Method for operating a process engineering system and process engineering system

Abstract

A method for operating a process plant (10) arranged in an enclosure (100) is proposed, comprising cooling a fluid stream (3, 7) provided by or used in the plant (10) using cooling air and further comprising ventilating the enclosure (100) using ventilation air, wherein the cooling air and the ventilation air are supplied using a common cooling device (13). A corresponding plant (10) is also proposed.

Description

[0001] The disclosure relates to a method for operating a process engineering plant and a corresponding plant. background

[0002] Hydrogen can be obtained using a variety of methods, for example by steam reforming of hydrogen-containing organic compounds such as methane, by co-electrolysis of water and carbon dioxide, or by electrolysis of water.

[0003] Water electrolysis can be carried out in particular using conventional alkaline electrolysis (AEL), proton exchange membranes (PEM), anion exchange membranes (AEM), or solid oxide electrolysis cells (SOEC). Several of these technologies can also be used in combination or in parallel within a single system.

[0004] Conventional water electrolysis typically uses pressures of less than 50 mbar (low-pressure electrolysis), whereas at least some of the previously mentioned processes are now also carried out at pressures between 3 and 40 or even 100 bar. This makes it possible, in particular, to avoid subsequent compression of the hydrogen.

[0005] Although the measures proposed here are described using the example of water electrolysis, they are not specifically limited to this process, but are equally suitable for use in other process engineering plants and offer particular advantages there as well. Examples of such plants are mentioned below.

[0006] There remains a need for improved efficiency and safety in the operation of such process engineering plants. Overview

[0007] Against this background, a method and a system with the features of the independent patent claims are proposed. Embodiments are the subject of the dependent patent claims and the following description.

[0008] The proposed method is for operating a process plant located in an enclosure. It comprises cooling a fluid flow generated and / or used in the plant using cooling air, and ventilating the enclosure using ventilation air. The cooling air and the ventilation air are supplied together using a cooling device.

[0009] The "fluid flow generated using the plant and / or used in the plant" can be a product flow generated in the plant, such as raw electrolysis gas or a component mixture taken from a reactor; a partial flow formed using such a product flow; or a fluid flow purified or separated from it. It can also be a feed stream processed in the plant, such as a hydrocarbon flow fed into a reactor. However, it can also be a material flow, such as cooling water, process water, steam to be condensed, or any other flow that is in heat and / or mass exchange with the plant—that is, a so-called utility flow.

[0010] The term "supplying" cooling and ventilation air refers to setting a volume of air in motion. For example, familiar air coolers supply cooling air by drawing it from the atmosphere and setting it in motion so that it encounters cooling structures such as cooling coils, cooling fins, or the fins of a fluid guide structure for a fluid to be cooled. The term "air cooler" is explained below. An exhaust system, for example in a building, can also generate an outward airflow by extracting air from the building. Air can then be drawn into the building through openings elsewhere, such as dedicated air inlets, creating a ventilation airflow. The exhaust system thus supplies ventilation air. Depending on the configuration, this ventilation air can also be partially or completely recirculated throughout the building.

[0011] Many plant cooling systems are based on guided airflow air coolers, meaning that correspondingly large fans are already installed. The method proposed here suggests a dual use of this airflow. In conventional plants, dedicated air coolers are used for process cooling—that is, for cooling a process stream supplied by the plant—to dissipate process heat. If ventilation is required within an enclosure (often a building on a large scale), a separate ventilation system is conventionally installed. This ventilation system is typically used only to ensure air exchange or to maintain a specific temperature within the building. The two parallel systems result in a significant space requirement. Furthermore, a large number of cooling water pipes, as well as corresponding steel structures and foundations, are necessary.Furthermore, this results in increased maintenance costs.

[0012] The proposed dual use of the air cooler can overcome these disadvantages. The air cooler is used not only for process cooling, i.e., cooling a specific process flow, but also for ventilating the enclosure. Instead of installing separate systems for process cooling and ventilation, the existing air cooler is used for both tasks. This eliminates the need for additional ventilation systems, significantly reducing the space required.

[0013] Since no separate ventilation system is required, fewer cooling water pipes, steel structures, and foundations are needed, reducing construction costs and material usage. At the same time, redundancy for building ventilation increases because the system can be used more flexibly. Maintenance is also reduced, as there are fewer components and maintenance can be concentrated on a single system. This leads to lower maintenance costs and overall higher efficiency of the entire cooling system. Separate heating can potentially be eliminated or at least made energy-efficient if and as long as waste heat from a process is available. Because the waste heat system for process cooling often has a higher air demand than typical building ventilation, appropriate designs can ensure greater dilution, and thus even more reliable system operation, without significant additional effort.

[0014] Further advantages arise in the removal of waste heat from process equipment such as electrolysis stacks in electrolyzers, compressors, etc. Air exchange rates (as, for example, in certain explosion protection zones) can be increased, so that even non-explosion-proof certified equipment can be used. However, the invention does not have to be used in connection with explosion protection, but is also suitable for simple ventilation or dilution or removal of other, non-explosive media.

[0015] Within the framework of the proposed method, it can be provided, in particular, that the cooling unit draws in cooling air and supplies it as ventilation air, or vice versa. A corresponding airflow for ventilation thus originates from the cooling unit ("exhaust operation") or is supplied to it ("intake operation"), which can also include generating a recirculated airflow or integrating the cooling unit into a corresponding recirculating air system. Furthermore, it is possible to switch between intake and exhaust operation by reversing the fan rotation direction. This allows, in particular, the heat to be dissipated from an air cooler in the enclosure to be blown away and / or blown into the enclosure for heating purposes.

[0016] The cooling unit can be located, in particular, in an upper area of ​​the enclosure that has an opening to the outside, for example, under the roof or ridge of a suitable machine house with external ventilation. This allows for the targeted removal of lighter-than-air compounds that accumulate there. Alternatively, the cooling unit can be arranged vertically and / or horizontally in a side wall of the enclosure with an exhaust and / or intake opening in the roof. Generally, the unit can also be located on top of or near the enclosure, with corresponding openings in the enclosure. The location near the enclosure can depend on the available space and ventilation requirements.

[0017] The proposed method is particularly suitable for cases in which inert, toxic, and / or flammable or explosive gases or vapors are produced using the process equipment. As mentioned several times, the enclosure can be a building. Embodiments of the invention allow for the dilution and / or removal of such gases or vapors.

[0018] The proposed method and its embodiments are particularly suitable for use in the context of so-called primary explosion protection, wherein the cooling device conveys the ventilation air into or out of an explosion protection zone, in particular a zone 1 or 2 as explained below, in the enclosure.

[0019] The proposed method and its embodiments provide, in particular, that the cooling unit is arranged in, on, or near the enclosure, so that no intake lines for air from outside the enclosure and no lines for the corresponding process fluid to the outside are required. In such embodiments, recirculation of the air is also simplified, resulting in significant energy savings.

[0020] The plant operated using the proposed method can be set up in particular to carry out electrolysis, for example in the form of water and / or carbon dioxide electrolysis (co-electrolysis).

[0021] In other configurations, the plant can be set up to carry out a process or process step consisting of reforming, in particular steam or carbon dioxide or dry reforming, thermal cracking, catalytic cracking, dehydrogenation, hydrogenation, or one or more combinations thereof. Products of such processes can include, for example, hydrogen, synthesis gas with varying proportions of hydrogen, carbon monoxide, and possibly carbon dioxide or hydrocarbons, such as paraffins and / or olefins. Inert, toxic, and / or flammable or explosive gases or vapors can also be introduced, handled, or reacted in such processes, and corresponding cooling steps may be required. Therefore, the configurations proposed here are also suitable for this purpose.

[0022] The proposed process plant is housed in an enclosure, which can also be considered part of the claim. The plant is configured to cool a fluid stream supplied and / or used in the plant using cooling air, and to ventilate the enclosure using ventilation air, with a common cooling device being provided for conveying the cooling air and the ventilation air.

[0023] For further features and advantages of a corresponding system and its embodiments, reference is expressly made to the above explanations concerning the method proposed according to the invention and its embodiments, since these apply in the same way. Drawings

[0024] Exemplary embodiments of the solutions proposed here are described below with reference to the attached drawing, wherein Figure 1 an arrangement that is operated according to a specific design, and Figure 2 an arrangement that is operated according to a different configuration. Designs

[0025] The embodiments and configurations described below are provided solely to assist the reader in understanding the claimed and previously explained features. They represent only representative examples and are not intended to be considered exhaustive or limiting with regard to the features of the proposed methods and devices.

[0026] It is understood that the advantages, embodiments, examples, functions, features, structures and / or other aspects described above and below are not to be considered as limitations of the scope of the claims or as limitations of equivalents thereto, and that other embodiments may be used and modifications made without deviating from the scope of the claims.

[0027] Explanations relating to devices, apparatus, arrangements, systems, etc., according to proposed embodiments may also apply to procedures, processes, methods, etc., according to other embodiments, and vice versa. Identical, functionally equivalent, structurally identical, or comparable elements, process steps, etc., may be indicated with identical reference numerals.

[0028] The following explanations and definitions relating to some fundamental aspects of the invention may apply to all or part of the embodiments presented here, and the explanation of certain aspects relating to only one part or one of the embodiments should not be understood to mean that these aspects cannot also be realized with other or all embodiments, insofar as technically possible and sensible.

[0029] The conjunction "and / or," when used before the last item in a list, should be understood to mean that all items mentioned before and after it can be combined in any way. In other words, "A, B and / or C" means "A and / or B and / or C" or "at least one of the elements A, B, and C in any combination."

[0030] As mentioned at the outset, one application area of ​​the measures proposed here is the electrolysis of water. Some of the processes that can be used for this purpose have been known for a long time and are described in the technical literature. Among many others, reference is made, for example, to a review article by M. EI-Shafie, "Hydrogen production by water electrolysis technologies: A review", Results in Engineering 20 (2023) 101426.

[0031] As mentioned at the outset, the proposed designs are not limited to the electrolysis of water, but are also suitable for other electrolysis processes, for example for the production of carbon monoxide from carbon dioxide, as described in WO 2014 / 154253 A1 and WO 2013 / 131778 A2.

[0032] WO 2015 / 014527 A1 and EP 2 940 773 A1 describe this process. In corresponding procedures, water can also be subjected to electrolysis in addition to carbon dioxide, so that a synthesis gas containing hydrogen and carbon monoxide can be formed. Details on this are also described in the technical literature and can also be used in the embodiments proposed here.

[0033] During electrolysis, hydrogen is initially produced as a gas dissolved in water. If hydrogen escapes unintentionally, it can form a mixture with oxygen that is explosive at concentrations between 4 and 77 percent by volume. An ignition energy of just 0.02 mJ is sufficient to trigger an explosion. The risks associated with handling hydrogen can be managed through appropriate explosion protection measures, for example, in accordance with standards IEC 60079 and ISO 22734.

[0034] A distinction can be made between primary and secondary explosion protection. Primary explosion protection is achieved, for example, through a tightly sealed construction or by diluting a gas or gas-air mixture. Escaping hydrogen is detected by gas sensors. Due to the small size of hydrogen molecules, which can diffuse through metals, ensuring a tight seal requires special measures, particularly in high-temperature processes. Contamination of the hydrogen by oxygen must also be prevented.

[0035] Secondary explosion protection is based on a zone classification, in particular according to IEC 60079-10-1. Potentially hazardous areas are divided into zones depending on how frequently an explosive atmosphere can occur there. Zone 0 describes areas with a constant hazard, Zone 1 those with an occasional hazard, and Zone 2 areas with a hazard that is rare and only occurs briefly. Protection in these zones focuses on preventing ignition sources. Another classification is Zone "NE" (negligible extent, where the volume of potentially explosive atmosphere is kept so small by high ventilation air velocities that even in the event of ignition, no significant adverse effects are expected). This form of explosion protection is chosen when ignition sources cannot be completely avoided. The embodiments disclosed here are specifically proposed for the ventilation of Zones 1, 2, and / or NE.

[0036] For low-pressure electrolyzers up to 50 mbar, less stringent requirements apply, provided hydrogen leaks remain minimal. High-pressure systems up to 100 bar, however, require stricter monitoring and fast-responding gas detectors. The area around the cell block is generally classified as Zone 2 or Zone 2 NE.

[0037] From a safety perspective, processes involving the handling of hydrogen are comparable. A certain degree of comparability also exists with processes involving the generation, handling, or consumption of other inert, toxic, and / or flammable or explosive gases or vapors in combination with oxygen, such as methane, carbon monoxide, and other hydrocarbons, as well as ignitable mixtures. Examples of such processes have already been mentioned in the explanations above.

[0038] In certain electrolysis processes, as well as in other process engineering applications, it is necessary to cool specific liquid or gaseous flows, for example, before feeding into and / or after extraction from an electrolysis cell or reactor, and / or after compression. Cooling can also be used for utility flows, as previously described. Air coolers can be employed for this purpose.

[0039] An "air cooler," which can be used as a cooling device in the configurations proposed here, is understood to be a cooling device in which one or more air streams are provided, for example by means of one or more fans, and guided over heat exchange structures that are thermally connected to a fluid guide structure for a fluid to be cooled. Air coolers are also referred to as air-cooled heat exchangers and are described, for example, in the subsection "Air Cooled Heat Exchangers" of Chapter 11, "Heat-Transfer Equipment," in "Perry's Chemical Engineers' Handbook," 7th edition, McGraw-Hill, 1997, starting on pages 11-48.

[0040] Air coolers, for example, comprise a tube bundle for the fluid to be cooled, which is typically equipped with spirally shaped fins, and a blower that moves the air over the tubes of the tube bundle and is driven by a drive, typically an electric motor. For further details and designs, which can also be used within the framework of the proposed configurations, please refer to the aforementioned literature.

[0041] In Figure 1 The arrangement, which is operable according to a configuration proposed here, is shown schematically and is designated as 1000 in its entirety. The arrangement 1000 comprises a process engineering plant 10, which is housed in an enclosure 100, for example a machine or operating building.

[0042] The example of implementation of Figure 1This diagram has been greatly simplified in many respects to better illustrate the core concept of the measures proposed here. For example, process flows, valves, pipes, drives, control and regulating units, and processing units, etc., are omitted, without limiting the scope of disclosure. The airflow is also represented symbolically only to ensure readability. The components are shown schematically and not according to their actual dimensions. In other configurations, the position of the air coolers and other components relative to each other and to the building may differ. Other configurations need not include all of the components shown, and components may be located in different positions relative to each other.

[0043] In the illustrated example, plant 10 comprises a process unit 11, for example an electrolysis unit or a reactor, to which a feedstock 1, for example water, is supplied, and from which a process stream 2, for example raw hydrogen, can be drawn. The process unit 11 can, for example, include separators for separating hydrogen and water, so-called deoxo units for the catalytic removal of oxygen, dryers, and any other units for separating or processing fluid streams.

[0044] The process stream 2, possibly after treatment and / or pre-cooling (not illustrated), is fed to a compression unit 12, resulting in a compressed process stream 3 heated by the compression heat. This is cooled in a cooling unit 13, which in the illustrated example is an air cooler located in the ridge or under a roof 101 of the enclosure 100.

[0045] The compressed and cooled process stream, now designated 4, can, for example, be fed to a purification unit 14 and subsequently stored in gaseous form as product hydrogen 5 in a tank not shown, supplied to a consumer, or liquefied.

[0046] As shown by the arrow, an airflow can be drawn in by means of the cooling device 13, so that ventilation air 102 can be drawn in through openings 103 in the enclosure 100, for example air inlet grilles, and the enclosure can be ventilated in this way. The ventilation air 102 is used as cooling air 104 to cool the process stream 3 and is then discharged from the enclosure 100.

[0047] In Figure 2 is an arrangement that can be operated according to a configuration proposed here, shown schematically and designated in its entirety as 2000. Arrangement 2000 comprises, as described in Figure 1Illustrated plant 1000, a process engineering plant 10, which is housed in an enclosure 100, for example a machine or operating building.

[0048] The system 10 used in Order 2000 also comprises a process unit 11, for example an electrolysis unit or a reactor, to which a feedstock 1, for example water, is supplied, and from which a process stream 2, for example raw hydrogen, can be drawn. For further possible equipment of the process unit 11, please refer to the explanations for Annex 1000.

[0049] Annex 10 of Order 2000 provides for a treatment unit 15, which may, for example, include a pre-cooling device or a separation column operated using cooling water. This unit is operated, for example, using a cooling water stream 8, which is withdrawn from the treatment unit 15 as a heated cooling water stream 7.

[0050] To cool the heated cooling water flow 7, which in the sense explained above is like a fluid flow used in the system 10, the cooling unit 13 is cooled, whereby an interruption of the corresponding flow arrows 7 and 8 in Figure 2 This is only a graphic representation for the sake of clarity. It is understood that the proposed configurations are not limited to a cooling water flow 7 as used in Annex 10.

[0051] The process stream treated in treatment unit 15, now designated 6, can also be fed to a purification unit 14 and subsequently discharged as product 5 or treated in any other way.

[0052] Generally, the following applies to the in the Figure 1 and 2As illustrated in Figures 1000 and 2000, the cooling can be extracted at any point, including after / within process unit 11, cooling unit 13, purification unit 14, and / or treatment unit 15. The representation in the figures is purely exemplary and not limiting. With regard to process unit 11, it should be noted in particular that this unit can also include separators or gas processing units as separate process units, and a corresponding representation has been omitted solely for the sake of clarity. The media used can be gas (hydrogen) for direct cooling in electrolysis, but also two-phase flows of water and gas or alkali and gas, etc.

Claims

1. Method for operating a process plant (10) arranged in an enclosure (100), comprising: cooling a fluid stream (3, 7) formed using the plant (10) or used in the plant (10) using cooling air, and ventilating the enclosure (100) using ventilation air, wherein the cooling air and the ventilation air are conveyed using a common cooling device (13).

2. Method according to claim 1, wherein the cooling air is drawn in by means of the cooling device (13) and provided as the ventilation air or vice versa.

3. Method according to claim 1 or 2, wherein the cooling device (13) is arranged in an upper area of ​​the enclosure (100) which has an opening to an outside area.

4. Method according to one of the preceding claims, wherein one or more inert, toxic and / or flammable or explosive gases or vapors are provided using the process equipment (10).

5. Method according to any of the preceding claims, wherein the enclosure (100) is a commercial building.

6. Method according to one of the preceding claims, wherein the cooling device (13) supplies the ventilation air into or out of an explosion protection zone in the enclosure (100).

7. Method according to one of the preceding claims, wherein the cooling device (13) is arranged in, on or next to the enclosure (100).

8. Method according to one of the preceding claims, wherein the system (10) is set up to carry out electrolysis.

9. The method of claim 8, wherein electrolysis comprises water and / or carbon dioxide electrolysis.

10. Method according to any one of claims 1 to 7, wherein the apparatus (10) is configured to carry out a process or process step comprising reforming, thermal cracking, catalytic cracking, dehydration and hydrogenation or one or more combinations thereof.

11. Process plant (10) in an enclosure (100) which is set up to carry out the following steps: cooling a fluid stream (3, 7) provided using the plant (10) or used in the plant using cooling air, and ventilating the enclosure (100) using ventilation air, wherein a common cooling device (13) is provided for conveying the cooling air and the ventilation air.

12. System (10) according to claim 10, wherein the system (10) is configured to carry out a method according to any one of claims 1 to 10.

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