Production device and method for synthesizing methyl ethyl carbonate by gas phase using ethanol and dimethyl carbonate as raw materials

Abstract

The application discloses a production device for gaseous synthesis of methyl ethyl carbonate by using ethanol and dimethyl carbonate as raw materials, which comprises a vaporizer for vaporizing ethanol and dimethyl carbonate liquid raw materials; a catalytic gaseous reactor for catalyzing gaseous reaction of ethanol and dimethyl carbonate; a rough separation tower for separating gaseous reaction products and extracting methyl ethyl carbonate crude product at the bottom of the tower; and a methyl ethyl carbonate tower for purifying the methyl ethyl carbonate crude product and extracting methyl ethyl carbonate at the top of the tower. Compared with the prior art, the application has the advantages of less catalyst damage, easy recovery and regeneration after inactivation, less reverse reaction and side reaction, high production capacity and high product purity.

Description

Technical Field

[0001] This invention relates to the field of methyl ethyl carbonate production, and more specifically to a production apparatus and method for gas-phase synthesis of methyl ethyl carbonate using ethanol and dimethyl carbonate as raw materials. Background Technology

[0002] Ethyl methyl carbonate is a colorless, transparent liquid, insoluble in water, and can be used in organic synthesis. It is an excellent solvent for lithium-ion battery electrolytes. Ethyl methyl carbonate can be synthesized by transesterification of dimethyl carbonate and ethanol under acidic or alkaline catalysts.

[0003] There are two main types of production facilities that synthesize ethyl methyl carbonate from ethanol and dimethyl carbonate:

[0004] 1. Fixed-bed process: This reactor uses a liquid-phase reaction with sodium methoxide or a solid alkali salt as the catalyst. The reaction liquid enters the first column to extract methanol, ethanol, and dimethyl carbonate. The bottom of the column contains methyl ethyl carbonate and diethyl carbonate. The bottom material enters the second column, where methyl ethyl carbonate is extracted at the top and diethyl carbonate remains at the bottom.

[0005] The disadvantages of this process are: 1) The catalyst is easily broken when immersed in liquid for a long time, and the broken catalyst increases the separation cost; 2) The environmental disposal cost after catalyst deactivation is relatively high; 3) The reaction device is operated intermittently, resulting in low production efficiency; 4) Because the reaction is reversible and side reactions occur, the raw materials and reactants will remain in the reaction device for a long time, which will lead to a decrease in product yield, an increase in the amount of by-products, and relatively high production costs; 5) The extract at the top of the first column is a mixture, with a narrow application range and low utilization value; 6) The remaining diethyl carbonate at the bottom of the second column contains impurities and has low utilization value.

[0006] 2. Catalytic distillation reaction process: This reaction device uses a liquid-phase reaction, with sodium methoxide or resin as the catalyst. A mixture of methanol, ethanol, and dimethyl carbonate is extracted from the top of the distillation unit; this extract is not further separated or purified. The reaction liquid from the bottom of the distillation unit enters the first column to extract the remaining methanol, ethanol, and dimethyl carbonate. Ethyl methyl carbonate and diethyl carbonate remain at the bottom of the first column. This bottom material enters the second column, where ethyl methyl carbonate is extracted from the top, and diethyl carbonate remains at the bottom.

[0007] The disadvantages of this process are: 1) The catalyst is easily broken due to long-term immersion in liquid, and the broken catalyst increases the separation cost; 2) The environmental disposal cost after catalyst deactivation is relatively high; 3) In order to protect the catalyst, the temperature of the reaction device must not exceed 120℃, so the reaction rate is slow, the probability of reverse reaction or side reaction is high, and the product purification cost is high; 4) Methanol, ethanol, and dimethyl carbonate remain at the bottom of the reaction device; 5) The extract at the top of the first column is a mixture, with a narrow application range and low utilization value; 6) The diethyl carbonate remaining at the bottom of the second column contains impurities and has low utilization value. Summary of the Invention

[0008] In view of the shortcomings of the above-mentioned fixed-bed or catalytic distillation process for producing ethyl methyl carbonate, such as the easy breakage of catalysts and the high cost of disposal after deactivation, one of the objectives of this invention is to provide a production apparatus for gas-phase synthesis of ethyl methyl carbonate using ethanol and dimethyl carbonate as raw materials.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A production apparatus for the gas-phase synthesis of ethyl methyl carbonate from ethanol and dimethyl carbonate includes:

[0011] A vaporizer is used to vaporize liquid feedstocks such as ethanol and dimethyl carbonate.

[0012] A catalytic gas-phase reactor used to enable a catalytic gas-phase reaction between ethanol and dimethyl carbonate;

[0013] A crude separation column is used to separate and extract crude methyl ethyl carbonate from the gas-phase reaction products at the bottom of the column;

[0014] The methyl ethyl carbonate column is used to purify crude methyl ethyl carbonate and extract methyl ethyl carbonate at the top of the column.

[0015] Preferably, the production apparatus further includes a mixer for mixing ethanol and dimethyl carbonate liquid raw materials.

[0016] Preferably, the coarse separation tower is a packed tower, and a condenser 401 and a vacuum pump are configured at the top of the tower.

[0017] Preferably, the methyl ethyl carbonate tower is a packed tower, with a vacuum pump at the top and a reboiler at the bottom.

[0018] Preferably, the production apparatus further includes:

[0019] A methanol column is used to separate the material extracted from the top of the crude fractionation column. Methanol and dimethyl carbonate are extracted from the top of the methanol column, and ethanol is extracted from the bottom of the methanol column.

[0020] The diethyl carbonate column is used to purify the material extracted from the bottom of the methyl ethyl carbonate column and to extract diethyl carbonate from the top of the diethyl carbonate column.

[0021] Preferably, the methanol tower is a packed tower with a reboiler at the bottom.

[0022] Preferably, the diethyl carbonate tower is a packed tower, with a vacuum pump at the top and a reboiler at the bottom.

[0023] A catalytic gas-phase reactor for the above-mentioned production apparatus, the catalytic gas-phase reactor comprising several reaction chambers, wherein,

[0024] Each reaction chamber is equipped with a support plate for placing the catalyst;

[0025] Each reaction chamber is equipped with an outer jacket located on the reaction chamber wall and a heating pipe that runs through the interior of the reaction chamber.

[0026] Preferably, the main body of the heating tube is substantially coaxial with the central axis of the reaction chamber.

[0027] Preferably, the outer jacket and heating tube are heated by steam at 180°C, and each reaction chamber is equipped with an independent temperature control interlocking system.

[0028] Preferably, the reaction chamber is erected and fixed on the skirt base, the feed inlet is located at the bottom of the reaction chamber, and the discharge outlet is located at the top of the reaction chamber.

[0029] Preferably, the reaction chamber has three sections.

[0030] The second objective of this invention is to provide a method for the gas-phase synthesis of ethyl methyl carbonate using ethanol and dimethyl carbonate as raw materials.

[0031] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0032] A method for gas-phase synthesis of ethyl methyl carbonate using ethanol and dimethyl carbonate as raw materials includes the following steps:

[0033] (1) Use a vaporizer to vaporize the liquid raw materials ethanol and dimethyl carbonate;

[0034] (2) The vaporized ethanol and dimethyl carbonate are fed into a catalytic gas phase reactor to undergo a catalytic gas phase reaction;

[0035] (3) The gas-phase reaction products are sent to a crude separation tower for separation, and crude methyl ethyl carbonate is extracted from the bottom of the tower;

[0036] (4) The crude methyl ethyl carbonate is fed into the methyl ethyl carbonate tower for purification, and methyl ethyl carbonate is extracted from the top of the tower.

[0037] Preferably, the ethanol and dimethyl carbonate liquid raw materials are mixed and then fed into a vaporizer at a vaporization temperature of 180°C, and the molar ratio of ethanol to dimethyl carbonate liquid raw materials is 1.1 to 1.4:1.

[0038] Preferably, the temperature of the catalytic gas-phase reaction is 160°C.

[0039] Preferably, the bottom temperature of the coarse fractionation column is 90°C, the top temperature is 70°C, and it operates under negative pressure.

[0040] Preferably, the bottom temperature of the methyl ethyl carbonate column is 110°C, the top temperature is 90°C, and it operates under negative pressure.

[0041] Preferably, the method further includes the following steps:

[0042] A mixture of methanol, ethanol and dimethyl carbonate is extracted from the top of the crude fractionation column and then fed into the methanol column for separation. Methanol and dimethyl carbonate are extracted from the top of the methanol column, and ethanol is extracted from the bottom of the methanol column.

[0043] Diethyl carbonate crude product is extracted from the bottom of the methyl ethyl carbonate column and then sent to a diethyl carbonate column for purification. Diethyl carbonate is then extracted from the top of the diethyl carbonate column.

[0044] Preferably, the methanol tower has a bottom temperature of 70°C and a top temperature of 65°C, and operates at atmospheric pressure.

[0045] Preferably, the diethyl carbonate column has a bottom temperature of 125°C and a top temperature of 100°C, and operates under negative pressure.

[0046] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0047] 1) It avoids the softening and pulverization problems caused by liquid reaction with the catalyst, significantly reducing losses. After deactivation, it is easy to recycle and regenerate, greatly reducing environmental disposal costs.

[0048] 2) It can maximize the reaction temperature, ensuring the catalyst's effectiveness, and thus improve the reaction rate and product yield;

[0049] 3) The equipment enables continuous production, which increases capacity and reduces investment;

[0050] 4) The gas-phase reaction feed and discharge occur simultaneously, the raw material residence time is short, and the probability of reverse reaction and side reaction is greatly reduced;

[0051] 5) For projects with the same investment scale, the production capacity can be increased by 50% and the overall cost of product purification can be reduced by 30% by adopting the technology of this invention;

[0052] 6) The quality of methyl ethyl carbonate and diethyl carbonate products can reach battery grade (purity above 99.99%), and the purity of ethanol can reach above 99.99%, significantly reducing the impurities that may be introduced when ethanol is recycled. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the apparatus for the gas-phase synthesis of ethyl methyl carbonate using ethanol and dimethyl carbonate as raw materials.

[0054] Figure 2 A schematic diagram of an apparatus for producing crude methyl ethyl carbonate via a catalytic gas-phase reaction.

[0055] Figure 3 This is a schematic diagram of a purification apparatus for crude methyl ethyl carbonate.

[0056] Figure 4 This is a schematic diagram of a separation device for a mixture of methanol, ethanol, and dimethyl carbonate.

[0057] Figure 5 This is a schematic diagram of a purification apparatus for crude diethyl carbonate.

[0058] Figure 6 This is a schematic diagram of the structure of a catalytic gas-phase reactor.

[0059] Among them, 1-static mixer, 101-ethanol feed pump, 102-dimethyl carbonate feed pump, 2-vaporizer, 3-catalytic gas phase reactor, 301-skirt, 302-feed inlet, (303, 1-303, 2-303)-outer jacket, 3031-steam inlet, 3032-condensate outlet, (304, 1-304, 2-304)-heating tube, 3041-steam inlet, 3042-condensate outlet, 305-manhole, 306-safety vent, 307-discharge outlet, ( 308, 1-308, 2-308) - Temperature measuring port; 309 - Drain port; 310 - Manhole; 4 - Coarse fractionation column; 401 - Condenser; 402 - Primary condenser; 403 - Secondary condenser; 404 - Light component buffer tank; 405 - Coarse fractionation column vacuum pump; 406 - Light component reflux pump; 407 - Heavy component receiving tank; 408 - Bottom reboiler; 409 - Bottom circulation pump; 410 - Heavy component discharge pump; 411 - Light component receiving tank; 412 - Light component discharge pump; 5 - Methyl methyl carbonate column 501 - Primary condenser, 502 - Secondary condenser, 503 - Ethyl methyl carbonate buffer tank, 504 - Ethyl methyl carbonate tower vacuum pump, 505 - Ethyl methyl carbonate reflux pump, 507 - Reboiler at the bottom of the tower, 508 - Bottom circulation pump, 509 - Bottom liquid receiving tank, 510 - Bottom liquid discharge pump, 511 - Ethyl methyl carbonate receiving tank, 512 - Ethyl methyl carbonate discharge pump, 6 - Methanol tower, 601 - Primary condenser, 602 - Secondary condenser, 603 - Methanol buffer tank, 604 - Methanol reflux pump. 605 - Reboiler at the bottom of the column; 606 - Bottom circulation pump; 607 - Ethanol receiving tank; 608 - Ethanol discharge pump; 609 - Methanol receiving tank; 610 - Methanol discharge pump; 7 - Diethyl carbonate column; 701 - Primary condenser; 702 - Secondary condenser; 703 - Diethyl carbonate buffer tank; 704 - Diethyl carbonate column vacuum pump; 705 - Diethyl carbonate reflux pump; 706 - Reboiler at the bottom of the column; 707 - Bottom circulation pump; 708 - Diethyl carbonate receiving tank; 709 - Diethyl carbonate discharge pump. Detailed Implementation

[0060] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0061] A schematic diagram of the apparatus for the gas-phase synthesis of ethyl methyl carbonate using ethanol and dimethyl carbonate as raw materials is shown below. Figure 1 As shown, the production apparatus includes:

[0062] The mixer thoroughly mixes the liquid raw materials of ethanol and dimethyl carbonate.

[0063] A vaporizer vaporizes a mixture of ethanol and dimethyl carbonate.

[0064] A catalytic gas-phase reactor allows the vaporized mixture to enter from the bottom of the reactor and undergo transesterification under the action of a catalyst within the reactor.

[0065] The coarse separator allows for the initial separation of the gaseous mixture at the top of the reactor.

[0066] The methyl ethyl carbonate column is used to purify the material extracted from the bottom of the coarse separation column and extract battery-grade methyl ethyl carbonate product from the top of the column.

[0067] The diethyl carbonate tower is used to purify the material extracted from the bottom of the methyl ethyl carbonate tower and extract the finished diethyl carbonate product from the top of the tower. The wastewater at the bottom of the tower is discharged intermittently according to the liquid level at the bottom of the tower.

[0068] The methanol column separates the material extracted from the top of the coarse separator, extracting a mixture of methanol and dimethyl carbonate at the top and ethanol as the final product at the bottom.

[0069] Specifically, a schematic diagram of the apparatus for producing crude methyl ethyl carbonate by catalytic gas-phase reaction according to the present invention is shown below. Figure 2 As shown, with a molar ratio of 1.1 to 1.4:1 and ethanol in excess to ensure complete reaction of dimethyl carbonate, ethanol and dimethyl carbonate are pumped to static mixer 1 (jacketed, with hot water flowing through the jacket to heat the materials) via ethanol feed pump 101 and dimethyl carbonate feed pump 102, respectively. After preheating and thorough mixing, the materials flow through a pipeline into vaporizer 2 (heated with 0.6 MPa, 180°C steam). The mixture is vaporized in the vaporizer and continuously fed through a pipeline from the bottom of catalytic gas-phase reactor 3 (heated with 0.6 MPa, 180°C steam). The resulting gas-phase mixture is continuously discharged from the top of the reactor and directly fed through a pipeline into coarse separation tower 4 (multi-layer packed tower, with top temperature controlled at 70°C). The bottom temperature is controlled at 90℃. Preliminary separation of products is carried out in this column. The light component (mixture of methanol, ethanol and dimethyl carbonate) at the top of the coarse fractionation column is condensed by condenser 401, first-stage condenser 402 and second-stage condenser 403 and then enters the light component buffer tank 404. The upper part of the light component buffer tank is connected to the vacuum pump 405 of the coarse fractionation column through a pipeline, so that the coarse fractionation column is operating under a slight negative pressure. The light component in the light component buffer tank is partially returned to the coarse fractionation column through the pipeline and light component reflux pump 406, and partially sent to the light component receiving tank 411. The heavy component (mixture of methyl ethyl carbonate and diethyl carbonate, i.e. crude methyl ethyl carbonate) at the bottom of the coarse fractionation column is partially extracted to the heavy component receiving tank 407 through the bottom circulation pump 409, and partially returned to the coarse fractionation column after being heated by the bottom reboiler 408.

[0070] The apparatus for purifying crude methyl ethyl carbonate to obtain battery-grade methyl ethyl carbonate is as follows: Figure 3As shown, the crude methyl ethyl carbonate in the heavy component receiving tank is directly fed into the methyl ethyl carbonate tower 5 (a multi-layer packed tower with a top temperature control of 90°C and a bottom temperature control of 110°C) via a pipeline through the heavy component discharge pump 410. Methyl ethyl carbonate is extracted from the top of the tower and condensed by the primary condenser 501 and the secondary condenser 502 before entering the methyl ethyl carbonate buffer tank 503. The upper part of the buffer tank is connected to the vacuum pump 504 of the methyl ethyl carbonate tower via a pipeline, allowing the methyl ethyl carbonate tower to operate under slight negative pressure. After the sample passes the test (purity above 99.99%), it is pumped into the ethyl methyl carbonate receiving tank via the ethyl methyl carbonate reflux pump 505, and then removed by the ethyl methyl carbonate discharge pump 512. If it does not meet the standard, it is refluxed back to the ethyl methyl carbonate tower via the ethyl methyl carbonate reflux pump 505. The bottom liquid of the ethyl methyl carbonate tower (diethyl carbonate and impurities, i.e. crude diethyl carbonate) is partially removed via the bottom circulation pump 508 and sent to the bottom liquid receiving tank 509, and part of it is heated by the bottom reboiler 507 and returned to the ethyl methyl carbonate tower.

[0071] A schematic diagram of the apparatus for separating a mixture of light components, methanol, ethanol, and dimethyl carbonate, is shown below. Figure 4 As shown, the light components in the light component receiving tank 411 are sent to the methanol tower 6 (multi-layer packed tower, atmospheric pressure operation, top temperature control 65℃, bottom temperature control 70℃) via pipeline and light component discharge pump 412. The extract at the top of the tower is condensed by the primary condenser 601 and the secondary condenser 602 and then enters the methanol buffer tank 603. Part of the extract in the methanol buffer tank is returned to the methanol tower via pipeline and methanol reflux pump 604, and part is sent to the azeotrope tank (methanol and dimethyl carbonate azeotrope) or methanol receiving tank 609 according to the sampling analysis results. The methanol product in the methanol receiving tank is taken out by methanol discharge pump 610. Liquid ethanol is retained at the bottom of the methanol tower. After sampling analysis and passing the test (purity above 99.99%), it is sent to the ethanol receiving tank 607 via pipeline and bottom circulation pump 606, and then taken out by ethanol discharge pump 608. The liquid retained at the bottom of the tower that does not pass the analysis is sent to the bottom reboiler 605 via pipeline and returned to the methanol tower after heating.

[0072] A schematic diagram of the purification apparatus for crude diethyl carbonate is shown below. Figure 5As shown, the crude diethyl carbonate in the bottom liquid receiving tank 509 is fed into the diethyl carbonate column 7 (a multi-layer packed column, with top temperature controlled at 100℃ and bottom temperature controlled at 125℃) via a pipeline and bottom liquid discharge pump 510. The extract at the top of the column is condensed by the primary condenser 701 and the secondary condenser 702 and then enters the diethyl carbonate buffer tank 703. The upper part of the diethyl carbonate buffer tank is connected to the diethyl carbonate column vacuum pump 704 via a pipeline, so that the diethyl carbonate column operates under slight negative pressure. After the sample in the diethyl carbonate buffer tank passes the test (purity above 99.99%), it is pumped into the diethyl carbonate receiving tank 708 through the diethyl carbonate reflux pump 705, and then taken out by the diethyl carbonate discharge pump 709. If it does not meet the standard, it is sent back to the diethyl carbonate tower through the diethyl carbonate reflux pump. The wastewater at the bottom of the tower is sent to the bottom reboiler 706 through the bottom circulation pump 707 for heating and then returned to the diethyl carbonate tower, and is discharged intermittently according to the bottom liquid level.

[0073] Figure 6This is a schematic diagram of the catalytic gas-phase reactor of the present invention. The catalytic gas-phase reactor includes three reaction chambers connected in series and vertically fixed on a skirt base 301. The feed inlet 302 is located at the bottom of the three reaction chambers, and the discharge outlet 307 is located at the top of the three reaction chambers. A safety vent 306 is also provided at the top of the three reaction chambers, and a drain outlet 309 is provided at the bottom of the three reaction chambers. Each reaction chamber is provided with a support plate for placing the catalyst. Each reaction chamber wall is provided with an outer jacket (303, 1-303, 2-303) for heating the reaction chamber section. Each reaction chamber is provided with a heating pipe (304, 1-304, 2-304) penetrating the interior of the reaction chamber section. The main body of the heating pipe is substantially coaxial with the central axis of the corresponding reaction chamber section. The flow rate of the heating medium is controlled by a regulating valve installed on the pipeline. Each reaction chamber is equipped with a manhole 305 for personnel access when placing or replacing the catalyst, and temperature measuring ports (308, 1-308, 2-308) for measuring the temperature inside the reaction chamber. Temperature sensors are installed at these measuring ports. Each temperature sensor is electrically connected to a controller, which is in turn electrically connected to the regulating valves of each outer jacket and heating pipe. Each reaction chamber has an independent temperature control interlocking system: the temperature of each reaction chamber is converted into an electrical signal by the temperature sensor and transmitted to the controller. The controller then sends control signals to the regulating valves of the outer jacket and heating pipe of each reaction chamber according to the preset temperature index value. Compared with liquid-phase reactions, gas-phase reactions have a shorter residence time in the reaction chamber, requiring more stringent and rapid temperature control. The independent temperature control interlocking system for each reaction chamber in this invention can fully guarantee the need for rapid adjustment of the reaction temperature in each reaction chamber and improve the temperature uniformity throughout the reactor. The outer jacket of each reaction chamber is heated by steam at 0.6 MPa and 180°C. Steam enters the outer jacket through steam inlet 3031, and steam condensate is discharged through condensate outlet 3032. The heating pipes inside each reaction chamber are heated by steam at 0.6 MPa and 180°C. Steam enters the outer jacket through steam inlet 3041, and steam condensate is discharged through condensate outlet 3042.

[0074] The catalyst can be a solid basic catalyst used in the liquid-phase catalytic transesterification reaction of ethanol and dimethyl carbonate to synthesize ethyl methyl carbonate, such as the catalysts disclosed in CN107473968A, CN109503377A, and CN1900047A.

[0075] The catalyst is packed in wire mesh packing material, which is then arranged on a support plate in the reaction chamber. After the catalyst is deactivated, it can be replaced by entering the reaction chamber through the manhole.

[0076] The wire mesh packing is customized according to the size of the reaction chamber.

[0077] This invention relates to a method for the gas-phase synthesis of ethyl methyl carbonate using ethanol and dimethyl carbonate as raw materials, comprising the following steps:

[0078] (1) Ethanol and dimethyl carbonate liquid raw materials are mixed at a molar ratio of 1.1 to 1.4:1;

[0079] (2) The mixed ethanol and dimethyl carbonate liquid raw materials are vaporized at a heating temperature of 180°C.

[0080] (3) The vaporized mixture is then fed into the catalytic gas phase reactor from the bottom, where a gas phase transesterification reaction occurs under the catalysis of a solid alkaline catalyst at a reaction temperature of 160°C.

[0081] (4) The reaction products are discharged from the top of the catalytic gas phase reactor and sent to the coarse separation tower (multi-layer packed tower) for separation. The bottom temperature of the tower is 90℃ and the top temperature is 70℃. The tower is operated under slight negative pressure. Crude methyl ethyl carbonate is extracted from the bottom of the tower and light components (a mixture of methanol, ethanol and dimethyl carbonate) are extracted from the top of the tower.

[0082] (5) The crude methyl ethyl carbonate extracted is then sent to a methyl ethyl carbonate tower (multi-layer packed tower) for purification. The bottom temperature of the tower is 110°C and the top temperature is 90°C. The tower is operated under slight negative pressure. Crude diethyl carbonate is extracted from the bottom of the tower, and battery-grade (purity above 99.99%) methyl ethyl carbonate is extracted from the top of the tower.

[0083] (6) The extracted crude diethyl carbonate is sent to a diethyl carbonate tower (multi-layer packed tower) for purification. The bottom temperature of the tower is 125°C and the top temperature is 100°C. The tower is operated under slight negative pressure. Battery grade (purity above 99.99%) diethyl carbonate is extracted from the top of the tower. Wastewater from the bottom of the tower is discharged intermittently according to the liquid level.

[0084] (7) The light components extracted from the top of the coarse fractionation tower are sent to the methanol tower (multi-layer packed tower) for secondary separation. The bottom temperature of the tower is 70°C and the top temperature is 65°C. The tower is operated at atmospheric pressure. Methanol and dimethyl carbonate are extracted from the top of the tower, and battery-grade (purity above 99.99%) ethanol is extracted from the bottom of the tower.

[0085] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A production device for synthesizing ethyl methyl carbonate by gas phase reaction using ethanol and dimethyl carbonate as raw materials, comprising: a vaporizer for vaporizing liquid raw materials of ethanol and dimethyl carbonate; a catalytic gas phase reactor for catalytic gas phase reaction of ethanol and dimethyl carbonate; a rough separation column for separating gas phase reaction products and extracting ethyl methyl carbonate crude at the bottom of the column; and an ethyl methyl carbonate column for purifying ethyl methyl carbonate crude and extracting ethyl methyl carbonate at the top of the column. The production device further comprises a mixer for mixing and preheating liquid raw materials of ethanol and dimethyl carbonate; the rough separation column is a packed column with a condenser and a vacuum pump at the top; the ethyl methyl carbonate column is a packed column with a vacuum pump at the top and a reboiler at the bottom. The production device further comprises: a methanol column for separating materials extracted from the top of the rough separation column, extracting methanol and dimethyl carbonate at the top of the methanol column, and extracting ethanol at the bottom of the methanol column; and a diethyl carbonate column for purifying materials extracted from the bottom of the ethyl methyl carbonate column and extracting diethyl carbonate at the top of the diethyl carbonate column.

4. The production device according to claim 3, wherein: the methanol column is a packed column with a reboiler at the bottom; and the diethyl carbonate column is a packed column with a vacuum pump at the top and a reboiler at the bottom. The catalytic gas phase reactor comprises a plurality of reaction chambers, wherein: each reaction chamber is provided with a support disc for placing catalysts; each reaction chamber is provided with an outer jacket on the wall of the reaction chamber and a heating pipe penetrating the interior of the reaction chamber. The main body of the heating pipe is substantially coaxial with the central axis of the reaction chamber. The reaction chamber is vertically fixed on a skirt, the feed inlet is arranged at the bottom of the reaction chamber, and the discharge outlet is arranged at the top of the reaction chamber.

2. The production apparatus according to claim 1, characterized by: The outer jacket and the heating pipe are heated by steam, and each reaction chamber is provided with an independent temperature control interlocking system.

9. A method for synthesizing ethyl methyl carbonate by gas phase reaction using ethanol and dimethyl carbonate as raw materials, comprising: (1) vaporizing liquid raw materials of ethanol and dimethyl carbonate by a vaporizer; (2) sending the vaporized ethanol and dimethyl carbonate into a catalytic gas phase reactor for catalytic gas phase reaction; (3) sending the gas phase reaction products into a rough separation column for separation, and extracting ethyl methyl carbonate crude from the bottom of the column; and (4) sending the ethyl methyl carbonate crude into an ethyl methyl carbonate column for purification, and extracting ethyl methyl carbonate from the top of the column. The liquid raw materials of ethanol and dimethyl carbonate are mixed and then sent into the vaporizer, the vaporization temperature is 180℃, and the molar ratio of ethanol to dimethyl carbonate liquid raw materials is 1.1-1.4:

1.

3. The production apparatus according to claim 1, characterized by:

11. The method according to claim 9, wherein: the temperature of the catalytic gas phase reaction is 160℃; the bottom temperature of the rough separation column is 90℃, the top temperature is 70℃, and the operation is under negative pressure; and the bottom temperature of the ethyl methyl carbonate column is 110℃, the top temperature is 90℃, and the operation is under negative pressure. The method further comprises the following steps: extracting a mixture of methanol, ethanol and dimethyl carbonate from the top of the rough separation column, and sending the mixture into a methanol column for separation, extracting methanol and dimethyl carbonate from the top of the methanol column, and extracting ethanol from the bottom of the methanol column. ​ ​ ​ ​ 5. The production apparatus according to claim 1, characterized by: ​ ​ ​ 6. The production apparatus according to claim 5, characterized in that: ​ 7. The production apparatus according to claim 5, characterized by: ​ 8. The production apparatus according to claim 5, characterized by: ​ ​ ​ ​ ​ ​ 10. The method of claim 9, wherein: ​ ​ ​ ​ ​ 12. The method of claim 9, wherein: ​ ​ The crude diethyl carbonate is extracted from the bottom of the methyl ethyl carbonate column and sent to the diethyl carbonate column for purification, and diethyl carbonate is extracted from the top of the diethyl carbonate column.

13. The method of claim 12, wherein: The bottom temperature of the methanol column is 70°C, the top temperature is 65°C, and the column is operated at normal pressure; The bottom temperature of the diethyl carbonate column is 125°C, the top temperature is 100°C, and the column is operated at negative pressure.

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