Atmospheric processing - Revision history

Michel Lamontagne: /* Filtering */

2024-05-01T13:47:53Z

Filtering

Michel Lamontagne: /* Compression */

2024-05-01T13:47:35Z

Compression

Michel Lamontagne: /* Filtering */

2024-05-01T13:47:00Z

Filtering

Michel Lamontagne: /* Dust */

2024-05-01T13:46:39Z

Dust

Michel Lamontagne: /* Collection of Atmosphere */

2023-02-22T18:27:59Z

Collection of Atmosphere

Michel Lamontagne: /* Filtering */

2022-11-10T19:14:39Z

Filtering

Michel Lamontagne at 15:07, 26 September 2022

2022-09-26T15:07:51Z

Michel Lamontagne at 18:48, 2 March 2022

2022-03-02T18:48:04Z

Michel Lamontagne at 18:42, 2 March 2022

2022-03-02T18:42:57Z

Michel Lamontagne: /* Collection of Atmosphere */

2022-01-19T15:25:34Z

Collection of Atmosphere

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 ===Filtering===
 The martian atmosphere contains 1.8*10<sup>-7</sup> kg of dust per m<sup>3</sup>, on average<ref>https://pdfs.semanticscholar.org/418a/88f31b87f3d615a1f6116d31a078cfde8802.pdf</ref>.  This dust must be removed to avoid process problems in subsequent steps.  [[Dust collector|Dust collectors]] or electrostatic precipitation will be required<ref>Chepko, Ariane, Michael Swanwick, Paul Sorensen, and Darius Modarress. "Two-Stage Dust Removal System for Mars In-Situ Resource Utilization Systems: System Sizing and Trade-offs." 48th International Conference on Environmental Systems, 2018.</ref>.
-For a process treating 1 kg of Mars air per second (50 m3) the filter system will remove, on average, 5,67 kg per year.  Dust loading will increase significantly during dust storms.
+*For a process treating 1 kg of Mars air per second (50 m3) the filter system will remove, on average, 5,67 kg per year.  Dust loading will increase significantly during dust storms.
-Since the Martian atmospheric pressure is quite low, filters will need to be installed after the fans, between the fans and the atmospheric treatment equipment.
+*Since the Martian atmospheric pressure is quite low, filters will need to be installed after the fans, between the fans and the atmospheric treatment equipment.
 ===Compression===

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 [[Compression]] from the initial atmospheric pressure of 600 Pa to 0,1 bar (10 kPa, or 1/10 Earth atmosphere) heats the atmosphere to 100°C but also creates adequate conditions for the condensation of water when it is cooled to about 40°C. It can then be collected at the bottom of a pressure vessel and removed.  A second compressor increases the gas pressure to a bit above 5,1 bar (520 kPa) but also boosts the temperature to over 800°C.  520 kPa is the lowest pressure at which CO<sub>2</sub> can change from a gas to a liquid (at lower pressures it turns directly into a solid), at about -57°C.  The liquid carbon dioxide can then be separated by gravity from the other gasses. The total compression ratio from 600 to 520 000 Pa is about 860 times.
-An exit temperature for a compressor of 800°C is extremely high.  Intermediate cooling with isobaric compression (change of volume with constant pressure) will be required to reduce the exit temperatures of the compressors.
+*An exit temperature for a compressor of 800°C is extremely high.  Intermediate cooling with isobaric compression (change of volume with constant pressure) will be required to reduce the exit temperatures of the compressors.
 ===Condensation===

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 The martian atmosphere contains 1.8*10<sup>-7</sup> kg of dust per m<sup>3</sup>, on average<ref>https://pdfs.semanticscholar.org/418a/88f31b87f3d615a1f6116d31a078cfde8802.pdf</ref>.  This dust must be removed to avoid process problems in subsequent steps.  [[Dust collector|Dust collectors]] or electrostatic precipitation will be required<ref>Chepko, Ariane, Michael Swanwick, Paul Sorensen, and Darius Modarress. "Two-Stage Dust Removal System for Mars In-Situ Resource Utilization Systems: System Sizing and Trade-offs." 48th International Conference on Environmental Systems, 2018.</ref>.
 For a process treating 1 kg of Mars air per second (50 m3) the filter system will remove, on average, 5,67 kg per year.  Dust loading will increase significantly during dust storms.
 ===Compression===

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 ==Process outputs==
 ===Dust===
-The Martian [[atmosphere]] contains variable amounts of [[dust]], which consists of [[minerals]] lifted by wind from the surface [[regolith]]. Electrostatic filters, cyclonic separators or dust collectors with fabric filters will be used to remove the dust to prevent it from damaging the equipment.
+The Martian [[atmosphere]] contains variable amounts of [[dust]], which consists of [[minerals]] lifted by wind from the surface [[regolith]]. Electrostatic filters, cyclonic separators or dust collectors with fabric filters will be used to remove the dust to prevent it from damaging the equipment.  The quantity will be quite small and can be returned to the environment.
 ===Water===

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 In mechanical compression systems, a fan collects Martian atmosphere and passes it through filters to separate out the dust.  Then a compressor increases the pressure of the atmosphere to reach a point when water can be condensed out.  Then a second compressor increases the pressure to the liquefaction point of CO2.  The liquid CO2 is removed, and the leftover gases can be cooled further, to condense out into their liquid phases.
-In chemical separation systems using liquid amines or ionic liquids<ref>https://pubs.acs.org/doi/full/10.1021/ja017593d</ref>, the CO<sub>2</sub> can be removed at atmospheric pressure, requiring only the N<sub>2</sub> and Ar fractions to be compressed.
+An alternative process might be to compress and liquify the bulk of the Martian atmosphere, then reheat it and separate the evaporation/distillation as the temperature increases.
 ==Process==

← Older revision		Revision as of 15:07, 26 September 2022
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	'''Atmospheric processing''' describes the extraction of substances out of the Martian [[atmosphere]] and the usage as raw material for further processing. Unlike surface and sub-surface mining, the atmospheric mining does not require the movement of large amounts of [[regolith]] or rock with heavy machinery, nor is expensive transport per [[rover]] or [[railroad]] necessary. The atmosphere can simply be sucked in through a pipe at every location, and the processing is done inside of [[building]]s. Also, the maintenance of all the atmospheric mining machinery could be in-house, which would be a major safety advantage.		'''Atmospheric processing''' describes the extraction of substances out of the Martian [[atmosphere]] and the usage as raw material for further processing. Unlike surface and sub-surface mining, the atmospheric mining does not require the movement of large amounts of [[regolith]] or rock with heavy machinery, nor is expensive transport per [[rover]] or [[railroad]] necessary. The atmosphere can simply be sucked in through a pipe at every location, and the processing is done inside of [[building]]s. Also, the maintenance of all the atmospheric mining machinery could be in-house, which would be a major safety advantage.
		+	*the Moxie experiment on the Insight Lander was a successful demonstration of atmospheric processing.

	==Collection of Atmosphere==		==Collection of Atmosphere==

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 In mechanical compression systems, a fan collects Martian atmosphere and passes it through filters to separate out the dust.  Then a compressor increases the pressure of the atmosphere to reach a point when water can be condensed out.  Then a second compressor increases the pressure to the liquefaction point of CO2.  The liquid CO2 is removed, and the leftover gases can be cooled further, to condense out into their liquid phases.
-In chemical separation systems using liquid amines or ionic liquids<ref>https://pubs.acs.org/doi/full/10.1021/ja017593d</ref>, the CO<sub>2</sub> can be removed at atmospheric pressure, requiring only the N<sub>2</sub> and Ar fractions to be compressed. This is usually a two step process of separation and regeneration.
+In chemical separation systems using liquid amines or ionic liquids<ref>https://pubs.acs.org/doi/full/10.1021/ja017593d</ref>, the CO<sub>2</sub> can be removed at atmospheric pressure, requiring only the N<sub>2</sub> and Ar fractions to be compressed.
 ==Process==
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 ===Desiccation (adsorption) and scrubbers===
 Desiccation might be used as an alternative to compression for water removal.  A desiccant bed, or a desiccant coated wheel, can be inserted into the gas stream, after filtration.  The desiccant captures the water, that is later removed from the desiccant using heat in a regenerative process.  This might use the heat from the secondary compression, that is significant at 520 kPa, rather than mechanical work.  Similar systems can be used for CO2, N2 and Argon separation as well.  For example, amines are used to remove CO2  from the atmosphere of submarines<ref>http://web.mit.edu/12.000/www/m2005/a2/8/pdf1.pdf</ref> and of the ISS.   Various types of [[Carbon Dioxide Scrubbers|carbon dioxide scrubbers]] exist or are under development<ref>https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber</ref>.  Adsorption of nitrogen is an existing industrial [[w:Nitrogen_generator|process]] that should use less energy than compression/condensation systems. Ionic liquids<ref>https://pubs.acs.org/doi/full/10.1021/ja017593d</ref><ref>https://ttu-ir.tdl.org/bitstream/handle/2346/74045/ICES_2018_31.pdf?sequence=1</ref> are an interesting development in scrubbers, as unlike amine scrubbers they have no vapor pressure. As such they can extract CO<sub>2</sub> from the Martian atmosphere at atmospheric pressure. This then makes compression more efficient, as it's only compressing the N<sub>2</sub> and Ar fractions.
 ==Process outputs==
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 ===Carbon Dioxide===
-% of the Martian atmosphere is [[Carbon dioxide]]. It can be used for [[hydrocarbon synthesis]], including the production of [[methane]] based [[fuel]]. It can also be used to produce [[Oxygen]] through splitting of the H<sub>2</sub>O produced during [[hydrocarbon synthesis]], or during the production of [[Carbon]] through the [https://en.wikipedia.org/wiki/Bosch_reaction Bosch process]. Alternatively, it can also be electrolysed in a [[Carbon_Dioxide_Scrubbers|MOXIE]], producing CO and O<sub>2</sub> or used in [[farming]].
+% of the Martian atmosphere is [[Carbon dioxide]]. It can be used for [[hydrocarbon synthesis]], including the production of [[methane]] based [[fuel]]. It can also be used to produce [[Oxygen]] through splitting of the H<sub>2</sub>O produced during [[hydrocarbon synthesis]], or during the production of [[Carbon]] through the [https://en.wikipedia.org/wiki/Bosch_reaction Bosch process]. Alternatively, it can also be electrolyzed in a [[Carbon_Dioxide_Scrubbers|MOXIE]], producing CO and O<sub>2</sub> or used in [[farming]].
 ===Nitrogen===
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 ===Argon===
-[[Argon]] is useful for industrial processes that must be performed in an inert atmosphere.  It can also be used for electric rocket propulsion.  It may be used as a complement for nitrogen in a martian settlement if it proves to be safe for that purpose.
+[[Argon]] is useful for industrial processes that must be performed in an inert atmosphere.  It can also be used for electric rocket propulsion.  It may be used as a complement for nitrogen in a Martian settlement if it proves to be safe for that purpose.
 ===Oxygen===

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 ==Collection of Atmosphere==
-There are a number of ways the Martian atmosphere can be processed to separate it into its individual components for process use.  Mechanical compression is one of the main possibilities for large scale operations
+There are a number of ways the Martian atmosphere can be processed to separate it into its individual components for process use.  Mechanical compression is one of the main possibilities for large scale operations.  Chemical separation is an alternative that might be used for the same purpose.
 In mechanical compression systems, a fan collects Martian atmosphere and passes it through filters to separate out the dust.  Then a compressor increases the pressure of the atmosphere to reach a point when water can be condensed out.  Then a second compressor increases the pressure to the liquefaction point of CO2.  The liquid CO2 is removed, and the leftover gases can be cooled further, to condense out into their liquid phases.