ECEG product elastic switching device

Abstract

The invention relates to the technical field of ethylene glycol production, in particular to an ECEG product elastic switching device which comprises an epoxy device, an EC device, an EG device and an EC tank area, the epoxy device is connected with the EC device, and ethylene oxide and carbon dioxide raw materials are conveyed to the EC device; a discharge pipeline of the EC device is divided into two paths, one path is connected with an EC tank area for storing EC products, and the other path is connected with the EG device; a first gate valve is arranged on the pipeline between the EC device and the EC tank area, and a second gate valve is arranged on the pipeline between the EC device and the EG device. Compared with the prior art, the device has the following beneficial effects that the device is small in secondary investment, small in occupied space and low in energy consumption and material consumption; according to the invention, the structure of the ethylene carbonate and ethylene glycol product can be effectively adjusted, and waste is avoided, so that the effects of reducing cost and improving efficiency are achieved, external market environment factors are solved to the maximum extent, and the difficulty of changing the structure of the product is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of ethylene glycol production, and in particular to an elastic switching device for ECEG products. Background Art

[0002] With the rapid development of modern industry, the demand for environmentally friendly and high-performance chemicals is growing. Ethylene carbonate (hereinafter referred to as EC), as an important organic chemical raw material, has excellent physical and chemical properties and is widely used in plastics, coatings, solvents and other fields. As one of the important raw materials for the production of EC, the optimization of ethylene oxide's production technology and process is of great significance for increasing EC production, reducing costs and protecting the environment. EC is an environmentally friendly organic solvent and plastic raw material with excellent solubility, stability and biocompatibility. As people's demand for environmentally friendly materials increases, the market demand for EC is also growing. Its application areas are constantly expanding, including plastics, coatings, battery electrolytes, etc.

[0003] Ethylene glycol (EG), an important organic solvent and synthetic raw material, continues to see increasing demand in industrial production. Therefore, developing efficient and environmentally friendly methods for converting EC into EG would not only improve production efficiency but also provide a viable waste conversion and resource recycling pathway for the industrial sector. Furthermore, this process research could help reduce production costs and promote the sustainable development of the related industrial chain. my country is expected to see a large number of new EC plants being established in the future; therefore, we are facing the pressure of overcapacity and operational challenges. This necessitates further adjustments to our own production processes, optimizing our production capacity structure, and enhancing our competitiveness.

[0004] In summary, due to industrial development, market expectations, and equipment maintenance, the supply and demand of EC and EG have been fluctuating for a long time, and their prices have also been fluctuating. Therefore, there is an urgent need for a flexible switching device that can switch the products produced by the device between EC and EG to maximize benefits. Summary of the Invention

[0005] The purpose of the present invention is to provide an ECEG product elastic switching device, which has the characteristic of being able to flexibly switch EC and EG products.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: an ECEG product elastic switching device, including an epoxy device, an EC device, an EG device, and an EC tank area,

[0007] The epoxy unit is connected to the EC unit to deliver ethylene oxide and carbon dioxide raw materials to the EC unit;

[0008] The discharge pipeline of the EC unit is divided into two routes, one is connected to the EC tank farm for storing EC products, and the other is connected to the EG unit;

[0009] Gate valve 1 is installed on the pipeline between the EC device and the EC tank area, and gate valve 2 is installed on the pipeline between the EC device and the EG device.

[0010] Preferably, the EC device includes an EC reactor I, an EC reactor II, a circulating liquid heat exchanger, a crude ester tank, a vent cooler, an ethyl carbon evaporation system, an ethyl carbon product buffer tank, and an ethyl carbon product pump;

[0011] The bottom of EC reactor I is connected to the bottom of EC reactor II, which is also connected to a circulating liquid heat exchanger. The circulating liquid heat exchanger is connected back to the feed end of EC reactor I. The tops of EC reactor I and EC reactor II are connected to a crude ester tank. The crude ester tank is connected to a crude ester tank vent cooler. The discharge end of the crude ester tank is connected to a carbon ethylene evaporation system, a carbon ethylene product buffer tank, and a carbon ethylene product pump in sequence.

[0012] Part of the material in EC reactor I enters EC reactor II from the bottom under the conditions of 4.0 MPag and 130°C, and the other part of the material enters the circulating liquid heat exchanger to preheat the fresh material;

[0013] After the gaseous materials at the top of EC reactor I and EC reactor II enter the crude ester tank, they are cooled by the crude ester tank vent cooler to condense the gas phase into liquid phase to reduce waste, and the material with EC content of 99% enters the ethyl carbon evaporation system from the crude ester tank.

[0014] Preferably, the carbon ethylene evaporation system includes a falling film evaporator, a falling film evaporator separation chamber, and a falling film evaporator cooler;

[0015] The bottom of the falling film evaporator is connected to the bottom of the falling film evaporator separation chamber, the bottom discharge pipelines of the falling film evaporator and the falling film evaporator separation chamber are connected to the concentrated liquid collection device, the top of the falling film evaporator separation chamber is connected to the falling film evaporator cooler through a pipeline, and the discharge end of the falling film evaporator cooler is connected to the ethyl carbon product buffer tank;

[0016] The material with an EC content of 99% enters the ethyl carbon evaporation system from the crude ester tank, and then enters the falling film evaporator and the falling film evaporator separation chamber in sequence. The concentrated liquid produced at the bottom of the falling film evaporator and the falling film evaporator separation chamber is recovered to the concentrated liquid recovery device; the EC after exiting the falling film evaporator separation chamber is a qualified polyester-grade product, which enters the falling film evaporator cooler for cooling and then enters the ethyl carbon product buffer tank. The ethyl carbon evaporation system purifies the material with an EC content of 99%, separates the catalyst I therein, and recycles it.

[0017] Preferably, the EG device includes an EG reaction feed tank, an EG reaction feed pump, an EG reactor I, an EG reactor II, an EG dehydration tower, and an EG refining tower;

[0018] The feed end of the EG reaction feed tank is connected to the discharge pipeline of the EC device, and the discharge end is connected to the EG reaction feed pump, EG reactor I, EG reactor II, EG dehydration tower, and EG refining tower in sequence;

[0019] The EG dehydration tower and the EG refining tower are of full vacuum design, and the tops of the towers are connected to a vacuum ejector group, and the vacuum ejector group 40 is connected to a wastewater system.

[0020] Preferably, the EG reaction feed tank is connected to a CAT feed pipeline and a DMW feed pipeline, the CAT concentration is ≥1%, and the hydration ratio of water to EC is not less than 1.4:1.

[0021] Preferably, EG reactor I and EG reactor II are horizontal reactors connected in series, and the internal structure of EG reactor II is provided with a plurality of baffles.

[0022] Preferably, EG reactor I generates an EG aqueous solution with a concentration of 78% under the conditions of 2.0 MPa and 150° C., and EG reactor I is connected to an EG reactor I cooler. The gas phase at the top of EG reactor I is condensed through the EG reactor I cooler, and the material at the bottom of EG reactor I enters EG reactor II.

[0023] Preferably, the EG reactor II is connected to an EG reactor II cooler, and the gas phase at the top of the EG reactor II is condensed through the EG reactor II cooler, and an EG aqueous solution with a concentration of 90% is generated in the EG reactor II under the conditions of 0.2 MPa and 150°C.

[0024] Preferably, the EG dehydration tower generates an EG aqueous solution with a concentration of 98% under the conditions of 12kpa and 145°C. The EG dehydration tower is connected to an EG dehydration tower reboiler. The bottom of the EG dehydration tower is connected to an EG dehydration tower kettle pump. The discharge end of the EG dehydration tower kettle pump is connected to the EG refining tower. The EG dehydration tower reboiler is a falling film reboiler and adopts 1.4Mpa steam heat exchange.

[0025] Preferably, the EG refining tower produces qualified EG products under the conditions of 8KPa and 141°C. The EG refining tower is connected to an EG refining tower reboiler and an EG refining tower side reboiler. The bottom of the EG refining tower is connected to an EG refining tower kettle pump, and the discharge port of the EG refining tower kettle pump is connected to a CAT recovery device.

[0026] The top of the EG refining tower is connected to the EG refining tower top cooler, the discharge end of the EG refining tower top cooler is connected to the EG refining tower reflux tank and the EG refining tower reflux pump, and the discharge pipeline of the EG refining tower reflux pump is divided into two routes, one route is connected to the EG refining tower, and the other route is connected to the EG tank area;

[0027] The EG refining tower reboiler and the EG refining tower side line reboiler are falling film reboilers, which use 0.6Mpa steam to provide heat exchange.

[0028] In summary, the present invention has the following beneficial effects: compared with the existing process, the device has small secondary investment, small floor space, and low energy and material consumption; it can effectively adjust the product structure of ethylene carbonate and ethylene glycol to avoid waste, thereby achieving the effect of reducing costs and increasing efficiency, maximizing the solution to external market environment factors, realizing the dilemma of changing product structure, and being able to flexibly respond to changes in market conditions. It solves the technical difficulties in the flexible switching of EC and EG products, ensuring the realization of technical breakthroughs in EC and EG products during the period of sustained growth in the future, maximizing profits, and creating tens of millions of yuan in value for the enterprise each year; at the same time, it saves about several million yuan in electricity and steam energy consumption each year. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural diagram of an embodiment;

[0030] Figure 2 yes Figure 1 A magnified schematic diagram of the EC device;

[0031] Figure 3 yes Figure 1 A magnified schematic diagram of the EG device;

[0032] Figure 4 Schematic diagram of the structure of the carbon ethylene evaporation system in the embodiment.

[0033] In the figure, 101, EC unit; 102, EG unit; 5, EC reactor I; 6, EC reactor II; 10, circulating liquid heat exchanger; 9, crude ester tank; 11, gate valve 1; 14, vent cooler; 15, ethyl carbon evaporation system; 16, ethyl carbon product buffer tank; 19, ethyl carbon product pump; 20, EG reaction feed tank; 25, EG reactor I; 29, EG reactor II; 30, EG reactor II cooler; 31, EG reactor I cooler; 36, EG dehydration tower reboiler; 39, EG dehydration tower; 40, Vacuum ejector group; 42, EG refining tower; 46, EG refining tower reboiler; 47, EG refining tower kettle pump; 48, EG refining tower side line reboiler; 51, EG refining tower reflux pump; 52, EG refining tower reflux tank; 56, EG refining tower top cooler; 57, gate valve 2; 58, EG dehydration tower kettle pump; 59, gate valve 3; 62, EG reaction feed pump; 63, gate valve 4; 64, falling film evaporator; 65, gate valve 5; 66, falling film evaporator separation chamber; 67, gate valve 6; 68, falling film evaporator cooler. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings.

[0035] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

[0036] Example:

[0037] An ECEG product elastic switching device, such as Figure 1-3 As shown, it includes an epoxy device, an EC device 101, and an EG device 102. The epoxy device is connected to the EC device 101 through a pipeline, and the EC device 101 is connected to the EG device 102 through a pipeline.

[0038] The EC device 101 includes an EC reactor I 5 and an EC reactor II 6. The epoxy device is connected to the feed of the EC reactor I 5 via two pipelines, both of which are equipped with flow meters and flow control valves.

[0039] The bottom of EC reactor I5 is connected to the bottom of EC reactor II6 via a pipeline. The bottom of EC reactor I5 is also connected to a circulating liquid heat exchanger 10, which is connected back to the feed end of EC reactor I5. The tops of EC reactor I5 and EC reactor II6 are connected to a crude ester tank 9. A flow meter and a flow control valve are installed on the pipeline between the top of EC reactor I5 and the crude ester tank 9. The crude ester tank 9 is connected to a crude ester tank vent cooler 14. The discharge of the crude ester tank 9 is connected in sequence to the ethyl carbon evaporation system 15, the ethyl carbon product buffer tank 16, and the ethyl carbon product pump 19.

[0040] like Figure 4 As shown, the ethyl carbon evaporation system 15 includes a falling film evaporator 64, a falling film evaporator separation chamber 66, and a falling film evaporator cooler 68. The top feed pipeline of the falling film evaporator 64 is installed with a gate valve 4 63. The bottom of the falling film evaporator 64 and the bottom of the falling film evaporator separation chamber 66 are connected by a pipeline, and a gate valve 5 65 is installed on the pipeline. The bottom discharge pipelines of the falling film evaporator 64 and the falling film evaporator separation chamber 66 are connected to the concentrated liquid collection device. The top of the falling film evaporator separation chamber 66 is connected to the falling film evaporator cooler 68 through a pipeline, and a gate valve 6 67 is installed on the pipeline. The discharge end of the falling film evaporator cooler 68 is connected to the ethyl carbon product buffer tank 16 through a pipeline.

[0041] like Figure 1-3 As shown, a flow control valve is installed on the pipeline between the ethylene carbon product buffer tank 16 and the ethylene carbon product pump 19. A liquid level gauge is connected to the ethylene carbon product buffer tank 16. The discharge pipeline of the ethylene carbon product pump 19 is divided into two routes. One route is connected to the EC tank farm via a pipeline equipped with a gate valve 11, a flow meter, and a flow control valve; the other route is connected to the EG reaction feed tank 20 via a pipeline equipped with an observation flow meter and gate valve 57.

[0042] The EG reaction feed tank 20 is connected to the CAT feed pipeline and the DMW feed pipeline. The CAT feed pipeline is installed with a gate valve 59, and the DMW feed pipeline is installed with a flow meter and a flow control valve.

[0043] The outlet of the EG reaction feed tank 20 is connected to an EG reaction feed pump 62. A flow control valve is connected to the pipeline between the EG reaction feed tank 20 and the EG reaction feed pump 62. A liquid level gauge is connected to the EG reaction feed tank 20. The outlet of the EG reaction feed pump 62 is connected to the EG reactor I 25.

[0044] EG Reactor I 25 is connected to a steam pipeline equipped with a flowmeter and flow control valve. EG Reactor I 25 is also connected to EG Reactor I cooler 31 and a flowmeter. The discharge port of EG Reactor I 25 is connected to EG Reactor II 29 via a pipeline equipped with a flow control valve. EG Reactor II 29 is connected to EG Reactor II cooler 30 and a level gauge. EG Reactor I 25 and EG Reactor II 29 are horizontal reactors connected in series, and EG Reactor II 29 is internally configured with multiple baffles.

[0045] The discharge line from EG reactor II 29 is connected to EG dehydration tower 39. The bottom of EG dehydration tower 39 is connected to a thermometer and EG dehydration tower reboiler 36. A flowmeter and a flow control valve are installed on the steam inlet line to EG dehydration tower reboiler 36. The bottom discharge line from EG dehydration tower 39 is connected to EG dehydration tower kettle pump 58. The discharge port of EG dehydration tower kettle pump 58 is connected to EG refining tower 42. The bottom of EG refining tower 42 is connected to a thermometer, EG refining tower reboiler 46, and EG refining tower side reboiler 48. Heat for EG refining tower 42 is provided by EG refining tower reboiler 46 and EG refining tower side reboiler 48. A flowmeter and a flow control valve are installed on the steam inlet line to EG refining tower reboiler 46, and a flowmeter and a control valve are installed on the steam inlet line to EG refining tower side reboiler 48. The bottom of the EG refining tower 42 is connected to an EG refining tower kettle pump 47 through a pipeline, and the discharge port of the EG refining tower kettle pump 47 is connected to a CAT recovery device.

[0046] The tops of the EG dehydration tower 39 and the EG refining tower 42 are both connected with thermometers. The EG dehydration tower 39 and the EG refining tower 42 are of full vacuum design. The tops of the towers are both connected with a vacuum ejector group 40, which is connected to the wastewater system.

[0047] The top of the EG refining tower 42 is connected to the EG refining tower overhead cooler 56. The discharge end of the EG refining tower overhead cooler 56 is connected to the EG refining tower reflux tank 52 and the EG refining tower reflux pump 51 via a pipeline. The discharge pipeline of the EG refining tower reflux pump 51 is divided into two routes, one connected to the EG refining tower 42 and the other connected to the EG tank area. A liquid level gauge is connected to the EG refining tower reflux tank 52. A flow control valve is connected to the pipeline between the EG refining tower reflux pump 51 and the EG refining tower 42. A flow meter and a flow control valve are connected to the pipeline between the EG refining tower reflux pump 51 and the EG tank area.

[0048] The EG dehydration tower reboiler 36, the EG refining tower reboiler 46, and the EG refining tower side reboiler 48 are all falling film reboilers.

[0049] The working principle of this embodiment is as follows:

[0050] Ethylene oxide and carbon dioxide delivered from the epoxidation unit enter EC reactor I5 via a pipeline. Flow meters and flow control valves precisely control the ratio of the two to ensure plant safety. A portion of the material in EC reactor I5, at approximately 4.0 MPa and 130°C, enters EC reactor II6 via a pipeline from the bottom. Another portion of the material enters circulating liquid heat exchanger 10 via a pipeline to preheat the fresh material. The overhead vaporous material from EC reactors I5 and II6 enters crude ester tank 9 via a pipeline. It is then cooled by crude ester tank vent cooler 14, condensing the vaporous material from EC reactor I5 into a liquid phase to minimize waste. 99% EC is delivered from crude ester tank 9 via a pipeline to ethylene carbon evaporation system 15, passing through gate valve 4 63 and into falling film evaporator 64. The concentrate produced at the bottom of falling film evaporator 64 and its separation chamber 66 is recovered via a pipeline to a concentrate recovery unit. The EC exiting falling film evaporator separation chamber 66 is a qualified product. It enters falling film evaporator cooler 68, where it is cooled and then enters ethylene carbon product buffer tank 16. Ethyl carbon evaporation system 15 purifies the material with an EC content of 99%, separating catalyst I from it so that catalyst I can be recycled. The EC content of the material exiting ethylene carbon evaporation system 15 reaches polyester-grade EC product and enters ethylene carbon product buffer tank 16 via a pipeline. Ethyl carbon product pump 19 pumps the EC product from buffer tank 16 to two locations via pipelines: the first is connected to the EC tank farm, and the second is pipelined to EG unit 102.

[0051] EC, delivered from EC unit 101, is piped into EG reactor feed tank 20. Simultaneously, DMW and catalyst II are added to the EG reactor feed tank 20. The concentration of catalyst II is ≥1%, and the hydration ratio of water to EC is no less than 1.4:1. The material in EG reactor feed tank 20 is pumped by EG reactor feed pump 62 into EG reactor I 25, where it is subjected to pressures of 2.0 MPa and 150°C to produce an aqueous EG solution with a concentration of approximately 78%. The vapor phase at the top of EG reactor I 25 is condensed in EG reactor I cooler 31. The material at the bottom of EG reactor I 25 is piped into EG reactor II 29. The vapor phase at the top of EG reactor II 29 is condensed in EG reactor II cooler 30, producing an aqueous EG solution with a concentration of 90% in EG reactor II 29 at 0.2 MPa and 150°C.

[0052] The bottoms of EG reactor II 29 are piped to EG dehydration tower 39, where a 98% EG aqueous solution is produced at 12 kPa and 145°C. Heat for EG dehydration tower 39 is provided by heat exchange between the EG dehydration tower reboiler 36 and 1.4 MPa steam. The EG aqueous solution enters EG dehydration tower 39 and then, via EG dehydration tower kettle pump 58, enters EG refining tower 42, where it produces qualified EG product at 8 kPa and 141°C. Heat for EG refining tower 42 is provided by EG refining tower reboiler 46 and EG refining tower side reboiler 48, both of which are fed with 0.6 MPa steam for heat exchange. The highest concentration of heavy components is observed in the EG refining tower side reboiler 48, and a thermometer is used to determine whether some heavy alcohol needs to be discharged to maintain system balance. EG refining tower 42 is maintained in a vacuum state by a vacuum ejector unit 40. The overhead material from EG refining tower 42 flows through a pipeline into EG overhead cooler 58. After cooling, it enters EG refining tower reflux tank 52. EG refining tower reflux pump 51 returns some of the material to EG refining tower 42 and sends the remaining portion to the EG tank area, where an EG product with a concentration of over 99.9% is produced. The heavy components in the bottom of EG refining tower 42 are recovered by EG refining tower bottom pump 47, which recovers CAT and discharges heavy alcohol to maintain system cleanliness.

[0053] When the producer plans to produce more EC products, the opening of gate valve 2 57 is reduced, and the flow of EC products to the EG device 102 is observed; at the same time, the opening of gate valve 11 is increased, and the flow of the flow control valve in front of gate valve 11 is increased, and the flow of EC products to the EC tank area is observed, thereby achieving the purpose of increasing the output of EC products.

[0054] When the producer plans to produce more EG products, the opening of gate valve 2 57 is increased, and the flow of EC products to the EG device 102 is observed; at the same time, the opening of gate valve 11 is reduced, and the flow of the flow control valve in front of gate valve 11 is reduced, and the flow of EC products to the EC tank area is observed, thereby achieving the purpose of increasing the output of EG products.

Claims

1. An ECEG product elastic switching device, characterized in that: Including epoxy unit, EC unit (101), EG unit (102), EC tank area, The epoxidation device is connected to the EC device (101) to deliver ethylene oxide and carbon dioxide raw materials to the EC device (101); The discharge pipeline of the EC device (101) is divided into two routes, one of which is connected to the EC tank area for storing EC products, and the other is connected to the EG device (102); A gate valve 1 (11) is provided on the pipeline between the EC device (101) and the EC tank farm, and a gate valve 2 (57) is provided on the pipeline between the EC device (101) and the EG device (102); When it is planned to produce more EC products, the opening of gate valve 2 (57) is reduced, and the opening of gate valve 1 (11) is increased; When it is planned to produce more EG products, the opening of gate valve 2 (57) is increased, while the opening of gate valve 1 (11) is decreased.

2. The ECEG product elastic switching device according to claim 1, characterized in that: The EC device (101) includes an EC reactor I (5), an EC reactor II (6), a circulating liquid heat exchanger (10), a crude ester tank (9), a vent cooler (14), an ethyl carbon evaporation system (15), an ethyl carbon product buffer tank (16), and an ethyl carbon product pump (19); The bottom of the EC reactor I (5) is connected to the bottom of the EC reactor II (6), and the bottom of the EC reactor I (5) is also connected to the circulating liquid heat exchanger (10). The circulating liquid heat exchanger (10) is connected back to the feed end of the EC reactor I (5). The tops of the EC reactor I (5) and the EC reactor II (6) are connected to the crude ester tank (9). The crude ester tank (9) is connected to the crude ester tank (9) vent cooler (14). The discharge end of the crude ester tank (9) is connected to the ethyl carbon evaporation system (15), the ethyl carbon product buffer tank (16), and the ethyl carbon product pump (19) in sequence. Part of the material in EC reactor I (5) enters EC reactor II (6) from the bottom under the conditions of 4.0 MPag and 130°C, and the other part of the material enters the circulating liquid heat exchanger (10) to preheat the fresh material; After the gaseous materials at the top of the EC reactor I (5) and EC reactor II (6) enter the crude ester tank (9), they are cooled by the crude ester tank (9) vent cooler (14) to condense the gaseous phase into the liquid phase to reduce waste, and the resulting material with an EC content of 99% enters the ethyl carbon evaporation system (15) from the crude ester tank (9).

3. The ECEG product elastic switching device according to claim 2, characterized in that: The carbon ethylene evaporation system (15) includes a falling film evaporator (64), a falling film evaporator separation chamber (66), and a falling film evaporator cooler (68); The bottom of the falling film evaporator (64) is connected to the bottom of the falling film evaporator separation chamber (66), the bottom discharge pipelines of the falling film evaporator (64) and the falling film evaporator separation chamber (66) are connected to the concentrated liquid collection device, the top of the falling film evaporator separation chamber (66) is connected to the falling film evaporator cooler (68) through a pipeline, and the discharge end of the falling film evaporator cooler (68) is connected to the ethyl carbon product buffer tank (16); The material with an EC content of 99% enters the ethyl carbon evaporation system (15) from the crude ester tank (9), and then enters the falling film evaporator (64) and the falling film evaporator separation chamber (66) in sequence. The concentrated liquid produced at the bottom of the falling film evaporator (64) and the falling film evaporator separation chamber (66) is recovered to the concentrated liquid recovery device; the EC coming out of the falling film evaporator separation chamber (66) is a qualified polyester-grade product, which enters the falling film evaporator cooler (68) and enters the ethyl carbon product buffer tank (16) after cooling. The ethyl carbon evaporation system (15) purifies the material with an EC content of 99%, separates the catalyst I therein and recycles it.

4. The ECEG product elastic switching device according to claim 1, characterized in that: The EG device (102) includes an EG reaction feed tank (20), an EG reaction feed pump (62), an EG reactor I (25), an EG reactor II (29), an EG dehydration tower (39), and an EG refining tower (42); The feed end of the EG reaction feed tank (20) is connected to the discharge pipeline of the EC device (101), and the discharge end is sequentially connected to the EG reaction feed pump (62), EG reactor I (25), EG reactor II (29), EG dehydration tower (39), and EG refining tower (42); The EG dehydration tower (39) and the EG refining tower (42) are of full vacuum design, and the tops of the towers are connected to a vacuum ejector group (40), which is connected to a wastewater system.

5. The ECEG product elastic switching device according to claim 4, characterized in that: The EG reaction feed tank (20) is connected to a CAT feed pipeline and a DMW feed pipeline, the CAT concentration is ≥1%, and the hydration ratio of water to EC is not less than 1.4:

1.

6. The ECEG product elastic switching device according to claim 4, characterized in that: EG reactor I (25) and EG reactor II (29) are horizontal reactors connected in series, and the internal structure of EG reactor II (29) is provided with a plurality of baffles.

7. The ECEG product elastic switching device according to claim 4, characterized in that: EG reactor I (25) generates an EG aqueous solution with a concentration of 78% under the conditions of 2.0 MPa and 150°C. EG reactor I (25) is connected to an EG reactor I cooler (31). The gas phase at the top of EG reactor I (25) is condensed through the EG reactor I cooler (31), and the material at the bottom of EG reactor I (25) enters EG reactor II (29).

8. The ECEG product elastic switching device according to claim 4, characterized in that: The EG reactor II (29) is connected to the EG reactor II cooler (30). The gas phase at the top of the EG reactor II (29) is condensed through the EG reactor II cooler (30). An EG aqueous solution with a concentration of 90% is generated in the EG reactor II (29) under the conditions of 0.2 MPa and 150°C.

9. The ECEG product elastic switching device according to claim 4, characterized in that: The EG dehydration tower (39) generates an EG aqueous solution with a concentration of 98% under the conditions of 12 kPa and 145°C. The EG dehydration tower (39) is connected to an EG dehydration tower reboiler (36). The bottom of the EG dehydration tower (39) is connected to an EG dehydration tower kettle pump (58). The discharge end of the EG dehydration tower kettle pump (58) is connected to an EG refining tower (42). The EG dehydration tower reboiler (36) is a falling film reboiler that uses 1.4 MPa steam for heat exchange.

10. The ECEG product elastic switching device according to claim 4, characterized in that: The EG refining tower (42) produces qualified EG products under the conditions of 8KPa and 141°C. The EG refining tower (42) is connected to an EG refining tower reboiler (46) and an EG refining tower side reboiler (48). The bottom of the EG refining tower (42) is connected to an EG refining tower kettle pump (47). The discharge port of the EG refining tower kettle pump (47) is connected to a CAT recovery device. The top of the EG refining tower (42) is connected to an EG refining tower top cooler (46), the discharge end of the EG refining tower top cooler (46) is connected to an EG refining tower reflux tank (52) and an EG refining tower reflux pump (51), and the discharge pipeline of the EG refining tower reflux pump (51) is divided into two routes, one route is connected to the EG refining tower (42), and the other route is connected to the EG tank area; The EG refining tower reboiler (46) and the EG refining tower side line reboiler (48) are falling film reboilers, and use 0.6 MPa steam to provide heat exchange.

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