Synthetic process method of ethyl acetate

Abstract

The invention relates to the technical field of esterification reaction catalysis, and particularly discloses an ethyl acetate synthesis method, which comprises the following steps: adding ethanol in a workshop into acetic acid, adding a certain amount of catalyst, stirring and heating until reaction reflux, judging the reaction endpoint according to reaction liquid and kettle liquid gas phase, and after the reaction is finished, sequentially washing and rectifying to obtain a finished product. The method has the beneficial effects that the use of concentrated sulfuric acid can be replaced or reduced from the source, the utilization rate of acetic acid is improved, the cost is saved, equipment is prevented from being corroded, the content of crude ethyl acetate can reach 80% or above, and the content of a finished product can reach 99.8% or above.

Description

Technical Field

[0001] The invention relates to the technical field of esterification reaction catalysis, in particular to a method for synthesizing ethyl acetate. Background Art

[0002] Ethyl acetate (EA), also known as ethyl acetate, is an important fine chemical with wide application. It has good solubility and quick drying properties. It is widely used in the production of cellulose acetate, ethyl cellulose, chlorinated rubber, vinyl resin, cellulose acetate resin, synthetic rubber, etc. It can also be used to produce liquid nitrocellulose ink for copiers; it is used as a cleaning agent in the textile industry; it is used as a flavor extractant for special modified alcohol in the food industry; it is an important flavor additive in the flavor industry and can be used as a component of flavoring agents. In addition, ethyl acetate can also be used as a solvent for adhesives, a thinner for paints, and a raw material for manufacturing drugs and dyes.

[0003] In recent years, the application of ethyl acetate has grown rapidly at home and abroad. Between 1990 and 2000, the annual growth rate of domestic production capacity was about 14%, and the annual growth rate of output was 10%. Although the domestic production capacity and output of ethyl acetate have been rising rapidly in recent years, the import volume has continued to increase. Ethyl acetate is currently the largest organic chemical product imported in China. Although the domestic production capacity is relatively large, most of the devices are small-scale and uncompetitive. They cannot compete with large-scale devices in terms of technology and cost, and will gradually be eliminated. Although domestic production enterprises are constantly improving technology and expanding production scale, and foreign companies have also entered China to establish joint ventures to build advanced acetate production equipment, the rapidly developing domestic market, especially the strong development of the construction, automobile and other industries in the next few years, will definitely drive the demand for domestic acetate;

[0004] For example, the announcement number CN113880712B discloses a method for preparing ethyl acetate, wherein the raw materials acetic acid, anhydrous ethanol and recovered ester (including first ester and supplementary ester) are metered into an esterification kettle, heated by steam under the action of a catalyst to generate ethyl acetate and water, and form an azeotrope in an esterification tower, which is evaporated from the top of the tower, condensed and cooled, and then enters a phase separator for separation, and the aqueous phase enters a recovery tower; a part of the ester phase is refluxed to the esterification tower, and the rest enters a crude ester buffer tank for preheating, and then enters a concentration tower, and is distilled to obtain a finished product with qualified ester content, acidity and moisture at the bottom of the tower, and a part of it is returned to the esterification kettle as supplementary ester after cooling, and the rest all enters a metering tank; the aqueous phase is wastewater containing ester and alcohol, which enters the recovery tower, is separated by distillation, and a certain content of first ester is recovered from the top of the recovery tower, and the first ester is returned to the esterification tower, and the recovered wastewater is discharged from the bottom of the recovery tower;

[0005] The preparation method of ethyl acetate in the prior art can meet the needs of use. First, in industry, ethyl acetate is mostly synthesized by acetic acid esterification method. Under the catalytic action of concentrated sulfuric acid, ethanol and acetic acid are esterified to produce ethyl acetate. However, this production process has the disadvantages of high reaction temperature, low acetic acid utilization, easy side reactions, equipment corrosion, waste liquid pollution of the environment and high production cost. Second, the existing equipment reacts the raw materials and the catalyst at high temperature in the reactor, but the raw materials and the catalyst react slowly, affecting the efficiency, resulting in a low content of crude ethyl acetate. Multiple reactions are required to reach the specified content of the finished product, low production efficiency and complex operation. Summary of the invention

[0006] The purpose of the present invention is to provide a synthetic process for ethyl acetate to solve the problems of low utilization rate of existing acetic acid, easy occurrence of side reactions and corrosion of equipment proposed in the above background technology, slow reaction of raw materials and catalysts, affecting efficiency, resulting in low crude ethyl acetate content, multiple reactions are required to reach the specified finished product content, low production efficiency and complex operation.

[0007] To achieve the above object, the present invention provides the following technical scheme: a synthetic process for ethyl acetate, comprising an operating table, a heating pool, an electric heating wire, a lifting mechanism, a clamping frame, a peristaltic pump, a transmission component, a stirring component, a clamping component, a reaction component, a four-necked flask, a constant pressure dropping funnel, a distillation column, a serpentine condenser and a thermometer, comprising the following steps:

[0008] S1, put the raw materials of the esterification stage into a L four-necked flask connected with a thermometer, a stirring assembly, a constant pressure dropping funnel and a serpentine condenser in order;

[0009] S2, heating the water in the heating pool by turning on the electric heating wire, the heated water can heat the four-necked flask to 50-60 degrees, and then add the catalyst;

[0010] S3, continue to raise the temperature to reflux and start collecting liquid, and use a peristaltic pump to press the reflux azeotropic ethanol back into the reaction liquid. During the reaction, the water produced by the reaction is continuously released to make the reaction proceed in the direction of esterification;

[0011] S4. When the reaction liquid is close to the theoretical value, sampling begins. According to the reaction liquid and the kettle liquid gas phase, sampling is performed once every h or h until the ethyl ester content in the reaction liquid gas phase is 80>%, which is regarded as the reaction endpoint;

[0012] S5. Wash the product twice at room temperature;

[0013] S6. The obtained product phase is purified by distillation at room temperature to obtain the final product ethyl acetate.

[0014] Preferably, a heating pool is provided on the left side of the table top of the operating table, an electric heating wire is installed inside the heating pool, a main mounting frame and a secondary mounting frame are respectively installed at the rear end of the operating table, a lifting mechanism is installed at the front end of the main mounting frame, and a clamping assembly is installed at the front of the secondary mounting frame.

[0015] Preferably, the lifting mechanism includes a lifting assembly and an L-shaped block, the front end of the lifting assembly is fixed with the L-shaped block, the lifting assembly includes a servo motor, a threaded rod and a long barrel nut, the bottom end of the servo motor drives the threaded rod to rotate on the rear side of the operating table, the center thread of the threaded rod is sleeved with a long barrel nut, the front end of the long barrel nut is fixed with the rear end of the L-shaped block, a circular opening is opened at the connection between the center of the L-shaped block and the transmission assembly, and a fixed bearing is fixed at the front end of the circular opening.

[0016] Preferably, a rotating shaft is installed at the driving center of the peristaltic pump, and a transverse bevel gear is fixed to the front end of the rotating shaft.

[0017] Preferably, the transmission assembly includes a rotating roller and a trombone gear, a trombone gear is fixedly provided at the center of the rotating roller, the trombone gear is in the circular opening, the top end of the rotating roller is fixedly provided on the inner wall of the main mounting frame, the bottom end of the rotating roller is fixedly provided on the top of the clamping frame, a vertical bevel gear is provided at the bottom end of the trombone gear, the vertical bevel gear is fixedly provided at the bottom end of the rotating roller and meshes with the transverse bevel gear at the rear end.

[0018] Preferably, the stirring assembly includes a rotating rod and a trumpet gear, the top side of the rotating rod is fixed to the center of the fixed bearing, the trumpet gear is fixed to the top of the rotating rod, the trumpet gear meshes with the trombone gear, the center of the rotating rod is fixed to the center of the limit bearing in the center of the sealing plug, and two sets of mirror-mounted telescopic stirring members are fixed to the bottom end of the rotating rod.

[0019] Preferably, a single group of the telescopic stirring member includes a fixed block and a sliding block, a square inner groove is opened inwardly from the center of the left wall of the fixed block, side grooves are opened in the centers of the two walls of the square inner groove, the sliding block slides in the square inner groove, the outer top end of the sliding block is opened as an arc-shaped inclined surface, and a stirring block is fixed to the outer bottom end of the sliding block.

[0020] Preferably, the clamping assembly includes a U-shaped block and a fixed column, the center of the U-shaped block is fixedly provided with a fixed column, the center of the fixed column is sleeved with a rotating block, a limiting clamping block is fixedly provided on the left side of the front end of the rotating block, a side plate is fixedly provided on the right side of the front end of the rotating block, a screw rod is inserted into the center thread of the side plate, and a movable clamping block is sleeved on the left end of the screw rod.

[0021] Preferably, the reaction assembly includes a four-necked flask, a constant-pressure dropping funnel, a distillation column, a serpentine condenser and a thermometer, a stirring assembly is inserted at the rear end of the four-necked flask, a constant-pressure dropping funnel is installed at the left end of the four-necked flask, a thermometer is inserted at the right end of the four-necked flask, a distillation column is installed at the front end of the four-necked flask, the rear side of the four-necked flask is clamped by a clamping frame, and the clamping frame is fixed at the front end center of the main mounting frame, a serpentine condenser is installed at the right end of the distillation column, the serpentine condenser is clamped by a clamping assembly, and the clamping assembly is fixed at the front end of the auxiliary mounting frame, and the top of the distillation column is also provided with a clamping assembly for clamping and fixed at the front end of the L-shaped block.

[0022] Preferably, a drain pipe is provided on the central bottom side of the serpentine condenser, a bull horn tube is installed on the right end of the serpentine condenser, the bull horn tube is provided with a rubber tube connected to the delivery end of the peristaltic pump, and the top of the distillation column is provided with a rubber tube connected to the output end of the peristaltic pump.

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

[0024] 1. The electric heating wire installed in the heating pool in the operating table can evenly heat the raw materials and catalysts in the four-necked flask, thereby improving the reaction efficiency and making the reaction more uniform. The lifting mechanism can drive the stirring assembly to lift and lower, so that the four-necked flask can be stirred at different depths, further improving the reaction efficiency. The telescopic stirring piece can be extended and stirred when rotating in the four-necked flask to expand the stirring area and improve the stirring efficiency. The telescopic stirring piece can be gradually recovered when rising to reduce the impact on the four-necked flask during operation, which is convenient for operation.

[0025] 2. By sequentially adding ethanol and acetic acid to the reactor and then adding a catalyst, the use of concentrated sulfuric acid can be replaced or reduced from the source, thereby improving the utilization rate of acetic acid, saving costs and preventing equipment from being corroded;

[0026] 3. The refluxed azeotropic ethanol is pressed back into the reaction liquid by a peristaltic pump. During the reaction, the water produced by the reaction is continuously released to make the reaction proceed in the direction of esterification. Then, when the reaction liquid is close to the theoretical value, sampling is started. According to the reaction liquid and the kettle liquid gas phase, sampling is performed every 1h or 2h until the ethyl ester content in the reaction liquid gas phase is greater than 80%, which is regarded as the reaction end point. That is, the crude ethyl acetate content produced can reach more than 80%, and the content of the finished product can reach more than 99.8%;

[0027] 4. In addition to the above structural design, a transmission component is provided to drive the stirring component to rotate under the transmission of the peristaltic pump. This design can further improve the reaction efficiency, while reducing energy consumption and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 It is a schematic side view of the structure of the present invention;

[0030] Figure 2 It is a side view schematic diagram of the main structure of the present invention;

[0031] Figure 3 It is a top view schematic diagram of the operating table of the present invention;

[0032] Figure 4 This is a schematic diagram of the installation position of the reaction component of the present invention;

[0033] Figure 5 It is a schematic side view of the lifting mechanism structure of the present invention;

[0034] Figure 6 This is a schematic diagram of the internal structure of a four-necked flask of the present invention;

[0035] Figure 7 It is a side cross-sectional schematic diagram of the telescopic stirring member structure of the present invention;

[0036] Figure 8 It is an enlarged schematic diagram of the clamping assembly structure of the present invention.

[0037] In the figure: 1. operating table; 11. heating pool; 12. electric heating wire; 13. main mounting frame; 14. auxiliary mounting frame; 2. lifting mechanism; 21. lifting assembly; 211. servo motor; 212. threaded rod; 213. long barrel nut; 22. L-shaped block; 221. round mouth; 222. fixed bearing; 3. clamping frame; 4. peristaltic pump; 41. rotating shaft; 42. transverse bevel gear; 5. transmission assembly; 51. rotating roller; 52. trumpet gear; 53. vertical bevel gear; 6. stirring assembly; 61. rotating rod; 62. trumpet gear; 63 , limit bearing; 64, telescopic stirring piece; 641, fixed block; 642, square inner groove; 643, side groove; 644, sliding block; 645, arc slope; 646, stirring block; 7, clamping assembly; 71, U-shaped block; 72, fixed column; 73, rotating block; 74, limit clamping block; 75, movable clamping block; 76, side plate; 77, screw; 8, reaction assembly; 81, four-necked flask; 82, constant pressure dropping funnel; 83, distillation column; 84, serpentine condenser; 841, ox-horn tube; 842, drain pipe; 85, thermometer. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0039] See also Figure 1-Figure 8 The present invention provides an embodiment: a synthetic process for ethyl acetate, comprising an operating table 1, a heating pool 11, an electric heating wire 12, a lifting mechanism 2, a clamping frame 3, a peristaltic pump 4, a transmission component 5, a stirring component 6, a clamping component 7, a reaction component 8, a four-necked flask 81, a constant pressure dropping funnel 82, a distillation column 83, a serpentine condenser 84 and a thermometer 85, and comprising the following steps:

[0040] S1, add the raw materials for the esterification stage in order into a 3L four-necked flask 81 connected with a thermometer 85, a stirring assembly 6, a constant pressure dropping funnel 82 and a serpentine condenser 84;

[0041] S2, heating the water in the heating pool 11 by energizing the electric heating wire 12, and the heated water can heat the four-necked flask 81 to 50 to 60 degrees, and then add the catalyst;

[0042] S3, continue to raise the temperature to reflux and start collecting liquid, and press the reflux azeotropic ethanol back into the reaction liquid through the peristaltic pump 4. During the reaction, the water produced by the reaction is continuously released to make the reaction proceed in the direction of esterification;

[0043] S4. When the reaction liquid is close to the theoretical value, sampling begins. According to the reaction liquid and the kettle liquid gas phase, sampling is performed every 1h or 2h until the ethyl ester content in the reaction liquid gas phase is greater than 80%, which is regarded as the reaction end point.

[0044] S5. Wash the product twice at room temperature;

[0045] S6. The obtained product phase is purified by distillation at room temperature to obtain the final product ethyl acetate.

[0046] As a further feature of the present invention, a heating pool 11 is provided on the left side of the table top of the operating table 1, an electric heating wire 12 is installed inside the heating pool 11, a main mounting frame 13 and an auxiliary mounting frame 14 are respectively installed at the rear end of the operating table 1, a lifting mechanism 2 is installed at the front end of the main mounting frame 13, and a clamping component 7 is installed at the front of the auxiliary mounting frame 14. Through this design, the water in the heating pool can be heated by the electric heating wire to heat the four-necked flask, thereby promoting the reaction efficiency.

[0047] Furthermore, the lifting mechanism 2 includes a lifting component 21 and an L-shaped block 22. The L-shaped block 22 is fixed at the front end of the lifting component 21. The lifting component 21 includes a servo motor 211, a threaded rod 212 and a long barrel nut 213. The bottom end of the servo motor 211 drives the threaded rod 212 to rotate on the rear side of the operating table 1. The center thread of the threaded rod 212 is sleeved with a long barrel nut 213. The front end of the long barrel nut 213 is fixed to the rear end of the L-shaped block 22. A circular opening 221 is provided at the connection between the center of the L-shaped block 22 and the transmission component 5. A fixed bearing 222 is fixed at the front end of the circular opening 221. This design makes it easy for the servo motor to drive the stirring component to lift and lower, which is beneficial to stirring the raw materials and catalyst in the four-necked flask and improving the reaction efficiency.

[0048] As a further feature of the present invention, a rotating shaft 41 is installed at the driving center of the peristaltic pump 4, and a transverse bevel gear 42 is fixedly arranged at the front end of the rotating shaft 41. The transmission assembly 5 includes a rotating roller 51 and a trombone gear 52. The trombone gear 52 is fixedly arranged at the center of the rotating roller 51. The trombone gear 52 is in the circular opening 221. The top of the rotating roller 51 is fixedly arranged on the inner wall of the main mounting frame 13, and the bottom end of the rotating roller 51 is fixedly arranged on the top of the clamping frame 3. A vertical bevel gear 53 is provided at the bottom end of the trombone gear 52. The vertical bevel gear 53 is fixedly arranged at the bottom end of the rotating roller 51 and meshes with the transverse bevel gear 42 at the rear end. This design can further improve the reaction efficiency, while reducing energy consumption and production costs.

[0049] As a further feature of the present invention, the stirring assembly 6 includes a rotating rod 61 and a trumpet gear 62. The top side of the rotating rod 61 is fixed to the center of the fixed bearing 222. The trumpet gear 62 is fixed to the top of the rotating rod 61. The trumpet gear 62 meshes with the trumpet gear 52. The center of the rotating rod 61 is fixed to the center of the limit bearing 63 at the center of the sealing plug. Two groups of telescopic stirring members 64 installed in a mirror image are fixed at the bottom end of the rotating rod 61. The single group of telescopic stirring members 64 includes a fixed block 641 and a sliding block 644. A square inner groove 642 is provided inwardly from the center of the left wall of the fixed block 641. Side grooves 643 are provided in the centers of the two walls of the square inner groove 642. The sliding block 644 slides in the square inner groove 642. The outer top end of the sliding block 644 is provided with an arc-shaped inclined surface 645. A stirring block 646 is fixed to the outer bottom end of the sliding block 644. This design is beneficial for extended stirring when rotating in a four-necked flask, thereby expanding the stirring area, improving the stirring efficiency and facilitating operation.

[0050] Furthermore, the clamping assembly 7 includes a U-shaped block 71 and a fixed column 72. The fixed column 72 is fixedly provided at the center of the U-shaped block 71. The center of the fixed column 72 is sleeved with a rotating block 73. A limit clamping block 74 is fixedly provided on the left side of the front end of the rotating block 73. A side plate 76 is fixedly provided on the right side of the front end of the rotating block 73. A screw rod 77 is inserted into the center thread of the side plate 76. The left end of the screw rod 77 is sleeved with a movable clamping block 75, which can clamp the reaction assembly at multiple angles. The structure is simple and easy to operate.

[0051] As a further feature of the present invention, the reaction assembly 8 includes a four-necked flask 81, a constant pressure dropping funnel 82, a distillation column 83, a serpentine condenser 84 and a thermometer 85. The rear end of the four-necked flask 81 is provided with a stirring assembly 6, the left end of the four-necked flask 81 is provided with a constant pressure dropping funnel 82, the right end of the four-necked flask 81 is provided with a thermometer 85, the front end of the four-necked flask 81 is provided with a distillation column 83, the rear side of the four-necked flask 81 is clamped by a clamping frame 3, the clamping frame 3 is fixedly arranged at the front end center of the main mounting frame 13, the right end of the distillation column 83 is provided with a serpentine condenser Condensation tube 84, the serpentine condenser 84 is clamped by a clamping assembly 7, and the clamping assembly 7 is fixed at the front end of the auxiliary mounting frame 14. The top of the distillation column 83 is also provided with a clamping assembly 7 for clamping and fixed at the front end of the L-shaped block 22. A drainage pipe 842 is provided on the central bottom side of the serpentine condenser 84. A bull horn tube 841 is installed at the right end of the serpentine condenser 84. The bull horn tube 841 is provided with a rubber tube connected to the delivery end of the peristaltic pump 4. The top of the distillation column 83 is provided with a rubber tube connected to the output end of the peristaltic pump 4, which improves the utilization rate of acetic acid, saves costs and prevents equipment from being corroded.

[0052] Embodiment 1:

[0053] Add ethanol and acetic acid to the reactor in sequence, stir and heat to 50-60°C, then add 0.1% 1-ethyl-3-methylimidazolium methanesulfonate catalyst and heat to reaction reflux, set the reaction temperature to 100°C, the reflux temperature to 92°C, and no air is required to be passed into the esterification reactor during the reaction. The crude ester gas phase of the reaction liquid is measured to be 81.56%, and the reaction is completed. The product is washed twice at room temperature and distilled at room temperature and pressure to a finished product content of 99.90%.

[0054] Embodiment 2:

[0055] Add ethanol and acetic acid to the reactor in sequence, stir and heat to 50-60°C, then add 0.1% glutamic acid p-toluenesulfonic acid ionic liquid catalyst and heat to reaction reflux, set the reaction temperature to 100°C, the reflux temperature to 92°C, and no air is needed to be passed into the esterification reactor during the reaction. The crude ester gas phase of the reaction liquid is measured to be 80.85%, and the reaction is completed. The product is washed twice at room temperature and distilled at room temperature and pressure to a finished product content of 99.88%.

[0056] Embodiment 3:

[0057] Add ethanol and acetic acid to the reactor in sequence, stir and heat to 50-60°C, then add 0.1% 2-pyrrolidone hydrogen sulfate ionic liquid catalyst and heat to reaction reflux, set the reaction temperature to 100°C, the reflux temperature to 92°C, and no air is required to be passed into the esterification reactor during the reaction. The crude ester gas phase of the reaction liquid is measured to be 80.02%, and the reaction is completed. The product is washed twice at room temperature and distilled at room temperature and pressure to a finished product content of 99.82%.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A process for synthesizing ethyl acetate, comprising an operating table (1), a heating tank (11), an electric heating wire (12), a lifting mechanism (2), a clamping frame (3), a peristaltic pump (4), a transmission component (5), a stirring component (6), a clamping component (7), a reaction component (8), a four-necked flask (81), a constant pressure dropping funnel (82), a distillation column (83), a serpentine condenser (84) and a thermometer (85), characterized in that: The steps include: S1, the raw materials for the esterification stage are sequentially added into a 3L four-necked flask (81) connected with a thermometer (85), a stirring assembly (6), a constant pressure dropping funnel (82) and a serpentine condenser (84); S2, heating the water in the heating pool (11) by turning on the electric heating wire (12), and the heated water can heat the four-necked flask (81) to 50 to 60 degrees, and then add the catalyst; S3, continue to raise the temperature to reflux and start collecting liquid, and use the peristaltic pump (4) to press the refluxed azeotropic ethanol back into the reaction liquid. During the reaction, the water produced by the reaction is continuously released to make the reaction proceed in the direction of esterification; S4. When the reaction liquid is close to the theoretical value, sampling begins. According to the reaction liquid and the kettle liquid gas phase, sampling is performed every 1h or 2h until the ethyl ester content in the reaction liquid gas phase is greater than 80%, which is regarded as the reaction end point. S5. Wash the product twice at room temperature; S6. The obtained product phase is purified by distillation at room temperature to obtain the final product ethyl acetate.

2. A process for synthesizing ethyl acetate according to claim 1, characterized in that: A heating pool (11) is provided on the left side of the tabletop of the operating table (1), an electric heating wire (12) is installed inside the heating pool (11), a main mounting frame (13) and a secondary mounting frame (14) are respectively installed at the rear end of the operating table (1), a lifting mechanism (2) is installed at the front end of the main mounting frame (13), and a clamping assembly (7) is installed at the front of the secondary mounting frame (14).

3. A synthetic process for ethyl acetate according to claim 1, characterized in that: The lifting mechanism (2) comprises a lifting assembly (21) and an L-shaped block (22); the L-shaped block (22) is fixedly arranged at the front end of the lifting assembly (21); the lifting assembly (21) comprises a servo motor (211), a threaded rod (212) and a long-barrel nut (213); the bottom end of the servo motor (211) drives the threaded rod (212) to rotate at the rear side of the operating table (1); the center thread of the threaded rod (212) is sleeved with a long-barrel nut (213); the front end of the long-barrel nut (213) is fixedly arranged at the rear end of the L-shaped block (22); a circular opening (221) is provided at the connection between the center of the L-shaped block (22) and the transmission assembly (5); a fixed bearing (222) is fixedly arranged at the front end of the circular opening (221).

4. A process for synthesizing ethyl acetate according to claim 1, characterized in that: A rotating shaft (41) is installed at the driving center of the peristaltic pump (4), and a transverse bevel gear (42) is fixed at the front end of the rotating shaft (41).

5. A synthetic process for ethyl acetate according to claim 1, characterized in that: The transmission assembly (5) comprises a rotating roller (51) and a trombone gear (52). The center of the rotating roller (51) is fixedly provided with a trombone gear (52). The trombone gear (52) is in the circular opening (221). The top end of the rotating roller (51) is fixedly provided on the inner wall of the main mounting frame (13). The bottom end of the rotating roller (51) is fixedly provided on the top end of the clamping frame (3). A vertical bevel gear (53) is provided at the bottom end of the trombone gear (52). The vertical bevel gear (53) is fixedly provided on the bottom end of the rotating roller (51) and meshes with the transverse bevel gear (42) at the rear end.

6. A synthetic process for ethyl acetate according to claim 1, characterized in that: The stirring assembly (6) comprises a rotating rod (61) and a trumpet gear (62); the top side of the rotating rod (61) is fixedly arranged at the center of a fixed bearing (222); the trumpet gear (62) is fixedly arranged at the top end of the rotating rod (61); the trumpet gear (62) meshes with the trumpet gear (52); the center of the rotating rod (61) is fixedly arranged at the center of a limit bearing (63) at the center of a sealing plug; and two sets of mirror-mounted telescopic stirring members (64) are fixedly arranged at the bottom end of the rotating rod (61).

7. A synthetic process for ethyl acetate according to claim 6, characterized in that: A single set of the telescopic stirring member (64) comprises a fixed block (641) and a sliding block (644); a square inner groove (642) is provided inwardly from the center of the left wall of the fixed block (641); side grooves (643) are provided in the centers of the two walls of the square inner groove (642); the sliding block (644) slides in the square inner groove (642); an arc-shaped inclined surface (645) is provided at the outer top end of the sliding block (644); and a stirring block (646) is fixedly provided at the outer bottom end of the sliding block (644).

8. A process for synthesizing ethyl acetate according to claim 1, characterized in that: The clamping assembly (7) comprises a U-shaped block (71) and a fixed column (72); the center of the U-shaped block (71) is fixedly provided with a fixed column (72); the center of the fixed column (72) is sleeved with a rotating block (73); a limit clamping block (74) is fixedly provided at the left front end of the rotating block (73); a side plate (76) is fixedly provided at the right front end of the rotating block (73); a screw rod (77) is inserted into the center of the side plate (76) through a thread; and a movable clamping block (75) is sleeved at the left end of the screw rod (77).

9. A synthetic process for ethyl acetate according to claim 1, characterized in that: The reaction assembly (8) comprises a four-necked flask (81), a constant pressure dropping funnel (82), a distillation column (83), a serpentine condenser (84) and a thermometer (85); a stirring assembly (6) is inserted at the rear end of the four-necked flask (81); a constant pressure dropping funnel (82) is installed at the left end of the four-necked flask (81); a thermometer (85) is inserted at the right end of the four-necked flask (81); a distillation column (83) is installed at the front end of the four-necked flask (81); The rear side of the flask (81) is clamped by a clamping frame (3), and the clamping frame (3) is fixed at the front center of the main mounting frame (13). The right end of the distillation column (83) is installed with a serpentine condenser (84), and the serpentine condenser (84) is clamped by a clamping assembly (7), and the clamping assembly (7) is fixed at the front end of the auxiliary mounting frame (14). The top of the distillation column (83) is also provided with a clamping assembly (7) for clamping and fixed at the front end of the L-shaped block (22).

10. A synthetic process for ethyl acetate according to claim 9, characterized in that: A drainage pipe (842) is provided at the central bottom side of the serpentine condenser (84), a bull horn tube (841) is installed at the right end of the serpentine condenser (84), and the bull horn tube (841) is provided with a rubber tube connected to the delivery end of the peristaltic pump (4), and the top of the distillation column (83) is provided with a rubber tube connected to the output end of the peristaltic pump (4).

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