A production process and system for electronic grade ethyl methyl carbonate

Abstract

The invention discloses an electronic-grade ethyl methyl carbonate production process and a system thereof. The production system comprises a first switching device, a first reaction tower, a second switching device and a second reaction tower. The first reaction tower and the second reaction tower are stacked up and down, a rotary joint is installed at the connection between the first reaction tower and the second reaction tower, the first switching device and the second switching device are symmetrically arranged on the left and right sides of the rotary joint, the ends of the first reaction tower and the second reaction tower facing each other are respectively installed with self-locking heads, the self-locking heads comprise a first clamping plate, a second clamping plate and a butt joint, a plurality of threaded holes are symmetrically arranged on the upper edge of the outer peripheral wall of the butt joint, a guide rail is arranged on the side facing the first clamping plate and the second clamping plate, a toothed bar is arranged in the guide rail, an upper discharge pipe and a lower discharge pipe have sealing heads that can correspond to the butt joint, a conversion bin is arranged outside the upper discharge pipe and the lower discharge pipe, a pair of drive components are symmetrically arranged in the conversion bin, and a transmission frame is arranged in the conversion bin.

Description

Technical Field

[0001] The invention relates to the technical field of ethyl methyl carbonate production, and in particular to an electronic-grade ethyl methyl carbonate production process and a system thereof. Background Art

[0002] Ethyl methyl carbonate (EMC), also known as ethyl methyl carbonate, is a colorless transparent liquid that is insoluble in water and can be used for organic synthesis. It is the latest product developed with the increase in the production of dimethyl carbonate and lithium-ion batteries. Because it has both methyl and ethyl groups, it has the characteristics of dimethyl carbonate and diethyl carbonate, and is also a solvent for special flavors and intermediates. It has now become the main solvent component, accounting for more than 10% of the mass in the electrolyte. At present, the commonly used electrolyte systems in China include EC+DMC, EC+DEC, EC+DMC+EMC, EC+DMC+DEC, etc.

[0003] Electronic-grade ethyl methyl carbonate is mainly produced using industrial-grade dimethyl carbonate and anhydrous ethanol as raw materials. The existing production process of electronic-grade ethyl methyl carbonate requires four reaction towers, namely, EMC reaction tower, DMC recovery tower, EMC deweighting tower and EMC refining tower, and various material conveying and control devices need to be set up between these towers. The process system has a large number of equipment settings, a complex control system, and a high operating cost. Summary of the invention

[0004] In order to solve the problems mentioned in the above background technology, the present invention provides an electronic grade ethyl methyl carbonate production process and system.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A production process for electronic grade ethyl methyl carbonate comprises the following steps:

[0007] S1: industrial-grade dimethyl carbonate and anhydrous ethanol are mixed in a predetermined ratio and then fed into a first switching device, and the raw materials are pre-reacted in the first switching device and then enter the first reaction tower;

[0008] S2: The materials react and separate simultaneously in the first reaction tower at normal pressure and at an operating temperature of 106-110° C., and a methanol content greater than 80% is extracted from the top of the tower;

[0009] S3: The triester mixture produced from the first reaction tower kettle enters the second reaction tower through the second switching device, unreacted DMC is produced from the top of the second reaction tower, and the diester mixture is produced from the kettle;

[0010] S4: The first reaction tower and the second reaction tower are turned upside down, the diester at the bottom of the second reaction tower enters the first reaction tower through the first switching device, the first reaction tower respectively extracts crude EMC and DEC from the top and bottom of the tower, and EMC enters the second reaction tower through the second switching device;

[0011] S5: The crude EMC is refined by the second reaction tower to produce electronic grade ethyl methyl carbonate EMC product;

[0012] S6: After the separation of the diester in the first reaction tower is completed, the first reaction tower and the second reaction tower are flipped again, and the second switching device storing the crude EMC continues to feed the second reaction tower, and the electronic grade ethyl methyl carbonate EMC product produced by the second reaction tower is received by the first switching device and then produced, and at the same time, the industrial grade dimethyl carbonate and anhydrous ethanol raw materials enter the first switching device to start the next production cycle.

[0013] Preferably, the production pressure of the first reaction tower is normal pressure, and the operating temperature is 106-110°C; the production pressure of the second reaction tower is -0.07 MPaG, and the operating temperature is 71-75°C.

[0014] An electronic-grade ethyl methyl carbonate production system, used in the aforementioned electronic-grade ethyl methyl carbonate production process, comprises a first switching device, a first reaction tower, a second switching device and a second reaction tower, the first reaction tower and the second reaction tower are stacked up and down, a rotary joint is installed at the connection between the first reaction tower and the second reaction tower, a forward rotating motor and a reverse rotating motor are installed at the front and rear ends of the rotary joint respectively, and the first switching device and the second switching device are symmetrically arranged on the left and right sides of the rotary joint;

[0015] The ends of the first reaction tower and the second reaction tower facing each other are each equipped with a self-locking head, the self-locking head comprises a first clamping plate, a second clamping plate and a butt joint, a plurality of threaded holes are symmetrically arranged on the upper edge of the outer peripheral wall of the butt joint, a guide rail is arranged on the side facing each other of the first clamping plate and the second clamping plate, and a toothed bar is arranged in the guide rail;

[0016] The upper discharge pipe and the lower discharge pipe have sealing heads that can correspond to the butt joints. The upper discharge pipe and the lower discharge pipe are surrounded by a conversion bin, a pair of drive components are symmetrically arranged in the conversion bin, and a transmission frame is arranged in the conversion bin.

[0017] Preferably, when the first reaction tower is above the second reaction tower, the top environment is connected to the first switching device and the second switching device through two branch pipes through the top pump, and the kettle environment of the first reaction tower is connected to the second switching device through the bottom flow pipe. The kettle environment of the second reaction tower located below is connected to the first switching device and the second switching device through two branch pipes through the top pump, and the top environment is connected to the first switching device through the bottom flow pipe.

[0018] Preferably, the first switching device and the second switching device are internally separated to have two independent spaces.

[0019] Preferably, the toothed bar can only move vertically within a certain range in the guide rail, a magnetic block is installed at the lower end of the toothed bar, an electromagnetic bar is installed below the magnetic block, and an elastic member is connected between the toothed bar installed in the second clamping plate and the guide rail.

[0020] Preferably, the sealing head includes a fixed ring, a threaded rod, a transmission ring and a driving member. The fixed ring is fixedly installed on the ends of the upper discharge pipe and the lower discharge pipe facing the reaction tower. The threaded rod is penetrated by the fixed ring according to the setting position of the threaded hole. The transmission ring is meshed with the upper ends of each threaded rod, and the upper end of the transmission ring is meshed with the helical teeth of the driving member.

[0021] Preferably, the driving assembly includes a threaded head, a connecting tube, a movable plate and a driving spring. The threaded head can be axially rotatably installed to protrude to the outside of the conversion bin. The connecting tube is arranged in the conversion bin and is coaxially connected to the threaded head. A spiral groove is arranged on the inner wall of the connecting tube. The movable plate has a portion embedded in the spiral groove. The two ends of the driving spring are respectively connected to the outer peripheral wall of the upper discharge pipe or the lower discharge pipe and the movable plate.

[0022] Preferably, the transmission frame includes a vertical limit block, a linkage rod and a vertical shift frame. The vertical limit block is fixedly installed in the conversion bin and limits the linkage rod to horizontal movement. One side of the vertical shift frame is connected to the linkage rod slide rail, and the other side is respectively connected to the connecting tube and the driving member inserted into the conversion bin through teeth.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention integrates the four reaction towers required for the existing production of electronic-grade ethyl methyl carbonate, namely, the EMC reaction tower, the DMC recovery tower, the EMC deweighting tower and the EMC refining tower, into two reaction towers stacked up and down, so that the reaction system is more streamlined, the number of equipment settings is small, and the operating cost is low.

[0025] 2. The present invention controls the docking state of the upper and lower discharge pipes with the self-locking head by alternating the forward rotating motor and the reverse rotating motor, so that the upper and lower discharge pipes can be well docked with the reaction tower without setting up an additional control system. The control system is simple, the docking is simple and efficient, and it can well adapt to the operation of the reaction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a schematic diagram of the overall structure of an electronic-grade ethyl methyl carbonate production system according to the present invention;

[0028] Figure 2 It is an independent cross-sectional view of the first reaction tower of the present invention;

[0029] Figure 3 for Figure 2 The enlarged schematic diagram at A in the middle;

[0030] Figure 4 This is a schematic diagram of the self-locking head structure of the present invention;

[0031] Figure 5 It is a cross-sectional view of the central axis of the self-locking head of the present invention;

[0032] Figure 6 It is a schematic diagram of the structure of the upper discharge pipe and the lower discharge pipe end head according to the present invention;

[0033] Figure 7 It is a structural schematic diagram of the driving assembly of the present invention in the conversion chamber;

[0034] Figure 8 The figure is a schematic diagram of the transmission frame structure of the present invention.

[0035] In the figure: 1, first switching device; 2, first reaction tower; 201, through channel; 21, outer tower shell; 22, inner tower body; 23, temperature control device; 24, pressure control device; 25, tower top pump; 26, tower bottom pump; 27, multi-layer tower plate; 28, catalyst plug cylinder; 29, plug cylinder; 3, second switching device; 4, second reaction tower; 5, forward rotating motor; 6, reverse rotating motor; 7, shunt pipe; 8, underflow pipe; 9, upper discharge pipe; 10, lower discharge pipe; 11, self-locking head; 1101, threaded hole; 1102, guide rail ; 111, first clamping plate; 112, second clamping plate; 113, docking joint; 114, toothed strip; 115, magnetic block; 116, electromagnetic strip; 117, elastic member; 12, sealing head; 121, fixed ring; 122, threaded rod; 123, transmission ring; 124, driving member; 13, conversion chamber; 14, driving assembly; 1401, screw ring groove; 141, threaded head; 142, connecting tube; 143, movable plate; 144, driving spring; 15, transmission frame; 151, vertical limit block; 152, linkage rod; 153, vertical moving frame. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Reference Figure 1-8 , a production process for electronic grade ethyl methyl carbonate, comprising the following steps:

[0038] S1: industrial-grade dimethyl carbonate and anhydrous ethanol are mixed in a predetermined ratio and sent to the first switching device 1. The raw materials are pre-reacted in the first switching device 1 at a temperature of 90-130° C. and a pressure of 0.2-0.5 MPaG and then enter the first reaction tower 2;

[0039] S2: The materials react and separate simultaneously in the first reaction tower 2 at normal pressure and an operating temperature of 106-110°C, and the by-product methanol is azeotropically distilled together with the raw material DMC to the top of the reaction tower, and finally extracted from the top of the tower, and the extracted methanol content is greater than 80%;

[0040] S3: The triester mixture (dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate) extracted from the bottom of the first reaction tower 2 enters the second reaction tower 4 through the second switching device 3, and the unreacted DMC is extracted from the top of the tower at an operating pressure of -0.07 MPaG and an operating temperature of 71-75° C., and the bottom of the tower produces a diester (ethyl methyl carbonate EMC and diethyl carbonate DEC) mixture. The unreacted DMC on the top of the tower re-enters the first switching device 1 to react with ethanol;

[0041] S4: The first reaction tower 2 and the second reaction tower 4 are turned upside down, and the diester at the bottom of the second reaction tower 4 enters the first reaction tower 2 through the first switching device 1. The first reaction tower 2 extracts crude EMC and DEC from the top and the bottom of the tower respectively at normal pressure and an operating temperature of 106-110° C., wherein DEC is discharged and enters the anti-disproportionation device, and EMC enters the second reaction tower 4 through the second switching device 3;

[0042] S5: The crude EMC is refined from the top of the second reaction tower 4 at an operating pressure of -0.07 MPaG and an operating temperature of 71-75° C. to produce electronic grade ethyl methyl carbonate EMC product, which is then dehydrated with a molecular sieve and stored in a product tank.

[0043] S6: After the separation of the diester in the first reaction tower 2 is completed, the first reaction tower 2 and the second reaction tower 4 are flipped again, and the second switching device 3 storing the crude EMC continues to feed the second reaction tower 4, and the electronic grade ethyl methyl carbonate EMC product produced by the second reaction tower 4 is received by the first switching device 1 and then produced, and at the same time, the industrial grade dimethyl carbonate and anhydrous ethanol raw materials enter the first switching device 1 to start the next production cycle.

[0044] An electronic-grade ethyl methyl carbonate production system is applicable to the above-mentioned electronic-grade ethyl methyl carbonate production process, comprising a first switching device 1, a first reaction tower 2, a second switching device 3 and a second reaction tower 4, wherein the first reaction tower 2 and the second reaction tower 4 are stacked up and down, a rotary joint is installed at the connection between the first reaction tower 2 and the second reaction tower 4, a forward rotating motor 5 and a reverse rotating motor 6 are respectively installed at the front and rear ends of the rotary joint, the forward rotating motor 5 and the reverse rotating motor 6 are respectively supported by brackets, when the forward rotating motor 5 is working, it can drive the first reaction tower 2 and the second reaction tower 4 to rotate clockwise, when the reverse rotating motor 6 is working, the first reaction tower 2 and the second reaction tower 4 are driven to rotate counterclockwise.

[0045] The first reaction tower 2 includes an outer tower shell 21, an inner tower body 22, a temperature control device 23, a pressure control device 24, a tower top pump 25 and a tower bottom pump 26. The inner tower body 22 is arranged in the outer tower shell 21, and the temperature control device 23, the pressure control device 24, the tower top pump 25 and the tower bottom pump 26 are arranged in the interlayer space between the inner tower body 22 and the outer tower shell 21 and are connected to an external control system. The temperature control device 23 and the pressure control device 24 maintain the inner tower body 22 at atmospheric pressure and a temperature of 106-110° C. under the regulation of the external control system.

[0046] The first switching device 1 and the second switching device 3 are symmetrically arranged on the left and right sides of the rotary joint. When the first reaction tower 2 is above the second reaction tower 4, the top environment of the inner tower body 22 is connected to the first switching device 1 and the second switching device 3 by two branch pipes 7 through the top pump 25, and the bottom environment of the first reaction tower 2 is connected to the second switching device 3 through the bottom flow pipe 8.

[0047] The second reaction tower 4 has an outer tower shell 21, an inner tower body 22, a temperature control device 23, a pressure control device 24, a tower top pump 25 and a tower bottom pump 26 like the first reaction tower 2. The tower bottom environment of the second reaction tower 4 located below is connected to the first switching device 1 and the second switching device 3 by two branch pipes 7 through the tower top pump 25, and the tower top environment is connected to the first switching device 1 through the bottom flow pipe 8.

[0048] The interior of the first switching device 1 is divided into two independent spaces, one of which is used for the pre-reaction of the raw materials and receives the unreacted DMC extracted from the top of the second reaction tower 4 and reacts with ethanol. After the pre-reaction of the raw materials, they are pumped to the first reaction tower 2 by the top pump 25 for reaction and separation. The by-product methanol generated at the top of the tower and the azeotropic mixture of the raw material DMC are discharged through the upper discharge pipe 9 connected to the top of the tower. The triester mixture extracted from the bottom of the tower enters the second reaction tower 4 through the second switching device 3, and the diester produced in the bottom of the second reaction tower 4 is pumped to another space by the top pump 25 for temporary storage.

[0049] A plurality of tower plates 27 are arranged in the first reaction tower 2, and a plurality of through channels 201 are opened in the tower plates 27. Catalyst plug cylinders 28 and blocking cylinders 29 are respectively installed in the through channels 201. Limiting parts are arranged at both upper and lower ends of the catalyst plug cylinders 28 and the blocking cylinders 29. A limiting ring is arranged on the inner wall of the through channel 201 with the catalyst plug cylinder 28 close to the second reaction tower 4, and a limiting ring is arranged on the inner wall of the through channel 201 with the blocking cylinder 29 away from the second reaction tower 4.

[0050] The end of the catalyst plug barrel 28 away from the second reaction tower 4 is arranged in the through channel 201, and the end of the blocking barrel 29 close to the second reaction tower 4 is arranged in the through channel 201. When the first reaction tower 2 is above the second reaction tower 4, the blocking barrel 29 is inserted into the through channel 201, and the upper end of the blocking barrel 29 covers the through channel 201 to block the through channel 201. At the same time, the catalyst plug barrel 28 protrudes downward from the through channel 201, and the limiting piece at the upper end of the catalyst plug barrel 28 is blocked by the limiting ring and suspended on the tower plate 27. The upper end of the catalyst plug barrel 28 is open and the lower part of the side wall is open. The catalyst plug barrel 28 is filled with catalyst, and the material must pass through the catalyst plug barrel 28 during reaction and distillation to complete the reaction.

[0051] After a batch of raw materials in the first reaction tower 2 is reacted, the forward rotating motor 5 is started to drive the first reaction tower 2 and the second reaction tower 4 to flip up and down, and the two fats stored in the first switching device 1 are sent to the first reaction tower 2 at the bottom for separation, and the crude DEC separated from the bottom of the tower is discharged from the lower discharge pipe 10 connected to the lower part of the first reaction tower 2, and the crude EMC separated from the top of the tower is sent to the second switching device 3 for temporary storage.

[0052] When the first reaction tower 2 performs separation operation, the catalyst plug cylinder 28 is inserted into the through channel 201 to block the through channel 201, and the plugging cylinder 29 protrudes out of the through channel 201 under the action of gravity. The upper end of the plugging cylinder 29 is open and the lower part of the side wall is open, so that the material can pass through the through channel 201 and each tower plate 27 smoothly.

[0053] The interior of the second switching device 3 is divided into two independent spaces, one part of which is used to store the crude EMC separated by the first reaction tower 2, and the other part is used to store part of the tri-fat produced when the first reaction tower 2 is above the second reaction tower 4. When the second reaction tower 4 is above the first reaction tower 2, the second switching device 3 continues to transport the tri-fat to the second reaction tower 4 for separation, and the di-fat produced in the bottom of the second reaction tower 4 will also continue to be transported to the first reaction tower 2 via the first switching device 1.

[0054] After the tri-fat in the second switching device 3 is exhausted and the DMC recovery process in the second reaction tower 4 is completed, the second switching device 3 transports the crude EMC to the second reaction tower 4 for refining to produce electronic-grade ethyl methyl carbonate EMC products. After the diester separation in the first reaction tower 2 is completed, the reverse rotating motor 6 flips the first reaction tower 2 and the second reaction tower 4, and the second switching device 3 storing the crude EMC continues to feed the second reaction tower 4. The electronic-grade ethyl methyl carbonate EMC product produced by the second reaction tower 4 is received by the first switching device 1 and then produced.

[0055] The ends of the first reaction tower 2 and the second reaction tower 4 facing each other are each installed with a self-locking head 11, and the self-locking head 11 includes a first clamping plate 111, a second clamping plate 112 and a docking head 113, and the docking head 113 is arranged between the first clamping plate 111 and the second clamping plate 112, and the upper edge of the outer peripheral wall of the docking head 113 is symmetrically provided with a plurality of threaded holes 1101, and the first clamping plate 111 and the second clamping plate 112 are arranged on the side facing each other with a guide rail 1102, and the guide rail 110 2 is provided with a toothed bar 114, the toothed bar 114 can only move vertically within a certain range within the guide rail 1102, a magnetic block 115 is installed at the lower end of the toothed bar 114, an electromagnetic bar 116 is installed below the magnetic block 115, and an elastic member 117 is connected between the toothed bar 114 installed in the second clamping plate 112 and the guide rail 1102, and when the elastic member 117 is at a normal length, the toothed bar 114 is pushed away from the guide rail 1102 to the side close to the reaction tower

[0056] The upper discharge pipe 9 and the lower discharge pipe 10 have a sealing head 12 that can correspond to the docking head 113, and the sealing head 12 includes a fixed ring 121, a threaded rod 122, a transmission ring 123 and a driving member 124. The fixed ring 121 is fixedly installed on the ends of the upper discharge pipe 9 and the lower discharge pipe 10 facing the reaction tower, and the threaded rod 122 is penetrated and arranged in the fixed ring 121 according to the setting position of the threaded hole 1101. The transmission ring 123 is meshed with the upper end of each threaded rod 122, and the upper end of the transmission ring 123 is meshed with the helical teeth of the driving member 124. The axial rotation of the driving member 124 can drive the transmission ring 123 to rotate axially outside the upper discharge pipe 9 or the lower discharge pipe 10, thereby driving each threaded rod 122 to rotate and screw in or out of the threaded hole 1101. After the threaded rod 122 is screwed into the threaded hole 1101, the upper discharge pipe 9 and the lower discharge pipe 10 can be better connected to the reaction tower.

[0057] A conversion bin 13 is provided outside the upper discharge pipe 9 and the lower discharge pipe 10, and the conversion bin 13 is symmetrically provided with a pair of driving components 14, and the driving component 14 includes a threaded head 141, a connecting tube 142, a movable plate 143 and a driving spring 144. The threaded head 141 can be axially rotatably installed to protrude to the outside of the conversion bin 13, the connecting tube 142 is arranged in the conversion bin 13 and is coaxially connected to the threaded head 141, and the inner wall of the connecting tube 142 is provided with a spiral groove 1401, and the movable plate 143 has a portion embedded in the spiral groove 1401, and the two ends of the driving spring 144 are respectively connected to the outer peripheral wall of the upper discharge pipe 9 or the lower discharge pipe 10 and the movable plate 143, so that the axially rotating connecting tube 142 can drive the movable plate 143 to move horizontally.

[0058] A transmission frame 15 is provided in the conversion bin 13, and the transmission frame 15 includes a vertical limit block 151, a linkage rod 152 and a vertical movement frame 153. The vertical limit block 151 is fixedly installed in the conversion bin 13 and limits the linkage rod 152 to only horizontal movement. One side of the vertical movement frame 153 is connected to the sliding rail of the linkage rod 152, and the other side is respectively connected to the connecting tube 142 and the driving member 124 through teeth for transmission. The size specification of the transmission frame 15 is set to when one vertical movement frame 153 is transmission-connected with the connecting tube 142 and the driving member 124, the teeth of the other vertical movement frame 153 will be separated from its corresponding connecting tube 142 and the driving member 124.

[0059] The driving assembly 14 is arranged on the rotation path of the guide rail 1102. The toothed bar 114 equipped with the magnetic block 115 can attract and stick to the unpowered electromagnetic bar 116 under the condition of overcoming its own gravity. When the forward rotating motor 5 is working, the electromagnetic bar 116 provided on the guide rail 1102 without the elastic member 117 is energized. At this time, the electromagnetic bar 116 generates a magnetic field and uses the magnetic repulsion to push the toothed bar 114 away. At this time, the electromagnetic bar 116 with magnetism will also attract the transmission frame 15 to move the vertical moving frame 153 to the unpowered electromagnetic bar 116. The connecting tube 142 and the driving member 124 on the same side of the guide rail 1102 of the elastic member 117, when the self-locking head 11 is driven to rotate by the forward rotating motor 5, the toothed bar 114 pushed by the magnetic repulsion force and the elastic force of the elastic member 117 can engage with the threaded head 141 to drive the threaded head 141 to rotate, thereby driving the movable plate 143 to move and compressing or stretching the driving spring 144. The rotation of the threaded head 141 can also drive the various threaded rods 122 to rotate and recover with the help of the transmission frame 15, so that the sealing head 12 can be smoothly docked with the docking head 113.

[0060] After the sealing head 12 and the docking joint 113 are docked, the forward rotating motor 5 stops working, and the electromagnetic strip 116 loses power supply and magnetism at this time, and the toothed strip 114 will also be sucked back by the magnetic force and detached from the threaded head 141. The connecting tube 142 is driven by the moving plate 143 driven by the restored driving spring 144 to rotate without restriction, thereby driving each threaded rod 122 to rotate and screw into the threaded hole 1101, so that the upper discharge pipe 9 and the lower discharge pipe 10 are well docked and connected with the reaction tower.

[0061] After the reverse rotating motor 6 is started, the electromagnetic strip 116 provided on the guide rail 1102 equipped with the elastic member 117 is energized. At this time, the electromagnetic strip 116 will generate a magnetic attraction to suck the toothed bar 114 away from the engaged and locked threaded head 141, and attract the transmission frame 15 to move the vertical moving frame 153 to the connecting tube 142 and the driving member 124 on the same side of the guide rail 1102 equipped with the elastic member 117. After the toothed bar 114 moves away from the threaded head 141, the driving assembly 14 that was previously driven by the toothed bar 114 to rotate will rotate back, thereby driving each threaded rod 122 to rotate out of the threaded hole 1101 to achieve unlocking, so that the reverse rotating motor 6 can continue to drive the first reaction tower 2 and the second reaction tower 4 to flip.

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the present invention will no longer explain the control method and circuit connection in detail.

[0065] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for producing electronic grade ethyl methyl carbonate, characterized in that: The following steps are involved: S1: industrial-grade dimethyl carbonate and anhydrous ethanol are mixed in a predetermined ratio and then fed into a first switching device (1); the raw materials are pre-reacted in the first switching device (1) and then enter a first reaction tower (2); S2: the materials react and separate simultaneously in the first reaction tower (2) at normal pressure and at an operating temperature of 106-110°C, and a methanol content of more than 80% is extracted from the top of the tower; S3: the triester mixture is taken out from the bottom of the first reaction tower (2) and enters the second reaction tower (4) through the second switching device (3); the unreacted DMC is taken out from the top of the second reaction tower (4), and the diester mixture is produced in the bottom of the tower; S4: the first reaction tower (2) and the second reaction tower (4) are turned upside down, the diester at the bottom of the second reaction tower (4) enters the first reaction tower (2) through the first switching device (1), the first reaction tower (2) extracts crude EMC and DEC from the top and bottom of the tower respectively, and EMC enters the second reaction tower (4) through the second switching device (3); S5: the crude EMC is refined by the second reaction tower (4) to produce electronic grade ethyl methyl carbonate EMC product; S6: After the separation of the diester in the first reaction tower (2) is completed, the first reaction tower (2) and the second reaction tower (4) are reversed again, and the second switching device (3) storing the crude EMC continues to supply the second reaction tower (4). The electronic grade ethyl methyl carbonate EMC product produced by the second reaction tower (4) is received by the first switching device (1) and then produced. At the same time, the industrial grade dimethyl carbonate and anhydrous ethanol raw materials enter the first switching device (1), and the next production cycle begins.

2. A process for producing electronic-grade ethyl methyl carbonate according to claim 1, characterized in that: The production pressure of the first reaction tower (2) is normal pressure, and the operating temperature is 106-110°C; the production pressure of the second reaction tower (4) is -0.07 MPaG, and the operating temperature is 71-75°C.

3. An electronic grade ethyl methyl carbonate production system, used for the electronic grade ethyl methyl carbonate production process according to any one of claims 1 or 2, comprising a first switching device (1), a first reaction tower (2), a second switching device (3) and a second reaction tower (4), characterized in that: The first reaction tower (2) and the second reaction tower (4) are stacked up and down, a rotary joint is installed at the connection between the first reaction tower (2) and the second reaction tower (4), a forward rotating motor (5) and a reverse rotating motor (6) are installed at the front and rear ends of the rotary joint respectively, and the first switching device (1) and the second switching device (3) are symmetrically arranged on the left and right sides of the rotary joint; The ends of the first reaction tower (2) and the second reaction tower (4) facing each other are each provided with a self-locking head (11), the self-locking head (11) comprising a first clamping plate (111), a second clamping plate (112) and a butt joint (113), a plurality of threaded holes (1101) are symmetrically arranged on the upper edge of the outer peripheral wall of the butt joint (113), a guide rail (1102) is arranged on the side of the first clamping plate (111) and the second clamping plate (112) facing each other, and a toothed bar (114) is arranged inside the guide rail (1102); The upper discharge pipe (9) and the lower discharge pipe (10) have sealing heads (12) that can correspond to the docking heads (113); a conversion chamber (13) is provided outside the upper discharge pipe (9) and the lower discharge pipe (10); a pair of drive assemblies (14) are symmetrically provided in the conversion chamber (13); and a transmission frame (15) is provided inside the conversion chamber (13).

4. An electronic grade ethyl methyl carbonate production system according to claim 3, characterized in that: When the first reaction tower (2) is located above the second reaction tower (4), the tower top environment is connected to the first switching device (1) and the second switching device (3) through two branch pipes (7) via a tower top pump (25), and the tower bottom environment of the first reaction tower (2) is connected to the second switching device (3) through an underflow pipe (8). The tower bottom environment of the second reaction tower (4) located below is connected to the first switching device (1) and the second switching device (3) through two branch pipes (7) via a tower top pump (25), and the tower top environment is connected to the first switching device (1) through an underflow pipe (8).

5. An electronic grade ethyl methyl carbonate production system according to claim 3, characterized in that: The first switching device (1) and the second switching device (3) are internally separated to have two independent spaces.

6. An electronic grade ethyl methyl carbonate production system according to claim 3, characterized in that: The toothed bar (114) can only move vertically within a certain range within the guide rail (1102); a magnetic block (115) is installed at the lower end of the toothed bar (114); an electromagnetic bar (116) is installed below the magnetic block (115); and an elastic member (117) is connected between the toothed bar (114) installed in the second clamping plate (112) and the guide rail (1102).

7. An electronic grade ethyl methyl carbonate production system according to claim 3, characterized in that: The sealing head (12) comprises a fixed ring (121), a threaded rod (122), a transmission ring (123) and a driving member (124); the fixed ring (121) is fixedly mounted on the ends of the upper discharge pipe (9) and the lower discharge pipe (10) facing the reaction tower; the threaded rod (122) is penetrated through the fixed ring (121) according to the setting position of the threaded hole (1101); the transmission ring (123) is meshed with the upper end of each threaded rod (122); and the upper end of the transmission ring (123) is meshed with the helical teeth of the driving member (124).

8. An electronic grade ethyl methyl carbonate production system according to claim 7, characterized in that: The driving assembly (14) comprises a threaded head (141), a connecting tube (142), a movable plate (143) and a driving spring (144); the threaded head (141) can be axially rotatably installed to protrude outside the conversion chamber (13); the connecting tube (142) is arranged in the conversion chamber (13) and is coaxially connected to the threaded head (141); the inner wall of the connecting tube (142) is provided with a spiral groove (1401); the movable plate (143) has a portion embedded in the spiral groove (1401); and the two ends of the driving spring (144) are respectively connected to the outer peripheral wall of the upper discharge pipe (9) or the lower discharge pipe (10) and the movable plate (143).

9. An electronic grade ethyl methyl carbonate production system according to claim 8, characterized in that: The transmission frame (15) comprises a vertical limit block (151), a linkage rod (152) and a vertical shift frame (153); the vertical limit block (151) is fixedly installed in the conversion bin (13) and limits the linkage rod (152) to move horizontally; one side of the vertical shift frame (153) is connected to a slide rail of the linkage rod (152), and the other side is respectively connected to a connecting tube (142) and a part of a driving member (124) inserted into the conversion bin (13) through teeth.

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