A method for synthesizing vinylene carbonate and its derivatives

Abstract

The present invention discloses a method for synthesizing vinylene carbonate and its derivatives, comprising: reacting a chain carbonate represented by formula (I), an olefin represented by formula (II) and an oxygen donor in the presence of a palladium catalyst and optionally a metal carbonate to produce a vinylene carbonate and its derivatives represented by formula (III); in formula (I), R1 and R2 are independently selected from alkyl or aryl groups; in formula (II), R3 and R4 are independently selected from hydrogen or alkyl groups; in formula (III), R3 and R4 are the same as described above; this method not only has an ideal yield, especially with few by-products and easy purification, but also avoids the drawbacks of the existing solutions that usually use ethylene chlorocarbonate as an intermediate, etc., and is suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the field of synthesis technology, in particular to additives for lithium-ion battery electrolytes such as vinylene carbonate, and specifically relates to a method for synthesizing vinylene carbonate and its derivatives. Background Art

[0002] Vinylene Carbonate, also known as 1,3-dioxol-2-one and ethylene carbonate, is an organic compound with the chemical formula C3H2O3. It is a colorless and transparent liquid. It is a new type of organic film-forming additive and overcharge protection additive for lithium-ion batteries. It can undergo an electrochemical reaction on the surface of the negative electrode during the first charge and discharge of the lithium battery to form a solid electrolyte interface film (SEI film), effectively inhibiting the embedding of solvent molecules and the gas expansion phenomenon of the lithium battery, and can improve the battery capacity and cycle life. It is mainly used in lithium iron phosphate batteries and ternary lithium batteries and is a relatively large amount of electrolyte additive currently in use. Vinylene carbonate can also be used as a monomer for preparing poly(ethylene carbonate) or for preparing photoresists, etc.

[0003] Currently, a relatively common method for preparing vinylene carbonate is as follows: using ethylene carbonate as a raw material, introducing chlorine gas and reacting under ultraviolet light irradiation to produce chloroethylene carbonate. Then, using chloroethylene carbonate as a raw material and a carbonate or ether substance as a solvent, by dropwise adding an acid-binding agent such as triethylamine and other organic amines, reacting at a certain temperature to obtain a crude product of vinylene carbonate, and obtaining a high-purity product through post-treatment such as filtration, vacuum distillation, and crystallization. The purity of the crude product of vinylene carbonate obtained by this method is not high, and it needs to undergo multiple distillation purifications. Moreover, the yield is low, and at the same time, a large amount of salt is generated and needs to be recycled, resulting in a relatively high overall cost. Therefore, it is of practical significance to study an efficient and green synthesis route for vinylene carbonate. Summary of the Invention

[0004] The object of the present invention is to overcome one or more deficiencies in the prior art and provide an improved green and environmentally friendly method for synthesizing vinylene carbonate and its derivatives that can avoid using chloroethylene carbonate and avoid generating a large amount of by-product salts.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for synthesizing vinylene carbonate and its derivatives, the method for synthesizing vinylene carbonate and its derivatives comprising: reacting a chain carbonate represented by formula (I), an olefin represented by formula (II), and an oxygen donor in the presence of a palladium catalyst and optionally a metal carbonate to form a vinylene carbonate and its derivatives represented by formula (III);

[0007] In formula (I), R1 and R2 are independently selected from an alkyl group or an aryl group; In formula (II), R3 and R4 are independently selected from hydrogen or alkyl; In formula (III), R3 and R4 are the same as described above.

[0008] According to some preferred and specific aspects of the present invention, the oxygen donor comprises oxygen or a gas capable of decomposing to produce oxygen.

[0009] In some embodiments of the present invention, the oxygen can be introduced in the form of pure oxygen gas (purity greater than 99%), or in the form of a mixed gas containing oxygen, specifically a mixed gas of oxygen and other gases that do not participate in the reaction, such as nitrogen, argon, etc. Doping these other gases that do not participate in the reaction can improve the safety of the entire preparation process.

[0010] According to a specific aspect of the present invention, the oxygen can be introduced in the form of a mixed gas of oxygen and nitrogen, and the volume ratio of oxygen to nitrogen is 1 - 5:1, preferably 1 - 3:1.

[0011] Furthermore, the gas capable of decomposing to produce oxygen comprises ozone, for example, it can decompose to produce oxygen under ultraviolet light irradiation of a specific wavelength.

[0012] According to some preferred and specific aspects of the present invention, R1 and R2 are independently selected from C 1-10 alkyl or C 6-10 aryl, and R3 and R4 are independently selected from hydrogen or C 1-5 alkyl.

[0013] In some embodiments of the present invention, R1 and R2 are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, phenyl, methylphenyl, ethylphenyl, propylphenyl or naphthyl, and R3 and R4 are independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

[0014] According to a specific aspect of the present invention, the olefin shown in formula (II) is ethylene, and the prepared product is vinylene carbonate.

[0015] In some embodiments of the present invention, the chain carbonate shown in formula (I) can be dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, etc.

[0016] According to some preferred aspects of the present invention, the palladium catalyst is at least one selected from the following catalysts supported on a carrier: Pd, Pd - Au, Pd - Pt, Pd - Cd, Pd - C, and the carrier is silica and / or alumina.

[0017] According to some preferred aspects of the present invention, in the palladium catalyst, the content of palladium is 0.5% - 10% by mass percentage.

[0018] Further, in the palladium catalyst, the content of palladium is 3% - 5% by mass percentage.

[0019] In some embodiments of the present invention, the palladium catalyst is Pd / SiO2, Pd - Au / SiO2, Pd - C / Al2O3, Pd - Au / Al2O3.

[0020] According to some preferred aspects of the present invention, the metal carbonate is a carbonate of at least one metal selected from the following metals: Na, K, Mg, Ca, Li, Zn, Fe, Mn, Cu.

[0021] Further, in some embodiments of the present invention, the metal carbonate is potassium carbonate, magnesium carbonate, sodium carbonate, zinc carbonate, etc.

[0022] According to some preferred aspects of the present invention, the dosage of the metal carbonate is 5% - 30% of the palladium catalyst by mass percentage. Further, the dosage of the metal carbonate is 10% - 20% of the palladium catalyst by mass percentage.

[0023] According to some preferred aspects of the present invention, the reaction temperature of the reaction is 100 - 350 °C, further 120 - 200 °C, and still further 130 - 180 °C.

[0024] According to some preferred aspects of the present invention, the reaction pressure of the reaction is 0.1 - 2.0 MPa, further 0.1 - 1.0 MPa, and still further 0.1 - 0.5 MPa. For example, it can be 0.1 MPa, 0.11 MPa, 0.12 MPa, 0.13 MPa, 0.14 MPa, 0.15 MPa, 0.16 MPa, 0.17 MPa, 0.18 MPa, 0.19 MPa, 0.2 MPa, 0.3 MPa, etc.

[0025] According to some preferred aspects of the present invention, the feed molar ratio of the chain carbonate shown in formula (I), the olefin shown in formula (II), and the oxygen donor is 1∶1 - 10∶1 - 3.

[0026] Further, the feed molar ratio of the chain carbonate shown in formula (I), the olefin shown in formula (II), and the oxygen donor is 2 - 4∶4 - 8∶1.

[0027] In some preferred embodiments of the present invention, the embodiments for synthesizing the vinylene carbonate and its derivatives include:

[0028] A fixed-bed reactor is used, filled with a palladium catalyst and optionally a metal carbonate;

[0029] The chain carbonate shown in formula (I) is introduced into an evaporator and heated to form a saturated vapor. The olefin shown in formula (II) is introduced into the evaporator. The chain carbonate shown in formula (I) and the olefin shown in formula (II) are brought into countercurrent contact and jointly discharged from the top of the evaporator, and then enter a mixer to be mixed with an oxygen donor to form a raw material gas with a pressure of 0.1 - 2.0 MPa. The raw material gas enters a fixed-bed reactor filled with a catalyst, contacts and reacts with the palladium catalyst and the optionally metal carbonate. A cooling system transfers the heat released by the reaction to maintain the reaction temperature and reaction pressure. The reaction product contains vinylene carbonate and its derivatives, alcohol, and the unreacted chain carbonate shown in formula (I), the olefin shown in formula (II), and the oxygen donor, and is discharged from the bottom of the fixed-bed reactor 3, cooled, and the liquid is collected. The unreacted raw material gas is pressurized by a compressor and then returned to participate in the reaction again.

[0030] Furthermore, the present invention provides a production device for synthesizing the vinylene carbonate and its derivatives. The production device includes:

[0031] An evaporator, a mixer, a fixed-bed reactor, a cooling system, a separator;

[0032] The upper part of the evaporator is provided with a feed port for the chain carbonate shown in formula (I), the lower part of the evaporator is provided with a feed port for the olefin shown in formula (II), and the top of the evaporator is provided with a discharge port;

[0033] The fixed-bed reactor includes a reaction chamber and a support frame for arranging the catalyst arranged inside the reaction chamber;

[0034] The cooling system is used to control the reaction temperature and reaction pressure inside the reaction chamber;

[0035] The discharge port is communicated with the mixer, the mixer is also communicated with the reaction chamber, the reaction chamber is also communicated with the separator, and the separator is also communicated with the evaporator and / or the mixer.

[0036] In some embodiments, the chain carbonate shown in formula (I) and the olefin shown in formula (II) are respectively introduced into the evaporator at a constant rate.

[0037] In some embodiments, when preparing vinylene carbonate, after the reaction ends, the reaction product contains vinylene carbonate, alcohol, unreacted ethylene, the chain carbonate shown in formula (I), and an oxygen donor (which can be, for example, pure oxygen gas or a mixed gas of oxygen and nitrogen), and is derived from the bottom of the fixed-bed reactor 3, cooled to below 30-40°C, the liquid is collected, the unreacted raw material gas is pressurized by a compressor and then returned to participate in the reaction again, and after the collected liquid is subjected to vacuum distillation, vinylene carbonate is obtained.

[0038] In some embodiments, the method for purifying the crude vinylene carbonate product includes: taking the crude vinylene carbonate product in a crystallizer, cooling it from 22°C to 15°C using gradient cooling, with a cooling rate of 0.1-1°C / minute, and holding for 5-20 minutes for every 1°C drop. After reaching the set temperature, the mother liquor is discharged, the needle-shaped crystals are taken out, and the crystals are restored to above 22°C under nitrogen protection until completely melted, and the above steps are repeated for multiple crystallizations.

[0039] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0040] Based on a large amount of research and experiments, the inventors of the present invention unexpectedly found that by using a palladium catalyst, the chain carbonate shown in formula (I) can be directly used as the starting material, and in the presence of the olefin shown in formula (II) and an oxygen donor, not only can vinylene carbonate and its derivatives be directly prepared, but also the yield is relatively ideal, especially with few by-products, easy to purify, and it also avoids the disadvantages of the existing solutions that usually use vinyl chloroformate as an intermediate product, etc., and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic structural diagram of the production device for preparing vinylene carbonate in an embodiment of the present invention; wherein, 1. evaporator; 2. mixer; 3. fixed-bed reactor; 4. cooling system; 5. separator;

[0042] Figure 2 It is a nuclear magnetic resonance hydrogen spectrum diagram of the vinylene carbonate prepared in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] Based on the defects existing in the existing preparation of vinylene carbonate, the present invention innovatively provides the chain carbonate shown in formula (I) which can itself be used as an electrolyte solvent as the starting material, and under the auxiliary action of a palladium catalyst, reacts with the olefin shown in formula (II) and an oxygen donor (preferably oxygen) to directly generate the target product, and an unexpected yield is obtained;

[0044] Furthermore, through further mechanism research, taking the preparation of vinylene carbonate as an example, it is analyzed that the reaction process mechanism of the present invention is generally as follows:

[0045] H2C=CH2 + 4Pd → Pd-HC=CH-Pd + 2Pd-H

[0046] O2 + 2Pd → 2Pd-O

[0047] Pd + R1OCOOR2 → Pd-R1OCOOR2

[0048] Pd-R1OCOOR2 + 2Pd-O → Pd-CO3 + R1O-Pd + R2O-Pd

[0049] Pd-CO3 + Pd-HC=CH-Pd → C3H2O3 + 3Pd

[0050] R1O-Pd + R2O-Pd + 2Pd-H → R1OH + R2OH + 4Pd;

[0051] In the reaction process of the present invention, while vinylene carbonate is prepared, the by-products are basically only alcohols, which are easy to remove. No solid salts are generated during the process, and the post-treatment of the product is simple, making it easy to obtain high-purity products. In particular, the chain carbonate shown in formula (I) itself can be a solvent for the electrolyte. Even if it remains in the target product, it does not affect its practical application. Moreover, raw materials such as ethylene and oxygen are gases, which are easy to separate and can be directly recycled to the front-end reaction, improving the atom economy.

[0052] Further, as Figure 1 shown, an exemplary structural schematic diagram of a production device for preparing vinylene carbonate is given. The production device includes: an evaporator 1, a mixer 2, a fixed-bed reactor 3, a cooling system 4, and a separator 5; a feed port for the chain carbonate shown in formula (I) is provided at the upper part of the evaporator 1, a feed port for the olefin shown in formula (II) is provided at the lower part of the evaporator 1, and a discharge port is provided at the top of the evaporator 1; the fixed-bed reactor 3 includes a reaction chamber and a support frame for setting the catalyst disposed inside the reaction chamber; the cooling system 4 is used to control the reaction temperature and reaction pressure inside the reaction chamber; the discharge port is communicated with the mixer 2, the mixer 2 is also communicated with the reaction chamber, the reaction chamber is also communicated with the separator 5, and the separator 5 is also communicated with the evaporator 1 and / or the mixer 2;

[0053] Specifically, the operation process is as follows:

[0054] The chain carbonate represented by formula (I) is introduced into the evaporator 1 through the chain carbonate feed port represented by formula (I) at the upper part of the evaporator 1, and is heated to form saturated vapor. Ethylene is introduced into the evaporator 1 through the olefin feed port represented by formula (II) at the lower part of the evaporator 1, and is countercurrently contacted with the chain carbonate represented by formula (I) flowing down from the upper part of the evaporator 1, and comes out from the discharge port at the top of the evaporator 1 together with the saturated vapor of the chain carbonate represented by formula (I), and then enters the mixer 2 to mix with the introduced oxygen to form a raw gas, and then enters the fixed bed reactor 3 filled with a catalyst to contact and react with the palladium catalyst and the selective metal carbonate. The cooling system 4 transfers the heat released by the reaction to maintain the reaction temperature and reaction pressure. The reaction product contains vinylene carbonate, alcohol and unreacted chain carbonate represented by formula (I), ethylene, oxygen, etc., which are discharged from the bottom of the fixed bed reactor 3, cooled, separated in the separator 5, and the liquid is collected. The unreacted raw gas is pressurized by the compressor and returned to participate in the reaction again.

[0055] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0056] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0057] Example 1

[0058] This example provides a method for preparing vinylene carbonate, using Figure 1 The device is carried out as shown, which comprises:

[0059] A fixed bed reactor was used, the main catalyst was Pd / SiO2 (palladium accounted for 5.0% of the main catalyst, purchased from Shaanxi Kaida Chemical Co., Ltd.), the filling volume was 50 mL, and the weight was 100 g. The co-catalyst was granular potassium carbonate, the filling volume was 10 mL, and the weight was about 15 g.

[0060] Dimethyl carbonate enters the evaporator 1 at a rate of 1.5 g / min and is heated to form saturated vapor. Ethylene enters the lower part of the evaporator 1 at a rate of 373.0 mL / min and contacts the dimethyl carbonate flowing down from the upper part of the evaporator 1 in a countercurrent manner. The dimethyl carbonate saturated vapor comes out from the top of the evaporator, is heated to 130 - 140 °C, and enters the mixer 2. At the same time, the nitrogen-oxygen mixture (volume ratio 1:1) enters at a rate of 600 mL / min. The three are rapidly and uniformly mixed in the mixer 2. The raw material gas derived from the mixer 2 maintains a pressure of 0.13 - 0.15 MPa and enters the fixed-bed reactor 3 equipped with a catalyst to contact and react with the catalyst. The cooling system 4 timely transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, methanol, and unreacted ethylene, dimethyl carbonate, oxygen, and nitrogen. They are derived from the bottom of the fixed-bed reactor, cooled to below 35 °C, separated by the separator 5, the liquid is collected, and the unreacted raw material gas is pressurized by a compressor and returned to participate in the reaction again. After 2 h, the feeding of dimethyl carbonate is stopped, 279.2 g of liquid is obtained. After vacuum distillation, 155.9 g of vinylene carbonate is obtained, and the yield is 90.6% (yield = actual output / theoretical output), and the purity is 93.7%.

[0061] Take the above-mentioned vinylene carbonate in a small glass crystallizer, and cool it from 22 °C to 15 °C by gradient cooling at a cooling rate of 0.5 °C / min, and keep it warm for 10 minutes for every 1 °C drop. After reaching the set temperature, release the mother liquor, take out the needle-shaped crystals, and restore the crystals to above 22 °C under nitrogen protection until they are completely melted. Repeat the above steps for secondary crystallization, and vinylene carbonate with a purity of 99.97% is obtained. Its nuclear magnetic resonance hydrogen spectrum is as Figure 2 shown.

[0062] Example 2

[0063] This example provides a method for preparing vinylene carbonate, which is carried out using the Figure 1 device shown, and it includes:

[0064] A fixed-bed reactor is used. The main catalyst: Pd / SiO2 (palladium accounts for 5.0% of the main catalyst, purchased from Shaanxi Kaida Chemical Co., Ltd.), the filling volume: 50 mL, and the weight: 100 g. The co-catalyst: granular magnesium carbonate, the filling volume: 10 mL, and the weight: about 16 g.

[0065] Dimethyl carbonate enters the evaporator 1 at a rate of 1.5 g / min and is heated to form saturated vapor. Ethylene enters the lower part of the evaporator 1 at a rate of 373.0 mL / min and contacts the dimethyl carbonate flowing down from the upper part of the evaporator 1 in a countercurrent manner. The dimethyl carbonate saturated vapor exits from the top of the evaporator, is heated to 130 - 140 °C, and enters the mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and uniformly mixed in the mixer 2. The raw material gas derived from the mixer 2, maintaining a pressure of 0.13 - 0.15 MPa, enters the fixed-bed reactor 3 equipped with a catalyst and reacts upon contact with the catalyst. The cooling system 4 promptly transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, methanol, and unreacted ethylene, dimethyl carbonate, oxygen, and nitrogen. They are derived from the bottom of the fixed-bed reactor, cooled to below 35 °C, separated by the separator 5, the liquid is collected, and the unreacted raw material gas is pressurized by a compressor and returned to participate in the reaction again. After 2 h, the feeding of dimethyl carbonate is stopped, 275.0 g of liquid is obtained. After vacuum distillation, 156.2 g of vinylene carbonate is obtained, with a yield of 90.8% and a purity of 95.1%.

[0066] Example 3

[0067] This example provides a method for preparing vinylene carbonate, which is carried out using the Figure 1 device shown, and it includes:

[0068] A fixed-bed reactor is used. The main catalyst: Pd-Au / Al2O3 (palladium accounts for 5% of the main catalyst, purchased from Shaanxi Ruike New Materials Co., Ltd.), the filling volume: 50 mL, and the weight: 102 g. The co-catalyst: granular potassium carbonate, the filling volume: 10 mL, and the weight: about 15 g.

[0069] Dimethyl carbonate enters the evaporator 1 at a rate of 1.5 g / min and forms saturated vapor after heating. Ethylene enters the lower part of the evaporator 1 at a rate of 373.0 mL / min and contacts the dimethyl carbonate flowing down from the upper part of the evaporator 1 in a countercurrent manner. The dimethyl carbonate saturated vapor comes out from the top of the evaporator, is heated to 130 - 140 °C, and enters the mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and uniformly mixed in the mixer 2. The raw material gas exported from the mixer 2 maintains a pressure of 0.13 - 0.15 MPa and enters the fixed-bed reactor 3 filled with a catalyst to contact and react with the catalyst. The cooling system 4 transfers the heat released by the reaction in a timely manner to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, methanol, and unreacted ethylene, dimethyl carbonate, oxygen, and nitrogen. They are exported from the bottom of the fixed-bed reactor, cooled to below 35 °C, separated by the separator 5, the liquid is collected, and the unreacted raw material gas is pressurized by a compressor and then returned to participate in the reaction again. After 2 h, the feeding of dimethyl carbonate is stopped, and 287.1 g of liquid is obtained. After vacuum distillation, 164.8 g of vinylene carbonate is obtained, with a yield of 95.8% and a purity of 93.1%.

[0070] Example 4

[0071] This example provides a method for preparing vinylene carbonate, which is carried out using the Figure 1 device shown, and it includes:

[0072] A fixed-bed reactor is used. The main catalyst: Pd-Au / Al2O3 (palladium accounts for 5% of the main catalyst, purchased from Shaanxi Ruike New Materials Co., Ltd.), the filling volume: 50 mL, and the weight: 102 g. The co-catalyst: granular sodium carbonate, the filling volume: 10 mL, and the weight: about 13 g.

[0073] Diethyl carbonate enters evaporator 1 at a rate of 2.0 g / min and is heated to form saturated vapor. Ethylene enters the lower part of evaporator 1 at a rate of 373.0 mL / min and contacts the diethyl carbonate flowing down from the upper part of evaporator 1 in a countercurrent manner. The saturated vapor of diethyl carbonate exits from the top of the evaporator, is heated to 155 - 165 °C, and enters mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and uniformly mixed in mixer 2. The feed gas derived from mixer 2, maintaining a pressure of 0.15 - 0.20 MPa, enters a fixed-bed reactor 3 filled with a catalyst and contacts the catalyst for reaction. Cooling system 4 promptly transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, ethanol, and unreacted ethylene, diethyl carbonate, oxygen, and nitrogen. They are derived from the bottom of the fixed-bed reactor, cooled to below 35 °C, separated by separator 5, the liquid is collected, and the unreacted feed gas is pressurized by a compressor and returned to participate in the reaction again. After 2 h, the feeding of diethyl carbonate is stopped, and 347.6 g of liquid is obtained. After vacuum distillation, 163.1 g of vinylene carbonate is obtained, with a yield of 93.4% and a purity of 94.6%.

[0074] Example 5

[0075] This example provides a method for preparing vinylene carbonate, which is carried out using the Figure 1 device shown, and it includes:

[0076] A fixed-bed reactor is used. The main catalyst: Pd-Au / SiO2 (palladium accounts for 5% of the main catalyst, Shaanxi Rare Chemical New Materials Co., Ltd.), the filling volume: 50 mL, and the weight: 102 g. The promoter: granular potassium carbonate, the filling volume: 10 mL, and the weight: about 15 g.

[0077] Diethyl carbonate enters the evaporator 1 at a rate of 2.0 g / min and is heated to form saturated vapor. Ethylene enters the lower part of the evaporator 1 at a rate of 373.0 mL / min and contacts the diethyl carbonate flowing down from the upper part of the evaporator 1 in a countercurrent manner. The saturated vapor of diethyl carbonate exits from the top of the evaporator, is heated to 155 - 165 °C, and enters the mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and uniformly mixed in the mixer 2. The raw material gas derived from the mixer 2, maintaining a pressure of 0.15 - 0.20 MPa, enters the fixed-bed reactor 3 equipped with a catalyst and reacts upon contact with the catalyst. The cooling system 4 promptly transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, ethanol, and unreacted ethylene, diethyl carbonate, oxygen, and nitrogen. They are derived from the bottom of the fixed-bed reactor, cooled to below 35 °C, separated by the separator 5, the liquid is collected, and the unreacted raw material gas is pressurized by a compressor and returned to participate in the reaction again. After 2 h, the feeding of diethyl carbonate is stopped, 349.9 g of liquid is obtained. After vacuum distillation, 162.7 g of vinylene carbonate is obtained, with a yield of 93.1% and a purity of 95.2%.

[0078] Example 6

[0079] This example provides a method for preparing vinylene carbonate, which is carried out using the Figure 1 device shown, and it includes:

[0080] A fixed-bed reactor is used. The main catalyst: Pd-C / Al2O3 (palladium accounts for 5% of the main catalyst, purchased from Shanghai Xunkai New Materials Technology Co., Ltd.), filling volume: 50 mL, weight 97 g. The promoter: granular potassium carbonate, filling volume: 10 mL, weight about 15 g.

[0081] Diethyl carbonate enters evaporator 1 at a rate of 2.0 g / min and forms saturated vapor after heating. Ethylene enters the lower part of evaporator 1 at a rate of 373.0 mL / min and contacts the diethyl carbonate flowing down from the upper part of evaporator 1 in a countercurrent manner. The saturated vapor of diethyl carbonate comes out from the top of the evaporator, is heated to 155 - 165 °C, and enters mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and uniformly mixed in mixer 2. The raw material gas derived from mixer 2, maintaining a pressure of 0.15 - 0.20 MPa, enters a fixed-bed reactor 3 filled with a catalyst and reacts upon contact with the catalyst. Cooling system 4 promptly transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, ethanol, and unreacted ethylene, diethyl carbonate, oxygen, and nitrogen. They are derived from the bottom of the fixed-bed reactor, cooled to below 35 °C, separated by separator 5, the liquid is collected, and the unreacted raw material gas is returned to participate in the reaction again after being pressurized by a compressor. After 2 h, the feeding of diethyl carbonate is stopped, and 353.4 g of liquid is obtained. After vacuum distillation, 164.4 g of vinylene carbonate is obtained, with a yield of 94.1% and a purity of 93.6%.

[0082] Example 7

[0083] This example provides a method for preparing vinylene carbonate, which is carried out using the Figure 1 device shown, and it includes:

[0084] A fixed-bed reactor is used. The main catalyst: Pd / SiO2 (palladium accounts for 5.0% of the main catalyst, purchased from Shaanxi Kaida Chemical Co., Ltd.), the loading volume: 50 mL, and the weight is about 103 g. The promoter: granular zinc carbonate, the filling volume: 10 mL, and the weight is about 16 g.

[0085] Ethyl methyl carbonate enters evaporator 1 at a rate of 1.8 g / min and is heated to form saturated vapor. Ethylene enters the lower part of evaporator 1 at a rate of 373.0 mL / min and contacts the ethyl methyl carbonate flowing down from the upper part of evaporator 1 in a countercurrent manner. The saturated vapor of ethyl methyl carbonate comes out from the top of the evaporator, is heated to 140 - 150 °C, and enters mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and evenly mixed in mixer 2. The raw material gas derived from mixer 2, maintaining a pressure of 0.15 - 0.20 MPa, enters fixed-bed reactor 3 equipped with a catalyst and reacts upon contact with the catalyst. Cooling system 4 promptly transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain vinylene carbonate, methanol, ethanol, and unreacted ethylene, ethyl methyl carbonate, oxygen, and nitrogen, and are derived from the bottom of the fixed-bed reactor. After being cooled to below 35 °C, they are separated by separator 5, the liquid is collected, and the unreacted raw material gas is returned to participate in the reaction again after being pressurized by a compressor. After 2 h, the feeding of ethyl methyl carbonate is stopped, 330.6 g of liquid is obtained, and after vacuum distillation, 171.6 g of vinylene carbonate is obtained, with a yield of 96.2% and a purity of 92.9%.

[0086] Example 8

[0087] Basically the same as Example 7, the only difference being that no cocatalyst is used. 150.9 g of vinylene carbonate is obtained, with a yield of 84.6% and a purity of 92.3%.

[0088] Example 9

[0089] This example provides a preparation method of a vinylene carbonate derivative 4,5-dimethyl-1,3-dioxol-2-one (structural formula: ), which is carried out using the Figure 1 shown device and includes:

[0090] A fixed-bed reactor is used. Main catalyst: Pd / SiO2 (palladium accounts for 5.0% of the main catalyst, purchased from Shaanxi Kaida Chemical Co., Ltd.), filling volume: 50 mL, weight: 100 g. Cocatalyst: granular magnesium carbonate, filling volume: 10 mL, weight: about 16 g.

[0091] Dibutyl carbonate enters the evaporator 1 at a rate of 2.9 g / min and forms saturated vapor after heating. 2-Butene enters the lower part of the evaporator 1 at a rate of 746.0 mL / min and contacts the dibutyl carbonate flowing down from the upper part of the evaporator 1 in a countercurrent manner. The saturated vapor of dibutyl carbonate comes out from the top of the evaporator, is heated to 250 - 260 °C, and enters the mixer 2. At the same time, a nitrogen-oxygen mixture (volume ratio 1:2) enters at a rate of 600 mL / min. The three are rapidly and evenly mixed in the mixer 2. The raw material gas derived from the mixer 2, maintaining a pressure of 0.13 - 0.15 MPa, enters the fixed-bed reactor 3 equipped with a catalyst and reacts upon contact with the catalyst. The cooling system 4 promptly transfers the heat released by the reaction to ensure the stability of the reaction temperature and reaction pressure. The reaction products contain 4,5-dimethyl-1,3-dioxol-2-one, butanol, and unreacted ethylene, dibutyl carbonate, oxygen, and nitrogen. They are derived from the bottom of the fixed-bed reactor, cooled to 85 - 90 °C, separated by the separator 5, the liquid is collected, and the unreacted raw material gas is returned to participate in the reaction after being pressurized by a compressor. After 2 h, the feeding of dibutyl carbonate is stopped, and 511.0 g of liquid is obtained. After vacuum distillation, 200.3 g of 4,5-dimethyl-1,3-dioxol-2-one is obtained, with a yield of 87.8% and a purity of 92.4%.

[0092] The above embodiments are only for illustrating the technical concept and characteristics of the present invention, and the purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

[0093] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

Claims

1. A method for synthesizing vinylene carbonate and its derivatives, characterized in that, The synthetic method of the vinylene carbonate and its derivatives includes: in the presence of a palladium catalyst, reacting a chain carbonate shown by formula (I), an olefin shown by formula (II) and an oxygen donor to generate the vinylene carbonate and its derivatives, and the vinylene carbonate and its derivatives have the structure shown by formula (III); , in formula (I), R1 and R2 are independently selected from alkyl or aryl; , in formula (II), R3 and R4 are independently selected from hydrogen or alkyl; , in formula (III), R3 and R4 are the same as described above; The palladium in the palladium catalyst exists as zero-valent palladium, and the oxygen donor is oxygen.

2. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The oxygen is introduced by passing pure oxygen gas with a purity greater than 99%, or by passing a mixed gas composed of oxygen and other gases that do not participate in the reaction.

3. The synthesis method of vinylene carbonate and its derivatives according to claim 2, characterized in that, The other gases that do not participate in the reaction are nitrogen or argon.

4. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, R1 and R2 are independently selected from C 1-10 alkyl or C 6-10 aryl, and R3 and R4 are independently selected from hydrogen or C 1-5 alkyl.

5. The synthesis method of vinylene carbonate and its derivatives according to claim 4, characterized in that, R1 and R2 are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, phenyl, methylphenyl, ethylphenyl, propylphenyl or naphthyl, and R3 and R4 are independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

6. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The palladium catalyst is at least one selected from the following catalysts supported on a carrier: Pd, Pd-Au, Pd-Pt, Pd-Cd, Pd-C, and the carrier is silica, aluminum oxide or a combination of the two.

7. The synthesis method of vinylene carbonate and its derivatives according to claim 6, characterized in that, In terms of mass percentage, the content of palladium in the palladium catalyst accounts for 0.5%-10%.

8. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The reaction is also carried out in the presence of a metal carbonate, and the metal carbonate is a carbonate of at least one selected from the following metals: Na, K, Mg, Ca, Li, Zn, Fe, Mn, Cu.

9. The synthesis method of vinylene carbonate and its derivatives according to claim 8, characterized in that, In terms of mass percentage, the dosage of the metal carbonate is 5%-30% of the palladium catalyst.

10. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The reaction temperature of the reaction is 100-350 °C.

11. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The reaction pressure of the reaction is 0.1-2.0 MPa.

12. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The molar ratio of the chain carbonate shown by formula (I), the olefin shown by formula (II) and the oxygen donor in the feed is 1∶1-10∶1-3.

13. The synthesis method of vinylene carbonate and its derivatives according to claim 1, characterized in that, The implementation mode of synthesizing the vinylene carbonate and its derivatives includes: Using a fixed-bed reactor, loading a palladium catalyst and optionally a metal carbonate; Passing the chain carbonate shown by formula (I) into an evaporator to form a saturated vapor by heating, passing the olefin shown by formula (II) into the evaporator, making the chain carbonate shown by formula (I) contact the olefin shown by formula (II) countercurrently and jointly discharging from the top of the evaporator, then entering a mixer to mix with the oxygen donor to form a raw material gas with a pressure of 0.1-2.0 MPa, entering the fixed-bed reactor filled with the catalyst, contacting and reacting with the palladium catalyst, and a cooling system transfers the heat released by the reaction to maintain the reaction temperature and reaction pressure. The reaction product contains the vinylene carbonate and its derivatives, alcohol, and the unreacted chain carbonate shown by formula (I), the olefin shown by formula (II), and the oxygen donor, is discharged from the bottom of the reactor, cooled by the cooling system, the liquid is collected, and the unreacted raw material gas is pressurized by a compressor and then returned to participate in the reaction again.

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