A supergravity ethylene oxide continuous production ethylene carbonate system and method

Abstract

This invention relates to a continuous process for preparing ethylene carbonate from ethylene oxide using a centrifugal reactor, comprising a falling film reactor, a centrifugal reactor, a gas-liquid separator, a ethylene carbonate storage tank, a condenser, a vacuum pump, and a heater. The falling film reactor is connected to the centrifugal reactor, the gas-liquid separator is connected to both the centrifugal reactor and the falling film reactor, the gas-liquid separator is connected to the condenser, and the condenser is connected to the ethylene carbonate storage tank. This invention innovatively combines a centrifugal reactor with a falling film reactor, allowing for uniform dispersion and rapid dehydration of the liquid flowing out of the falling film. Crucially, the centrifugal reactor design eliminates the need for external heating, further reducing liquid temperature and minimizing side reactions. Under the process conditions of this invention, the conversion rate of ethylene oxide is >99%, and the selectivity of ethylene carbonate is >99.5%, exhibiting significant advantages such as low energy consumption, fewer byproducts, and high production efficiency.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a system and method for the continuous preparation of ethylene carbonate from ethylene oxide under ultragravity. Background Technology

[0002] Ethylene carbonate (EC), with the molecular formula C3H4O3 and chemical name 1,3-dioxane, also known as ethylene carbonate or ethylene glycol carbonate, is a high-performance solvent and organic synthesis intermediate, and a potential fundamental raw material for the organic chemical industry. In recent years, researchers both domestically and internationally have developed a series of high-value-added fine chemicals using EC as a raw material, such as dimethyl carbonate, ethylene glycol, polycarbonate, and high-energy electrolytes. These are considered fundamental raw materials for green organic chemicals in the new century, with enormous market potential.

[0003] Synthetic methods for producing EC both domestically and internationally include the phosgene method, transesterification method, haloalcohol method, urea alcoholysis method, direct oxidation of ethylene with CO2, and CO2 cycloaddition method. In terms of applications, it is mainly used in battery electrolytes, ester intermediates, fertilizers, fibers, pharmaceuticals, and organic synthesis industries.

[0004] The continuous production process of ethylene oxide to ethylene carbonate using carbon dioxide primarily involves cycloaddition / esterification reactions, coupling the unstable three-membered ring structure EO with CO2 under certain pressure and catalyst conditions to generate the more stable EC. Patent CN1699359A discloses a clean production process for cyclic alkyl carbonates, characterized by the synthesis of cyclic alkyl carbonates from epoxides and carbon dioxide. While the reaction conditions are mild using this method, two side reactions occur simultaneously with the EO ring-opening addition reaction to generate EC due to the presence of water in the system. Therefore, this process requires careful control of the water content during the reaction. Furthermore, relevant thermodynamic data show that the equilibrium conversion rate of EO is essentially unaffected by thermodynamics and can reach 100% when the reaction temperature is below 130℃. However, when the reaction temperature is further increased to above 150℃, the equilibrium conversion rate of EO decreases significantly.

[0005] Based on the above, developing a method to achieve rapid and uniform heat supply and water content separation in the ethylene carbonate reaction process is crucial. This is of great significance for the conversion rate of ethylene oxide and the selectivity of ethylene carbonate. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention specifically relates to a system and method for the continuous preparation of ethylene carbonate from ethylene oxide under centrifugal conditions. This invention enables rapid and uniform heating and separation of water content during the reaction process, maintaining uniform dispersion of ethylene oxide in the gas phase and avoiding excessively high local concentrations during heating.

[0007] The primary objective of this invention is to provide a continuous process for preparing ethylene carbonate from ethylene oxide under hypergravity conditions, comprising a falling film assembly, a hypergravity assembly, a gas-liquid separator, an ethylene carbonate storage tank, and a condenser.

[0008] The falling film assembly is connected to the hypergravity assembly, the gas-liquid separator is connected to the hypergravity assembly, the bottom of the gas-liquid separator is connected to the falling film assembly via a pipeline, the top of the gas-liquid separator is connected to the condenser via a pipeline, and the condenser is connected to the ethylene carbonate storage tank.

[0009] Preferably, the system further includes a vacuum pump, which is located on the pipeline connecting the gas-liquid separator and the falling film assembly.

[0010] Preferably, a heater is also connected to the top of the falling film assembly.

[0011] In a preferred embodiment of the present invention, the falling film assembly consists of a falling film tube, a temperature control unit, a pressure sensor, a sealing door, and a driver. The temperature control unit, the pressure sensor, and the sealing door for opening and closing the inlet are provided at the inlet of the falling film assembly. The sealing door is connected to the driver, and the driver is electrically connected to the pressure sensor. The falling film tube is provided below the driver.

[0012] Preferably, the falling film tube adopts a sleeve structure, and the heat exchange fluid is introduced into the sleeve of the falling film tube; there are several falling film tubes, and a jacket is provided outside the falling film tube for heat exchange to heat the fluid.

[0013] The supergravity component consists of a shell, a cutting unit located inside the shell cavity, and a rotating unit.

[0014] Furthermore, the cutting unit is fixed on the rotating unit, which consists of a rotating shaft, a turntable, and a fluid distributor; the rotating shaft passes through the turntable, and the cutting unit is fixed on the turntable; the fluid distributor is connected to the liquid outlet of the falling film assembly to form a fluid channel; the fluid distributor is arranged around the rotating shaft.

[0015] The fluid distributor is provided with multiple branch pipes, which are arranged toward the cutting unit and have multiple openings. The surface of the cutting unit is coated with a hydrophobic coating.

[0016] Another object of this invention is to claim protection for a method for the continuous preparation of ethylene carbonate from ethylene oxide under ultragravity, comprising:

[0017] Step 1: The reactants ethylene oxide, catalyst, and carbon dioxide are introduced into the falling film assembly to obtain a gas-liquid mixture;

[0018] Step 2: The gas-liquid mixture is introduced into the hypergravity component to react and obtain the reaction products;

[0019] Step 3: Perform gas-liquid separation on the reaction product to obtain ethylene carbonate.

[0020] The process conditions are: reaction temperature 130-135℃, pressure 1.0-1.2MPa, catalyst dosage 1.8-2‰, and reaction time 4.5-5.5h.

[0021] Furthermore, in step 3, the reaction products in the hypergravity component enter the gas-liquid separator for gas-liquid separation. Ethylene oxide and carbon dioxide, after passing through the separation components in the gas-liquid separator, are returned to the falling film component by a vacuum pump to continue being used as raw materials. Ethylene carbonate, on the other hand, passes through a condenser to obtain the target product, which then enters the ethylene carbonate storage tank.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention discloses a continuous process system and method for preparing ethylene carbonate from ethylene oxide using a supergravity reactor. This system innovatively combines a supergravity reactor with a falling film reactor. The supergravity reactor allows for further uniform dispersion and rapid dehydration of the liquid flowing out of the falling film. Crucially, the supergravity reactor design eliminates the need for external heating, further reducing liquid temperature and minimizing side reactions caused by prolonged residence time after the material enters the gas-liquid separator. Under these process conditions, the conversion rate of ethylene oxide is >99%, and the selectivity of ethylene carbonate is >99.5%, exhibiting significant advantages such as low energy consumption, fewer byproducts, and high production efficiency. Furthermore, this invention enables continuous production; the inlet automatically opens when the reactants reach it, ensuring stable operation and high safety. This innovation not only improves production efficiency but also significantly enhances the commercial value and market competitiveness of the product, opening up new avenues for the industrial application of ethylene oxide conversion to ethylene carbonate. Attached Figure Description

[0024] Figure 1a This is a schematic diagram of the apparatus for continuous preparation of ethylene carbonate from ethylene oxide under ultragravity in an embodiment of the present invention.

[0025] Figure 1b This is a schematic diagram of the specific structure of the falling film assembly in an embodiment of the present invention;

[0026] Figure 1c This is a schematic diagram of the specific structure of the hypergravity component in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram illustrating the reaction principle of continuous preparation of ethylene carbonate from ethylene oxide in an embodiment of the present invention.

[0028] Figure 3 The infrared spectrum of ethylene carbonate in an embodiment of the present invention;

[0029] Figure 4 The above are the hydrogen NMR and carbon NMR spectra of ethylene carbonate in the embodiments of the present invention.

[0030] Figure 5 The images show the mass spectra of the ethylene carbonate standard and the prepared product in the embodiments of the present invention.

[0031] Among them, 1. Falling film assembly, 2. Ultragravity assembly, 3. Gas-liquid separator, 4. Vacuum pump, 5. Heater, 6. Ethylene carbonate storage tank, 7. Condenser;

[0032] 101. Temperature control unit; 102. Pressure sensor; 103. Sealing door; 104. Actuator; 105. Falling film tube;

[0033] 201. Cutting unit; 202. Turntable; 203. Rotating shaft; 204. Fluid distributor. Detailed Implementation

[0034] To more clearly illustrate the objectives, technical solutions, and advantages of this invention, the following detailed description of the invention will be provided in conjunction with embodiments. It should be understood that the following description of the embodiments is intended to explain and illustrate the overall concept of the invention and should not be construed as limiting this disclosure.

[0035] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are used solely for the convenience and simplicity of describing this disclosure, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only to distinguish different components and should not be construed as indicating or implying relative importance. The word "a" or "an" does not exclude multiple components. Words such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0036] Furthermore, the technical features involved in the different embodiments of this disclosure described below can be combined with each other as long as they do not conflict with each other.

[0037] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains.

[0038] The inventive concept of this invention is as follows:

[0039] EO (Electrodeionate) is coupled with CO2 to synthesize EC (Extracorporeal Electrolyte). CO2 is a nonpolar molecule with weak acidity and can donate protons. The reaction between CO2 and EO is a nucleophilic addition reaction, proceeding according to the nucleophilic addition mechanism. The catalyst acts as a nucleophile (denoted as Nu). The reaction proceeds in three steps: the nucleophilic center of the catalyst attacks the carbon atom of EO bonded to oxygen, causing ring opening and forming transition state I; subsequently, CO2 inserts into the carbon atom to form carbonate transition state II; and transition state II then undergoes intramolecular anti-addition to form EC. The reaction process is as follows:

[0040]

[0041] Where I represents the transition state -O-CH2-CH2-Nu:, and II represents the transition state Nu-CH2-CH2-O-CO-O-. The formation of transition states I and II in the process is the slow step of the reaction and is the determining step of the entire reaction.

[0042] If the equilibrium constants of the two-step reaction are set as k1 and k2 respectively, then the calculation formulas are as shown in equation (1) and equation (2).

[0043] c I =k1c EO c Cat (1)

[0044]

[0045] In the formula, c is the concentration of the substance.

[0046] The process of transition state II generating EC is a reversible reaction. Let the equilibrium constants be k3+ and k3-, respectively. Then the reaction rate equation is:

[0047]

[0048] Substituting into equations (1) and (2), we get:

[0049]

[0050] Since the forward reaction rate is much greater than the reverse reaction rate, the effect of the reverse reaction can be ignored, resulting in:

[0051]

[0052] Considering the continuous replenishment of CO2 during the reaction process and its thorough mixing with the reaction solution, the concentration of dissolved CO2 can be regarded as a constant. Furthermore, the volume change during the reaction is relatively small, thus it can be considered a constant-volume process. The catalyst concentration remains constant and can also be regarded as a constant. Therefore, let...

[0053]

[0054] Equation (5) can be simplified to:

[0055] r = kc EO (7)

[0056] and

[0057]

[0058] In the formula, n is the amount of substance, V is the volume, and t is the time.

[0059] Then there is

[0060]

[0061] so

[0062]

[0063] Integrating (10) yields:

[0064]

[0065] Let x be the EO conversion rate, then n(EO) = n0(EO)(1-x), substituting into equation (10) yields:

[0066]

[0067] Possible side reactions include:

[0068] EO + H2O → EG

[0069] EG+EG→DEG

[0070] EC + H₂O → EG + CO₂

[0071] Table 1. Heat of reaction for main and side reactions

[0072]

[0073] Therefore, achieving rapid and uniform heat supply and water separation during the reaction process are crucial. Furthermore, the reaction process should strive to maintain a uniform dispersion of ethylene oxide in the gas phase to avoid excessively high local concentrations during heating.

[0074] The catalyst used in this invention is an ionic liquid catalyst, preferably the catalyst described in patent CN 105642343A, and the amount of catalyst used is 1.8-2‰ of the mass concentration in the final output.

[0075] Example 1

[0076] like Figure 1aAs shown, this invention provides a continuous process system for preparing ethylene carbonate from ethylene oxide under hypergravity. The system includes: a falling film assembly 1, a hypergravity assembly 2, a gas-liquid separator 3, a vacuum pump 4, a heater 5, an ethylene carbonate storage tank 6, and a condenser 7. The liquid outlet of the falling film assembly 1 is connected to the liquid inlet of the hypergravity assembly 2. The gas-liquid separator 3 is connected to the hypergravity assembly 2, and its bottom is connected to the falling film assembly 1 via a pipeline. The vacuum pump 4 is installed on this pipeline. A pipeline at the top of the gas-liquid separator 3 connects to the condenser 7, which is connected to the ethylene carbonate storage tank 6. The heater 5 is connected to the top of the falling film assembly 1.

[0077] The reaction products in the supergravity component 2 enter the gas-liquid separator 3, where the reaction products can be separated into gas and liquid. Ethylene oxide and carbon dioxide, after passing through the separation components in the gas-liquid separator 3, return to the falling film component 1 via the vacuum pump 4 to continue to be used as raw materials. Ethylene carbonate, on the other hand, passes through the condenser 7 to obtain the target product, which then enters the ethylene carbonate storage tank 6.

[0078] Example 2

[0079] like Figure 1b As shown, the falling film assembly 1 of the present invention comprises a falling film tube 105, a temperature control unit 101, a pressure sensor 102, a sealing door 103, and a driver 104. Ethylene oxide, a catalyst, and heated carbon dioxide are introduced into the inlet of the falling film assembly 1. The ethylene oxide, catalyst, and carbon dioxide mix within the falling film assembly 1 to form a gas-liquid mixture. The temperature control unit 101 is installed at the inlet of the falling film assembly 1 to control the reaction temperature of the ethylene oxide, catalyst, and carbon dioxide. A pressure sensor is also installed at the inlet of the falling film assembly. The system includes a sensor 102 and a sealing door 103 for opening and closing the inlet. The sealing door 103 is connected to an actuator 104, which drives the inlet to open and close. The actuator 104 is electrically connected to the pressure sensor 102 and drives the sealing door 103 to open the inlet in response to a pressure signal from the pressure sensor 102. A falling film tube is located below the actuator 104. The falling film tube has a sleeve structure, allowing heat exchange fluid to be introduced into the sleeve, thereby controlling the temperature of the reactants ethylene oxide, catalyst, and carbon dioxide within the falling film tube. One or more falling film tubes 105 are included. Each falling film tube 105 has an external jacket for heat exchange, heating the fluid (reaction temperature controlled between 130-140°C).

[0080] Example 3

[0081] like Figure 1cAs shown, the hypergravity component 2 of the present invention can introduce the gas-liquid mixture, which reacts within the hypergravity component 2 to obtain the reaction product ethylene carbonate. The hypergravity component 2 consists of a shell, a cutting unit 201 disposed within the shell cavity, and a rotating unit. The cutting unit 201 is fixed to the rotating unit and is used to shear the gas-liquid mixture introduced therein to form fluid micro-elements. The rotating unit consists of a rotating shaft 203, a turntable 202, and a fluid distributor 204. The rotating shaft 203 passes through the turntable 202, and the cutting unit 201 is fixed to the turntable 202. The fluid distributor 204 is connected to the liquid outlet of the falling film component 1 to form a fluid channel. The fluid distributor 204 is arranged around the rotating shaft 203 and has multiple branch pipes on it. The branch pipes face the cutting unit 201 and have multiple openings on them. The surface of the cutting unit 201 is coated with a hydrophobic coating.

[0082] The gas-liquid separator 3 is connected to the hypergravity component 2. The reaction products in the hypergravity component 2 enter the gas-liquid separator 3, where the reaction products can be separated into gas and liquid. Ethylene oxide and carbon dioxide are returned to the falling film component via a vacuum pump after passing through the separation component and are used as raw materials. Ethylene carbonate is then processed through the condenser 7 to obtain the target product, which enters the ethylene carbonate storage tank 6.

[0083] Example 4

[0084] A system for the continuous production of ethylene carbonate from ethylene oxide under centrifugal force includes: a falling film assembly 1, a centrifugal assembly 2, a gas-liquid separator 3, a vacuum pump 4, a heater 5, an ethylene carbonate storage tank 6, and a condenser 7. The liquid outlet of the falling film assembly 1 is connected to the liquid inlet of the centrifugal assembly 2. The gas-liquid separator 3 is connected to the centrifugal assembly 2, and its bottom is connected to the falling film assembly 1 via a pipeline. The vacuum pump 4 is installed on this pipeline. A pipeline at the top of the gas-liquid separator 3 connects to the condenser 7, which is connected to the ethylene carbonate storage tank 6. The heater 5 is connected to the top of the falling film assembly 1.

[0085] A temperature control unit 101, a pressure sensor 102, and a closing door 103 for opening and closing the inlet are provided at the inlet of the falling film assembly 1. The closing door 103 is connected to a driver 104, which drives the opening and closing of the inlet. The driver 104 is electrically connected to the pressure sensor 102. A falling film tube with a sleeve structure is provided below the driver 104. The falling film tube 105 includes one or more tubes. The falling film tube 105 is externally equipped with a jacket for heat exchange.

[0086] The supergravity component 2 consists of a shell, a cutting unit 201 disposed in the inner cavity of the shell, and a rotating unit. The cutting unit 201 is fixed on the rotating unit, which consists of a rotating shaft 203, a turntable 202, and a fluid distributor assembly 204. The rotating shaft 203 passes through the turntable 202, and the cutting unit 201 is fixed on the turntable 202. The fluid distributor 204 is connected to the liquid outlet of the falling film component 1 to form a fluid channel. The fluid distributor 204 is arranged around the rotating shaft 203 and has multiple branch pipes on it. The branch pipes are arranged towards the cutting unit 201 and have multiple openings on them. The surface of the cutting unit 201 is coated with a hydrophobic coating.

[0087] The gas-liquid separator 3 is connected to the hypergravity component 2. The reaction products in the hypergravity component 2 enter the gas-liquid separator 3. The bottom of the gas-liquid separator 3 is connected to the falling film component 1 through a pipeline. A vacuum pump 4 is installed on the pipeline. Ethylene oxide and carbon dioxide return to the falling film component after passing through the separation component and are used as raw materials again. A pipeline is installed at the top of the gas-liquid separator 3 to connect to the condenser 7. The condenser 7 is connected to the ethylene carbonate storage tank 6. The ethylene carbonate passes through the condenser 7 to obtain the target product and enters the ethylene carbonate storage tank 6.

[0088] Example 5

[0089] This invention also provides a method for the continuous preparation of ethylene carbonate from ethylene oxide under supergravity conditions, comprising:

[0090] The reactants, ethylene oxide, catalyst, and carbon dioxide, are introduced into a falling film assembly to obtain a gas-liquid mixture.

[0091] The gas-liquid mixture is introduced into the hypergravity component to react, and reaction products are obtained.

[0092] The reaction product was subjected to gas-liquid separation to obtain ethylene carbonate.

[0093] The preparation method has the following process conditions: reaction temperature 130-135℃, pressure 1.0-1.2MPa, catalyst dosage 1.8-2‰, and reaction time 4.5-5.5h.

[0094] The present invention provides a continuous process for preparing ethylene carbonate from ethylene oxide using a supergravity reactor. This process combines a supergravity reactor with a falling film reactor. The supergravity reactor allows for further uniform dispersion and rapid dehydration of the liquid exiting the falling film. Simultaneously, the supergravity reactor eliminates the need for heating, further reducing the liquid temperature and minimizing side reactions after the material enters the gas-liquid separator (where the residence time is relatively long). A specially designed gas-liquid mixing feed distributor ensures the liquid in the falling film section is dispersed as uniformly as possible, while precise temperature control further reduces the occurrence of side reactions.

[0095] The reaction pressure was controlled at 1.2 MPa, the catalyst concentration at 2‰, and the reaction temperature was adjusted for the experiment. The reaction pressure was kept constant, and the EO feed rate was increased. The critical value at which the instantaneous CO2 rate could be equal to the EO rate was the maximum EO feed rate. The EO rate was adjusted to keep the cumulative difference between EO and CO2 not exceeding 2% of the EO feed amount until the aging was completed. The total reaction time was recorded, and the catalyst activity was calculated and compared with the maximum EO feed rate (the number of grams of EC synthesized per hour per gram of catalyst was regarded as the catalyst activity). In addition, the reaction sample was taken for gas chromatography to analyze the EC content.

[0096] The catalyst activity was 99.0 g / g·h at 115℃, 114.8 g / g·h at 135℃, and reached 118.5 g / g·h at 155℃. The catalytic activity gradually increased with increasing temperature, but the increasing trend gradually decreased. The total reaction time was 346 min at 115℃, 303 min at 135℃, and reached 291 min at 155℃. The total reaction time gradually decreased with increasing temperature, and the decreasing trend gradually diminished, matching the maximum EO feed rate. Gas-phase results showed that the EC content was greater than 99.8% below 135℃. However, with further temperature increases, trace amounts of water in the system reacted with EO to form ethylene glycol and even diethylene glycol, leading to a decrease in EC selectivity. The EC content dropped to 99.5% at 145℃ and to 98.9% at 155℃.

[0097] Example 6

[0098] Using the reaction system as described in Example 4, the reaction temperature was controlled at 135°C and the catalyst concentration at 2‰. Experiments were conducted under different reaction pressures, maintaining a constant reaction pressure. The EO feed rate was increased, and the critical value at which the instantaneous CO2 rate could match the EO rate was the maximum EO feed rate. The EO rate was adjusted to keep the cumulative difference between EO and CO2 not exceeding 2% of the EO feed amount until aging was completed. The total reaction time was recorded, and the catalyst activity was calculated and compared using the maximum EO feed rate (the number of grams of EC synthesized per hour per gram of catalyst was considered as the catalyst activity). In addition, the post-reaction sample was taken for gas chromatography analysis to determine the EC content.

[0099] The catalyst activity was 111.0 g / g·h at 1.0 MPa, 114.8 g / g·h at 1.2 MPa, 115.5 g / g·h at 1.4 MPa, and 116.3 g / g·h at 1.8 MPa. The reaction could proceed at pressures as low as 1.0 MPa, but due to the partial pressure in the gas phase space caused by the oxygen-liquid equilibrium, the CO2 content was insufficient, resulting in low reaction activity, accumulation of EO concentration, and increased side reactions. The EC content in the reaction products was 99.4%, indicating a significant increase in byproducts. Increasing the pressure to 1.2 MPa significantly improved the reaction activity, raising the EC content to 99.8%. Further increases in pressure above 1.6 MPa had little impact on the reaction activity and EC selectivity, demonstrating sufficient gas-liquid mixing in the reactor, thus eliminating CO2 concentration as a limiting factor.

[0100] Example 7

[0101] Using the reaction system as described in Example 4, the reaction temperature was controlled at 135°C and the reaction pressure at 1.2 MPa. Experiments were conducted at different catalyst concentrations, while maintaining a constant reaction pressure. The EO feed rate was increased, and the critical value at which the instantaneous CO2 rate could match the EO rate was the maximum EO feed rate. The EO rate was adjusted to keep the cumulative difference between EO and CO2 not exceeding 2% of the EO feed amount until aging was completed. The total reaction time was recorded, and the catalyst activity was calculated and compared using the maximum EO feed rate (the number of grams of EC synthesized per hour per gram of catalyst was considered as catalyst activity). In addition, the post-reaction samples were subjected to gas chromatography to analyze the EC content.

[0102] Increasing the catalyst concentration significantly improves the reaction activity. The catalyst activity is 64.5 g / g·h at 1‰, 114.8 g / g·h at 2‰, 138.8 g / g·h at 3‰, and 150.8 g / g·h at 4‰. However, the reduction in reaction time is relatively small after the concentration reaches 3‰, and side reactions occur. The EC content is 99.3% at 3‰ and 98.5% at 4‰, with a significant increase in by-products. Insufficient catalyst can also lead to EO accumulation and increased impurities.

[0103] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-gravity ethylene oxide continuous system for the production of ethylene carbonate, characterized in that, It includes a falling film assembly (1), a supergravity assembly (2), a gas-liquid separator (3), a ethylene carbonate storage tank (6), and a condenser (7); Among them, the falling film assembly (1) is connected to the supergravity assembly (2), the gas-liquid separator (3) is connected to the supergravity assembly (2), the gas-liquid separator (3) is connected to the falling film assembly (1) through a pipeline, the gas-liquid separator (3) is connected to the condenser (7) through a pipeline, and the condenser (7) is connected to the ethylene carbonate storage tank (6).

2. The system of claim 1, wherein, The system also includes a vacuum pump (4), which is located on the pipeline connecting the gas-liquid separator (3) and the falling film assembly (1).

3. The system of claim 1, wherein, A heater (5) is also connected to the top of the falling film assembly (1).

4. The system of claim 1, wherein, The falling film assembly (1) consists of a falling film tube (105), a temperature control unit (101), a pressure sensor (102), a sealing door (103), and a driver (104). The temperature control unit (101), the pressure sensor (102), and the sealing door (103) for opening and closing the inlet are provided at the inlet of the falling film assembly (1). The sealing door (103) is connected to the driver (104), and the driver (104) is electrically connected to the pressure sensor (102). The falling film tube is provided below the driver (104).

5. The system of claim 4, wherein, The falling film tube (105) adopts a sleeve structure, and the heat exchange fluid is introduced into the sleeve of the falling film tube (105); there are several falling film tubes (105), and a jacket is provided outside the falling film tube (105) for heat exchange to heat the fluid.

6. The system of claim 1, wherein, The supergravity component (2) consists of a shell, a cutting unit (201) located in the inner cavity of the shell, and a rotating unit.

7. The system of claim 6, wherein, The cutting unit (201) is fixed on the rotating unit, which consists of a rotating shaft (203), a turntable (202), and a fluid distributor (204). The rotating shaft (203) passes through the turntable (202), and the cutting unit (201) is fixed on the turntable (202). The fluid distributor (204) is connected to the liquid outlet of the falling film assembly (1) to form a fluid channel. The fluid distributor (204) is arranged around the rotating shaft (203).

8. The system of claim 7, wherein, The fluid distributor (204) is provided with several branch pipes, which are arranged toward the cutting unit (201) and have multiple openings. The surface of the cutting unit (201) is coated with a hydrophobic coating.

9. A method for continuous preparation of ethylene carbonate from ethylene oxide under ultragravity conditions, comprising: Step 1: The reactants ethylene oxide, catalyst and carbon dioxide are introduced into the falling film assembly (1) to obtain a gas-liquid mixture; Step 2: The gas-liquid mixture is introduced into the hypergravity component (2) for reaction to obtain the reaction product; Step 3: Perform gas-liquid separation on the reaction product to obtain ethylene carbonate; The process conditions are: reaction temperature 130-135℃, pressure 1.0-1.2MPa, catalyst dosage 1.8-2‰, and reaction time 4.5-5.5h.

10. The system of claim 8, wherein, In step 3, the reaction products in the supergravity component (2) enter the gas-liquid separator (3) to separate the reaction products into gas and liquid. Ethylene oxide and carbon dioxide are separated by the separation components in the gas-liquid separator (3) and then returned to the falling film component (1) by the vacuum pump (4) to continue to be used as raw materials. Ethylene carbonate is then separated by the condenser (7) to obtain the target product and enter the ethylene carbonate storage tank (6).

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