APPARATUS AND PROCESS FOR OXYGEN RECOVERY
20240369293 ยท 2024-11-07
Assignee
Inventors
- Alan D. Berger (Ambler, PA, US)
- QIAO JOSH ZHAO (MACUNGIE, PA, US)
- Donn Michael Herron (Fogelsville, PA, US)
Cpc classification
F25J1/0017
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/0201
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J2210/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/0035
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J2220/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/0045
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/004
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J2270/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J2230/20
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/005
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/0037
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J3/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J1/0228
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J2230/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F25J1/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25J3/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
C25B15/08
CHEMISTRY; METALLURGY
Abstract
An apparatus and process for liquid oxygen production can be configured to avoid use of a feed compressor and a recycle compressor. Embodiments can be configured for open loop operation so that a relatively low yield liquid oxygen recovery can be obtained from a feed output from an electrolyzer that is comprised mostly of oxygen (e.g. at least 80 volume percent oxygen, between 80 vol % and 100 vol % oxygen, etc.). The relatively low yield liquid oxygen recovery can be surprisingly provided to permit an advantageous recovery of oxygen to limit waste oxygen that may ultimately be vented while also minimizing equipment and power requirements for the liquid oxygen recovery.
Claims
1. An apparatus for liquid oxygen production, the apparatus comprising: a purification unit positioned to receive a feed from at least one electrolyzer and output the feed as a purified feed, the feed comprising oxygen, the feed having a pressure that is within a pre-selected feed pressure range; a heat exchanger positioned to receive at least a portion of the purified feed outputtable from the purification unit to cool the purified feed and output at least one stream of cooled purified feed; a first expander positioned to receive at least a first stream of cooled purified feed of the at least one stream of cooled purified feed outputtable from the heat exchanger to expand the first stream of cooled purified feed and output an expanded purified feed stream; a first phase separator positioned to receive the expanded purified feed stream to form a first liquid oxygen (LOX) stream and a first oxygen vapor stream to feed the first oxygen vapor stream to the heat exchanger as a cooling medium for the heat exchanger.
2. The apparatus of claim 1, wherein the oxygen is between 90 volume percent (vol %) of the feed and 100 vol % of the feed and the pressure that is within the pre-selected feed pressure range is a pressure between 5 bar absolute (bara) and 50 bara.
3. The apparatus of claim 1, comprising a second phase separator that is positioned so that a second purified feed stream of the at least one stream of cooled purified feed outputtable from the heat exchanger is feedable to the second phase separator for formation of a second oxygen vapor stream and a second LOX stream, the second phase separator connected to the heat exchanger so that the second oxygen vapor stream is feedable to the heat exchanger as a cooling medium to cool the purified feed fed to the heat exchanger before the second oxygen vapor stream is vented.
4. The apparatus of claim 3, comprising: a second expander positioned to receive the first oxygen vapor stream from the heat exchanger after the first oxygen vapor stream is warmed from passing through the heat exchanger as a second expander feed stream to expand the first oxygen vapor stream for feeding to the heat exchanger as an expanded cooling medium stream.
5. The apparatus of claim 1, comprising: a second expander positioned to receive the first oxygen vapor stream from the heat exchanger after the first oxygen vapor stream is warmed from passing through the heat exchanger as a second expander feed stream to expand the first oxygen vapor stream for feeding to the heat exchanger as an expanded cooling medium stream.
6. The apparatus of claim 1, comprising a first compander, wherein the first expander is an expander of the first compander and the first compander also has at least one first compression stage positioned to compress at least a portion of the purified feed stream to a pre-selected cooling feed pressure before it is fed to the heat exchanger, the first expander being interconnected to the at least one first compression stage such that expansion of the first stream of the cooled purified feed outputtable from the heat exchanger at least partially powers compression of the at least one first compression stage of the compander.
7. The apparatus of claim 1, wherein the at least a portion of the purified feed outputtable from the purification unit includes a first stream of the purified feed and a second stream of the purified feed, the apparatus also comprising: a first compander, wherein the first expander is an expander of the first compander and the first compander also has at least one first compression stage positioned to compress the first stream of the purified feed before it is fed to the heat exchanger, the first expander being interconnected to the at least one first compression stage such that expansion of the first stream of cooled purified feed outputtable from the heat exchanger at least partially powers compression of the at least one first compression stage of the compander.
8. The apparatus of claim 7, comprising: a second expander positioned to receive the first oxygen vapor stream from the heat exchanger after the first oxygen vapor stream is warmed from passing through the heat exchanger as a second expander feed stream to expand the first oxygen vapor stream for feeding to the heat exchanger as an expanded cooling medium stream.
9. The apparatus of claim 8, comprising: a second phase separator that is positioned so that the second purified feed stream output from the heat exchanger is feedable to the second phase separator for formation of a second oxygen vapor stream and a second LOX stream, the second phase separator connected to the heat exchanger so that the second oxygen vapor stream is feedable to the heat exchanger as a cooling medium to cool the purified feed fed to the heat exchanger before the second oxygen vapor stream is vented.
10. The apparatus of claim 1, wherein the at least a portion of the purified feed outputtable from the purification unit includes a first stream of the purified feed and a second stream of the purified feed, the apparatus also comprising: a first compander, wherein the first expander is an expander of the first compander and the first compander also has at least one first compression stage positioned to compress the first stream of the purified feed before it is fed to the heat exchanger or the second stream of the purified feed, the first expander being interconnected to the at least one first compression stage such that expansion of the first expander at least partially powers compression of the at least one first compression stage of the compander; a second expander positioned to receive the first oxygen vapor stream from the heat exchanger after the first oxygen vapor stream is warmed from passing through the heat exchanger or positioned to receive the second stream of the purified feed as a second expander feed stream to expand the stream for feeding to the heat exchanger as an expanded cooling medium stream; a second compander, wherein the second expander is an expander of the second compander and the second compander also has at least one second compression stage positioned to compress the first stream of the purified feed before it is fed to the heat exchanger or the second stream of the purified feed, the second expander being interconnected to the at least one second compression stage such that expansion of the second expander at least partially powers compression of the at least one second compression stage of the compander.
11. The apparatus of claim 1, wherein the apparatus is positioned and configured to form LOX from the feed at a yield of between 5% and 35% without a feed compressor and/or without a recycle compressor.
12. The apparatus of claim 1, wherein the apparatus is positioned and configured as an open loop arrangement for the feed that only uses fluid from the feed as a cooling medium for the heat exchanger.
13. The apparatus of claim 1, comprising: a second expander positioned to receive a bypass portion of the purified feed outputtable from the purification unit to expand the bypass portion for feeding to the heat exchanger as a cooling medium; and the heat exchanger positioned to receive a first stream of the purified feed outputtable from the purification unit to cool the first stream of the purified feed and output the first stream of the purified feed for feeding to the first expander.
14. The apparatus of claim 1, wherein the at least a portion of the purified feed outputtable from the purification unit or the at least one stream of cooled purified feed outputtable from the heat exchanger includes a first stream of the purified feed and a second stream of the purified feed, wherein the first phase separator is positioned such that the second stream of the purified feed is outputtable from the heat exchanger to bypass the first expander for being fed to the first phase separator while the first stream of the purified feed is outputtable from the heat exchanger as the first stream of cooled purified feed for being fed to the first expander.
15. A process for forming liquid oxygen (LOX) from a feed output from at least one electrolyzer, the feed comprising oxygen, the feed being at a pressure that is within a pre-selected feed pressure range, the process comprising: receiving the feed and purifying the feed to form a purified feed; cooling at least a portion of the purified feed via a heat exchanger and at least one expander to form a cooled feed; separating the cooled feed to form at least one stream of LOX and at least one stream of oxygen vapor; feeding each stream of the at least one stream of oxygen vapor to the heat exchanger as a cooling medium for cooling the purified feed.
16. The process of claim 15, wherein the feed comprises oxygen, the oxygen being between 90 volume percent (vol %) of the feed and 99 vol % of the feed and the pressure that is within the pre-selected feed pressure range is a pressure between 5 bar absolute (bara) and 50 bara.
17. The process of claim 15, wherein the at least one expander includes a first expander, the process comprising: compressing at least a portion of the feed via at least one first compression stage of a first compander, the first expander being an expander of the first compander, the first expander being interconnected to the at least one first compression stage of the first compander such that expansion of at least a portion of the purified feed at least partially powers compression of the at least a portion of the feed provided by the at least one first compression stage.
18. The process of claim 15, wherein the at least one stream of LOX is formed from the feed at a yield of between 5% and 35% without a feed compressor and/or without a recycle compressor.
19. The process of claim 15, comprising: outputting the at least one stream of oxygen vapor from the heat exchanger as a warmed at least one stream of oxygen vapor for venting and/or use as a regeneration gas.
20. The process of claim 19, wherein the process is an open loop arrangement for the feed that only uses fluid from the feed as the cooling medium for the heat exchanger.
21. The process of claim 15, wherein the feed is not compressed to a higher pressure via a feed compressor and the at least one stream of oxygen vapor is not compressed to a higher pressure via a recycle compressor.
22. The process of claim 15, wherein: the cooling of at least a portion of the purified feed via the heat exchanger and at least one expander comprises: splitting the purified feed into a first stream of purified feed and a bypass stream of purified feed and feeding the first stream of the purified feed to the heat exchanger to undergo cooling therein and feeding the bypass stream of the purified feed to an expander to undergo expansion so that the expanded bypass stream of the purified feed is feedable to the heat exchanger as a cooling medium; and the separating of the cooled feed to form the at least one stream of LOX and the at least one stream of oxygen vapor includes feeding the first stream of purified feed from the heat exchanger to a phase separator for forming a first stream of LOX and a first stream of oxygen vapor; and the feeding each stream of the at least one stream of oxygen vapor to the heat exchanger as a cooling medium for cooling the purified feed includes feeding the first stream of oxygen vapor to the heat exchanger as a cooling medium.
23. An apparatus for liquid oxygen production, the apparatus comprising: a purification unit positioned to receive a feed from at least one electrolyzer and output the feed as a purified feed, the feed comprising oxygen, the feed having a pressure that is within a pre-selected feed pressure range; a heat exchanger positioned to receive at least a portion of the purified feed outputtable from the purification unit to cool the purified feed and output at least one stream of cooled purified feed; a first expander positioned to receive at least a first stream of cooled purified feed of the at least one stream of cooled purified feed outputtable from the heat exchanger or a portion of the purified feed to expand it and output an expanded purified feed stream to feed to the heat exchanger as a cooling medium; a first phase separator positioned to receive a first stream of the at least one stream of cooled purified feed outputtable from the heat exchanger or a second stream of the at least one stream of cooled purified feed outputtable from the heat exchanger to form a first liquid oxygen (LOX) stream and a first oxygen vapor stream to feed the first oxygen vapor stream to the heat exchanger as a cooling medium for the heat exchanger.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Exemplary embodiments of processes for liquid oxygen production, apparatuses for liquid oxygen production, and systems for liquid oxygen production, and methods of making and using the same are shown in the drawings included herewith. It should be understood that like reference characters used in the drawings may identify like components.
[0043]
[0044]
[0045]
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[0048]
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[0050]
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[0054]
[0055] It should be understood that
DETAILED DESCRIPTION
[0056] Referring to
[0057] In some embodiments, the feed 2 output from the electrolyzer(s) 3 for being fed to the apparatus 1 can include hydrogen (e.g. between 2 volume percent (vol %) hydrogen and 0 vol % hydrogen, less than 2 vol % hydrogen, between 1 vol % hydrogen and 0 vol % hydrogen, etc.) at a concentration that is significantly lower than the concentration of oxygen within the feed 2 and can also include water at a concentration that is significantly lower than the concentration of oxygen within the feed (e.g. The water content for the feed 2 can be in a range of 0.01 vol % and 5 vol % or other suitable range). Other impurities may also be present in the feed 2.
[0058] The feed 2 can be at a pre-selected temperature, which can be, for example, an ambient temperature or at a relatively ambient temperature (e.g. a temperature that is below the boiling point of water, a temperature that is less than 90 C. and more than 0 C., a temperature that is less than 90 C., etc.). The feed 2 can also be at an elevated pressure. The pressure of the feed 2 can be at a pre-selected feed pressure of greater than or equal to 5 bara, at least 20 bara, or other suitable elevated pressure range (e.g. a pressure of between 5 bara and 40 bara, etc.).
[0059] The apparatus 1 for liquid oxygen production can be configured to process the feed 2 to remove hydrogen, moisture (e.g. water), and/or other impurities from the feed for subsequent liquefaction for the formation of at least one stream of liquid oxygen (e.g. a LOX product stream). The LOX product that is formed can include at least one liquid oxygen product stream, for example. Each LOX product stream can be at least 99 vol % oxygen (e.g. between 99 vol % oxygen and 100 vol % oxygen), or other suitable oxygen concentration range (e.g. at least 99.9 vol % oxygen, between 99.9 vol % oxygen and 99.999 vol % oxygen, between 100 vol % oxygen and 99.9 vol % oxygen, etc.). The LOX product stream can be stored in a storage device 21 (e.g. one or more LOX storage vessels) for subsequent use or transport.
[0060] As may best be appreciated from
[0061] The purified feed can be fed to the main heat exchanger 7 (Main HX) via a single stream or can be split for providing the purified feed to the main heat exchanger 7 in multiple streams. For instance, the purified feed can be fed from the PPU 5 to the main heat exchanger 7 as a first stream of purified feed 4 or can be split and fed to the main heat exchanger as a first stream of purified feed 4 and a second stream of purified feed 6. The first stream of purified feed 4 can also be referred to herein as a first purified feed stream and the second stream of purified feed 6 can also be referred to herein as a second purified feed stream.
[0062] One or more feed conduits can be positioned between the PPU 5 and the main heat exchanger 7 to feed each purified feed stream from the PPU 5 to the main heat exchanger 7. The main heat exchanger 7 can be configured and positioned to cool the one or more purified feed streams for feeding to one or more phase separators 11 and/or expanders 9. For instance, the first stream of purified feed 4 can be fed to the main heat exchanger 7 to undergo go cooling therein from a first pre-selected feed temperature that is within a pre-selected feed temperature range to a second pre-selected temperature that is within a pre-selected liquefaction processing temperature range.
[0063] An example of such a pre-selected liquefaction processing range can be 50 C. to 150 C., less than or equal to 50 C., or other suitable temperature range. An example of a first pre-selected feed temperature that is within a pre-selected feed temperature range can be a relatively ambient temperature or a temperature that is less than 100 C. and greater than 0 C. For example, the first pre-selected feed temperature can be a temperature that is between 5 C. and 40 C.
[0064] The first purified feed stream that is cooled can be output from the main heat exchanger 7 as a first cooled purified feed stream 8 and be fed to a first expander 9. A first expander feed conduit can be positioned between the main heat exchanger 7 and the first expander 9 to facilitate the flow of the first cooled purified feed stream 8 from the main heat exchanger 7 to the first expander 9.
[0065] The location at which the inlet for the first expander feed conduit is positioned at the main heat exchanger 7 can be adapted to meet a particular set of design criteria. For example, the first expander feed conduit can be positioned to receive the first cooled purified feed stream 8 at an end of the main heat exchanger or at a suitable intermediate position between the warm input end and the cold output end of the main heat exchanger 7.
[0066] The first expander 9 can be positioned and configured to expand the first cooled purified feed stream 8 to output a reduced pressure and further cooled first purified feed stream 10 for feeding to a first phase separator 11 (PS). The further cooled first purified feed stream 10 can include only oxygen gas or can include a mixture of oxygen gas and oxygen liquid due to the cooling that can occur via expansion. The amount of liquid within the further cooled first purified feed stream 10 can range from 0% liquid to 20% liquid in some arrangements. Other arrangements may utilize different splits between liquid oxygen and gaseous oxygen within the further cooled first purified feed stream 10 output from the first expander 9 (e.g. between 1% and 3% liquid and between 99% and 97% gas, between 3% and 10% liquid and between 97% and 90% gas, between 8% liquid and 15% liquid and between 92% and 85% gas, between greater than or equal to 0% liquid and 1% liquid and less than or equal to 100% gas and 99% gas, etc.).
[0067] In some embodiments, the further cooled first purified feed stream 10 that is output from the first expander 9 can be routed directly to the main heat exchanger 7 as a cooling medium to provide cooling therein prior to being vented as a waste stream 16.
[0068] In other embodiments, the further cooled first purified feed stream 10 can be fed from the first expander 9 to the first phase separator 11. For example, the first phase separator (PS) can be connected to the first expander 9 via a first phase separator feed conduit positioned between the first phase separator 11 and the first expander 9 for the first phase separator 11 to receive the further cooled first purified feed stream 10 from the first expander 9. The first phase separator 11 can separate the further cooled first purified feed stream 10 to form a first oxygen gas stream 14 for outputting to the main heat exchanger 7 and also form a first liquid oxygen stream for outputting as a first LOX stream 12 for providing to LOX storage 21 (e.g. one or more vessels for LOX storage) or to a second phase separator as shown by broken line arrow 12a to form a first LOX stream 12 for sending to LOX storage 21. The stored LOX can be subsequently used in another plant process or provided for transport for use by one or more end users or customers.
[0069] The first LOX stream 12 can be fed from the first phase separator 11 to the LOX storage 21 via a first storage conduit positioned between the first phase separator 11 and the LOX storage. The first phase separator 11 can also be connected to the main heat exchanger 7 so that the first oxygen gas stream 14 that is formed via the first phase separator 11 can be fed to the main heat exchanger 7 to function as a cooling medium therein for cooling of the one or more purified feed streams fed to the main heat exchanger 7. The first oxygen gas stream 14 can subsequently be vented as waste as a waste stream 16. Prior to venting, the warmed oxygen gas stream can be utilized for regeneration of one or more beds of adsorbent material within one or more adsorbers of the PPU in some embodiments.
[0070] In some implementations, the first oxygen gas stream 14 can undergo further expansion prior to being vented as a waste stream. In such an implementation, the first oxygen gas steam can be at a pressure that is greater than ambient pressure so that the first oxygen gas stream 14 can undergo additional expansion. For example, the first oxygen gas stream 14 can be passed through the main heat exchanger 7 to undergo warming as a cooling medium therein and subsequently be output from the main heat exchanger as a second expander feed stream 14a for being fed to a second expander 9 for undergoing expansion therein for being output as a cooled, expanded cooling medium stream 14b that can be fed to the main heat exchanger 7 for providing additional cooling therein before being output as a waste stream 14c from the main heat exchanger for being vented as a waste stream 16.
[0071] A second expander feed conduit can be positioned between the main heat exchanger 7 and the second expander 9 for feeding of the warmed first oxygen gas stream 14 to the second expander 9 as the second expander feed stream 14a. The location at which the warmed first oxygen gas stream 14 is output from the main heat exchanger 7 for feeding to the second expander as the second expander feed stream 14a can be a location at which the oxygen gas stream is at its warmest temperature after having passed through the heat exchanger 7 or can be another suitable intermediate location that can be considered suitable for feeding the gas to the second expander 9. A second expander output conduit can be positioned between the second expander 9 and the main heat exchanger 7 to feed the cooled and expanded oxygen gas back to the main heat exchanger 7 as the cooling medium stream 14b. The second expander output conduit can be positioned and configured so that the cooling medium stream 14b is fed to an intermediate section of the main heat exchanger 7 to pass through a portion of the main heat exchanger for providing additional cooling therein. The particular feed location for the cooling medium stream 14b at the main heat exchanger 7 can be selected based on the temperature of that stream and the cooling that the cooling medium stream 14b is to provide in the main heat exchanger for cooling of the one or more purified feed streams.
[0072] In implementations that include split purified feed streams, a second stream of purified feed 6 can also be fed to the main heat exchanger 7 via a second purified feed conduit positioned between the PPU 5 and the main heat exchanger 7. Alternatively, the second stream of purified feed 6 can be split from the first stream of purified feed 4 within the main heat exchanger 7 after this first stream is fed to the main heat exchanger 7. The second stream of purified feed 6 can be output from the main heat exchanger 7 as a second cooled purified stream 6a for being fed to a second phase separator 11 (PS) or for being fed to the first phase separator 11 as a second phase separator feed 6d that can be fed to the first phase separator so that a portion of the purified feed that is fed to the first phase separator bypasses the first expander 9 (see e.g. example implementations shown in
[0073] In implementations that utilize the second phase separator 11, the second phase separator 11 can be positioned to receive the second cooled purified feed stream 6a via a second phase separator feed conduit positioned between the second phase separator 11 and the main heat exchanger 7. The second phase separator 11 can form a second oxygen gas stream 6c and a second liquid oxygen stream 6b. The second liquid oxygen gas stream 6b can be output for feeding to LOX storage 21 via an LOX storage feed conduit positioned between the second phase separator 11 and the LOX storage 21. The second liquid oxygen gas stream 6b can be fed separately to LOX storage via a separate conduit or can be fed for mixing with the first LOX stream 12 for providing to LOX storage 21. If mixing with first LOX stream 12 occurs, one or more valves can be positioned in the conduit(s) to account for pressure differentials to facilitate the feeding of the liquid oxygen streams to LOX storage 21. The second oxygen gas stream 6c can be fed to the main heat exchanger 7 as a second cooling medium for cooling of the purified feed streams fed to the main heat exchanger 7. The warmed second oxygen gas stream 6c can be output from the main heat exchanger as a waste stream 16 for venting to atmosphere. Prior to venting, the warmed oxygen gas can be utilized for regeneration of one or more beds of adsorbent material within one or more adsorbers of the PPU in some embodiments.
[0074] One or more companders 15 can be utilized in embodiments to increase the pressure of the purified feed or feed prior to the purified feed being fed to the main heat exchanger 7. Each compander can include at least one compressor stage C that is linked to a different expander. For instance, a first compander 15 can include at least one first compressor stage C that is linked to the first expander 9 via an interconnection 17 so that expansion of gas provided by the first expander 9 provides power for the compression of the at least one first compressor stage C of the first compander 15. It should be appreciated that the first compander 15 includes the at least one first compressor stage C and the first expander 9 interconnected to the at least one first compressor stage in such an arrangement.
[0075] A second compander 15 can also be utilized in some implementations that may utilize multiple companders 15. The second compander 15, when utilized, can include at least one second compressor stage C that is linked to the second expander 9 via an interconnection 17 so that expansion of gas provided by the second expander 9 provides power for the compression of the at least one second compressor stage C of the second compander 15. It should be appreciated that the second compander 15 includes the at least one second compressor stage C and the second expander 9 interconnected to the at least one first compressor stage in such an arrangement. In some implementations, the second compander 15 can be positioned in series with the first compander 15 for compression of a first stream of purified feed 4 (e.g. exemplary implementation shown in
[0076] In other implementations, the first compander 15 can be positioned for compression of the first stream of purified feed 4 and the second compander 15 can be positioned for compression of the second stream of purified feed 6 (e.g., exemplary implementation of
[0077] In some implementations, it is contemplated that only the second compander 15 may be utilized (e.g. a compander including an interconnection 17 with the second expander 9 may be utilized, but the first compander including an interconnection 17 with the first expander 9 may not also be used). In such an implementation, the second compander 15 can be considered a first compander as it may be the only compander in the apparatus 1.
[0078] In some implementations, the first stream of purified feed 4 can also be split to include a bypass stream 4bp portion of the purified feed that can be fed to a second expander 9 to cool that portion of the feed via expansion and subsequently feed the cooled bypass stream portion to the main heat exchanger 7 to function as a cooling medium therein. At least one compander 15 can also be included in such an implementation for compression of this bypass stream 4bp portion of the purified feed stream before the bypass stream 4bp is fed to the expander 9 and before that stream is fed to the main heat exchanger 7. In some embodiments, the bypass stream 4bp can be passed through main heat exchanger 7 to be cooled before discharging to the inlet of the second expander 9.
[0079] A compression stage C of at least one compander 15 of the bypass stream can be linked or interconnected to the second expander 9 or first expander in some embodiments. This type of arrangement may be utilized when additional cooling duty from the purified feed stream may be utilized in the main heat exchanger 7 to suitably cool the purified feed portion that is to be used for forming at least one LOX product stream for feeding to LOX storage 21 while also permitting no other cooling medium source to be used for cooling and formation of the at least one LOX stream for feeding to LOX storage 21.
[0080]
[0081] As may be appreciated from
[0082] As can be appreciated from
[0083] As can be appreciated from
[0084] As noted above, the second expander feed conduit can be positioned between the main heat exchanger 7 and the second expander 9 for feeding of the warmed first oxygen gas stream 14 to the second expander 9 as the second expander feed stream 14a. The location of the inlet for this feed conduit can be any suitable location (e.g. near warm end of the main heat exchanger or at the warm end of the main heat exchanger 7, etc.). For example, the warmed first oxygen gas stream 14 can be fed to the second expander 9 after being output from the hot end of the main heat exchanger 7 when the warmed first oxygen gas stream 14 is at its warmest temperature after being passed through the main heat exchanger 7 or from another location that may be considered suitable for feeding to the second expander 9. The second expander output conduit can be positioned between the second expander 9 and the main heat exchanger 7 to feed the cooled and expanded oxygen gas back to the main heat exchanger 7 as the cooling medium stream 14b. The second expander output conduit can be positioned and configured so that the cooling medium stream 14b is fed to an intermediate section of the main heat exchanger 7 to pass through a portion of the main heat exchanger for providing additional cooling therein. The particular feed location for the cooling medium stream 14b at the main heat exchanger 7 can be selected based on the temperature of that stream and the cooling that the cooling medium stream 14b is to provide in the main heat exchanger for cooling of the one or more purified feed streams.
[0085] Referring to
[0086] The second compander 15 can include an interconnection 17 between the at least one second compressor stage C of the second compander and the second expander 9 of the second compander 15. The interconnection can be arranged and configured so that the expansion of gas provided by the second expander 9 powers or helps power compression of the purified feed provided by the at least one second compression stage C of the second compander 15.
[0087] Referring to
[0088] The second compander 15 can include an interconnection 17 between the at least one second compressor stage C of the second compander 15 and the second expander 9 of the second compander 15. The interconnection 17 can be arranged and configured so that the expansion of gas provided by the second expander 9 powers or helps power compression of the purified feed provided by the at least one second compression stage C of the second compander 15.
[0089] In the implementation of
[0090] As noted above, the second expander feed conduit for the implementation of
[0091]
[0092] The bypass stream 4bp can include one or more companders 15 (e.g. as shown in broken line in
[0093] The cooling provided by the expanded bypass stream 4bp fed to the main heat exchanger as a cooled, expanded cooling medium stream 14b can help cool the portion of the purified feed that is to undergo processing for formation of LOX. This can provide an additional source of cooling in addition to one or more oxygen gas streams that may be provided by one or more phase separators so that no other cooling medium source is needed for the cooling provided by the apparatus 1. This can help permit the apparatus 1 to be utilized without use of other process streams for functioning as a cooling medium in the main heat exchanger 7, for example.
[0094] It should be appreciated from
[0095] It should be appreciated that other implementations can also utilize a second stream of purified feed 6 that can be split from the first stream of purified feed 4 either upstream of the heat exchanger 7 or within the heat exchanger 7 as well for feeding to a second phase separator for formation of a second stream of LOX (e.g. as shown in
[0096] Embodiments of the apparatus 1 can be configured to provide a relatively low yield recovery of the oxygen gas as LOX when compared to an oxygen recycle liquefier or a liquid nitrogen/LOX exchange paired with a recycle liquefier with a different working fluid (e.g. nitrogen). For example, the exemplary implementation shown in
[0097] It should be appreciated that the embodiments of the apparatus 1 for liquid oxygen production can be arranged and configured for an open loop configuration that can avoid recycling of the oxygen gas to improve the recovery yield of the process. This open loop process can be provided to avoid use of any feed compression (e.g. example implementations of
[0098] The low oxygen yield provided by the open loop embodiments of the apparatus 1 can be implemented to help reduce waste and further improve the efficiency and operation of hydrogen production processes that utilize one or more electrolyzers 3. Such processes can help provide improved opportunities for non-carbon dioxide producing systems used for formation of hydrogen (e.g., green hydrogen production processes) which can help provide an improvement in environmental operation of hydrogen production systems while also permitting an additional liquid oxygen product to be formed and reducing waste to be vented from operation of such systems.
[0099] Additionally, we have determined that embodiments can provide an improvement in safety. An oxygen gas feed compressor and/or recycle compressor can include an inherent safety risk (e.g., fire or an explosion) as noted above. Avoidance of any type of compression that can be provided by some embodiments of the apparatus 1 (e.g. exemplary implementations shown in
[0100] Embodiments of the apparatus 1 can also be configured so that there is no need for any other flows of fluid for use of the system beyond the feed 2 provided by the electrolyzer(s) 3 (e.g. can be positioned and configured as a closed processing system). For instance, embodiments can be provided that do not need any cryogenic fluid or a cooling medium from another plant or source beyond the feed 2 to facilitate liquefaction of the oxygen into LOX. Instead, the oxygen vapor from phase separation can be utilized as the only cooling medium used in the main heat exchanger. The combination of expansion and use of the expanded oxygen gas vapor for cooling and liquefaction helps avoid use of other cooling medium fluids and can permit embodiments of the apparatus 1 to be more effectively incorporated into a plant via a retrofit operation, for example, and have a simpler arrangement that may need a smaller overall footprint.
[0101] It should be appreciated that embodiments of the apparatus 1 for liquid oxygen production can be arranged to practice an exemplary embodiment of a process for liquid oxygen production. An example of such an exemplary embodiment of the process is shown in
[0102] As can be appreciated from
[0103] In a second step S2, the purified feed can be cooled via a main heat exchanger and/or at least one expander. Each expander that can be utilized for expansion can be a turboexpander, a valve, or other type of expander. In some arrangements utilizing multiple expanders, some expanders can be configured as a turboexpander and others can be configured as a valve, for example. In other implementations, all the expanders can be the same type of expander or all of the expanders may be different types of expanders.
[0104] In a third step S3, one or more (or all) of the cooled purified feed stream(s) can undergo phase separation to form at least one liquid oxygen (LOX) stream and at least one oxygen vapor stream. Each LOX stream can be fed to storage while each oxygen vapor stream can be fed to the main heat exchanger as a cooling medium for the heat exchanger.
[0105] In situations where one LOX stream may be at a higher pressure than another LOX stream, an LOX stream can undergo pressure adjustment via a valve or being fed to another unit (e.g. LOX output from a first phase separator can be fed to a second phase separator, etc.) to facilitate merging of the formed LOX for feeding to LOX storage 21.
[0106] In an optional fourth step S4, a portion of the oxygen vapor can be output from the main heat exchanger as a warmed oxygen vapor flow for feeding to another expander to undergo additional cooling via expansion of that gas. The expanded gas output from that expander can then be fed back to the main heat exchanger as a cooling medium.
[0107] In another optional step, S1, at least a portion of the purified feed can undergo compression via at least one compression stage of at least one compander that is interconnected to an expander so expansion provided by the linked expander of the compander can help power compression provided by the at least one compression stage of the compander that is linked to the expander. The portion(s) of the purified feed can undergo such compression prior to undergoing cooling via the main heat exchanger 7 and/or expansion, for example.
[0108] Embodiments of the process shown in
[0109] It should be appreciated that modifications to the embodiments explicitly shown and discussed herein can be made to meet a particular set of design objectives or a particular set of design criteria. For instance, the arrangement of valves, piping, and other conduit elements (e.g., conduit connection mechanisms, tubing, seals, valves, etc.) for interconnecting different units of the apparatus for fluid communication of the flows of fluid between different elements (e.g., pumps, heat exchangers, cooling devices, chillers, compressors, etc.) can be arranged to meet a particular plant layout design that accounts for available area of the plant, sized equipment of the plant, and other design considerations. As another example, the flow rate, pressure, and temperature of the fluid passed through the various apparatus or system elements can vary to account for different design configurations and other design criteria.
[0110] Embodiments of the apparatus for liquid oxygen production, process for liquid oxygen production, and/or system for liquid oxygen production can each be configured to include process control elements positioned and configured to monitor and control operations (e.g., temperature and pressure sensors, flow sensors, an automated process control system having at least one work station that includes a processor, non-transitory memory and at least one transceiver for communications with the sensor elements, valves, and controllers for providing a user interface for an automated process control system that may be run at the work station and/or another computer device of the plant, etc.). It should be appreciated that embodiments can utilize a distributed control system (DCS) for implementation of one or more processes and/or controlling operations of an apparatus as well.
[0111] As another example, it is contemplated that a particular feature described, either individually or as part of an embodiment, can be combined with other individually described features, or parts of other embodiments. The elements and acts of the various embodiments described herein can therefore be combined to provide further embodiments. Thus, while certain exemplary embodiments of the process, apparatus, system, and methods of making and using the same have been shown and described above, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.