A method for the continuous synthesis of fluorinated ethylene carbonate in a microchannel

Abstract

The application discloses a flow guide component and a method for continuously synthesizing fluoroethylene carbonate in a microchannel by using the flow guide component. The method comprises the following steps: mixing a first organic amine, triethylamine polyhydrogen fluoride and a first diluent to generate a first-stage reaction; and then introducing a second organic amine and a second diluent through the flow guide component, so as to continuously synthesize fluoroethylene carbonate in the microchannel. The method has the advantages of safety and high efficiency, and is green for synthesizing fluoroethylene carbonate. In addition, the utilization rate of reaction raw materials is improved, and high-selectivity synthesis of the target product is realized under full conversion.

Description

Technical Field

[0001] This invention relates to the field of fluoroethylene carbonate synthesis, specifically a method for the continuous microchannel synthesis of fluoroethylene carbonate. Background Technology

[0002] Fluorinated ethylene carbonate is an important additive component in lithium-ion battery electrolytes. With the rapid development of the electric vehicle industry, the safety and lifespan of lithium-ion batteries are receiving increasing attention. As a highly efficient additive, fluoroethylene carbonate can effectively improve battery charge / discharge capacity retention and reduce battery impedance, thereby significantly enhancing battery performance.

[0003] Traditional synthesis processes for fluoroethylene carbonate include direct fluorination of ethylene carbonate, electrochemical fluorination, and solid fluoride halogen exchange. These processes all have drawbacks such as vigorous reactions, numerous byproducts, heterogeneous reactions, yields generally below 70%, and the fluorinating reagents used are highly toxic and corrosive, resulting in significant equipment wear and tear.

[0004] Relevant literature discloses several methods for the one- or two-step continuous preparation of fluoroethylene carbonate using microchannel reactors. CN113121491A reports a method for producing fluoroethylene carbonate using a microchannel reactor, comprising: ethylene carbonate and fluorine gas undergoing a fluorination reaction under ultraviolet light irradiation in a microchannel reactor to obtain fluoroethylene carbonate; CN105968083A reports the use of a mixture of chloroethylene carbonate feedstock and liquid hydrogen fluoride introduced into a microchannel reactor, with the reaction carried out at -20 to 20°C. These methods using microchannel reactors often employ fluorine gas or hydrogen fluoride as the fluorinating agent, which is hazardous and prone to causing safety accidents. Furthermore, these fluorinating agents are highly reactive and readily produce polyfluorinated byproducts, leading to reduced yields. The reaction conditions require extremely stringent control.

[0005] Currently, methods for preparing fluoroethylene carbonate using a mixture of organic base, hydrogen fluoride, and acid-binding agent exist in the chemical industry. CN110684007A reports a batch process for preparing fluoroethylene carbonate using chloroethylene carbonate, triethylamine trihydrofluorate, and triethylamine in a one-pot reaction, but the yield is low and the byproducts are complex. CN104529992A discloses the preparation of fluorinated chloroethylene carbonate using organic amine hydrofluorate, inorganic base, and pyridine acid-binding agent in a reaction vessel. CN101774923A discloses the preparation of fluoroethylene carbonate using a nitrogen-containing organic base hydrogen fluoride complex and an acid-binding agent, wherein the ratio of hydrogen fluoride to organic base in the selected nitrogen-containing organic base hydrogen fluoride complex is 2–4. These types of reactions often use triethylamine trifluoride as the fluorinating agent and triethylamine as the acid-binding agent. The reaction rate is relatively slow, usually 5 to 8 hours, and the atom utilization rate is low. The amount of triethylamine used as the acid-binding agent is relatively large, and direct discharge will cause great pollution to water quality. Summary of the Invention

[0006] To address the shortcomings of existing technologies, such as the potential for safety accidents when using fluorine or hydrogen fluoride as fluorinating agents, low yields of the target product, and slow reaction rates, complex byproducts, and low yields of fluoroethylene carbonate when using triethylamine-hydrogen trifluoride as the fluorinating agent, this invention provides a method for the continuous synthesis of fluoroethylene carbonate using a flow-guiding component and a microchannel incorporating the flow-guiding component. This method offers advantages such as safety, efficiency, and green synthesis of fluoroethylene carbonate, while also improving the utilization rate of reaction raw materials and achieving highly selective synthesis of the target product (selectivity ≥ 99%) at full conversion.

[0007] The first aspect of the present invention provides a flow guiding component, the flow guiding component comprising a reaction tube, a first sleeve, and a second sleeve;

[0008] The reaction tube is provided with an inlet and an outlet, so that the reaction system enters the reaction tube from the inlet and flows out of the reaction tube from the outlet.

[0009] The first sleeve and the second sleeve are spirally arranged side by side around the outside of the reaction tube and / or inside the wall of the reaction tube, and the first sleeve and the second sleeve are not connected to each other; the first sleeve and the second sleeve are provided with multiple communicating holes corresponding to the reaction tube;

[0010] The first sleeve is located near the feed inlet of the reaction tube, and a first liquid inlet is provided on the first sleeve.

[0011] The second sleeve is located near the discharge port of the reaction tube, and a second liquid inlet is provided on the second sleeve.

[0012] According to the present invention, the flow guiding member further includes a first conical feed pipe and a second conical feed pipe; wherein,

[0013] The first tapered feed tube is used to connect the corresponding hole of the first sleeve and the reaction tube;

[0014] The second conical feed tube is used to connect the corresponding hole of the second sleeve and the reaction tube.

[0015] According to the present invention, the reaction tube is a microreaction reaction tube.

[0016] According to the present invention, a first inlet baffle and a second inlet baffle are further provided inside the reaction tube; wherein,

[0017] The first cutting section baffle is located behind the first conical feed pipe and extends towards the outlet of the reaction pipe; preferably, the angle α between the first cutting section baffle and the horizontal plane containing the inner wall of the reaction pipe is 40 to 50°.

[0018] The second infeed section baffle is located behind the second conical feed pipe and extends toward the feed inlet of the reaction pipe; preferably, the angle β between the second infeed section baffle and the horizontal plane containing the inner wall of the reaction pipe is 120 to 150°.

[0019] According to the present invention, the length of the first cutting section baffle and / or the second cutting section baffle is 1 to 1.5 mm.

[0020] According to the present invention, the second organic amine is added through a flow guiding member. Specifically, the second organic amine enters the first sleeve through the first inlet of the flow guiding member, flows through the first conical feed pipe, and is introduced into the reaction tube via the first cutting section baffle.

[0021] According to the present invention, the second diluent is added through a flow guiding member. Specifically, the second diluent enters the second sleeve through the second inlet of the flow guiding member, flows through the second conical feed pipe, and is introduced into the reaction tube via the second cutting section baffle.

[0022] According to the present invention, the function of the second organic amine and the second diluent introduced through the flow guiding member in the second-stage reaction is to maintain the catalytically active phase, pulverize the generated by-product solid salt particles, improve the reaction conversion rate and selectivity, and at the same time avoid the blockage of the microchannels.

[0023] According to the present invention, the diameter of the plurality of holes distributed on the first sleeve and the second sleeve is 1 to 2 mm;

[0024] According to the present invention, the aperture of the hole on the reaction tube is slightly smaller than the aperture of the holes on the first sleeve and the second sleeve; the aperture of the hole on the reaction tube is 0.5 to 0.7 mm.

[0025] According to the present invention, the taper of the first conical feed tube and / or the second conical feed tube is 1:2 to 1:3.

[0026] According to the present invention, the inner diameter of the reaction tube is 1.5 to 4.0 mm.

[0027] According to the present invention, the ratio of the inner diameter of the first sleeve and / or the second sleeve to the inner diameter of the reaction tube is 1:2 to 5.

[0028] According to the present invention, the ratio of the length of the reaction tube to the inner diameter of the reaction tube is 40 to 60:1.

[0029] According to the present invention, the wall thickness of the reaction tube is 1.5 to 4 mm, preferably 1.8 to 2.3 mm.

[0030] According to the present invention, the ratio of the length of the first sleeve projected onto the axial direction of the reaction tube to the length of the reaction tube is 0.4 to 0.6:1.

[0031] According to the present invention, the ratio of the length of the second sleeve projected onto the axial direction of the reaction tube to the length of the reaction tube is 0.4 to 0.6:1.

[0032] According to the present invention, the reaction system formed by mixing the first-stage reaction effluent with chloroethylene carbonate enters the reaction tube through the feed inlet of the flow guiding member.

[0033] A second aspect of the present invention provides a method for the continuous microchannel synthesis of fluoroethylene carbonate, wherein the above-mentioned flow guiding component is used, and the method includes:

[0034] The first organic amine, triethylamine polyfluoride, and the first diluent are mixed to undergo a first-stage reaction. The reaction system formed by mixing the first-stage reaction effluent with chloroethylene carbonate begins a second-stage reaction. The reaction system then enters the reaction tube through the inlet of the flow guide member, where it mixes with the second organic amine fed through the first liquid inlet on the first sleeve of the flow guide member and the second diluent fed through the second liquid inlet on the second sleeve. After mixing, the mixture enters the pipeline until the second-stage reaction ends at the product collection device. The effluent from the second-stage reaction is the target product, chloroethylene carbonate.

[0035] According to the present invention, the triethylamine polyfluoride includes at least one of triethylamine trifluoride and triethylamine pentafluoride.

[0036] According to the present invention, the first organic amine includes one or more combinations of triethylamine, ethylenediamine, and pyridineamine, preferably a combination of triethylamine and ethylenediamine, and more preferably a combination of triethylamine and ethylenediamine, wherein the molar ratio of triethylamine to ethylenediamine is 2:1 to 5:1.

[0037] According to the present invention, the second organic amine comprises one or more combinations of triethylamine, ethylenediamine, and pyridineamine, preferably a combination of triethylamine and ethylenediamine, and more preferably a combination of triethylamine and ethylenediamine, wherein the molar ratio of triethylamine to ethylenediamine is 2:1 to 5:1. The second organic amine and the first organic amine may be the same or different.

[0038] According to the present invention, the first diluent comprises one or a combination of several of haloalkanes, ethyl acetate, methyl acetate, acetonitrile, and benzonitrile, preferably a combination of acetonitrile and ethyl acetate, and more preferably, wherein the molar ratio of acetonitrile to ethyl acetate is 5:1 to 10:1. The haloalkanes include at least one of dichloromethane, trichloromethane, and 1,2-dichloroethane.

[0039] According to the present invention, the second diluent comprises one or a combination of several selected from halogenated alkanes, ethyl acetate, methyl acetate, acetonitrile, and benzonitrile, preferably a combination of acetonitrile and ethyl acetate, and more preferably, wherein the molar ratio of acetonitrile to ethyl acetate is 5:1 to 10:1. The halogenated alkanes include at least one selected from dichloromethane, trichloromethane, and 1,2-dichloroethane. The second diluent and the second diluent may be the same or different.

[0040] According to the present invention, the first-stage reaction effluent includes HF2. - At least one of triethylamine and hydrogen fluoride. The first-order reaction is HF2. - In-situ dynamic synthesis of triethylamine and hydrogen fluoride.

[0041] According to the present invention, the molar ratio of the first organic amine, triethylamine polyfluoride, and the first diluent is 1.2–2.3:1:15–30, preferably 1.2–1.5:1:15–30 or 2.0–2.3:1:15–30. The present invention obtains different active phases by controlling the different feed ratios of the reaction raw materials. The active phase of the present invention, i.e., the first-stage reaction effluent, includes HF2. - At least one of triethylamine monofluoride (Et3N-HF).

[0042] According to the present invention, the molar ratio of triethylamine polyfluoride to chloroethylene carbonate is 0.2 to 0.5:1.

[0043] According to the present invention, the molar ratio of the second organic amine to chloroethylene carbonate is 0.2 to 0.4:1.

[0044] According to the present invention, the molar ratio of the second diluent to ethylene chlorocarbonate is 4 to 8:1.

[0045] According to the present invention, the pressure and temperature of the first-stage reaction are not particularly limited. The preferred reaction pressure is 90–110 kPa. The reaction temperature of the first-stage reaction is room temperature, preferably 15–25 °C.

[0046] According to the present invention, preferably, the reaction system formed by mixing the first-stage reaction effluent with ethylene chlorocarbonate is passed through a heating unit. The temperature of the reaction system is controlled at 40–70°C by the heating unit. That is, the reaction temperature of the second-stage reaction is 40–70°C.

[0047] According to the present invention, the residence time of the second-stage reaction is 15 to 30 minutes. The residence time of the second-stage reaction begins after the effluent from the first-stage reaction is mixed with ethylene chlorocarbonate and the temperature of the reaction system reaches 40 to 70°C, and ends when the second-stage reaction is completed in the product collection device.

[0048] According to the present invention, the initial installation position of the flow guiding member is located at 30% to 60% of the residence time of the second-stage reaction, preferably 40% to 60%; more preferably, the residence time of the reaction system in the flow guiding member is 15 to 35 seconds.

[0049] According to the present invention, the mixing of the first organic amine, triethylamine polyfluoride and the first diluent, and the mixing of the first-stage reaction effluent with chloroethylene carbonate can be carried out in a mixer; the materials of the microchannel and the mixer include at least one of Hastelloy and polytetrafluoroethylene.

[0050] According to the present invention, the mixer is an impingement flow micro mixer, not limited to a conventional three-way mixer, and the mixer outlet channel size is 0.5 to 2 mm.

[0051] According to the present invention, the second-stage reaction in the method is carried out in a microchannel; preferably, the inner diameter of the microchannel is 1.5 to 4 mm.

[0052] According to the present invention, the first-stage reaction in the method is carried out in a microchannel; preferably, the inner diameter of the microchannel is 1.5 to 4 mm.

[0053] According to the present invention, the inner diameter of the microchannels in the method can be the same or different.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] This invention utilizes microchannels for the continuous synthesis of fluoroethylene carbonate and innovatively introduces flow-guiding components to maintain the catalytically active phase throughout the reaction cycle, while simultaneously preventing blockage of the microchannel reaction tubing by byproduct solid salts. By identifying the interaction patterns between organic amines and fluorinating reagents, a highly efficient catalytically active phase, HF2, was synthesized in situ and dynamically. - Compared to the traditionally reported triethylamine-trifluoride catalytic active phase (Et3N-3HF), the reaction rate of Et3N-HF is increased by 10-20 times under the same conditions, and the reaction cycle for complete conversion (i.e., the second reaction residence time) is shortened from 4 hours to within 30 minutes. However, it should be noted that the reaction byproduct, solid triethylamine hydrochloride, is extremely prone to clogging the pipeline. Therefore, in continuous synthesis, an appropriate diluent must be selected to pulverize the solid salt. In addition, although the excessive use of the acid-binding agent triethylamine can accelerate the reaction to some extent, it can easily lead to the formation of vinylene carbonate polymers in the later stages of the reaction. Therefore, by controlling the composition ratio of raw materials, the type of diluent, and the entry time of the flow guiding component, the selectivity of fluoroethylene carbonate is significantly improved (can be >99%), and the occurrence of side reactions and the clogging of micro-reaction channels are suppressed. This invention significantly improves the atomic utilization rate of raw materials, and the reaction process is simple to operate and suitable for large-scale production. Attached Figure Description

[0056] Figure 1 The process flow diagrams for the continuous microchannel synthesis of fluoroethylene carbonate in Examples 1-4 are shown.

[0057] Figure 2 These are cross-sectional views of the flow guiding components in Examples 1-4;

[0058] Figure 3 These are perspective views of the flow guiding components in Examples 1-4;

[0059] Explanation of key figure labels:

[0060] 10-Reaction tube, 11-Inlet, 12-Outlet

[0061] 20 - First sleeve, 21 - First conical feed pipe, 22 - First infeed section baffle, 23 - First liquid inlet.

[0062] 30 - Second sleeve, 31 - Second conical feed pipe, 32 - Second infeed section baffle, 33 - Second liquid inlet.

[0063] α - The angle between the first inlet baffle and the horizontal plane containing the inner wall of the reaction tube.

[0064] β- The angle between the second inlet baffle and the horizontal plane containing the inner wall of the reaction tube;

[0065] 400 - Organic amine storage tank; 401 - Organic amine horizontal flow pump; 402 - First diluent storage tank; 403 - First diluent horizontal flow pump; 404 - Triethylamine polyfluoride storage tank; 405 - Triethylamine polyfluoride horizontal flow pump; 406 - First mixer; 407 - First heat exchanger; 408 - Vinyl chloride carbonate storage tank; 409 - Vinyl chloride carbonate horizontal flow pump; 410 - Second diluent storage tank; 411 - Second diluent horizontal flow pump; 412 - Second heat exchanger; 413 - Second mixer; 414 - Third heat exchanger; 415 - Flow guiding component; 416 - Product collection device. Detailed Implementation

[0066] The present invention will be further described in detail below through embodiments. It should be understood that the described embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention. Based on the embodiments of the present invention, non-essential improvements and modifications made to the present invention by those skilled in the art without creative effort are all within the scope of protection of the present invention.

[0067] like Figure 1As shown, organic amines are discharged from organic amine storage tank 400 under the action of organic amine horizontal flow pump 401. One path can be used as the raw material for the first organic amine; the other path can be used as the raw material for the second organic amine and enter the flow guiding component. The first organic amine, the first diluent discharged from the first diluent storage tank 402 under the action of the first diluent horizontal flow pump 403, and the triethylamine polyfluoride discharged from the triethylamine polyfluoride storage tank 404 under the action of the triethylamine polyfluoride horizontal flow pump 405 are mixed in the first mixer 406, and then heat exchanged through the first heat exchanger 407. After heat exchange with the chloroethylene carbonate discharged from the chloroethylene carbonate storage tank 408 under the action of the chloroethylene carbonate horizontal flow pump 409, they are mixed in the second mixer 413 to obtain the reaction system. The reaction system, after heat exchange in the third heat exchanger 414, enters the flow guiding member 415, where it mixes with the second diluent and the second organic amine added through the flow guiding member. The mixture then enters a pipeline and is finally collected by the product collection device 416 to obtain the microchannel continuously synthesized fluoroethylene carbonate. The second organic amine can be the same as that used in the first-stage reaction. The second diluent is stored in a second diluent tank 410 and can be discharged via a second diluent horizontal flow pump 411.

[0068] like Figure 2 As shown in Figure 3, Figure 2 These are cross-sectional views of the flow guiding components in Examples 1-4. Figure 3 This is a perspective view of the flow guiding components in Examples 1 to 4. The flow guiding component includes a reaction tube 10, a first sleeve 20, and a second sleeve 30. The reaction tube 10 is provided with an inlet 11 and an outlet 12, for the reaction system to enter the reaction tube 10 through the inlet 11, react with the second organic amine and the second diluent added through the flow guiding component 415, and then flow out of the reaction tube 10 through the outlet 12. The first sleeve 20 and the second sleeve 30 are spirally arranged side by side around the outside of the reaction tube 10, and the first sleeve 20 and the second sleeve 30 are not interconnected. The first sleeve 20 and the second sleeve 30 are provided with multiple interconnected holes corresponding to the reaction tube. The first sleeve 20 is located near the inlet 11 of the reaction tube and is provided with a first liquid inlet 23 for feeding the second organic amine into the first sleeve. The second sleeve 30 is located near the outlet 12 of the reaction tube and is provided with a second liquid inlet 33 for feeding the second diluent into the second sleeve.

[0069] The flow guiding component 415 further includes a first conical feed pipe 21 and a second conical feed pipe 31; wherein, the first conical feed pipe 21 is used to connect the corresponding holes of the first sleeve 20 and the reaction tube 10; the second organic amine is introduced into the reaction tube 10 through the first conical feed pipe 21; the second conical feed pipe 31 is used to connect the corresponding holes of the second sleeve 30 and the reaction tube 10; the second diluent is introduced into the reaction tube through the second conical feed pipe 31. The reaction tube 10 is further provided with a first inlet baffle 22 and a second inlet baffle 32; wherein, the first inlet baffle 22 is located behind the first conical feed tube and extends towards the discharge port 12 of the reaction tube; preferably, the angle α between the first inlet baffle and the horizontal plane containing the inner wall of the reaction tube is 40-50°; the second inlet baffle 32 is located behind the second conical feed tube and extends towards the feed port 11 of the reaction tube; preferably, the angle β between the second inlet baffle and the horizontal plane containing the inner wall of the reaction tube is 120-150°. The lengths of the first inlet baffle and the second inlet baffle are 1-1.5 mm.

[0070] The specific implementation of the flow guiding component is as follows: the second organic amine enters the first sleeve 20 through the first inlet 23 of the flow guiding component 415, flows through the first conical feed pipe 21, and is introduced into the reaction tube 10 through the first cutting section baffle 22; the second diluent enters the second sleeve 30 through the second inlet 33 of the flow guiding component 10, flows through the second conical feed pipe 31, and is introduced into the reaction tube 10 through the second cutting section baffle 32. The reaction system formed by the first-stage reaction effluent and chloroethylene carbonate enters the reaction tube 10 through the feed inlet 11 of the flow guiding component and mixes with the second organic amine fed through the first inlet 23 of the first sleeve 20 and the second diluent fed through the second inlet 33 of the second sleeve 30. After mixing, it flows out through the outlet 12 of the flow guiding component 415, enters the pipeline, and is finally collected by the product collection device 416 to obtain fluoroethylene carbonate.

[0071] In various embodiments of the present invention, the flow guiding component is as follows: Figure 2 , 3 As shown, the process flow diagram for the microchannel synthesis of fluoroethylene carbonate is as follows: Figure 1 As shown. In each embodiment, the reaction tube is 200mm long, the first and second sleeves are both 100mm long, the inner diameter of the first and second sleeves is 1mm, and the diameter of the multiple holes distributed on the first and second sleeves is 1mm; the diameter of the holes on the reaction tube is 0.5mm; the taper of the first and second conical feed tubes is 1:2. The outlet spacing is 10mm. The angle of the first cut-in section baffle is 45°, and the angle of the second cut-in section baffle is 135°. The length of both the first and second cut-in section baffles is 1mm. The inner diameter of the reaction tube is 4mm.

[0072] In this invention, the first sleeve spirally wraps around the reaction tube 5 to 7 times; the second sleeve spirally wraps around the reaction tube 5 to 7 times. For example... Figure 2 , 3 As shown, in the flow guiding components of each embodiment, the first sleeve spirally wraps around the reaction tube 5 times, and the second sleeve spirally wraps around the reaction tube 5 times. Holes are formed on the opposite walls of the reaction tubes; the first sleeve and / or the second sleeve have corresponding interconnected holes. A total of 20 holes are provided on the reaction tube, respectively located on the opposite walls, of which 10 holes are connected to the first sleeve through the first tapered feed pipe, and the other 10 holes are connected to the second sleeve through the second tapered feed pipe.

[0073] In the embodiments of this invention, the reaction conditions for the first-stage reaction are ambient temperature and pressure. Ambient temperature is 20°C.

[0074] In this invention, the conversion percentage (%) of chloroethylene carbonate and the selectivity percentage (%) of fluoroethylene carbonate are molar percentages, and they are analyzed by gas chromatography. The test parameters are as follows: DB-1701 capillary column; injection volume: 1 μl; carrier gas flow rate: 30 ml / min; vaporization chamber temperature: 250 °C; detection chamber temperature: 250 °C.

[0075] Example 1

[0076] The first-stage reaction consists of three feed streams: triethylamine + ethylenediamine (molar ratio 2:1), triethylamine trifluoride, and acetonitrile diluent, with feed flow rates of 0.93 ml / min, 0.91 ml / min, and 5.81 ml / min (molar ratio 1.2:1:20), respectively. The microchannel (i.e., microchannel) for the first-stage reaction has an inner diameter of 1.8 mm. The second-stage reaction feed stream for ethylene carbonate is 2 ml / min (molar ratio of triethylamine trifluoride to ethylene carbonate is 0.23:1). The flow rate of the second organic amine (triethylamine + ethylenediamine, molar ratio 2:1) is 0.68 ml / min (molar ratio of the second organic amine to ethylene chloride carbonate is 0.2:1), and the flow rate of the second diluent (acetonitrile, molar ratio of the second diluent to ethylene chloride carbonate is 5.11 ml / min (molar ratio of the second diluent to ethylene chloride carbonate is 4:1). The mixer outlet channel size is 0.5 mm, the inner diameter of the micro-reaction channel for the second-stage reaction is 1.8 mm, the temperature of the second-stage reaction is 50 °C, and the residence time of the second-stage reaction is 30 minutes. The initial installation position of the flow guide component is located at 40% of the residence time of the second-stage reaction.

[0077] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of chloroethylene carbonate was 99.5%, and the selectivity of fluoroethylene carbonate was 99.2%.

[0078] Example 2

[0079] The three feed streams for the first-stage reaction consist of triethylamine + ethylenediamine (molar ratio 5:1), triethylamine trifluoride, and acetonitrile + ethyl acetate (molar ratio 5:1) as diluent, with feed flow rates of 4.08 ml / min, 3.20 ml / min, and 30.68 ml / min (molar ratio 1.5:1:30), respectively. The inner diameter of the microreaction channel for the first-stage reaction is 4 mm. The feed flow rate of ethylene carbonate in the second-stage reaction is 4 ml / min (molar ratio of triethylamine / hydrogen trifluoride to ethylene carbonate is 0.4:1). The flow rate of the second organic amine, triethylamine + ethylenediamine (molar ratio 5:1), introduced through the flow guide is 2.72 ml / min (molar ratio of the second organic amine to ethylene carbonate is 0.4:1). The flow rate of the second diluent, acetonitrile, introduced is 20.45 ml / min (molar ratio of the second diluent to ethylene carbonate is 8:1). The mixer outlet channel size is 2 mm, the inner diameter of the micro-reaction channel in the second-stage reaction is 4 mm, the temperature of the second-stage reaction is 40 °C, and the residence time of the second-stage reaction is 30 minutes. The initial installation position of the flow guide is located at 60% of the residence time of the second-stage reaction.

[0080] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of chloroethylene carbonate was 99.0%, and the selectivity of fluoroethylene carbonate was 99.3%.

[0081] Example 3

[0082] The first-stage reaction consists of three feed streams: triethylamine + pyridineamine (molar ratio 3:1), triethylamine pentafluoride, and acetonitrile diluent, with feed flow rates of 3.20 ml / min, 1.64 ml / min, and 15.69 ml / min (molar ratio 2.3:1:30), respectively. The microreactor channel for the first-stage reaction has an inner diameter of 1.5 mm. The second-stage reaction feed stream for chloroethylene carbonate is 3 ml / min (molar ratio of triethylamine pentafluoride to chloroethylene carbonate is 0.22:1). The flow rate of triethylamine + pyridineamine (molar ratio 3:1) is 2.04 ml / min (molar ratio of the second organic amine to ethylene chloride carbonate is 0.4:1), and the flow rate of acetonitrile diluent is 9.59 ml / min (molar ratio of the second diluent to ethylene chloride carbonate is 5:1). The mixer outlet channel size is 1.0 mm, the inner diameter of the micro-reaction channel for the second-stage reaction is 1.5 mm, the temperature of the second-stage reaction is 60 °C, and the residence time of the second-stage reaction is 15 minutes. The initial installation position of the flow guide component is located at 40% of the residence time of the second-stage reaction.

[0083] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of chloroethylene carbonate was 100%, and the selectivity of fluoroethylene carbonate was 99.1%.

[0084] Example 4

[0085] The first-stage reaction consists of three feed streams: triethylamine, triethylamine trifluoride, and acetonitrile diluent, with feed flow rates of 1.59 ml / min, 0.93 ml / min, and 4.47 ml / min (molar ratio 2:1:15), respectively. The inner diameter of the micro-reaction channel for the first-stage reaction is 1.8 mm. The second-stage reaction involves a chloroethylene carbonate feed flow rate of 2 ml / min (molar ratio of triethylamine trifluoride to chloroethylene carbonate is 0.24:1). Triethylamine is introduced through a flow guide at a flow rate of 1.02 ml / min (molar ratio of the second organic amine to chloroethylene carbonate is 0.3:1), and acetonitrile diluent is introduced at a flow rate of 10.22 ml / min (molar ratio of the second diluent to chloroethylene carbonate is 8:1). The mixer outlet channel size is 1 mm. The inner diameter of the micro-reaction channel for the second-stage reaction is 1.8 mm. The temperature of the second-stage reaction is 60 °C, and the residence time is 30 minutes. The initial installation position of the flow guiding component is located at 50% of the residence time of the second-stage reaction.

[0086] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of chloroethylene carbonate was 98.5%, and the selectivity of fluoroethylene carbonate was 99.6%.

[0087] Example 5

[0088] Same as Example 4, except that the initial installation position of the flow guiding component is located at 30% of the residence time of the second-stage reaction.

[0089] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of chloroethylene carbonate was 96.8%, and the selectivity of fluoroethylene carbonate was 95.2%.

[0090] Comparative Example 1

[0091] The difference between Comparative Example 1 and Example 4 is that there is no flow guiding component in the process flow diagram, and the second organic amine triethylamine and the second diluent acetonitrile are not cut into it by the flow guiding component.

[0092] The first-stage reaction consists of three feed streams: triethylamine, triethylamine trifluoride, and acetonitrile diluent, with feed flow rates of 1.59 ± 1.02 ml / min, 0.93 ml / min, and 4.47 ml / min, respectively (molar ratio of 3.3:1:15; the triethylamine introduced by the flow guide in Example 4 is added to the first-stage reaction). The inner diameter of the micro-reaction channel in the first-stage reaction is 1.8 mm. The second-stage reaction has a chloroethylene carbonate feed flow rate of 2 ml / min (molar ratio of triethylamine trifluoride to chloroethylene carbonate is 0.24:1), a mixer outlet channel size of 1 mm, a micro-reaction channel inner diameter of 1.8 mm, a temperature of 60°C, and a residence time of 30 minutes.

[0093] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of chloroethylene carbonate was 95.0%, and the selectivity of fluoroethylene carbonate was 93.1%.

[0094] Comparative Example 2

[0095] The difference between Comparative Example 1 and Example 4 is that there is no first-stage reaction and no flow-guiding component. Fluoroethylene carbonate is synthesized via a microchannel after mixing triethylamine, triethylamine trifluoride, and acetonitrile.

[0096] Triethylamine, triethylamine trifluoride, and acetonitrile diluent were premixed in a molar ratio of 3.3:1:15 and then mixed with vinyl chloride carbonate at a feed flow rate of 2 ml / min at a feed flow rate of 8 ml / min. The mixer outlet channel size was 1 mm, the micro-reaction channel inner diameter was 1.8 mm, the temperature of the second-stage reaction was 60 °C, and the residence time of the second-stage reaction was 30 minutes.

[0097] The product at the outlet was collected, cooled to 0°C, filtered, and then analyzed. The conversion rate of ethylene chlorocarbonate was 70.2%, and the selectivity was 80.5%.

Claims

1. A flow guiding component, characterized in that, The flow guiding component includes a reaction tube, a first sleeve, and a second sleeve; The reaction tube is provided with an inlet and an outlet, so that the reaction system enters the reaction tube from the inlet and flows out of the reaction tube from the outlet. The first sleeve and the second sleeve are spirally arranged side by side around the outside of the reaction tube or inside the wall of the reaction tube, and the first sleeve and the second sleeve are not connected to each other; the first sleeve and the second sleeve are provided with multiple communicating holes corresponding to the reaction tube; The first sleeve is located near the feed inlet of the reaction tube, and a first liquid inlet is provided on the first sleeve. The second sleeve is located near the outlet of the reaction tube, and a second liquid inlet is provided on the second sleeve; the flow guiding component further includes a first conical feed pipe and a second conical feed pipe; wherein, The first conical feed tube is used to connect the corresponding holes of the first sleeve and the reaction tube; the two ends of the first conical feed tube, with the smaller diameter hole facing into the reaction tube; The second conical feed tube is used to connect the corresponding holes of the second sleeve and the reaction tube; at both ends of the second conical feed tube, the end with the smaller hole diameter faces into the reaction tube; The reaction tube is a microreaction tube; The reaction tube is also equipped with a first inlet baffle and a second inlet baffle; among which, The first inlet baffle is located behind the first conical feed pipe and extends toward the outlet of the reaction pipe; The second infeed section baffle is located behind the second conical feed pipe and extends toward the feed inlet of the reaction pipe.

2. The flow guiding component according to claim 1, characterized in that, The angle α between the first inlet baffle and the horizontal plane containing the inner wall of the reaction tube is 40~50°.

3. The flow guiding member according to claim 1, characterized in that, The angle β between the second entry section baffle and the horizontal plane containing the inner wall of the reaction tube is 120~150°.

4. The flow guiding member according to claim 1, characterized in that, The length of the first cutting section baffle and / or the second cutting section baffle is 1~1.5 mm.

5. The flow guiding member according to claim 1, characterized in that, The diameter of the multiple holes distributed on the first and second sleeves is 1~2mm; And / or, the diameter of the hole on the reaction tube is slightly smaller than the diameter of the hole on the first sleeve and the second sleeve; the diameter of the hole on the reaction tube is 0.5~0.7mm; And / or, the taper of the first conical feed tube and / or the second conical feed tube is 1:2 to 1:

3.

6. The flow guiding member according to claim 1, characterized in that, The inner diameter of the reaction tube is 1.5~4.0 mm; And / or, the ratio of the inner diameter of the first sleeve and / or the second sleeve to the inner diameter of the reaction tube is 1:2~5; And / or, the ratio of the length of the reaction tube to the inner diameter of the reaction tube is 40~60:1; And / or, the wall thickness of the reaction tube is 1.5~4 mm; And / or, the ratio of the length of the first sleeve projected onto the axial direction of the reaction tube to the length of the reaction tube is 0.4~0.6:1; And / or, the ratio of the length of the second sleeve projected onto the axial direction of the reaction tube to the length of the reaction tube is 0.4~0.6:

1.

7. The flow guiding member according to claim 6, characterized in that, The reaction tube has a wall thickness of 1.8~2.3 mm.

8. A method for continuous microchannel synthesis of fluoroethylene carbonate, wherein, The method, employing the flow guiding member according to any one of claims 1 to 7, comprises: The first organic amine, triethylamine polyfluoride, and the first diluent are mixed to undergo a first-stage reaction. The reaction system formed by mixing the effluent from the first-stage reaction with chloroethylene carbonate begins a second-stage reaction. The reaction system then enters the reaction tube through the inlet of the flow guide member, where it mixes with the second organic amine fed through the first liquid inlet on the first sleeve of the flow guide member and the second diluent fed through the second liquid inlet on the second sleeve. After mixing, the mixture enters the pipeline to the product collection device, and the second-stage reaction ends. The effluent from the second-stage reaction is the target product, chloroethylene carbonate. In the method, the first-order reaction and the second-order reaction are carried out in a microchannel.

9. The method according to claim 8, characterized in that, The triethylamine polyfluoride includes at least one of triethylamine trifluoride and triethylamine pentafluoride; And / or, the first organic amine includes one or more combinations of triethylamine, ethylenediamine, and pyridineamine; And / or, the second organic amine includes one or more combinations of triethylamine, ethylenediamine, and pyridineamine; And / or, the first diluent comprises one or more combinations of haloalkanes, ethyl acetate, methyl acetate, acetonitrile, and benzonitrile; And / or, the second diluent comprises one or more combinations of haloalkanes, ethyl acetate, methyl acetate, acetonitrile, and benzonitrile.

10. The method according to claim 9, characterized in that, The first organic amine comprises a combination of triethylamine and ethylenediamine, wherein the molar ratio of triethylamine to ethylenediamine is 2:1 to 5:1; And / or, the second organic amine comprises a combination of triethylamine and ethylenediamine, wherein the molar ratio of triethylamine to ethylenediamine is 2:1 to 5:1; And / or, the first diluent comprises a combination of acetonitrile and ethyl acetate, wherein the molar ratio of acetonitrile to ethyl acetate is 5:1 to 10:1; And / or, the second diluent comprises a combination of acetonitrile and ethyl acetate, wherein the molar ratio of acetonitrile to ethyl acetate is 5:1 to 10:

1.

11. The method according to claim 8, characterized in that, The molar ratio of the first organic amine, triethylamine polyfluoride, and the first diluent is 1.2~2.3:1:15~30; And / or, the molar ratio of triethylamine polyfluoride to chloroethylene carbonate is 0.2~0.5:1; And / or, the molar ratio of the second organic amine to chloroethylene carbonate is 0.2~0.4:1; And / or, the molar ratio of the second diluent to ethylene chlorocarbonate is 4~8:

1.

12. The method according to claim 11, characterized in that, The molar ratio of the first organic amine, triethylamine polyfluoride, and the first diluent is 1.2~1.5:1:15~30 or 2.0~2.3:1:15~30.

13. The method according to claim 8, characterized in that, The reaction temperature for the second-order reaction is 40~70℃.

14. The method according to claim 8, characterized in that, The residence time for the second-order reaction is 15-30 minutes.

15. The method according to claim 8, characterized in that, The initial installation position of the flow guiding component is located at 30% to 60% of the residence time of the second-stage reaction.

16. The method according to claim 8, characterized in that, The initial installation position of the flow guiding component is located at 40% to 60% of the residence time of the second-stage reaction.

17. The method according to claim 8, characterized in that, In the second-stage reaction, the inner diameter of the microchannel is 1.5~4 mm; And / or, in the first-stage reaction, the inner diameter of the microchannel is 1.5~4 mm.

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