Process device and method for continuously synthesizing glycidol

Abstract

The invention belongs to the field of chemical engineering, and relates to a process device and method for continuously synthesizing glycidyl (3-chloro-1, 2-propylene glycol and sodium hydroxide (hereinafter referred to as NaOH) as raw materials). The device comprises a raw material feeding pump, a heat exchanger, a micro-reactor, a delay tube reactor 1, a neutralization micro-reactor and a delay tube reactor 2 which are sequentially in fluid communication through pipelines, the heat exchangers are divided into two groups, one group is used for heat exchange of 3-chloro-1, 2-propylene glycol solution, and the other group is used for heat exchange of alkaline solution. According to the method, a 3-chloro-1, 2-propylene glycol solution and a sodium hydroxide solution (NaOH) are adopted as raw materials, glycidol is continuously prepared through a microchannel reactor, on the basis, an acid-base neutralization reaction can be carried out in situ according to needs to remove redundant alkali, redundant heat generated by the acid-base neutralization reaction is absorbed through a low-temperature material, and energy consumption is reduced; the product is analyzed by gas chromatography, and the generated glycidol does not have hydrolysates or auto-polymerization products, so that the product selectivity is higher.

Description

Technical Field

[0001] This invention belongs to the field of chemical engineering and relates to a process apparatus and method for the continuous synthesis of glycidyl ether (using 3-chloro-1,2-propanediol and sodium hydroxide (hereinafter referred to as NaOH) as raw materials). Background Technology

[0002] Glycidol, also known as epichlorohydrin, is an important chemical raw material. Its molecular structure contains both hydroxyl and epoxy groups, making it a common intermediate in the synthesis of surfactants, polymers, and dyes, and it is widely used in solvent extraction and separation processes. Its derivatives can also serve as raw materials in the plastics, pharmaceutical, pesticide, and auxiliary industries.

[0003] Currently, glycidol can be prepared using various methods, including the allyl alcohol epoxidation method, the 3-chloro-1,2-propanediol method, the glycidaldehyde hydrogenation method after acrolein epoxidation, the ester hydrolysis method, and the glycerol carbonate method. Each method has its own advantages and limitations. With the continuous depletion of non-renewable petroleum resources, the drawbacks of using petroleum as a raw material to prepare glycidol are becoming increasingly apparent. In recent years, research on biodiesel based on renewable energy sources has gradually gained attention. Its production process generates a large amount of glycerol as a byproduct, making continuous research using glycerol as a raw material of significant necessity. Against this background, this paper selects the 3-chloro-1,2-propanediol method using glycerol as a raw material as the research object to study the preparation of glycidol using this method.

[0004] Currently, the industrial production of glycidol in China mainly adopts the propylene alcohol epoxidation method, while research on the synthetic route based on 3-chloro-1,2-propanediol is relatively limited. Chinese patent CN103012322B discloses a synthetic method using 3-chloro-1,2-propanediol as a raw material. This method involves the reaction in a system where an organic solvent, a basic catalyst, and a phase transfer catalyst coexist, controlling the reaction temperature at 40-100℃ and the reaction time at 1-4 hours to ultimately obtain glycidol. However, this process has the following technical drawbacks: it relies on the use of organic solvents and phase transfer catalysts; the raw material conversion is incomplete after the reaction; the reaction temperature is high; and the reaction cycle is long.

[0005] In the preparation of glycidyl ether using the 3-chloro-1,2-propanediol method, excessively high temperatures or prolonged reaction times can easily lead to hydrolysis and intermolecular condensation of glycidyl ether, resulting in increased byproducts and higher separation costs, thus weakening the practicality of the process. Furthermore, the molar ratio of feedstock to alkali is also crucial: excessively high alkali content reduces glycidyl ether yield, and additional acid must be added during subsequent separation to neutralize the excess alkali; the heat released during acid-base neutralization further affects the final product yield. Conversely, lower alkali content, while eliminating the need for acid neutralization, leads to decreased product yield, increased feedstock residue, higher separation costs, and reduced overall production capacity. Therefore, there is an urgent need to develop a green process route that can achieve high selectivity and high conversion rates at low temperatures and in a short time, with high alkali utilization, in-situ acid-base neutralization, and without the need for organic solvents or phase transfer catalysts. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the current 3-chloro-1,2-propanediol method for preparing glycidyl glycerol by providing a process apparatus and method for the continuous synthesis of glycidyl glycerol (using 3-chloro-1,2-propanediol and NaOH as raw materials).

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A process apparatus for the continuous synthesis of glycidol, the apparatus comprising the following components in sequential fluid communication via pipelines: a feed pump, a heat exchanger, a microreactor, a time-delay reactor 1, a neutralization microreactor, and a time-delay reactor 2; The heat exchanger is divided into two groups: one group is a 3-chloro-1,2-propanediol solution heat exchanger, and the other group is an alkaline solution heat exchanger.

[0008] The microreactor consists of a heat exchange channel and a reaction channel. The reaction channel consists of a continuous phase channel and a dispersed phase channel. The dispersed phase channel is connected to the continuous phase channel through micropores. The inlet of the dispersed phase channel is connected to the alkaline solution heat exchanger through a pipeline. The inlet of the continuous phase reaction channel is connected to the material outlet of the heat exchanger for the 3-chloro-1,2-propanediol solution through a pipeline. The outlet of the continuous phase reaction channel is connected to the inlet of the delay tube reactor 1 through a pipeline. One end of the heat exchange channel is connected to the medium outlet of the integrated heat exchanger, and the other end is connected to the medium inlet of the integrated heat exchanger. The heat exchange medium and the heat exchange material exchange heat in a countercurrent manner.

[0009] The microreactor has a continuous phase channel with a hydraulic radius of 1.5-2 mm, a dispersed phase micropore inner diameter of 0.2 mm, and a liquid holding capacity of 10 ml. The heat exchange channel has a hydraulic radius of 2 mm and a liquid holding capacity of 20 ml. All of these are made of 316L stainless steel.

[0010] The heat exchanger consists of a heat exchange medium channel and a material channel. The material channel inlet is connected to a feed horizontal flow pump via a pipeline, and the outlet is connected to a microreactor. One end of the heat exchange medium channel is connected to the medium outlet of the integrated heat exchanger, and the other end is connected to the medium inlet of the integrated heat exchanger. The heat exchange medium and the heat exchange material exchange heat in a countercurrent manner.

[0011] The material channel of the heat exchanger has a hydraulic radius of 2 mm and a liquid holding capacity of 20 ml.

[0012] The time-delay tube reactor 1 is composed of a stainless steel coil with an inner diameter of 2 mm and a liquid holding capacity of 20 ml. The material is 316L and it is completely immersed in the external heat exchange medium.

[0013] The neutralization microreactor has the same structure and liquid holding capacity as the microreactor, except that the inner diameter of the dispersed phase micropores is 0.1 mm and the material is Hastelloy alloy. The inlet of the continuous phase channel of the neutralization microreactor is connected to the outlet of the delay tube reactor 1 through a pipeline, the outlet of the continuous phase channel is connected to the inlet of the delay tube reactor 2, and the inlet of the dispersed phase channel is connected to the horizontal flow pump for the hydrochloric acid solution through a pipeline.

[0014] The outlet of the delayed-time tube reactor 2 is connected to a product receiving container, which consists of a stainless steel coil with an inner diameter of 2 mm and a liquid holding capacity of 10 ml. The material is 316L, and the coil is completely immersed in the external heat exchange medium.

[0015] A method for continuous synthesis of glycidyl ether using the aforementioned apparatus involves transporting two raw materials separately via a horizontal flow pump and cooling them through heat exchange. The two raw materials are then subjected to forced mixing and reaction in a microreactor, followed by an epoxidation reaction in a delayed-time tube reactor 1 to generate glycidyl ether.

[0016] A horizontal flow pump is used to separately transport the 3-chloro-1,2-propanediol solution and the alkaline solution to a heat exchanger for cooling. After both materials have cooled to 5-10°C, the alkaline solution enters through the dispersed phase channel inlet of the microreactor and merges with the 3-chloro-1,2-propanediol solution pumped in through the continuous phase inlet. The two are forcibly mixed in the microreactor channel. The mixture then enters the delayed-phase reactor 1 from the continuous phase outlet of the microreactor to continue the reaction until the 3-chloro-1,2-propanediol is completely converted into glycidyl glycerol. The reaction residence time for this step is 31-41 seconds.

[0017] The outlet of the delayed-phase reactor 1 is equipped with a three-way valve to control the subsequent process: if no excess alkali is required, the reaction solution is directly discharged to the receiving container; if neutralization is required, the material enters the continuous phase channel of the neutralization microreactor. At this point, the hydrochloric acid feed pump is started, and the hydrochloric acid enters the neutralization microreactor through the dispersed phase channel to undergo an acid-base neutralization reaction with the glycidyl solution in the continuous phase. To ensure complete neutralization of residual alkali, a delayed-phase reactor 2 is connected to the outlet of the neutralization microreactor to further break down excess alkali in the reaction solution. The final glycidyl solution obtained from the outlet of the delayed-phase reactor 2 is neutral or slightly alkaline and is collected in the receiving container.

[0018] The ratio of the 3-chloro-1,2-propanediol solution to the alkaline solution is 1:0.9-1.06; wherein the 3-chloro-1,2-propanediol solution is a 36% (w / w) aqueous solution. The alkaline solution is a 24-26% (w / w) NaOH aqueous solution.

[0019] The temperature of the microreactor is set such that the temperature during the reaction of the 3-chloro-1,2-propanediol solution and the alkaline solution is maintained at 0°C.

[0020] The flow rate of the advection pump is set as follows: the feed rate of 3-chloro-1,2-propanediol solution is set to 30-40 ml / min; the feed rate of alkaline solution is set to 13-19 ml / min.

[0021] Compared with the prior art, the present invention has the following beneficial effects: This invention uses 3-chloro-1,2-propanediol solution and NaOH solution as raw materials to continuously prepare glycidyl ether via a microchannel reactor. Based on this, an in-situ acid-base neutralization reaction can be carried out as needed to remove excess alkali, and the excess heat generated by the acid-base neutralization reaction is absorbed by the low-temperature material, reducing energy consumption. The product is analyzed by gas chromatography, and the generated glycidyl ether has no hydrolysis products or self-polymerization products, and the product has high selectivity.

[0022] The method of this invention has simple operation, high reaction efficiency, mild reaction conditions, and does not require the use of organic solvents other than water or phase transfer catalysts.

[0023] The method of this invention can effectively suppress the formation of byproducts during the reaction process, with short reaction time and high product selectivity. Attached Figure Description

[0024] Figure 1 This is a simplified diagram of the reaction process.

[0025] Figure 2 This is a schematic diagram of a microreactor structure.

[0026] Figure 3 for Figure 2Microscopic view of the continuous phase channel and dispersed phase in the microreactor.

[0027] Figure 4 for Figure 2 Cross-sectional view of a microreactor.

[0028] Figure 5 for Figure 2 Schematic diagram of micropores in a microreactor.

[0029] Among them, 1 is a microreactor, 2 is a neutralization microreactor, 3 is a time-delay tube reactor, 4 is a heat exchanger, 5 is a 3-chloro-1,2-propanediol solution feed pump, 6 is a NaOH solution feed pump, 7 is a hydrochloric acid solution feed pump, 8 is a product receiving container, 9 is the external heat exchange medium of the time-delay tube reactor, 10 is a three-way ball valve, 11 is the reactor heat exchange medium inlet, 12 is the reactor heat exchange medium outlet, 13 is the microreactor microporous flow channel, 14 is the microreactor continuous phase channel, 15 is the microreactor dispersed phase channel, and 16 is the microreactor continuous phase channel inlet. Detailed Implementation

[0030] This invention enables complete conversion of raw materials without the generation of byproducts. The reaction solution is controlled by a three-way valve at the outlet of the delayed-tube reactor 1, allowing for direct product collection or online neutralization with hydrochloric acid in a neutralization microreactor. After passing through the delayed-tube reactor 2, the product is adjusted to neutral or slightly alkaline before collection. This online neutralization process has no impact on the composition of the main reaction product. This invention employs a microchannel continuous reaction system, offering advantages such as high reaction efficiency, strong process controllability, mild reaction conditions, and high product purity, making it suitable for the large-scale preparation of glycidol.

[0031] The 3-chloro-1,2-propanediol, NaOH, hydrochloric acid, etc. used in the embodiments of the present invention are all commercially available.

[0032] Product purity testing methods Instrument: Agilent GC7890A gas chromatograph; Solvent: N,N-dimethylformamide; Analytical conditions: flow rate 3 ml / min, column temperature 220℃; The gas phase analysis results in the case studies were all normalized content. Example 1 like Figure 1 and 2 As shown, the process apparatus for continuous synthesis of glycidol includes the following components that are sequentially fluidly connected via pipelines: a feed pump, a heat exchanger, a microreactor, a time-delay reactor 1, a neutralization microreactor, and a time-delay reactor 2. The heat exchanger is divided into two groups: one group is a 3-chloro-1,2-propanediol solution heat exchanger, and the other group is an alkaline solution heat exchanger.

[0033] The microreactor consists of a heat exchange channel and a reaction channel. The reaction channel consists of a continuous phase channel and a dispersed phase channel. The dispersed phase channel is connected to the continuous phase channel through micropores. The inlet of the dispersed phase channel is connected to the alkaline solution heat exchanger through a pipeline. The inlet of the continuous phase reaction channel is connected to the material outlet of the heat exchanger for the 3-chloro-1,2-propanediol solution through a pipeline. The outlet of the continuous phase reaction channel is connected to the inlet of the delay tube reactor 1 through a pipeline. One end of the heat exchange channel is connected to the medium outlet of the integrated heat exchanger, and the other end is connected to the medium inlet of the integrated heat exchanger. The heat exchange medium and the heat exchange material exchange heat in a countercurrent manner.

[0034] The microreactor has a continuous phase channel with a hydraulic radius of 2 mm, a dispersed phase micropore inner diameter of 0.2 mm, and a liquid holding capacity of 10 ml. The heat exchange channel has a hydraulic radius of 2 mm and a liquid holding capacity of 20 ml. All of these are made of 316L.

[0035] The heat exchanger consists of a heat exchange medium channel and a material channel. The material channel inlet is connected to a feed horizontal flow pump via a pipeline, and the outlet is connected to the reactor. One end of the heat exchange medium channel is connected to the medium outlet of the integrated heat exchanger, and the other end is connected to the medium inlet of the integrated heat exchanger. The heat exchange medium and the heat exchange material exchange heat in a countercurrent manner.

[0036] The material channel of the heat exchanger has a hydraulic radius of 2 mm and a liquid holding capacity of 20 ml.

[0037] The time-delay tube reactor 1 is composed of a stainless steel coil with an inner diameter of 2 mm and a liquid holding capacity of 20 ml. The material is 316L and it is completely immersed in the external heat exchange medium.

[0038] The neutralization microreactor has the same structure as the microreactor, except that the inner diameter of the dispersed phase micropores is 0.1 mm and the material is Hastelloy alloy. The inlet of the continuous phase channel of the neutralization microreactor is connected to the outlet of the delay tube reactor 1 through a pipeline, the outlet of the continuous phase channel is connected to the inlet of the delay tube reactor 2, and the inlet of the dispersed phase channel is connected to the horizontal flow pump for the hydrochloric acid solution through a pipeline.

[0039] The outlet of the delayed-time tube reactor 2 is connected to a product receiving container, which consists of a stainless steel coil with an inner diameter of 2 mm and a liquid holding capacity of 10 ml. The material is 316L, and the coil is completely immersed in the external heat exchange medium.

[0040] The method of continuously synthesizing glycidol using the aforementioned device involves transporting two raw materials separately via a horizontal flow pump and cooling them through heat exchange. The two raw materials are then subjected to forced mixing and reaction in a microreactor, and subsequently enter a delayed-time tube reactor 1 to complete the epoxidation reaction, generating glycidol.

[0041] A horizontal flow pump is used to transport the 3-chloro-1,2-propanediol solution and the alkaline solution to a heat exchanger for cooling. After both materials have cooled to 5°C, the alkaline solution enters through the dispersed phase channel inlet of the microreactor and merges with the 3-chloro-1,2-propanediol solution pumped in through the continuous phase inlet. The two are forcibly mixed in the microreactor channel. The mixture then enters the delayed-phase reactor 1 from the continuous phase outlet of the microreactor to continue the reaction until the 3-chloro-1,2-propanediol is completely converted into glycidyl glycerol. The reaction residence time for this step is 31-41 seconds.

[0042] The outlet of the delayed-phase reactor 1 is equipped with a three-way valve to control the subsequent process: if no excess alkali is required, the reaction solution is directly discharged to the receiving container; if neutralization is required, the material enters the continuous phase channel of the neutralization microreactor. At this point, the hydrochloric acid feed pump is started, and the hydrochloric acid enters the neutralization microreactor through the dispersed phase channel to undergo an acid-base neutralization reaction with the glycidyl solution in the continuous phase. To ensure complete neutralization of residual alkali, a delayed-phase reactor 2 is connected to the outlet of the neutralization microreactor to further break down excess alkali in the reaction solution. The final glycidyl solution obtained from the outlet of the delayed-phase reactor 2 is neutral or slightly alkaline and is collected in the receiving container.

[0043] Example 2 A 36% (w / w) aqueous solution of 3-chloro-1,2-propanediol and a 24% (w / w) aqueous solution of NaOH were prepared. The feed pump flow rate of the 3-chloro-1,2-propanediol solution was set to 34.29 ml / min, and the feed pump flow rate of the NaOH aqueous solution was set to 15.71 ml / min. The molar ratio of raw material to alkali was 1:0.9. The temperatures of the heat exchange media in the raw material heat exchanger, microreactor, and time-delay reactor 1 were adjusted to maintain the material temperature at 5°C before entering the reaction, and to maintain the reaction temperature at 0°C in the microreactor and time-delay reactor 1. The three-way ball valve at the outlet of time-delay reactor 1 was switched to the direct discharge position, and feeding began after the parameters were adjusted. The total residence time of the reaction system was 36 s. After the feed stabilized, the product was collected, and a sample was taken for gas chromatography analysis. The results are recorded as serial number 1 in Table 1.

[0044] Example 3 Prepare a 36% (w / w) aqueous solution of 3-chloro-1,2-propanediol, a 25% (w / w) aqueous solution of NaOH, and a 2% (w / w) aqueous solution of hydrochloric acid. Set the feed pump flow rate for the 3-chloro-1,2-propanediol solution to 34.29 ml / min, the NaOH solution to 15.71 ml / min, and the hydrochloric acid solution to 3 ml / min. The raw material:base:acid molar ratio is 1:1.01:0.01. Adjust the heat exchange medium temperatures in the raw material heat exchanger, microreactor, and time-delay reactor 1 to maintain the material temperature at 5°C before entering the reaction and to keep the reaction temperature at 0°C within the microreactor and time-delay reactor 1. Switch the three-way ball valve at the outlet of time-delay reactor 1 to the direct discharge position. After parameter adjustments, begin feeding. Once the feed stabilizes, take a sample for gas chromatography analysis, recording this as result 2. The reaction residence time for this step is 36 s. Then, quickly switch the three-way ball valve to the neutralization microreactor section, turn on the hydrochloric acid feed pump to carry out the acid-base neutralization reaction. The reaction residence time in the acid-base neutralization section is 23s. After the system stabilizes, it is received when the pH test paper shows that it is neutral. If the pH value is deviated, it can be adjusted to neutral by the hydrochloric acid feed pump before receiving the material. Test the gas chromatography again and record the result as serial number 3 in Table 1.

[0045] Example 4 Prepare a 36% (w / w) aqueous solution of 3-chloro-1,2-propanediol, a 26% (w / w) aqueous solution of NaOH, and an 8% (w / w) aqueous solution of hydrochloric acid. Set the feed pump flow rate for the 3-chloro-1,2-propanediol solution to 34.29 ml / min, the NaOH solution to 15.71 ml / min, and the hydrochloric acid solution to 3 ml / min. The raw material:base:acid molar ratio is 1:1.06:0.06. Adjust the heat exchange medium temperatures in the raw material heat exchanger, microreactor, and time-delay reactor 1 to maintain the material temperature at 5°C before entering the reaction, and maintain the reaction temperature at 0°C within the microreactor and time-delay reactor 1. Switch the three-way ball valve at the outlet of time-delay reactor 1 to the direct discharge position. After parameter adjustments, begin feeding. Once the feed stabilizes, take a sample for gas chromatography analysis, recording it as result 4. The reaction residence time for this step is 36 s. Then, quickly switch the three-way ball valve to the neutralization microreactor section, turn on the hydrochloric acid feed pump to carry out the acid-base neutralization reaction. The reaction residence time in the acid-base neutralization section is 23s. After the system stabilizes, it is received when the pH test paper shows that it is neutral. If the pH value is deviated, it can be adjusted to neutral by the hydrochloric acid feed pump before receiving the material. Test the gas chromatography again and record the result as serial number 5 in Table 1.

[0046] Comparative Example 1 111.24 g of 3-chloro-1,2-propanediol aqueous solution (36% by mass) was used as the reaction substrate and placed in a reaction vessel. The temperature was lowered and maintained at 0°C. 58.81 g of NaOH aqueous solution (25% by mass) was similarly cooled to 0°C and then slowly added dropwise to the reaction vessel over 1 hour. After the addition was complete, the reaction was continued at 0°C for another hour. Samples were taken at 0 min, 10 min, 20 min, 30 min, and 60 min after the addition was completed, and gas chromatographic analysis was performed. The results are recorded as items 6-10 in Table 1.

[0047] Example 5 Prepare a 36% (w / w) aqueous solution of 3-chloro-1,2-propanediol and a 25% (w / w) aqueous solution of NaOH. Set the feed pump flow rate of the 3-chloro-1,2-propanediol solution to 40 ml / min and the feed pump flow rate of the NaOH solution to 18.32 ml / min. The raw material to alkali ratio is 1:1.01 (molar ratio). Adjust the heat exchange medium temperatures in the raw material heat exchanger, microreactor, and time-delay reactor 1 to maintain the material temperature at 5°C before entering the reaction and to keep the reaction temperature at 0°C within the microreactor and time-delay reactor 1. Switch the three-way ball valve at the outlet of time-delay reactor 1 to the direct discharge position. After the parameters are adjusted, start feeding. The reaction residence time is 31 s. After the feed stabilizes, take a sample for gas chromatography analysis, and record the results as serial number 11 in Table 1.

[0048] Example 6 A 36% (w / w) aqueous solution of 3-chloro-1,2-propanediol and a 25% (w / w) aqueous solution of NaOH were prepared. The feed pump flow rate of the 3-chloro-1,2-propanediol solution was set to 30 ml / min, and the feed pump flow rate of the NaOH aqueous solution was set to 13.74 ml / min. The molar ratio of raw material to alkali was 1:1.01. The temperatures of the heat exchange media in the raw material heat exchanger, microreactor, and time-delay reactor 1 were adjusted to maintain the material temperature at 5°C before entering the reaction, and to maintain the reaction temperature at 0°C in the microreactor and time-delay reactor 1. The three-way ball valve at the outlet of time-delay reactor 1 was switched to the direct discharge position. After the parameters were adjusted, feeding began. The reaction residence time was 41 s. After the feed stabilized, a sample was taken for gas chromatography analysis, and the results are recorded as serial number 12 in Table 1.

[0049] Table 1

[0050] As can be seen from Examples 2-4, the raw material conversion rate and product selectivity are outstanding, and the reaction time is short (from hours to seconds). At the same time, the excess alkali is neutralized in situ online during the continuous reaction process, which is highly efficient and has no impact on the product composition, making it suitable for mass production.

[0051] Comparing Example 3 and Comparative Example 1, it can be seen that the continuous reaction can be completed in 36 seconds without any byproducts. However, under the same reaction conditions, the batch reaction still did not react completely after 3600 seconds, and the byproduct content increased significantly with the increase of reaction time. The increase in byproduct content will lead to an increase in subsequent separation costs, which is not conducive to industrial production.

[0052] A comparison of Examples 3 and 11 shows that a higher reaction flow rate within the system reduces the residence time of materials. In this case, mass transfer is not the primary influencing factor; rather, the reaction time becomes the determining factor. Therefore, for the reactor described in this patent, a reaction time of 31 seconds is too short.

[0053] A comparison of Examples 3 and 12 shows that a lower reaction flow rate within the system increases the residence time of the materials, allowing for more reaction time. However, mixing and mass transfer are the primary influencing factors in this case. Poor mass transfer leads to prolonged reaction time, causing hot spots to form in localized areas of the reactor. Heat cannot dissipate, resulting in side reactions and increased byproduct content. However, the mass transfer effect is still better than in Comparative Example 1, thus the byproduct content is lower. Therefore, for the reactor described in this patent, a 41-second reaction time is too long.

Claims

1. A process apparatus for the continuous synthesis of glycidol, characterized in that: The apparatus comprises the following components in sequential fluid communication via pipelines: a feed pump, a heat exchanger, a microreactor, a time-delayed tube reactor 1, a neutralization microreactor, and a time-delayed tube reactor 2; The heat exchanger is divided into two groups: one group is a 3-chloro-1,2-propanediol solution heat exchanger, and the other group is an alkaline solution heat exchanger.

2. The apparatus for continuous synthesis of glycidol according to claim 1, characterized in that: The microreactor consists of a heat exchange channel and a reaction channel. The reaction channel consists of a continuous phase channel and a dispersed phase channel. The dispersed phase channel is connected to the continuous phase channel through micropores. The inlet of the dispersed phase channel is connected to the alkaline solution heat exchanger through a pipeline. The inlet of the continuous phase reaction channel is connected to the material outlet of the heat exchanger for the 3-chloro-1,2-propanediol solution through a pipeline. The outlet of the continuous phase reaction channel is connected to the inlet of the delay tube reactor 1 through a pipeline. One end of the heat exchange channel is connected to the medium outlet of the integrated heat exchanger, and the other end is connected to the medium inlet of the integrated heat exchanger. The heat exchange medium and the heat exchange material exchange heat in a countercurrent manner.

3. The apparatus for continuous synthesis of glycidol according to claim 1, characterized in that: The heat exchanger consists of a heat exchange medium channel and a material channel. The material channel inlet is connected to a feed horizontal flow pump via a pipeline, and the outlet is connected to a microreactor. One end of the heat exchange medium channel is connected to the medium outlet of the integrated heat exchanger, and the other end is connected to the medium inlet of the integrated heat exchanger. The heat exchange medium and the heat exchange material exchange heat in a countercurrent manner.

4. The apparatus for continuous synthesis of glycidol according to claim 1, characterized in that: The neutralization microreactor has the same structure as the microreactor, except that the inner diameter of the dispersed phase micropores is 0.1 mm and the material is Hastelloy alloy. The inlet of the continuous phase channel of the neutralization microreactor is connected to the outlet of the delay tube reactor 1 through a pipeline, the outlet of the continuous phase channel is connected to the inlet of the delay tube reactor 2, and the inlet of the dispersed phase channel is connected to the horizontal flow pump for the hydrochloric acid solution through a pipeline.

5. A method for continuous synthesis of glycidol using the apparatus of claim 1, characterized in that: The two raw materials are transported separately by a horizontal flow pump and cooled by heat exchange. They are then subjected to forced mixing and reaction in a microreactor, and subsequently enter the delayed tube reactor 1 to complete the epoxidation reaction and generate glycidyl ether.

6. The method for continuous synthesis of glycidol according to claim 5, characterized in that: A horizontal flow pump is used to separately transport the 3-chloro-1,2-propanediol solution and the alkaline solution to a heat exchanger for cooling. After both materials have cooled to 5-10°C, the alkaline solution enters through the dispersed phase channel inlet of the microreactor and merges with the 3-chloro-1,2-propanediol solution pumped in through the continuous phase inlet. The two are forcibly mixed in the microreactor channel. The mixture then enters the delayed-phase reactor 1 from the continuous phase outlet of the microreactor to continue the reaction until the 3-chloro-1,2-propanediol is completely converted into glycidyl glycerol. This reaction step takes 31-41 seconds.

7. The method for continuous synthesis of glycidol according to claim 6, characterized in that: The ratio of the 3-chloro-1,2-propanediol solution to the alkaline solution is 1:0.9-1.06; wherein the 3-chloro-1,2-propanediol solution is a 36% (w / w) aqueous solution. The alkaline solution is a sodium hydroxide aqueous solution with a mass concentration of 24-26%.

8. The method for continuous synthesis of glycidol according to claim 6, characterized in that: The temperature of the microreactor is set such that the temperature during the reaction of the 3-chloro-1,2-propanediol solution and the alkaline solution is maintained at 0-5°C. The flow rate of the advection pump is set as follows: the feed rate of 3-chloro-1,2-propanediol solution is set to 30-40 ml / min; the feed rate of alkaline solution is set to 13-19 ml / min.

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