phase is sent to the working section for the synthesis of dichloropropanol from glycerol chlorination as raw material. The liquid mixture is discharged to the first microporous filter 3 through the mixture conveying pipe 22 under the action of the second centrifugal pump 23. The first microporous filter 3 has a first recovery port 31 on its lower side for recovering the catalyst.

[0054] Reference Figure 4 The number of first microporous filters 3 can be several, and the first microporous filters 3 are arranged in parallel. The mixture liquid conveying pipe 22 and the second centrifugal pump 23 are respectively arranged one-to-one with each of the first microporous filters 3. In this embodiment, the number of first microporous filters 3 is preferably two, one in use and one on standby, which are used alternately. When one or more of the first microporous filters 3 need to be cleaned, maintained or malfunctions, the conveying pipe valve of the corresponding malfunctioning filter can be closed to achieve individual treatment of the filter, while the other filters can still work normally without affecting the entire production process, ensuring the continuity and stability of production, and timely recovery of tungsten oxide and tungsten phosphate catalysts after switching.

[0055] Reference Figure 5 and Figure 6The cooler 4 is connected between the first microporous filter 3 and the second microporous filter 5, and a third centrifugal pump 32 is installed between the cooler 4 and the first microporous filter 3. The liquid material output from the first microporous filter 3 is transported to the cooler 4 by the third centrifugal pump 32. A chilled water circulation pipe 41 is connected to the cooler 4. The filtered liquid is pumped to the cooler 4 for cooling with chilled water to a temperature of 25-30℃. The chilled water circulates within the cooler 4 through the circulation pipe, quickly removing heat from the material to be cooled. This provides a better cooling effect than ordinary cooling water, allowing materials containing adipic acid crystals to reach the required low temperature in a shorter time, thus improving cooling efficiency. Simultaneously, the chilled water circulation pipe 41 provides a stable low-temperature environment, helping to control the growth rate and morphology of adipic acid crystals, ensuring product quality stability and consistency, and promoting the precipitation of adipic acid crystals during cooling.

[0056] Reference Figure 5 and Figure 6 After the liquid containing adipic acid crystals is discharged from the cooler 4, it is discharged to the second microporous filter 5. The second microporous filter 5 has a second recovery port 51 on its lower side for recovering the crystals. There are several second microporous filters 5, and they are arranged in parallel. In this embodiment, it is preferable to have two second microporous filters 5, one in use and one on standby, used alternately. When a second microporous filter 5 becomes clogged, malfunctions, or requires periodic maintenance, the parallel standby filter can still work normally to ensure continuous filtration of the liquid and recovery of adipic acid crystals, maintain stable production operation, and recover adipic acid crystals in a timely manner after switching.

[0057] The second microporous filter 5 is connected to a glycerol mixing tank 6 at the second recovery port 51. The recovered adipic acid crystals are sent to the glycerol mixing tank 6 and dissolved in glycerol at 50°C to prepare a catalyst for the chlorination of glycerol to produce dichloropropanol. The concentration is controlled at 4-5 wt%, realizing the resource recycling from impurity to key catalyst, avoiding the treatment of adipic acid as waste, significantly improving the material utilization rate of the entire production system, and reducing dependence on external catalysts and procurement costs.

[0058] The implementation principle of a production system for producing dichloropropanol from glycerol using an embodiment of this application is as follows: First, in a hexadaldehyde mixing tank 1, a circulating pump 13 prepares a 20wt% aqueous solution of hexadaldehyde and 80℃ pure water. The operating pressure is 5-10 kPaG. After adding 3%-6% tungsten phosphate catalyst, the solution is sent to a gas-liquid reaction vessel 2 via a first centrifugal pump 16. Simultaneously, a hydrogen chloride compressor 212 inputs crude hydrogen chloride generated by a paraffin chlorination mechanism 211 into the reaction vessel. Under conditions of 90-100℃ and 0.4 mPaG, the hexadaldehyde aqueous solution absorbs chlorine gas. The exothermic reaction is regulated by a jacketed temperature control layer 26 and a temperature-controlled water cooling mechanism 261, and the heat is used to preheat the glycerol. A stirring paddle 27 ensures the homogeneity of the reaction system and improves reaction efficiency.

[0059] After the reaction, the purified gaseous hydrogen chloride is sent to the glycerol chlorination synthesis section. The liquid mixture is pumped by a second centrifugal pump 23 to a first microporous filter 3 for catalyst recovery, with one filter in use and one in reserve to ensure continuous production. The filtrate is pumped by a third centrifugal pump 32 to a cooler 4, where it is cooled to 25-30°C with chilled water, causing adipic acid crystals to precipitate. The liquid containing the crystals enters a second microporous filter 5, with one filter in use and one in reserve for crystal recovery. The crystals are sent to a glycerol mixing tank 6 to produce a 4-5 wt% catalyst, achieving resource regeneration and reducing costs.

[0060] Example 2

[0061] Reference Figure 7 and Figure 8 The difference between this embodiment and Embodiment 1 is that a recovery tank 7 for recovering the liquid phase is connected to the side of the second microporous filter 5 away from the cooler 4. In this embodiment, after the liquid phase filtered by the second microporous filter 5 is output, it can be reused by the recovery tank 7 to continue dissolving hexamethylenedialdehyde.

[0062] During the entire process of glycerol chlorination to produce dichloropropanol, after the adipic acid crystals are removed by the second microporous filter 5, the remaining liquid phase still contains various usable substances, such as unreacted hexamethylenetetramine and small amounts of other soluble substances. These liquid phases are recycled to the recovery tank 7 and reused to dissolve hexamethylenetetramine, achieving material recycling, improving resource utilization, and reducing raw material waste.

[0063] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A production system for producing dichloropropanol by chlorination of glycerol, characterized in that: It includes an adipaldehyde mixing tank (1) for mixing adipaldehyde and pure water, a gas-liquid reaction vessel (2) for absorbing chlorine from crude hydrogen chloride, a first microporous filter (3) for filtering out the catalyst, a cooler (4) for cooling crystallization, and a second microporous filter (5) for removing crystals. The adipaldehyde mixing tank (1) is provided with an adipaldehyde feed pipe (11) and a pure water feed pipe (12) connected to the interior, and an adipaldehyde aqueous solution conveying pipe (15) connected to the gas-liquid reaction vessel (2). The adipaldehyde mixing tank (1) is provided with a catalyst inlet (14), and the adipaldehyde aqueous solution conveying pipe (15) is provided with a first centrifugal pump (16). The gas-liquid reactor (2) is provided with a crude hydrogen chloride input pipe (21) communicating with the interior, a mixture liquid conveying pipe (22) for outputting the liquid phase, and a hydrogen chloride exhaust pipe (24) for outputting the gas phase. The end of the mixture liquid conveying pipe (22) away from the gas-liquid reactor (2) is connected to the first microporous filter (3). The mixture liquid conveying pipe (22) is provided with a second centrifugal pump (23). The first microporous filter (3) is provided with a first recovery port (31) for recovering the catalyst. The cooler (4) is connected between the first microporous filter (3) and the second microporous filter (5), and a third centrifugal pump (32) is provided between the cooler (4) and the first microporous filter (3); The second microporous filter (5) has a second recovery port (51) for recovering crystals.

2. The production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The gas-liquid reactor (2) has a jacketed temperature control layer (26), and the gas-liquid reactor (2) is provided with a temperature control water cooling mechanism (261) for connecting the jacketed temperature control layer (26) on the outside.

3. The production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The gas-liquid reactor (2) is equipped with a stirring paddle (27) inside.

4. The production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The adipaldehyde feed pipe (11) and the pure water feed pipe (12) are equipped with a circulating pump (13) for fully circulating and dissolving adipaldehyde and pure water.

5. The production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The crude hydrogen chloride input pipe (21) is connected to a chlorinated paraffin mechanism (211) and a hydrogen chloride compressor (212) at the end away from the gas-liquid reactor (2).

6. The production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The number of the first microporous filters (3) is several and each of the first microporous filters (3) is arranged in parallel. The mixture liquid conveying pipe (22) and the second centrifugal pump (23) are arranged in a one-to-one correspondence with each of the first microporous filters (3).

7. The production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The number of the second microporous filters (5) is several, and each of the second microporous filters (5) is arranged in parallel.

8. A production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The cooler (4) is connected to a chilled water circulation pipe (41).

9. A production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The second microporous filter (5) is connected to a glycerol mixing tank (6) at the second recovery port (51).

10. A production system for producing dichloropropanol by chlorination of glycerol according to claim 1, characterized in that: The second microporous filter (5) is connected to a recovery tank (7) for recovering the liquid phase on the side away from the cooler (4).

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