Hydration treatment device for tailings of pure ethylene oxide device

Abstract

The invention discloses a pure ethylene oxide device tailing hydration treatment device, which belongs to the technical field of chemical production and comprises a high-concentration ethylene oxide tailing pipeline, a one-way valve is arranged on the high-concentration ethylene oxide tailing pipeline, and a tailing cooling unit is connected onto the high-concentration ethylene oxide tailing pipeline. The system can consume medium-pressure steam generated by heat removal of a steam pocket of the pure epoxy device, reduces energy waste, improves the tailing recovery efficiency of the pure epoxy device, reduces the long-distance transportation risk of an ethylene oxide aqueous solution, reduces the generation amount of isomerization impurities, and improves the production efficiency of the pure epoxy device. The product quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical production, in particular to a tailings hydration treatment device for a pure ethylene oxide device. Background Art

[0002] Conventional ethylene oxide / ethylene glycol units using ethylene as raw material include: ethylene oxidation, carbon dioxide removal, ethylene oxide refining, hydration reaction, multi-effect evaporation, ethylene glycol refining and other units. In recent years, due to the difference in demand and price between ethylene oxide and ethylene glycol, the number of newly built or renovated pure ethylene oxide units has increased day by day for economic benefit considerations. Pure ethylene oxide units only include ethylene oxidation, carbon dioxide removal, and ethylene oxide refining units, and some ethylene oxide tailings will be generated after the refining process.

[0003] In the production process of pure ethylene oxide device, due to the lack of ethylene glycol production section, the ethylene oxide tailings that cannot be used locally need to be sent to the ethylene oxide / ethylene glycol device with ethylene glycol production section through pipelines for treatment. On the one hand, during long-distance transportation, ethylene oxide may be isomerized into acetaldehyde, acetic acid and other substances, affecting product quality, and increasing the heavy components such as heavy alcohols generated by the device, increasing the cost of heavy component processing; on the other hand, there is a high risk of long-distance transportation of high-temperature ethylene oxide solution. Through research, the applicant found that hydrating the tailings of pure epoxy device with different components in proportion can completely consume the ethylene oxide in the tailings, reduce isomerized products, and reduce transportation risks.

[0004] 202410180565.6 discloses a method for preparing ethylene glycol by catalytic hydration of ethylene oxide, comprising placing a first material containing a certain proportion of ethylene oxide and water into a catalytic hydration reactor, and obtaining a second material containing ethylene glycol and a small amount of ethylene oxide after the reaction; placing the second material into a preheater, and preheating to a preset temperature to obtain a second material; placing the third material into a plug flow reactor, and allowing the remaining small amount of ethylene oxide to react completely to obtain a fourth material; placing the fourth material into the middle of an evaporation tower, and obtaining an ethylene glycol aqueous solution at the bottom of the tower after separation. The technical solution of the present invention not only solves the problems of high water ratio, high energy consumption, and high equipment investment in direct hydration production of ethylene glycol, but also requires fewer reactors and reduces catalyst costs compared with the existing ethylene oxide catalytic hydration production process of ethylene glycol; the concentration of ethylene oxide entering the evaporation tower can be effectively controlled to ensure process safety. However, the above system cannot solve the isomerization and safety risk problems of long-distance transportation of high-temperature logistics, resulting in the inability to reduce the external transmission temperature of the hydration product, increased energy consumption, increased operating costs, and reduced economic benefits. Summary of the invention

[0005] In order to solve the technical problems mentioned in the above background technology, the present invention provides a tailings hydration treatment device for a pure ethylene oxide device, and the technical solution adopted is as follows:

[0006] The invention comprises a high-concentration ethylene oxide tail material pipeline, a one-way valve is arranged on the high-concentration ethylene oxide tail material pipeline, a tail material cooling unit is connected to the high-concentration ethylene oxide tail material pipeline, and the tail material cooling unit is respectively connected to an ethylene glycol unit and a hydration reaction unit through pipelines.

[0007] Preferably, the tailings cooling unit comprises an epoxy tailings circulating cooler and a high-concentration ethylene oxide tailings storage tank, the high-concentration ethylene oxide tailings pipeline is connected to the epoxy tailings circulating cooler, the epoxy tailings circulating cooler is connected to the high-concentration ethylene oxide tailings storage tank through a pipeline, the high-concentration ethylene oxide tailings storage tank is connected to the upper desalted water pipeline through a pipeline and a tank bottom reflux control valve is arranged on the pipeline, a desalted water regulating valve a, a one-way valve, an epoxy tailings reflux pump, an EO tailings flow regulator and a tailings delivery amount regulating valve are arranged on the upper desalted water pipeline from left to right, a bypass pipeline connected to the high-concentration ethylene oxide tailings pipeline is arranged on the upper desalted water pipeline, and a tailings reflux amount regulating valve and a reflux orifice are arranged on the bypass pipeline.

[0008] Preferably, the ethylene glycol unit comprises a circulating ethylene glycol aqueous solution cooler and a low-concentration ethylene glycol aqueous solution tank, the circulating ethylene glycol aqueous solution cooler is connected to the low-concentration ethylene glycol aqueous solution tank through a pipeline, the low-concentration ethylene glycol aqueous solution tank is connected to the lower desalted water pipeline through a pipeline and an ethylene glycol solution reflux control valve is arranged on the pipeline, the upper desalted water pipeline is connected to the lower desalted water pipeline, the lower desalted water pipeline is provided with a desalted water regulating valve b, a one-way valve, an ethylene glycol solution reflux pump, an EG water flow control regulating valve and an ethylene glycol solution delivery amount regulating valve from left to right, the lower desalted water pipeline is provided with a bypass connected to the circulating ethylene glycol aqueous solution cooler and an ethylene glycol solution reflux amount regulating valve and a reflux orifice plate are arranged on the bypass, and the low-concentration ethylene glycol aqueous solution tank is provided with a low-concentration ethylene glycol aqueous solution pipeline.

[0009] Preferably, the hydration unit comprises a hydration reaction feed heat exchanger, a hydration reaction secondary preheater and a high-efficiency hydration reactor, the hydration reaction feed heat exchanger is provided with a pipeline connected to the upper desalted water pipeline and the lower desalted water pipeline, and a stop valve, a hydration reactor feed pump and a one-way valve are provided on the pipeline, a pipeline is provided at the bottom of the hydration reaction feed heat exchanger, and an external transmission regulating valve and a hydration product external transmission pump are provided on the pipeline, the hydration reaction feed heat exchanger and the hydration reaction secondary preheater are connected by a pipeline, the hydration reaction secondary preheater is provided with a pipeline and a heat exchanger steam regulating valve is provided on the pipeline, the hydration reaction secondary preheater is connected to the high-efficiency hydration reactor through a pipeline, and a hydration feed temperature controller is provided on the pipeline, the high-efficiency hydration reactor is provided with a temperature monitor a and a temperature monitor b, the hydration reaction feed heat exchanger and the high-efficiency hydration reactor are connected by a pipeline, and a pressure difference monitoring interlocking alarm is provided on the pipeline.

[0010] Preferably, the ethylene oxide concentration in the high-concentration ethylene oxide tailings pipeline is 50-70 wt % and the temperature is 20-35°C.

[0011] Preferably, the ethylene glycol concentration in the low-concentration ethylene glycol aqueous solution pipeline is 8-14 wt %, and the temperature is 100-120°C.

[0012] Preferably, the inlet temperature of the high-efficiency hydration reactor is 180-200°C, the pressure is 3.6-3.8 MPag, and the outlet temperature is 220-240°C.

[0013] Preferably, the shell side inlet temperature of the hydration reaction feed heat exchanger is 60-80°C, the shell side outlet temperature is 140-160°C, the tube side inlet temperature is 220-240°C, and the outlet temperature is 140-160°C.

[0014] The present invention has the following advantages: the high-concentration ethylene oxide tails generated by a pure ethylene oxide device are mixed with a low-concentration ethylene glycol aqueous solution in proportion through a tail cooling unit and an ethylene glycol unit, and then completely hydrated after primary preheating in a hydration reaction unit and secondary preheating of steam. The present invention can consume the medium-pressure steam generated by the steam drum of the pure epoxy device to reduce energy waste, improve the tail recovery efficiency of the pure epoxy device, reduce the risk of long-distance transportation of the ethylene oxide aqueous solution, reduce the generation of isomerized impurities, and improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of the present invention.

[0016] Figures: 1-high concentration ethylene oxide tail material pipeline, 2-epoxy tail material circulation cooler, 3-high concentration ethylene oxide tail material storage tank, 4-tank bottom reflux control valve, 5-epoxy tail material reflux pump, 6-tail material reflux flow regulating valve, 7-tail material delivery flow regulating valve, 8-low concentration ethylene glycol aqueous solution pipeline, 9-low concentration ethylene glycol aqueous solution tank, 10-circulating ethylene glycol aqueous solution cooler, 11-ethylene glycol solution reflux control valve, 12-ethylene glycol solution reflux pump, 13-ethylene glycol solution reflux flow regulating valve, 14-ethylene glycol solution delivery flow regulating valve, 15-reflux orifice plate, 16-desalting water regulating valve a, 17-desalting water Water regulating valve b, 18-stop valve, 19-hydration reactor feed pump, 20-hydration reaction feed heat exchanger, 21-hydration reaction secondary preheater, 22-heat exchanger steam regulating valve, 23-high-efficiency hydration reactor, 24-external transmission regulating valve, 25-hydration product external transmission pump, 26-check valve, 27-epoxy tailings storage tank level monitoring interlock alarm, 28-water tank level monitoring interlock alarm, 29-EO tailings flow control regulating valve, 30-EG water flow control regulating valve, 31-hydration feed temperature controller, 32-temperature monitor a, 33-temperature monitor b, 34-pressure difference monitoring interlock alarm. DETAILED DESCRIPTION

[0017] 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.

[0018] The invention provides a tail material hydration processing device for a pure ethylene oxide device, comprising a high-concentration ethylene oxide tail material pipeline 1. The high-concentration ethylene oxide tail material generated by the pure ethylene oxide device enters the high-concentration ethylene oxide tail material pipeline 1. A one-way valve 26 is arranged on the high-concentration ethylene oxide tail material pipeline 1. The high-concentration ethylene oxide tail material pipeline 1 is connected to a tail material cooling unit. When the one-way valve 26 is opened, the high-concentration ethylene oxide tail material enters the tail material cooling unit through the high-concentration ethylene oxide tail material pipeline 1, enters a hydration reaction unit together with ethylene glycol of an ethylene glycol unit for hydration after heat exchange cooling, and the tail material cooling unit is respectively connected to the ethylene glycol unit and the hydration reaction unit through pipelines.

[0019] The tailings cooling unit comprises an epoxy tailings circulating cooler 2 and a high-concentration ethylene oxide tailings storage tank 3. The high-concentration ethylene oxide tailings pipeline 1 is connected to the epoxy tailings circulating cooler 2. The high-concentration ethylene oxide tailings enter the epoxy tailings circulating cooler 2 through the high-concentration ethylene oxide tailings pipeline 1 to cool down and cool the high-concentration ethylene oxide tailings. The epoxy tailings circulating cooler 2 is connected to the high-concentration ethylene oxide tailings storage tank 3 through a pipeline. The cooled high-concentration ethylene oxide tailings enter the high-concentration ethylene oxide tailings storage tank 3 through a pipeline for storage. The high-concentration ethylene oxide tailings storage tank 3 is connected to the upper desalted water pipeline through a pipeline and a tank bottom reflux control valve 4 is arranged on the pipeline. The tank bottom reflux control valve 4 is opened to allow the high-concentration ethylene oxide tailings to enter the upper desalted water pipeline through the pipeline and mix with the desalted water. The upper desalted water pipeline is connected from left to right according to A desalted water regulating valve a16, a one-way valve 26, an epoxy tailings reflux pump 5, an EO tailings flow regulating valve 29 and a tailings delivery regulating valve 7 are provided to adjust the opening of the desalted water regulating valve a16, the one-way valve 26, the EO tailings flow regulating valve 29 and the tailings delivery regulating valve 7, and then the desalted water is transported to the hydration reaction feed heat exchanger 20 through the epoxy tailings reflux pump. A bypass pipeline connected to the high-concentration ethylene oxide tailings pipeline 1 is provided on the upper desalted water pipeline, and a tailings reflux regulating valve 6 and a reflux orifice 15 are provided on the bypass pipeline. If the cooling temperature of the high-concentration ethylene oxide tailings in the upper desalted water pipeline is higher than the set temperature, the tailings reflux regulating valve 6 is opened to reflux it into the high-concentration ethylene oxide tailings pipeline 1 and re-enter the epoxy tailings circulating cooler 2 for cooling, and the minimum reflux amount is ensured by the reflux plate 15.

[0020] The high-concentration ethylene oxide tailings react with desalted water to produce ethylene glycol, which is sent to the downstream unit together with the ethylene glycol of the ethylene glycol unit.

[0021] The ethylene glycol unit comprises a circulating ethylene glycol aqueous solution cooler 10 and a low-concentration ethylene glycol aqueous solution tank 9. The low-concentration ethylene glycol aqueous solution enters the low-concentration ethylene glycol aqueous solution tank 9 through a low-concentration ethylene glycol aqueous solution pipeline 8. The circulating ethylene glycol aqueous solution cooler 10 is connected to the low-concentration ethylene glycol aqueous solution tank 9 through a pipeline. The low-concentration ethylene glycol aqueous solution tank 9 is connected to a lower desalted water pipeline through a pipeline and an ethylene glycol solution reflux control valve 11 is arranged on the pipeline. The ethylene glycol solution reflux control valve 11 is opened to allow the low-concentration ethylene glycol aqueous solution in the low-concentration ethylene glycol aqueous solution tank 9 to enter the lower desalted water pipeline through the pipeline and be mixed with the desalted water in the lower desalted water pipeline to adjust the concentration. The upper desalted water pipeline is connected to the lower desalted water pipeline so that the solution in the upper desalted water pipeline is mixed with the solution in the lower desalted water pipeline in a certain ratio and then enter the hydration reaction feed heat exchanger 20 together. The lower desalted water pipeline is provided with a desalted water regulating valve b17, a single The opening of the desalted water regulating valve b17, the one-way valve 26, the EG water flow control regulating valve 30 and the ethylene glycol solution delivery regulating valve 14 are adjusted to deliver the low-concentration ethylene glycol aqueous solution in the lower desalted water pipeline into the hydration reaction feed heat exchanger 20 through the ethylene glycol solution reflux pump 12. The lower desalted water pipeline is provided with a cooling medium that is connected to the circulating ethylene glycol aqueous solution. A bypass is connected to the cooler 10 and a ethylene glycol solution reflux regulating valve 13 and a reflux orifice 15 are arranged on the bypass. A low-concentration ethylene glycol aqueous solution pipeline 8 is arranged on the low-concentration ethylene glycol aqueous solution tank 9. If the temperature of the low-concentration ethylene glycol aqueous solution in the lower desalted water pipeline is higher than the set temperature, the ethylene glycol solution reflux regulating valve 13 is opened to allow the low-concentration ethylene glycol aqueous solution to enter the circulating ethylene glycol aqueous solution cooler 10 through the pipeline for cooling and then enter the low-concentration ethylene glycol aqueous solution tank 9.

[0022] The hydration unit includes a hydration reaction feed heat exchanger 20, a hydration reaction secondary preheater 21 and a high-efficiency hydration reactor 23. The hydration reaction feed heat exchanger 20 is provided with a pipeline connected to the upper desalted water pipeline and the lower desalted water pipeline, and the pipeline is provided with a stop valve 18, a hydration reactor feed pump 19 and a one-way valve 26. The stop valve 18 is opened and the opening of the one-way valve 26 is adjusted, and the solution in the upper desalted water pipeline and the lower desalted water pipeline enters the hydration reactor through the hydration reactor feed pump 19. The feed heat exchanger 20 is heated, and then enters the hydration reaction secondary preheater 21 through a pipeline for preheating. A pipeline is arranged at the bottom of the hydration reaction feed heat exchanger 20, and an external transmission regulating valve 24 and a hydration product external transmission pump 25 are arranged on the pipeline. The external transmission regulating valve 24 is opened, and the exchange water in the hydration reaction feed heat exchanger 20 is transported to the external transmission pipeline through the hydration product external transmission pump 25. The hydration reaction feed heat exchanger 20 and the hydration reaction secondary preheater 21 are connected by a pipeline. A pipeline is provided on the reaction secondary preheater 21 and a heat exchanger steam regulating valve 22 is provided on the pipeline. The solution preheated in the hydration reaction feed heat exchanger 20 enters the high-efficiency hydration reactor 20 through the pipeline for hydration reaction, and the high-concentration ethylene oxide tail material is converted into ethylene glycol. The hydration reaction secondary preheater 21 is connected to the high-efficiency hydration reactor 23 through a pipeline and a hydration feed temperature controller 31 is provided on the pipeline. The high-efficiency hydration reactor 23 is provided with a temperature monitor a32 and a temperature monitor b33. The temperature of the solution in the high-efficiency hydration reactor 23 is monitored by the temperature monitor a32 and the temperature monitor b33. The hydration reaction feed heat exchanger 20 is connected to the high-efficiency hydration reactor 23 through a pipeline and a pressure difference monitoring interlocking alarm 34 is provided on the pipeline. When the temperature of the solution in the high-efficiency hydration reactor 23 is unqualified, the pressure difference monitoring interlocking alarm 34 alarms, and the solution in the high-efficiency hydration reactor 23 returns to the hydration reaction feed heat exchanger 20 through the pipeline.

[0023] The present invention is simple to operate, convenient to use, and suitable for comprehensive promotion and application. Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tailings hydration treatment device for a pure ethylene oxide device, comprising a high-concentration ethylene oxide tailings pipeline (1), characterized in that: A one-way valve (26) is arranged on the high-concentration ethylene oxide tail material pipeline (1), and a tail material cooling unit is connected to the high-concentration ethylene oxide tail material pipeline (1), and the tail material cooling unit is respectively connected to the ethylene glycol unit and the hydration reaction unit through pipelines.

2. A hydration treatment device for tailings of a pure ethylene oxide device according to claim 1, characterized in that: The tail cooling unit comprises an epoxy tail circulation cooler (2) and a high-concentration ethylene oxide tail storage tank (3); the high-concentration ethylene oxide tail pipeline (1) is connected to the epoxy tail circulation cooler (2); the epoxy tail circulation cooler (2) is connected to the high-concentration ethylene oxide tail storage tank (3) through a pipeline; the high-concentration ethylene oxide tail storage tank (3) is connected to an upper desalted water pipeline through a pipeline and a tank bottom reflux control valve (4) is arranged on the pipeline; a desalted water regulating valve a (16), a one-way valve (26), an epoxy tail reflux pump (5), an EO tail flow regulator (29) and a tail delivery amount regulating valve (7) are arranged on the upper desalted water pipeline from left to right; a bypass pipeline connected to the high-concentration ethylene oxide tail pipeline (1) is arranged on the upper desalted water pipeline and a tail reflux amount regulating valve (6) and a reflux orifice plate (15) are arranged on the bypass pipeline.

3. The tailings hydration treatment device of a pure ethylene oxide device according to claim 1, characterized in that: The ethylene glycol unit comprises a circulating ethylene glycol aqueous solution cooler (10) and a low-concentration ethylene glycol aqueous solution tank (9), wherein the circulating ethylene glycol aqueous solution cooler (10) is connected to the low-concentration ethylene glycol aqueous solution tank (9) via a pipeline, the low-concentration ethylene glycol aqueous solution tank (9) is connected to a lower desalted water pipeline via a pipeline and an ethylene glycol solution reflux control valve (11) is arranged on the pipeline, the upper desalted water pipeline is connected to the lower desalted water pipeline, and the lower desalted water pipeline is sequentially provided with desalted water valves (11) from left to right. A brine regulating valve b (17), a one-way valve (26), an ethylene glycol solution reflux pump (12), an EG water flow control regulating valve (30) and an ethylene glycol solution delivery regulating valve (14); a bypass connected to a circulating ethylene glycol aqueous solution cooler (10) is arranged on the lower desalted water pipeline, and an ethylene glycol solution reflux regulating valve (13) and a reflux orifice plate (15) are arranged on the bypass; and a low-concentration ethylene glycol aqueous solution tank (9) is provided with a low-concentration ethylene glycol aqueous solution pipeline (8).

4. A hydration treatment device for tailings of a pure ethylene oxide device according to claim 2 or 3, characterized in that: The hydration unit comprises a hydration reaction feed heat exchanger (20), a hydration reaction secondary preheater (21) and a high-efficiency hydration reactor (23); a pipeline connected to an upper desalted water pipeline and a lower desalted water pipeline is arranged on the hydration reaction feed heat exchanger (20), and a stop valve (18), a hydration reactor feed pump (19) and a one-way valve (26) are arranged on the pipeline; a pipeline is arranged at the bottom of the hydration reaction feed heat exchanger (20), and an external transmission regulating valve (24) and a hydration product external transmission pump (25) are arranged on the pipeline; the hydration reaction feed heat exchanger (20) and the hydration reaction secondary preheater (21) are connected to a high-efficiency hydration reactor (23); The hydration reaction secondary preheater (21) is connected by a pipeline, the hydration reaction secondary preheater (21) is provided with a pipeline and a heat exchanger steam regulating valve (22) is provided on the pipeline, the hydration reaction secondary preheater (21) is connected to the high-efficiency hydration reactor (23) by a pipeline and a hydration feed temperature controller (31) is provided on the pipeline, the high-efficiency hydration reactor (23) is provided with a temperature monitor a (32) and a temperature monitor b (33), the hydration reaction feed heat exchanger (20) and the high-efficiency hydration reactor (23) are connected by a pipeline and a pressure difference monitoring interlocking alarm (34) is provided on the pipeline.

5. A hydration treatment device for tailings of a pure ethylene oxide device according to claim 1, characterized in that: The ethylene oxide concentration in the high-concentration ethylene oxide tail material pipeline (1) is 50-70wt% and the temperature is 20-35°C.

6. A hydration treatment device for tailings of a pure ethylene oxide device according to claim 1, characterized in that: The ethylene glycol concentration in the low-concentration ethylene glycol aqueous solution pipeline (8) is 8-14 wt % and the temperature is 100-120°C.

7. A hydration treatment device for tailings of a pure ethylene oxide device according to claim 1, characterized in that: The inlet temperature of the high-efficiency hydration reactor (23) is 180-200°C, the pressure is 3.6-3.8Mpag, and the outlet temperature is 220-240°C.

8. The tailings hydration treatment device of a pure ethylene oxide device according to claim 1, characterized in that: The shell side inlet temperature of the hydration reaction feed heat exchanger (20) is 60-80°C, the shell side outlet temperature is 140-160°C, the tube side inlet temperature is 220-240°C, and the outlet temperature is 140-160°C.

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