Preparation device of ethylene glycol

Abstract

The utility model discloses a preparation device of ethylene glycol. The preparation device at least comprises a cryogenic tower; an inlet of the oxidation reactor is connected with the top of the cryogenic tower; the outlet of the oxidation reactor is connected to the stripping tower; the hydration reactor is connected with the bottom of the stripping tower; an inlet of the refrigerating unit is connected to the tower bottom of the cryogenic tower, and an outlet of the refrigerating unit is connected to the tower top of the cryogenic tower; the first cooling unit is connected with the top of the stripping tower; the second cooling unit is connected with the top of the stripping tower after being arranged in parallel with the first cooling unit; or after the second cooling unit and the refrigerating unit are arranged in parallel, inlets of the second cooling unit and the refrigerating unit are connected to the tower bottom of the cryogenic tower, and outlets of the second cooling unit and the refrigerating unit are connected to the tower top of the cryogenic tower. According to the ethylene glycol preparation device provided by the utility model, the energy consumption in the ethylene glycol preparation process can be reduced, and the economic benefit is improved.

Description

Technical Field

[0001] This utility model relates to the field of ethylene glycol preparation technology, specifically to an apparatus for preparing ethylene glycol. Background Technology

[0002] Ethylene glycol, as an important basic petrochemical raw material, is widely used in polyester, polyester filament, polyester staple fiber, surfactants, printing, and antifreeze. Among these, the process of producing ethylene glycol using ethylene as a raw material is the most mature and holds a dominant market position. However, the process of producing ethylene glycol using ethylene as a raw material suffers from high energy consumption and poor economic efficiency, severely limiting the further development of this process. Utility Model Content

[0003] The purpose of this invention is to provide an apparatus for preparing ethylene glycol, which can reduce energy consumption and improve economic efficiency during the preparation process.

[0004] To achieve the above-mentioned and other related objectives, this utility model is implemented through the following technical solution.

[0005] This invention provides an apparatus for preparing ethylene glycol, comprising at least:

[0006] cryogenic tower;

[0007] An oxidation reactor, the inlet of which is connected to the top of the cryogenic tower;

[0008] A stripping tower is provided, and the outlet of the oxidation reactor is connected to the stripping tower.

[0009] A hydration reactor is connected to the bottom of the stripping tower;

[0010] The refrigeration unit has its inlet connected to the bottom of the cryogenic tower and its outlet connected to the top of the cryogenic tower.

[0011] The first cooling unit is connected to the top of the stripping tower; and

[0012] The second cooling unit is connected in parallel with the first cooling unit and then connected to the top of the stripping tower; or, the second cooling unit and the refrigeration unit are connected in parallel, with their inlets connected to the bottom of the cryogenic tower and their outlets connected to the top of the cryogenic tower.

[0013] In one embodiment of this utility model, the preparation apparatus further includes an absorption tower, and the outlet of the oxidation reactor and the top of the stripping tower are each connected to the absorption tower.

[0014] In one embodiment of this utility model, the bottom of the stripping tower is connected to the top of the absorption tower.

[0015] In one embodiment of the present invention, the preparation apparatus further includes a first selection valve, which is disposed between the top of the stripping tower and the inlet of the second cooling unit.

[0016] In one embodiment of the present invention, the preparation device further includes a second selection valve, which is disposed between the bottom of the cryogenic tower and the inlet of the second cooling unit.

[0017] In one embodiment of the present invention, the preparation device further includes a third selection valve, which is disposed between the outlet of the first cooling unit and the outlet of the second cooling unit.

[0018] In one embodiment of the present invention, the preparation device further includes a fourth selection valve, which is disposed between the outlet of the second cooling unit and the top of the cryogenic tower.

[0019] In one embodiment of the present invention, the first cooling unit and the second cooling unit each include multiple cooling groups arranged in parallel, and each cooling group includes multiple coolers arranged in series.

[0020] In one embodiment of this utility model, the cooler is an air cooler, and the refrigeration unit is a lithium bromide refrigeration unit.

[0021] In one embodiment of the present invention, the preparation apparatus further includes a stripping gas generator, the outlet of which is connected to the bottom of the stripping tower.

[0022] In summary, this invention provides an apparatus for preparing ethylene glycol, which can adjust its operation according to changes in ambient temperature, improving its flexibility and economy. Furthermore, the apparatus reduces energy consumption during the preparation process, increasing economic efficiency and making it suitable for large-scale application. It also yields a high-purity ethylene oxide solution, which can be used as a raw material to prepare high-purity ethylene glycol.

[0023] Of course, implementing any of the methods of this utility model does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of an apparatus for preparing ethylene glycol in one embodiment of the present invention.

[0026] Marker explanation:

[0027] 11. Cryogenic tower; 12. Refrigeration unit; 13. Oxidation reactor; 14. Absorption tower; 15. Stripping tower; 16. Hydration reactor; 17. First cooling unit; 171. Cooling group; 18. Second cooling unit; 19. Pump; 20. Stripping gas generator; 21. First selector valve; 22. Second selector valve; 23. Third selector valve; 24. Fourth selector valve. Detailed Implementation

[0028] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this utility model can be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] In this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used only for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0031] Please see Figure 1 As shown, this utility model provides an apparatus for preparing ethylene glycol, including, for example, a cryogenic tower 11, a refrigeration unit 12, an oxidation reactor 13, a stripping tower 15, a hydration reactor 16, a first cooling unit 17, and a second cooling unit 18. The top of the cryogenic tower 11 is connected to the inlet of the oxidation reactor 13, the outlet of the oxidation reactor 13 is connected to the stripping tower 15, the bottom of the stripping tower 15 is connected to the hydration reactor 16, the inlet of the refrigeration unit 12 is connected to the bottom of the cryogenic tower 11, and the outlet of the refrigeration unit 12 is connected to the top of the cryogenic tower 11. The first cooling unit 17 is connected to the top of the stripping tower 15. The second cooling unit 18 is connected in parallel with the first cooling unit 17 and then connected to the top of the stripping tower 15. The inlets of the second cooling unit 18 and the refrigeration unit 12 are connected to the bottom of the cryogenic tower 11, and their outlets are connected to the top of the cryogenic tower 11. In the ethylene glycol preparation apparatus provided by this invention, the actual operating process can be adjusted according to changes in ambient temperature, thereby saving energy and improving economic efficiency. Specifically, when the ambient temperature is high, the first cooling unit 17 and the second cooling unit 18 are connected in parallel to cool the gas at the top of the stripping tower 15, while the refrigeration unit 12 provides cooling capacity solely for the cryogenic tower 11. When the ambient temperature is low, the first cooling unit 17 cools the gas at the top of the stripping tower 15 solely, while the second cooling unit 18 and the refrigeration unit 12 are connected in parallel to provide cooling capacity for the cryogenic tower 11.

[0032] Please see Figure 1 As shown, in one embodiment of this invention, a cryogenic tower 11 is used to remove moisture from the circulating gas. Specifically, in the cryogenic tower 11, the circulating gas enters from the bottom and rises to the top, while cooling water enters from the top and descends to the bottom. Simultaneously, the cooling water sprays the rising circulating gas to cool the water vapor in the circulating gas to liquid water. The liquid water descends to the bottom along with the cooling water, and the circulating gas, now free of water vapor, flows out of the cryogenic tower 11 from the top, thus achieving the purpose of removing moisture from the circulating gas. The circulating gas may contain, for example, ethylene, methane, oxygen, carbon dioxide, water vapor, and other impurity gases, and the cooling water may be, for example, demineralized water. By using a cryogenic tower 11 to remove moisture from the circulating gas, the occurrence of side reactions in the subsequent oxidation reactor 13 can be suppressed, and the yield of the target product can be improved.

[0033] Please see Figure 1As shown, in one embodiment of this utility model, the inlet of the refrigeration unit 12 is connected to the bottom of the cryogenic tower 11, and the outlet is connected to the top of the cryogenic tower 11. The refrigeration unit 12 is, for example, a lithium bromide refrigeration unit. Because the circulating gas and cooling water exchange heat within the cryogenic tower 11, the temperature of the cooling water flowing out from the bottom of the cryogenic tower 11 increases. Therefore, the refrigeration unit 12 is provided to cool the cooling water flowing out from the bottom of the cryogenic tower 11 before sending it to the top of the cryogenic tower 11. This cycle repeats, with the cooling water circulating between the top and bottom of the cryogenic tower 11 and the refrigeration unit 12, achieving the purpose of removing moisture from the circulating gas.

[0034] Please see Figure 1 As shown, in one embodiment of this utility model, a pump 19 is provided between the refrigeration unit 12 and the bottom of the cryogenic tower 11. By providing the pump 19, the cooling water flowing out from the bottom of the cryogenic tower 11 is pressurized so that the cooling water flowing out from the bottom of the cryogenic tower 11 can flow smoothly into the refrigeration unit 12.

[0035] Please see Figure 1 As shown, in one embodiment of this invention, the oxidation reactor 13 is connected to the top of the cryogenic tower 11. Specifically, after the moisture in the circulating gas is removed in the cryogenic tower 11, the circulating gas flows from the top of the cryogenic tower 11 to the oxidation reactor 13. In the oxidation reactor 13, the ethylene and oxygen in the circulating gas react to generate the target product, ethylene oxide. Since the circulating gas entering the oxidation reactor 13 has had its moisture removed, the occurrence of side reactions in the oxidation reactor 13 can be suppressed, thereby increasing the yield of the target product, ethylene oxide.

[0036] Please see Figure 1 As shown, in one embodiment of this invention, the preparation apparatus further includes an absorption tower 14, which is connected to the outlet of the oxidation reactor 13. Specifically, the circulating gas reacts in the oxidation reactor 13, and the reacted gas includes ethylene oxide, methane, carbon dioxide, other impurity gases, and unreacted ethylene and oxygen, etc., and flows into the absorption tower 14 and gradually rises to the top of the absorption tower 14. Simultaneously, an absorbent enters from the top of the absorption tower 14, descends to the bottom of the absorption tower 14, and contacts the reacted gas, causing ethylene oxide, methane, ethylene, oxygen, and carbon dioxide to dissolve in the absorbent, obtaining an ethylene oxide mixed solution, which leaves the absorption tower 14 from the bottom. The absorbent may include, for example, water. By setting up the absorption tower 14, the gas at the outlet of the oxidation reactor 13 can be purified, and impurity gases can be removed.

[0037] Please see Figure 1As shown, in one embodiment of this invention, the outlet of the oxidation reactor 13 is connected to a stripping tower 15. In this embodiment, the top of the stripping tower 15 is connected to the bottom of the absorption tower 14. Specifically, the ethylene oxide mixed solution at the bottom of the absorption tower 14 flows to the top of the stripping tower 15 and then descends to the bottom of the stripping tower 15. Simultaneously, stripping gas rises from the bottom of the stripping tower 15, stripping methane, ethylene, oxygen, and carbon dioxide from the ethylene oxide mixed solution to obtain an ethylene oxide solution, which exits from the bottom of the stripping tower 15. Meanwhile, methane, ethylene, oxygen, carbon dioxide, and stripping gas exit from the top of the stripping tower 15. By setting up the stripping tower 15, methane, ethylene, oxygen, and carbon dioxide can be removed from the ethylene oxide mixed solution to obtain a high-purity ethylene oxide mixed solution.

[0038] Please see Figure 1 As shown, in one embodiment of this utility model, the bottom of the stripping tower 15 is connected to the top of the absorption tower 14 so that the ethylene oxide solution at the bottom of the stripping tower 15 is sent to the absorption tower 14 as an absorbent to absorb and dissolve the ethylene oxide, methane, ethylene, oxygen and carbon dioxide in the outlet gas of the oxidation reactor 13, thereby increasing the ethylene oxide content in the final obtained ethylene oxide solution and thus increasing the purity of ethylene glycol.

[0039] Please see Figure 1 As shown, in one embodiment of this utility model, the bottom of the stripping tower 15 is also connected to the hydration reactor 16 to send the ethylene oxide solution into the hydration reactor 16, where the ethylene oxide solution undergoes a hydration reaction to generate ethylene glycol.

[0040] Please see Figure 1 As shown, in one embodiment of this invention, a stripping gas generator 20 is also connected to the bottom of the stripping tower 15 to provide stripping gas for the stripping tower 15. In this embodiment, the stripping gas generator 20 is, for example, a reboiler. Specifically, the ethylene oxide mixed solution flows from the bottom of the absorption tower 14 to the stripping tower 15 and descends to the bottom of the stripping tower 15. The reboiler at the bottom evaporates the low-boiling-point components in the ethylene oxide mixed solution into a gas phase, which rises to the top of the stripping tower 15 as stripping gas to strip the methane, ethylene, oxygen, and carbon dioxide in the ethylene oxide mixed solution.

[0041] Please see Figure 1As shown, in one embodiment of this utility model, the first cooling unit 17 is connected to the top of the stripping tower 15. The first cooling unit 17 includes multiple cooling groups 171 connected in parallel, and each cooling group 171 contains multiple coolers connected in series. In this embodiment, the first cooling unit 17 has, for example, six cooling groups 171, and within each cooling group 171, there are, for example, two coolers, such as air coolers. Specifically, in the stripping tower 15, methane, ethylene, oxygen, and carbon dioxide in the ethylene oxide mixed solution are stripped by stripping gas, which flows from the top of the stripping tower 15 to the first cooling unit 17. The first cooling unit 17 recovers heat from the methane, ethylene, oxygen, carbon dioxide, and stripping gas, and the methane, ethylene, oxygen, carbon dioxide, and stripping gas are cooled to a preset temperature for reuse. The cooling effect of the cooling unit 171 varies with the ambient temperature. The first cooling unit 17 can only meet the cooling requirements of the stripping tower 15 under winter conditions. However, under summer conditions, the first cooling unit 17 cannot cool methane, ethylene, oxygen, carbon dioxide and stripping gas to the preset temperature.

[0042] Please see Figure 1 As shown, in one embodiment of this utility model, the second cooling unit 18 and the first cooling unit 17 are connected in parallel and then connected to the top of the stripping tower 15. The second cooling unit 18 includes multiple cooling groups 171 connected in parallel, and each cooling group 171 contains multiple coolers connected in series. In this embodiment, the second cooling unit 18 has, for example, four cooling groups 171, and within each cooling group 171, there are, for example, two coolers, such as air coolers. Since the first cooling unit 17 cannot meet the cooling requirements of the stripping tower 15 under summer conditions, the second cooling unit 18 is used in parallel with the first cooling unit 17 during summer conditions to jointly cool the methane, ethylene, oxygen, carbon dioxide, and stripping gas flowing from the top of the stripping tower 15 to a preset temperature.

[0043] Please see Figure 1As shown, in one embodiment of this utility model, the second cooling unit 18 is also connected in parallel with the refrigeration unit 12. The inlets of the second cooling unit 18 and the refrigeration unit 12 are connected to the bottom of the cryogenic tower 11, and the outlets are connected to the top of the cryogenic tower 11. Since the second cooling unit 18 does not need to be started during winter operation, the first cooling unit 17 alone can meet the cooling requirements of the stripping tower 15. Therefore, under winter operation, by setting the second cooling unit 18 and the refrigeration unit 12 in parallel, the refrigeration unit 12 and the second cooling unit 18 jointly cool the cooling water flowing out from the bottom of the cryogenic tower 11 before sending it to the top of the cryogenic tower 11, thereby reducing the cooling load and energy consumption of the refrigeration unit 12 and improving the economic efficiency of the entire preparation device.

[0044] Please see Figure 1 As shown, in one embodiment of this utility model, a first selection valve 21 is provided between the top of the stripping tower 15 and the inlet of the second cooling unit 18. Specifically, the first selection valve 21 is located between the top of the stripping tower 15, the inlet of the second cooling unit 18, and the inlet of the first cooling unit 17. The first selection valve 21 can be, for example, a ball valve, a butterfly valve, or a gate valve. By controlling the opening and closing of the first selection valve 21, it is possible to determine whether the gas at the bottom of the stripping tower 15 flows into the second cooling unit 18, and thus whether the second cooling unit 18 and the first cooling unit 17 are connected in parallel.

[0045] Please see Figure 1 As shown, in one embodiment of this utility model, a second selection valve 22 is provided between the bottom of the cryogenic tower 11 and the inlet of the second cooling unit 18. Specifically, the second selection valve 22 is located between the bottom of the cryogenic tower 11, the inlet of the refrigeration unit 12, and the inlet of the second cooling unit 18. The second selection valve 22 can be, for example, a ball valve, a butterfly valve, or a gate valve. By controlling the opening and closing of the second selection valve 22, it is possible to determine whether the cooling water at the bottom of the cryogenic tower 11 flows into the second cooling unit 18, and thus determine whether the second cooling unit 18 and the refrigeration unit 12 are connected in parallel.

[0046] Please see Figure 1 As shown, in one embodiment of this utility model, a third selector valve 23 is provided between the outlet of the first cooling unit 17 and the outlet of the second cooling unit 18. Specifically, the third selector valve 23 is located between the outlet of the first cooling unit 17, the outlet of the second cooling unit 18, and the outlet of the refrigeration unit 12. The third selector valve 23 may be, for example, a ball valve, a butterfly valve, or a gate valve.

[0047] Please see Figure 1As shown, in one embodiment of this utility model, a fourth selector valve 24 is provided between the outlet of the second cooling unit 18 and the top of the cryogenic tower 11. Specifically, the fourth selector valve 24 is located between the outlet of the second cooling unit 18 and the outlet of the refrigeration unit 12. The fourth selector valve 24 is, for example, a ball valve, a butterfly valve, or a gate valve.

[0048] Please see Figure 1 As shown, in one embodiment of this utility model, by controlling the opening and closing of the first selection valve 21, the second selection valve 22, the third selection valve 23, and the fourth selection valve 24, it is possible to determine whether the second cooling unit 18 is used in parallel with the first cooling unit 17 or in parallel with the refrigeration unit 12, so as to adjust the actual operating conditions of the preparation device according to the ambient temperature. Specifically, in summer operation, the first selection valve 21 and the third selection valve 23 are open, and the second selection valve 22 and the fourth selection valve 24 are closed, so that the first cooling unit 17 and the second cooling unit 18 can be connected in parallel to jointly cool the gas at the bottom of the stripping tower 15 to meet the cooling requirements of the stripping tower 15, while the refrigeration unit 12 cools the cooling water flowing out from the bottom of the cryogenic tower 11 separately. Conversely, during winter operation, the first selector valve 21 and the third selector valve 23 are closed, while the second selector valve 22 and the fourth selector valve 24 are open. This allows the refrigeration unit 12 and the second cooling unit 18 to operate in parallel and jointly cool the cooling water flowing out from the bottom of the cryogenic tower 11, thereby reducing the energy consumption of the refrigeration unit 12. Meanwhile, the first cooling unit 17 cools the gas at the bottom of the stripping tower 15 separately.

[0049] In summary, this invention provides an apparatus for preparing ethylene glycol. By incorporating a first cooling unit, a second cooling unit, and a refrigeration unit, the actual operating process of the apparatus can be adjusted according to changes in ambient temperature, thereby improving the flexibility and economy of the apparatus. Furthermore, the ethylene glycol preparation apparatus provided by this invention can reduce energy consumption in the preparation process, improve economic efficiency, and is suitable for large-scale application.

[0050] Throughout this specification, the terms "one embodiment," "an embodiment," or "a specific embodiment" refer to a particular feature, structure, or characteristic described in connection with an embodiment, which is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0051] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features. It should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application. Except for the technical features described in the specification, the remaining technical features are known to those skilled in the art. To highlight the innovative features of this utility model, the remaining technical features will not be described further here.

Claims

1. An apparatus for the production of ethylene glycol, characterized in that At least comprising: a deep cooling column; an oxidation reactor, an inlet of which is connected to a top of the deep cooling column; a stripping column, an outlet of the oxidation reactor is connected to the stripping column; a hydration reactor, connected to a bottom of the stripping column; a refrigeration unit, an inlet of which is connected to a bottom of the deep cooling column, and an outlet of which is connected to a top of the deep cooling column; a first cooling unit, connected to a top of the stripping column; and a second cooling unit, connected to the top of the stripping column after being connected in parallel with the first cooling unit, or the second cooling unit and the refrigeration unit are connected in parallel, and inlets of the second cooling unit and the refrigeration unit are connected to the bottom of the deep cooling column, and outlets of the second cooling unit and the refrigeration unit are connected to the top of the deep cooling column.

2. The preparation device according to claim 1, characterized in that The preparation device further comprises an absorption column, and the outlet of the oxidation reactor and the top of the stripping column are each connected to the absorption column.

3. The preparation device according to claim 2, characterized in that The bottom of the stripping column is connected to a top of the absorption column.

4. The preparation device according to claim 1, characterized in that The preparation device further comprises a first selection valve, which is arranged between the top of the stripping column and an inlet of the second cooling unit.

5. The preparation device of claim 1, wherein The preparation device further comprises a second selection valve, which is arranged between the bottom of the deep cooling column and the inlet of the second cooling unit.

6. The preparation device of claim 1, wherein The preparation device further comprises a third selection valve, which is arranged between an outlet of the first cooling unit and an outlet of the second cooling unit.

7. The preparation device of claim 1, wherein The preparation device further comprises a fourth selection valve, which is arranged between the outlet of the second cooling unit and the top of the deep cooling column.

8. The preparation device of claim 1, wherein, The first cooling unit and the second cooling unit each comprise a plurality of cooling groups arranged in parallel, and each of the cooling groups comprises a plurality of coolers arranged in series.

9. The preparation device according to claim 8, characterized in that The coolers are air coolers, and the refrigeration unit is a lithium bromide refrigeration unit.

10. The preparation device of claim 1, wherein, The preparation device further comprises a stripping gas generator, and an outlet of the stripping gas generator is connected to the bottom of the stripping column.

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