Catalyst for preparing vinylene carbonate, preparation method and method for preparing vinylene carbonate by using catalyst

Abstract

The invention discloses a catalyst for preparing vinylene carbonate, a preparation method and a method for preparing vinylene carbonate.The method includes the steps that chloroethylene carbonate serves as a raw material, a catalytic reaction is carried out in a fixed bed to generate gas-phase vinylene carbonate, and the catalyst comprises a carrier and an active component, the carrier is a mixture of vinylene carbonate and polyvinyl carbonate, and the active components are chlorides or oxides of metals such as calcium, barium, nickel, magnesium, copper and the like. According to the method for preparing the vinylene carbonate, the vinylene carbonate crude product with the purity larger than 98% can be directly obtained through one-step reaction, and the vinylene carbonate product with the purity larger than 99.995% can be directly obtained through melt crystallization purification without rectification purification. The method for preparing vinylene carbonate disclosed by the invention is simple in process, simple in equipment, simple in catalyst preparation, low in cost and capable of realizing large-scale production, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of chemical synthesis technology, and relates to a catalyst for preparing vinylene carbonate, a preparation method thereof, and a method for preparing vinylene carbonate. Background Technology

[0002] Vinylene carbonate (VC) is a core additive in lithium-ion battery electrolytes, promoting the formation of a solid electrolyte interphase (SEI) film during the initial charge-discharge cycle. This film exhibits stable electrochemical performance and effectively inhibits solvent molecule intercalation, thereby preventing a decline in battery cycle life and other performance characteristics.

[0003] Currently, there is only one mature industrial method for preparing vitamin C, which uses ethylene chloride carbonate (CEC) as raw material. A certain amount of CEC, solvent, and polymerization inhibitor are added to a reaction vessel, and then triethylamine is added dropwise at a certain temperature. Triethylamine and CEC undergo an acid elimination reaction to produce vitamin C and triethylamine hydrochloride. After the reaction, solid-liquid separation is performed. The liquid phase containing vitamin C undergoes separation processes such as solvent removal, coke removal, light content removal, and distillation to obtain crude vitamin C product with a purity of ≥97%. This crude vitamin C product enters the melt crystallization process to obtain qualified vitamin C product. The triethylamine hydrochloride enters the triethylamine recovery process to recover triethylamine. Traditional production methods are batch processes, resulting in long batch times and low efficiency. The reaction generates solid triethylamine hydrochloride, which has poor solubility in both the solvent and the product. Continuous processes inevitably lead to engineering problems such as pipeline blockage. Furthermore, due to the heat sensitivity of vitamin C (VC), the generated VC cannot leave the reaction system during prolonged reactions, resulting in polymerization side reactions and a selectivity of <75%. The reacted VC requires multiple separation steps to obtain the final VC product. During separation, the heat sensitivity of VC further leads to polymerization side reactions, further reducing the yield. In summary, traditional VC preparation processes are energy-intensive, generate significant amounts of waste, and incur high treatment costs. They are also lengthy, complex, and require substantial equipment investment. Therefore, improving production efficiency, enhancing VC selectivity, and streamlining the VC preparation process are the main optimization directions for VC production.

[0004] CN114797957A provides a solid catalyst for the liquid-phase catalytic removal of hydrogen chloride from chloroethylene carbonate to prepare vinylene carbonate, effectively improving the conversion rate and selectivity of chloroethylene carbonate. The catalyst comprises a support, which is a molecular sieve, and the active component is a group IA or IIA hydroxide, carbonate, or bicarbonate. The molecular sieve is at least one selected from Y, Beta, MOR, ZSM, and magnesium aluminum hydrotalcite. This reaction is a liquid-phase reaction, and the products are VC and a large amount of unreacted CEC. Due to the high boiling point of CEC, thermosensitive polymerization of VC inevitably occurs during subsequent separation, resulting in yield loss.

[0005] CN115043812A describes a method for reacting nitrogen gas with fluoroethylene carbonate in a fixed-bed reactor in the presence of a catalyst to obtain vinylene carbonate. The catalyst is an acidic catalyst, which may be activated carbon, aluminum fluoride, chromium fluoride, magnesium fluoride, aluminum fluoride, chromium fluoride, magnesium fluoride, aluminum fluoride, chromium fluoride, or magnesium fluoride. This method produces no liquid or solid waste, is environmentally friendly, and has a simple operation. However, the raw material, fluoroethylene carbonate, is difficult to obtain, and its price is currently close to that of vinylene carbonate in the market, resulting in a higher synthesis cost.

[0006] CN117402134A discloses a solventless method for preparing vinylene carbonate. The specific steps involve mixing chloroethylene carbonate with a catalyst, heating to the reaction temperature, introducing a protective gas, and carrying out a dechlorination reaction. The catalyst is a supported Schiff base metal complex catalyst, comprising an Al₂O₃ support and an active component supported on the support. The active component is one or more of Cu(II) Schiff base complexes, Mn(II) Schiff base complexes, and Co(II) Schiff base complexes. This method inevitably uses distillation for subsequent separation, and VC may undergo thermosensitive polymerization, resulting in yield loss.

[0007] Therefore, developing a continuous, simple, low-investment, and highly selective method for preparing VC is of great significance to the development of the lithium battery electrolyte industry. Summary of the Invention

[0008] To address the shortcomings of existing technologies, one objective of this invention is to provide a catalyst for preparing vinylene carbonate, which can directly obtain crude vinylene carbonate with a purity greater than 98% in a one-step reaction, and can directly obtain vinylene carbonate with a purity greater than 99.995% through melt crystallization purification without the need for distillation purification.

[0009] Another object of the present invention is to provide a method for preparing the above-mentioned catalyst.

[0010] Another object of the present invention is to provide a method for preparing vinylene carbonate using this catalyst. Furthermore, the method for preparing vinylene carbonate disclosed in this invention is simple in process and requires minimal equipment. Simultaneously, the catalyst preparation is simple and low in cost, enabling large-scale production and possessing broad application prospects.

[0011] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0012] A catalyst for preparing vinylene carbonate, the catalyst comprising a support and an active component; the support being a mixture of polyvinylene carbonate and polyvinyl carbonate, and the active component being a chloride or oxide of calcium, barium, nickel, magnesium, or copper.

[0013] In some specific embodiments, the mass ratio of polyvinyl carbonate to polyvinyl carbonate is 1:5 to 1:100, preferably 1:10 to 1:50;

[0014] Preferably, the active component is added at a mass of 0.5% to 10% of the total mass of polyvinyl carbonate and polyvinyl carbonate, more preferably 2% to 8%.

[0015] On the other hand, a method for preparing the aforementioned catalyst for preparing vinylene carbonate includes the following steps:

[0016] 1) Mix vinylene carbonate, ethylene carbonate, and triethylamine, and heat at temperature T1;

[0017] 2) Raise the temperature to T2, add one or more active components to the mixture, and simultaneously add triethylamine hydrochloride, and stir thoroughly;

[0018] 3) Raise the temperature to T3, and introduce nitrogen gas preheated to T3 into the mixed liquid. The mixed liquid will coke and form a solid precipitate.

[0019] 4) The generated solid is calcined to obtain the catalyst.

[0020] In some specific implementations, in step 1), the mass ratio of vinylene carbonate to ethylene carbonate is 1:5 to 1:100, preferably 1:10 to 1:50; the mass ratio of vinylene carbonate to triethylamine is 1:0.005 to 1:0.2, preferably 1:0.02 to 1:0.1.

[0021] In some specific implementations, the temperature T1 in step 1) is 50-80℃, preferably 65-75℃.

[0022] In some specific implementations, the temperature T2 in step 2) is 60-100℃, preferably 80-90℃.

[0023] In some specific implementations, the active component in step 2) is selected from one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, cuprous chloride, calcium oxide, barium oxide, nickel oxide, magnesium oxide, copper oxide, and cuprous oxide, preferably one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, and cuprous chloride;

[0024] Preferably, the added active component is 0.5% to 10% of the total mass of vinylene carbonate and ethylene carbonate, more preferably 2% to 8%;

[0025] More preferably, the mass ratio of the added triethylamine hydrochloride to vinylene carbonate is 0.01:1 to 0.2:1, preferably 0.03:1 to 0.1:1.

[0026] In some specific implementations, the temperature T3 in step 3) is 120-200℃, preferably 150-180℃; and / or

[0027] In step 4), calcination is carried out in a nitrogen atmosphere at 300-500℃ for 5-30 hours.

[0028] Furthermore, the method for preparing vinylene carbonate using the aforementioned catalyst or the catalyst prepared by the aforementioned method includes the following steps:

[0029] A) After preheating the liquid-phase chloroethylene carbonate, it is passed into a fixed bed containing a catalyst to carry out the dehydrochlorination reaction.

[0030] B) The products after the reaction are separated into gas and liquid phases. The liquid phase is unreacted vinyl chloride carbonate, and the gas phase is vinylene carbonate and hydrogen chloride.

[0031] C) After the gas phase is condensed, the vinylene carbonate is condensed into a liquid phase, and the gas phase hydrogen chloride enters the alkali absorption unit.

[0032] In some specific implementations, in step A), after the prepared catalyst is loaded into a fixed bed, ammonia gas is introduced at 400-600°C for 2-10 hours, preferably at 450-550°C for 5-8 hours.

[0033] Preferably, in step A), the preheating temperature of ethylene chlorocarbonate is 80-120℃, more preferably 90-110℃; the feed space velocity of ethylene chlorocarbonate is 0.1-10m / s, more preferably 2-7m / s.

[0034] Preferably, the reaction temperature in step A) is 70-130℃, more preferably 80-115℃; the pressure is 50PaA-1000PaA, more preferably 100PaA-500PaA.

[0035] Preferably, the condensation temperature in step C) is 10-25℃, more preferably 14-20℃.

[0036] Compared with the prior art, the advantages and effects of the present invention are as follows:

[0037] The catalyst of this invention is used in a method for preparing vinylene carbonate, which can directly obtain crude vinylene carbonate with a purity greater than 98% in a one-step reaction, without the need for distillation purification, and can be directly purified by melt crystallization to obtain vinylene carbonate with a purity greater than 99.995%. Furthermore, the method for preparing vinylene carbonate disclosed in this invention is simple in process and requires basic equipment. The catalyst preparation is also simple and low in cost, enabling large-scale production and possessing broad application prospects. Detailed Implementation

[0038] To better understand the technical solution of the present invention, the following embodiments will further illustrate the method provided by the present invention. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0039] According to a first embodiment of the present invention, a catalyst for preparing vinylene carbonate is provided, the catalyst comprising a support and an active component; the support is a mixture of polyvinylene carbonate and polyvinyl carbonate, and the active component is a chloride or oxide of a metal such as calcium, barium, nickel, magnesium, or copper.

[0040] According to a second embodiment of the present invention, a method for preparing the above-mentioned catalyst is provided, the method comprising the following steps:

[0041] 1) Mix vinylene carbonate, ethylene carbonate, and triethylamine, and heat at temperature T1;

[0042] 2) Raise the temperature to T2, add one or more active components to the mixture, and add a certain amount of triethylamine hydrochloride at the same time, and stir thoroughly;

[0043] 3) Raise the temperature to T3, and introduce nitrogen gas preheated to T3 temperature into the mixed liquid. The mixed liquid will quickly coke and form a solid precipitate.

[0044] 4) The generated solid is calcined (e.g., calcined in a nitrogen atmosphere at 300-500℃ for 5-30 hours) to obtain the solid catalyst.

[0045] Preferably, in catalyst synthesis step 1), the mass ratio of vinylene carbonate to ethylene carbonate is 1:5 to 1:100, for example, 1:8, 1:10, 1:20, 1:25, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, etc., more preferably 1:10 to 1:50; the mass ratio of vinylene carbonate to triethylamine is 1:0.005 to 1:0.2, for example, 1:0.01, 1:0.03, 1:0.05, 1:0.08, 1:0.1, 1:0.12, 1:0.15, 1:0.18, 1:0.2, etc., more preferably 1:0.02 to 1:0.1;

[0046] Preferably, in catalyst synthesis step 1), T1 is 50-80°C, such as 55°C, 60°C, 65°C, 70°C, 75°C, etc., more preferably 65-75°C;

[0047] Preferably, in catalyst synthesis step 1), the mixture is heated at a preferred temperature, and the color gradually changes from colorless and transparent to black. When the color has completely turned black, heating is continued for 2 hours to end step 1).

[0048] Preferably, the active component in catalyst synthesis step 2) is selected from one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, cuprous chloride, calcium oxide, barium oxide, nickel oxide, magnesium oxide, copper oxide, and cuprous oxide, more preferably metal chlorides, such as one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, and cuprous chloride.

[0049] Preferably, in catalyst synthesis step 2), the mass of the active component added is 0.5% to 10% of the total mass of vinylene carbonate and ethylene carbonate, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc., more preferably 2% to 8%; the mass ratio of the added triethylamine hydrochloride to vinylene carbonate is 0.01:1 to 0.2:1, for example, 0.02:1, 0.05:1, 0.06:1, 0.08:1, 0.1:1, 0.13:1, 0.15:1, 0.18:1, 0.2:1, etc., more preferably 0.03:1 to 0.1:1.

[0050] Preferably, in catalyst synthesis step 2), T2 is 60-100℃, such as 60℃, 65℃, 70℃, 75℃, 85℃, 95℃, etc., more preferably 80-90℃;

[0051] Preferably, the solubility of vinylene carbonate and ethylene carbonate added in catalyst synthesis step 2) increases with increasing temperature. After adding the active component, step 2) is ended after stirring at the preferred temperature for 30 minutes.

[0052] Preferably, when performing catalyst synthesis step 3), the mixture in step 2) should be transferred to an open beaker, and the volume percentage of the mixture in the beaker should be <30%.

[0053] Preferably, in catalyst synthesis step 3), the beaker is immersed in an oil bath at a temperature of 120-200°C, such as 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, etc., with 150-180°C being the most preferred.

[0054] Preferably, preheated nitrogen gas is introduced into the mixture; as the heating time increases, the liquid mixture gradually transforms into a solid and its volume gradually expands until the volume no longer changes, at which point the nitrogen gas introduction is stopped, and step 3) ends.

[0055] Preferably, after step 4), the obtained catalyst is compressed into 3mm×3mm sheet catalyst.

[0056] According to a third embodiment of the present invention, a method for preparing vinylene carbonate using the above-described catalyst is provided, the preparation method being carried out according to the following steps:

[0057] (A) After preheating the liquid-phase vinyl chloride carbonate, it is passed into a fixed bed containing a catalyst loaded with the active components of the above-prepared polyvinyl carbonate and a mixture of polyvinyl carbonate. The dehydrochlorination reaction is carried out.

[0058] (B) The products after the reaction are separated into gas and liquid phases. The liquid phase is unreacted vinyl chloride carbonate, and the gas phase is vinylene carbonate and hydrogen chloride.

[0059] (C) After the gas phase passes through three stages of condensation, the vinylene carbonate is condensed into a liquid phase, and the gas phase hydrogen chloride enters the alkali absorption unit.

[0060] Preferably, in the vinylene carbonate synthesis step (A), after the prepared catalyst is loaded into a fixed bed, ammonia gas is introduced at 400-600°C for 2-10 hours, more preferably at 450-550°C for 5-8 hours.

[0061] Preferably, in the vinylene carbonate synthesis step (A), the preheating temperature of chloroethylene carbonate is 80-120°C, more preferably 90-110°C; and the feed space velocity of chloroethylene carbonate is 0.1-10 m / s, more preferably 2-7 m / s.

[0062] Preferably, the reaction temperature in the vinylene carbonate synthesis step (A) is 70-130°C, more preferably 80-115°C; the pressure is preferably 50 PaA-1000 PaA, more preferably 100 PaA-500 PaA.

[0063] Preferably, the condensation temperature in the vinylene carbonate synthesis step (C) is 10-25°C, more preferably 14-20°C.

[0064] The gas-liquid separation of the reaction products and the alkaline absorption of hydrogen chloride gas are all performed using operations well known to those skilled in the art, and will not be described in detail here.

[0065] All chemicals used in the following examples were purchased from Beijing Innocare Technology Co., Ltd.

[0066] The product was analyzed by gas chromatography. The gas chromatography conditions were as follows: gas chromatographic column: 0.25 μm × 0.25 mm × 30 m Innowax capillary column; FID detector; vaporization chamber temperature: 300 °C; column oven temperature: 280 °C; detector temperature: 280 °C; nitrogen flow rate: 1.0 mL / min; hydrogen flow rate: 40 mL / min; air flow rate: 400 mL / min; injection volume: 1 μL. Analytical method: relative correction factor method.

[0067] The obtained catalyst was analyzed for metal content using atomic emission spectrometry (ICP).

[0068] Example 1

[0069] This embodiment provides a method for preparing a catalyst, the specific steps of which are as follows:

[0070] Add 20g of vinylene carbonate, 600g of ethylene carbonate, and 1g of triethylamine to a 1000ml three-necked flask. Place the flask in an oil bath and control the internal temperature at 70℃. After heating for 1 hour, the solution turns completely black. Continue heating for another 2 hours and then stop heating.

[0071] Add 21g calcium chloride, 10g barium chloride, and 1.2g triethylamine hydrochloride to the flask, control the internal temperature at 85℃, and stir for 30 minutes.

[0072] Pour the material from the flask into a 3000ml open beaker, increase the temperature of the oil bath to control the internal temperature at 165℃, introduce nitrogen gas preheated to 165℃, and heat for 1 hour until the volume of the solid no longer changes. Stop heating and remove the solid.

[0073] The solid was calcined in a muffle furnace at 400℃ for 10 hours under nitrogen atmosphere to obtain the desired catalyst. The catalyst was then pressed into 3mm×3mm sheet catalysts.

[0074] Example 2

[0075] Add 20g of vinylene carbonate, 1200g of ethylene carbonate, and 0.2g of triethylamine to a 2000ml three-necked flask. Place the flask in an oil bath and control the internal temperature at 80℃. After heating for 1.5 hours, the solution turns completely black. Continue heating for another 2 hours and then stop heating.

[0076] Add 42g calcium chloride, 40g nickel chloride, 40g barium chloride, and 4g triethylamine hydrochloride to the flask, control the internal temperature at 70℃, and stir for 30 minutes.

[0077] Pour the material from the flask into a 5000ml open beaker, increase the temperature of the oil bath to 190℃, introduce nitrogen gas preheated to 190℃, and heat for 40 minutes until the volume of the solid no longer changes. Stop heating and remove the solid.

[0078] The solid was calcined in a muffle furnace at 500°C for 15 hours under nitrogen atmosphere to obtain the desired catalyst. The catalyst was then pressed into 3mm×3mm sheet catalysts.

[0079] Example 3

[0080] Add 20g of vinylene carbonate, 2000g of ethylene carbonate, and 2g of triethylamine to a 3000ml three-necked flask. Place the flask in an oil bath and control the internal temperature at 50℃. After heating for 3 hours, the solution turns completely black. Continue heating for another 2 hours and then stop heating.

[0081] Add 4.1g calcium chloride, 3g magnesium chloride, 3g copper chloride, and 0.6g triethylamine hydrochloride to the flask, maintain the internal temperature at 100℃, and stir for 30 minutes.

[0082] Pour the material from the flask into a 5000ml open beaker, increase the temperature of the oil bath to 200℃, introduce nitrogen gas preheated to 200℃, and heat for 30 minutes until the volume of the solid no longer changes. Stop heating and remove the solid.

[0083] The solid was calcined in a muffle furnace at 300°C for 15 hours under nitrogen atmosphere to obtain the desired catalyst. The catalyst was then pressed into 3mm×3mm sheet catalysts.

[0084] Example 4

[0085] Add 20g of vinylene carbonate, 100g of ethylene carbonate, and 0.1g of triethylamine to a 500ml three-necked flask. Place the flask in an oil bath and control the internal temperature at 65℃. After heating for 2 hours, the solution turns completely black. Continue heating for another 2 hours and then stop heating.

[0086] Add 4.8g of calcium oxide, 4.8g of magnesium oxide, and 0.2g of triethylamine hydrochloride to the flask, control the internal temperature at 60℃, and stir for 30 minutes.

[0087] Pour the material from the flask into a 1000ml open beaker, increase the temperature of the oil bath to 120℃, introduce nitrogen gas preheated to 120℃, heat for 90 minutes until the volume of the solid no longer changes, stop heating, and remove the solid.

[0088] The solid was calcined in a muffle furnace at 400℃ for 15 hours under nitrogen atmosphere to obtain the desired catalyst. The catalyst was then pressed into 3mm×3mm sheet catalysts.

[0089] Example 5

[0090] Add 20g of vinylene carbonate, 600g of ethylene carbonate, and 4g of triethylamine to a 1000ml three-necked flask. Place the flask in an oil bath and control the internal temperature at 75℃. After heating for 1 hour, the solution turns completely black. Continue heating for another 2 hours and then stop heating.

[0091] Add 4.4g barium oxide, 4g copper oxide, 4g nickel oxide, and 2g triethylamine hydrochloride to the flask, control the internal temperature at 80℃, and stir for 30 minutes.

[0092] Pour the material from the flask into a 5000ml open beaker, increase the temperature of the oil bath to 150℃, introduce nitrogen gas preheated to 150℃, and heat for 60 minutes until the volume of the solid no longer changes. Stop heating and remove the solid.

[0093] The solid was calcined in a muffle furnace at 400℃ for 15 hours under nitrogen atmosphere to obtain the desired catalyst. The catalyst was then pressed into 3mm×3mm sheet catalysts.

[0094] Example 6

[0095] Add 20g of vinylene carbonate, 600g of ethylene carbonate, and 1.6g of triethylamine to a 1000ml three-necked flask. Place the flask in an oil bath and control the internal temperature at 70℃. After heating for 2 hours, the solution turns completely black. Continue heating for another 2 hours and then stop heating.

[0096] Add 11g calcium chloride, 10g barium oxide, 10g magnesium oxide, and 1.4g triethylamine hydrochloride to the flask, control the internal temperature at 90℃, and stir for 30 minutes.

[0097] Pour the material from the flask into a 5000ml open beaker, raise the temperature of the oil bath to 180℃, introduce nitrogen gas preheated to 180℃, and heat for 40 minutes until the volume of the solid no longer changes. Stop heating and remove the solid.

[0098] The solid was calcined in a muffle furnace at 400℃ for 15 hours under nitrogen atmosphere to obtain the desired catalyst. The catalyst was then pressed into 3mm×3mm sheet catalysts.

[0099] Application Example 1

[0100] 20 ml of the catalyst prepared in Example 1 was added to a fixed-bed reactor with an inner diameter of 14 mm. A nitrogen purging system of 1 MPa was introduced 3-5 times, and the reactor was heated to 500 °C. Ammonia was continuously introduced for 5 hours. After stopping the ammonia supply, the reactor was cooled to 100 °C. Vinyl chloride carbonate with a purity of 98% was preheated to 100 °C and introduced into the fixed-bed reactor. The reactor pressure was controlled at 200 PaA, the fixed-bed liquid phase feed space velocity was 3 m / s, and the gas phase condensation temperature was 18 °C. After 8 hours of reaction, the reaction was stopped. Liquid was taken from the gas-liquid separator for gas phase analysis to determine the vinyl chloride carbonate concentration and calculate the vinyl chloride carbonate conversion rate. Liquid vinyl carbonate was taken from the condenser for gas phase analysis to determine its purity. The vinyl chloride carbonate conversion rate was 55%, the vinylene carbonate purity was 98.5%, and the vinylene carbonate selectivity was 99%.

[0101] Application Example 2

[0102] 20 ml of the catalyst prepared in Example 2 was added to a fixed-bed reactor with an inner diameter of 14 mm. A nitrogen purging system of 1 MPa was introduced 3-5 times, and the reactor was heated to 500 °C. Ammonia gas was continuously introduced for 5 hours. After stopping the ammonia introduction, the reactor was cooled to 120 °C. Vinyl chloride carbonate with a purity of 98% was preheated to 120 °C and introduced into the fixed-bed reactor. The reactor pressure was controlled at 500 PaA, the fixed-bed liquid phase feed space velocity was 8 m / s, and the gas phase condensation temperature was 16 °C. After 8 hours of reaction, the reaction was stopped. Liquid was taken from the gas-liquid separator for gas phase analysis to determine the vinyl chloride carbonate concentration and calculate the vinyl chloride carbonate conversion rate. Liquid vinyl carbonate was taken from the condenser for gas phase analysis to determine its purity. The vinyl chloride carbonate conversion rate was 69%, the vinylene carbonate purity was 98.1%, and the vinylene carbonate selectivity was 98.6%.

[0103] Application Example 3

[0104] 20 ml of the catalyst prepared in Example 3 was added to a fixed-bed reactor with an inner diameter of 14 mm. A nitrogen purging system of 1 MPa was introduced 3-5 times, and the reactor was heated to 450 °C. Ammonia was continuously introduced for 8 hours. After stopping the ammonia supply, the reactor was cooled to 70 °C. Vinyl chloride carbonate with a purity of 98% was preheated to 70 °C and introduced into the fixed-bed reactor. The reactor pressure was controlled at 100 PaA, the fixed-bed liquid phase feed space velocity was 0.1 m / s, and the gas phase condensation temperature was 10 °C. After 8 hours of reaction, the reaction was stopped. Liquid was taken from the gas-liquid separator for gas phase analysis to determine the vinyl chloride carbonate concentration and calculate the vinyl chloride carbonate conversion rate. Liquid vinyl carbonate was taken from the condenser for gas phase analysis to determine its purity. The vinyl chloride carbonate conversion rate was 97%, the vinylene carbonate purity was 97.7%, and the vinylene carbonate selectivity was 98%.

[0105] Application Example 4

[0106] 20 ml of the catalyst prepared in Example 4 was added to a fixed-bed reactor with an inner diameter of 14 mm. A nitrogen purging system of 1 MPa was introduced 3-5 times, and the reactor was heated to 550 °C. Ammonia was continuously introduced for 8 hours. After stopping the ammonia supply, the reactor was cooled to 130 °C. Vinyl chloride carbonate with a purity of 98% was preheated to 120 °C and introduced into the fixed-bed reactor. The reactor pressure was controlled at 50 PaA, the fixed-bed liquid phase feed space velocity was 10 m / s, and the gas phase condensation temperature was 25 °C. After 8 hours of reaction, the reaction was stopped. Liquid was taken from the gas-liquid separator for gas phase analysis to determine the vinyl chloride carbonate concentration and calculate the vinyl chloride carbonate conversion rate. Liquid vinyl carbonate was taken from the condenser for gas phase analysis to determine its purity. The vinyl chloride carbonate conversion rate was 54%, the vinylene carbonate purity was 98.1%, and the vinylene carbonate selectivity was 98.3%.

[0107] Application Example 5

[0108] 20 ml of the catalyst prepared in Example 5 was added to a fixed-bed reactor with an inner diameter of 14 mm. A nitrogen purging system of 1 MPa was introduced 3-5 times, and the reactor was heated to 500 °C. Ammonia was continuously introduced for 6 hours. After stopping the ammonia supply, the reactor was cooled to 80 °C. Vinyl chloride carbonate with a purity of 98% was preheated to 80 °C and introduced into the fixed-bed reactor. The reactor pressure was controlled at 1000 PaA, the fixed-bed liquid phase feed space velocity was 2 m / s, and the gas phase condensation temperature was 14 °C. After 8 hours of reaction, the reaction was stopped. Liquid was taken from the gas-liquid separator for gas phase analysis to determine the vinyl chloride carbonate concentration and calculate the vinyl chloride carbonate conversion rate. Liquid vinyl carbonate was taken from the condenser for gas phase analysis to determine its purity. The vinyl chloride carbonate conversion rate was 60%, the vinylene carbonate purity was 97.9%, and the vinylene carbonate selectivity was 98.1%.

[0109] Application Example 6

[0110] 20 ml of the catalyst prepared in Example 6 was added to a fixed-bed reactor with an inner diameter of 14 mm. A nitrogen purging system of 1 MPa was introduced 3-5 times, and the reactor was heated to 500 °C. Ammonia was continuously introduced for 6 hours. After stopping the ammonia supply, the reactor was cooled to 115 °C. Vinyl chloride carbonate with a purity of 98% was preheated to 115 °C and introduced into the fixed-bed reactor. The reactor pressure was controlled at 200 PaA, the fixed-bed liquid phase feed space velocity was 7 m / s, and the gas phase condensation temperature was 20 °C. After 8 hours of reaction, the reaction was stopped. Liquid was taken from the gas-liquid separator for gas phase analysis to determine the vinyl chloride carbonate concentration and calculate the vinyl chloride carbonate conversion rate. Liquid vinyl carbonate was taken from the condenser for gas phase analysis to determine its purity. The vinyl chloride carbonate conversion rate was 65%, the vinylene carbonate purity was 98.5%, and the vinylene carbonate selectivity was 98.9%.

[0111] Comparative Example 1

[0112] The reaction system used the fixed-bed reactor from Application Example 1, filled with calcium chloride and barium chloride particles with an average particle size of 8 mesh and a mass ratio of 2:1. Other conditions were the same as in Application Example 1. The conversion rate of chloroethylene carbonate was 20%, the purity of vinylene carbonate was 52%, and the selectivity of vinylene carbonate was 57%.

[0113] Comparative Example 2

[0114] The reaction system used the fixed-bed reactor from Application Example 1, filled with calcium chloride, nickel chloride, and barium chloride particles of equal mass ratio and an average particle size of 8 mesh. Other conditions were the same as in Application Example 2. The conversion rate of chloroethylene carbonate was 25%, the purity of vinylene carbonate was 55%, and the selectivity of vinylene carbonate was 61%.

[0115] Comparative Example 3

[0116] The reaction system used the fixed-bed reactor from Application Example 1, filled with calcium chloride, magnesium chloride, and copper chloride particles of average 8 mesh size in an equal mass ratio of 4:3:3. Other conditions were the same as in Application Example 3. The conversion rate of chloroethylene carbonate was 19%, the purity of vinylene carbonate was 47%, and the selectivity of vinylene carbonate was 52%.

[0117] The comparison results above show that the catalyst prepared by the present invention, using a mixture of polyvinyl carbonate and polyvinyl carbonate as a support, can more efficiently catalyze the one-step preparation of chlorovinyl carbonate to obtain vinylene carbonate.

[0118] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A catalyst for preparing vinylene carbonate, characterized in that, The catalyst comprises a support and an active component; the support is a mixture of polyvinyl carbonate and polyvinyl carbonate, and the active component is a chloride or oxide of calcium, barium, nickel, magnesium, or copper.

2. The catalyst according to claim 1, characterized in that, The mass ratio of polyvinyl carbonate to polyvinyl carbonate is 1:5 to 1:100, preferably 1:10 to 1:50; Preferably, the active component is added at a mass of 0.5% to 10% of the total mass of polyvinyl carbonate and polyvinyl carbonate, more preferably 2% to 8%.

3. A method for preparing the catalyst for preparing vinylene carbonate as described in claim 1 or 2, characterized in that, Includes the following steps: 1) Mix vinylene carbonate, ethylene carbonate, and triethylamine, and heat at temperature T1; 2) Raise the temperature to T2, add one or more active components to the mixture, and simultaneously add triethylamine hydrochloride, and stir thoroughly; 3) Raise the temperature to T3, and introduce nitrogen gas preheated to T3 into the mixed liquid. The mixed liquid will coke and form a solid precipitate. 4) The generated solid is calcined to obtain the catalyst.

4. The preparation method according to claim 3, characterized in that, In step 1), the mass ratio of vinylene carbonate to ethylene carbonate is 1:5 to 1:100, preferably 1:10 to 1:50; the mass ratio of vinylene carbonate to triethylamine is 1:0.005 to 1:0.2, preferably 1:0.02 to 1:0.

1.

5. The preparation method according to claim 3 or 4, characterized in that, In step 1), the temperature T1 is 50-80℃, preferably 65-75℃.

6. The preparation method according to claim 3, characterized in that, In step 2), the temperature T2 is 60-100℃, preferably 80-90℃.

7. The preparation method according to claim 3 or 6, characterized in that, In step 2), the active component is selected from one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, cuprous chloride, calcium oxide, barium oxide, nickel oxide, magnesium oxide, copper oxide, and cuprous oxide, preferably one or more of calcium chloride, barium chloride, nickel chloride, magnesium chloride, copper chloride, and cuprous chloride. Preferably, the added active component is 0.5% to 10% of the total mass of vinylene carbonate and ethylene carbonate, more preferably 2% to 8%; More preferably, the mass ratio of the added triethylamine hydrochloride to vinylene carbonate is 0.01:1 to 0.2:1, preferably 0.03:1 to 0.1:

1.

8. The preparation method according to claim 3, characterized in that, In step 3), the temperature T3 is 120-200℃, preferably 150-180℃; and / or In step 4), calcination is carried out in a nitrogen atmosphere at 300-500℃ for 5-30 hours.

9. A method for preparing vinylene carbonate using the catalyst according to claim 1 or 2 or the catalyst prepared by any one of claims 3-8, characterized in that, Includes the following steps: A) After preheating the liquid-phase chloroethylene carbonate, it is passed into a fixed bed containing a catalyst to carry out the dehydrochlorination reaction. B) The products after the reaction are separated into gas and liquid phases. The liquid phase is unreacted vinyl chloride carbonate, and the gas phase is vinylene carbonate and hydrogen chloride. C) After the gas phase is condensed, the vinylene carbonate is condensed into a liquid phase, and the gas phase hydrogen chloride enters the alkali absorption unit.

10. The method according to claim 9, characterized in that, In step A), after the prepared catalyst is loaded into a fixed bed, ammonia gas is introduced at 400-600℃ for 2-10 hours, preferably at 450-550℃ for 5-8 hours. Preferably, in step A), the preheating temperature of ethylene chlorocarbonate is 80-120℃, more preferably 90-110℃; the feed space velocity of ethylene chlorocarbonate is 0.1-10m / s, more preferably 2-7m / s. Preferably, the reaction temperature in step A) is 70-130℃, more preferably 80-115℃; the pressure is 50PaA-1000PaA, more preferably 100PaA-500PaA. Preferably, the condensation temperature in step C) is 10-25℃, more preferably 14-20℃.