A hydrogen recovery system for ethylene glycol production

Abstract

The utility model provides a kind of hydrogen recovery system for ethylene glycol production, by additionally adding parallel emergency pipeline and buffer tank with pipeline, the technical problem of torch gas pipe network overpressure fluctuation caused by fuel gas pipe network failure parking makes analytical gas emission blocked is solved, in the system use, the design of emergency pipeline improves gas flow capacity, ensure that when fuel gas pipe network suddenly parking, large amount of analytical gas can pass through emergency pipeline into buffer tank after dampening airflow impact, absorb the flow peak of analytical gas emission initial stage, prevent emergency pipeline instantaneous overload, then discharge to torch gas pipe network smoothly, effectively avoid the torch gas pipe network pressure violent oscillation caused by emission pressure too high. The system eliminates the systematic overpressure risk in the prior art, and reduces the impact of pressure fluctuation on the downstream torch gas pipe network through the damping effect of the buffer tank, and improves the continuous operation safety and process stability of the ethylene glycol production system.

Description

Technical Field

[0001] This utility model belongs to the field of hydrogen recovery technology in ethylene glycol production, and specifically relates to a hydrogen recovery system for ethylene glycol production. Background Technology

[0002] Ethylene glycol is an important petrochemical raw material, widely used in the production of polyester fibers, polyethylene terephthalate (PET) resin, antifreeze, solvents, plasticizers, surfactants, cosmetics, and explosives. In the industrial production of ethylene glycol, liquid-phase hydrogenation is a key step, aimed at improving product quality through catalytic hydrogenation reactions. For example, in the coal-to-ethylene glycol process, hydrogenation removes impurities such as aldehydes, ketones, acids, and esters from industrial-grade ethylene glycol to improve its ultraviolet transmittance, bringing it up to polyester-grade standards.

[0003] In ethylene glycol production, the tail gas produced after the hydrogenation reaction still contains unreacted hydrogen. To improve resource utilization, reduce production costs, and minimize environmental impact, this hydrogen needs to be recovered and reused. Current processes often employ pressure swing adsorption (PSA) systems for hydrogen recovery.

[0004] In existing technologies, the PSA system directly sends the recovered hydrogen to the fuel gas network or flare gas network using a desorbed gas compressor. However, in actual production, when the fuel gas network shuts down due to excessive pressure or other reasons, all the hydrogen will go to the flare gas network, causing severe fluctuations in the overpressure of the desorbed gas in the flare gas network, which in turn affects the production of ethylene glycol. Utility Model Content

[0005] To address the technical problem in the background art where, when the fuel gas pipeline shuts down due to excessive pressure or other reasons, all the hydrogen will go to the flare gas pipeline, causing severe fluctuations in the overpressure of the flare gas pipeline and thus affecting ethylene glycol production, this utility model provides a hydrogen recovery system for ethylene glycol production.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A hydrogen recovery system for ethylene glycol production includes a PSA assembly and a desorbed gas compressor. The inlet of the PSA assembly is connected to the ethylene glycol production system. The desorbed gas compressor is connected to the outlet of the PSA assembly, a flare gas network, and a fuel gas network via pipelines. The system also includes an emergency pipeline that connects the desorbed gas compressor to the flare gas network.

[0008] A buffer tank, which is connected to the emergency pipeline.

[0009] Optionally, the system further includes a regulating valve assembly disposed on the emergency pipeline.

[0010] Optionally, the system further includes a central control component and a pressure detection component;

[0011] The regulating valve assembly is an electrically controlled valve;

[0012] The pressure detection component is installed on the pipeline between the desorbed gas compressor and the fuel gas pipeline network, and is electrically connected to the central control component;

[0013] The central control component is electrically connected to the regulating valve group.

[0014] Optionally, the diameter of the emergency pipeline is larger than the diameter of the main pipeline.

[0015] Optionally, the ratio of the diameter of the emergency pipeline to the diameter of the main pipeline is 1.5:1 to 2:1.

[0016] Optionally, a drain valve is provided at the bottom of the buffer tank.

[0017] The beneficial effects of this utility model are:

[0018] This invention provides a hydrogen recovery system for ethylene glycol production. By adding an emergency pipeline and a buffer tank parallel to the main pipeline, it solves the technical problem of overpressure fluctuations in the flare gas pipeline caused by obstructed desorbed gas emissions due to fuel gas pipeline failures. In the application of this system, the design of the emergency pipeline improves gas flow capacity, ensuring that in the event of a sudden fuel gas pipeline shutdown, a large amount of desorbed gas can enter the buffer tank through the emergency pipeline to smooth the airflow impact, absorb the initial flow peak of desorbed gas emission, prevent instantaneous overload of the emergency pipeline, and then smoothly discharge to the flare gas pipeline. This effectively avoids violent pressure fluctuations in the flare gas pipeline caused by excessively high emission pressure, maintains the dynamic pressure balance within the PSA module, and ensures adsorbent regeneration efficiency and hydrogen recovery purity. This system eliminates the systemic overpressure risk in existing technologies and reduces the impact of pressure fluctuations on the downstream flare gas pipeline through the damping effect of the buffer tank, comprehensively improving the continuous operation safety and process stability of the ethylene glycol production system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a hydrogen recovery system for ethylene glycol production according to this utility model;

[0020] Figure 2 This is a further schematic diagram of a hydrogen recovery system for ethylene glycol production according to this utility model.

[0021] The components include: 1. PSA assembly; 2. Desorbed gas compressor; 3. Ethylene glycol production system; 4. Pipelines; 5. Flare gas pipeline network; 6. Fuel gas pipeline network; 61. Pressure detection assembly; 7. Emergency pipeline; 71. Regulating valve assembly; 8. Buffer tank; 9. Central control assembly. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0025] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0026] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0027] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] See Figure 1 The diagram shows a schematic of a hydrogen recovery system for ethylene glycol production according to the present invention. The system includes at least a PSA assembly 1 and a desorbed gas compressor 2. The inlet of the PSA assembly 1 is connected to the ethylene glycol production system 3. The desorbed gas compressor 2 is connected to the outlet of the PSA assembly 1, the flare gas network 5, and the fuel gas network 6 via pipelines 4. The system also includes an emergency pipeline 7, which connects the desorbed gas compressor 2 and the flare gas network 5; and a buffer tank 8, which is connected to the emergency pipeline 7.

[0029] In this embodiment, by adding an emergency pipeline 7 and a buffer tank 8 parallel to pipeline 4, the technical problem of overpressure fluctuations in the flare gas pipeline 5 caused by obstructed desorption gas discharge due to a failure to shut down the fuel gas pipeline network 6 is solved. In the use of this system, the design of the emergency pipeline 7 improves the gas flow capacity, ensuring that in the event of a sudden shutdown of the fuel gas pipeline network 6, a large amount of desorption gas can enter the buffer tank 8 through the emergency pipeline 7 to smooth the airflow impact, absorb the flow peak at the beginning of desorption gas discharge, prevent the emergency pipeline 7 from instantaneously overloaded, and then smoothly discharge to the flare gas pipeline network 5. This effectively avoids violent pressure fluctuations in the flare gas pipeline network 5 caused by excessively high discharge pressure, maintains the dynamic pressure balance within the PSA module 1, and ensures the adsorbent regeneration efficiency and hydrogen recovery purity. This system eliminates the systemic overpressure risk in the prior art and reduces the impact of pressure fluctuations on the downstream flare gas pipeline network 5 through the damping effect of the buffer tank 8, comprehensively improving the continuous operation safety and process stability of the ethylene glycol production system.

[0030] Optionally, refer to Figure 2 The hydrogen recovery system for ethylene glycol production in this utility model also includes a regulating valve group 71, which is installed on the emergency pipeline 7.

[0031] In this embodiment, the integration of the regulating valve group 71 further optimizes the precise control capability of emergency emissions. When the fuel gas pipeline 6 and the desorbed gas compressor 2 are operating normally, the regulating valve group 71 is in a normally closed state, ensuring that the flow distribution of the conventional emission path (entering the fuel gas pipeline 6 through pipeline 4) is not disturbed. Once an emergency condition is triggered, the regulating valve group 71 can be quickly opened to avoid the resulting gas accumulation and overpressure, thus enhancing the system's regulation capability. Compared with a straight-through pipeline without a valve group, this solution improves the controllability and reliability of the emission process, provides a stable airflow input to the flare gas pipeline 5, and suppresses the chain negative impact of pressure fluctuations on the ethylene glycol synthesis reaction.

[0032] Preferably, the regulating valve group 71 is located between the buffer tank 8 and the desorbed gas compressor 2 to prevent desorbed gas from entering the buffer tank 8 and causing overall pressure fluctuations when the fuel gas pipeline network 6 is operating normally.

[0033] Optionally, refer to Figure 2 The hydrogen recovery system for ethylene glycol production in this utility model also includes a central control component 9 and a pressure detection component 61; the regulating valve group 71 is an electrically controlled valve; the pressure detection component 61 is installed on the pipeline 4 between the desorbed gas compressor 2 and the fuel gas pipeline network 6, and is electrically connected to the central control component 9; the central control component 9 is electrically connected to the regulating valve group 71.

[0034] In this embodiment, the introduction of the central control component 9 and the pressure detection component 61 enables the system to respond quickly. During use, the pressure detection component 61 monitors the pressure of key nodes from the desorbed gas compressor 2 to the fuel gas pipeline 6 in real time and transmits the signal to the central control component 9. The central control component 9 outputs control commands to the electronically controlled valve based on preset logic (such as pressure threshold comparison and compressor status diagnosis) to control the opening and closing of the electronically controlled valve, transforming manual intervention into a fully automatic response and eliminating the risk of emergency delay caused by operation delay.

[0035] Optionally, the diameter of the emergency pipeline 7 in this invention is larger than the diameter of the pipeline 4.

[0036] In this embodiment, the larger diameter of the emergency pipeline 7 significantly reduces gas flow resistance and increases the maximum ventable gas volume per unit time. This ensures that even under extreme conditions such as the shutdown of the desorbed gas compressor 2, the instantaneously surging desorbed gas flow can still be fully released through the emergency pipeline 7, preventing system overpressure due to insufficient flow capacity. Simultaneously, the wider inner wall of the emergency pipeline 7 reduces the retention effect of micro-droplets or solid particles, lowering the risk of blockage. Furthermore, the enhanced gas scouring effect in high-velocity areas (such as valve throttling points) further inhibits impurity deposition, extends the pipeline's maintenance-free cycle, and provides inherently safe emission redundancy for the system.

[0037] Optionally, the ratio of the diameter of the emergency pipeline 7 to the diameter of the pipeline 4 in this utility model is 1.5:1 to 2:1.

[0038] Optionally, the bottom of the buffer tank 8 in this invention is provided with a drain valve.

[0039] In this embodiment, a drain valve is provided at the bottom of the buffer tank 8 to address the possibility that the desorption gas generated by the ethylene glycol process may carry components such as methanol and water vapor that have not been completely separated. These components may condense into liquid after cooling in the buffer tank 8. The drain valve is provided to periodically or automatically discharge these accumulated liquids, preventing the effective volume reduction and gas-liquid carryover caused by excessively high liquid levels in the tank.

[0040] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A hydrogen recovery system for ethylene glycol production, comprising a PSA assembly (1) and a desorbed gas compressor (2), wherein the inlet of the PSA assembly (1) is connected to an ethylene glycol production system (3), and the desorbed gas compressor (2) is connected via pipelines (4) to the outlet of the PSA assembly (1), a flare gas network (5), and a fuel gas network (6), characterized in that, Also includes: Emergency pipeline (7), the emergency pipeline (7) is connected to the desorption gas compressor (2) and the flare gas pipeline (5); Buffer tank (8), which is connected to the emergency pipeline (7) 1.

2. The hydrogen recovery system for ethylene glycol production according to claim 1, characterized in that, The system also includes a regulating valve assembly (71), which is installed on the emergency pipeline (7).

3. The hydrogen recovery system for ethylene glycol production according to claim 2, characterized in that, The system also includes a central control component (9) and a pressure detection component (61). The regulating valve assembly (71) is an electrically controlled valve; The pressure detection component (61) is installed on the pipeline between the desorbed gas compressor (2) and the fuel gas pipeline (6), and is electrically connected to the central control component (9); The central control component (9) is electrically connected to the regulating valve group (71).

4. The hydrogen recovery system for ethylene glycol production according to claim 1, characterized in that, The diameter of the emergency pipeline (7) is larger than the diameter of the pipeline (4).

5. The hydrogen recovery system for ethylene glycol production according to claim 4, characterized in that, The ratio of the diameter of the emergency pipeline (7) to the diameter of the pipeline (4) is 1.5:1 to 2:

1.

6. The hydrogen recovery system for ethylene glycol production according to claim 1, characterized in that, The bottom of the buffer tank (8) is equipped with a drain valve.

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