Difference between revisions of "Nitrogen"

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==Storage==  
 
==Storage==  
Nitrogen from [[atmospheric processing]] will probably be used immediately to create the settlement atmosphere.  If any excess nitrogen is produced it can be stored in some form of containment, or pressure, vessel.  The boiling point of nitrogen is -195.79 °C at atmospheric pressure. Unless the nitrogen is actively cooled by a refrigeration system, it will eventually heat up to ambient temperatures and the pressure will increase.  If the nitrogen is obtained though CO<sub>2</sub> compression to 520 kPa (about 5 atmosphere, or 75 psi) it can remain a liquid if cooled to about -170°C.  To keep the nitrogen liquid at a room temperature of 23°C, requires a pressure of about 1500 kPa (220 psi)  which can be easily maintained in small pressure vessels but requires extremely strong and heavy vessels in large volumes.  
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Nitrogen from [[atmospheric processing]] will probably be used immediately to create the settlement atmosphere.  If any excess nitrogen is produced it can be stored in some form of containment, or pressure vessel.  The boiling point of nitrogen is -195.79 °C at atmospheric pressure. Unless the nitrogen is actively cooled by a refrigeration system, it will eventually heat up to ambient temperatures and the pressure will increase.  If the nitrogen is obtained though CO<sub>2</sub> compression to 520 kPa (about 5 atmosphere, or 75 psi) it can remain a liquid if cooled to about -170°C.  To keep the nitrogen liquid at a room temperature of 23°C requires a pressure of about 1500 kPa (220 psi). This can be easily maintained in small pressure vessels but requires extremely strong and heavy vessels in large volumes.  
  
 
It is likely that all the nitrogen obtain through atmospheric processing will become part of the colony atmosphere, at least in the early stages.  So large scale storage is not an immediate problem.  In all cases nitrogen can be stored at lower pressures when cooled bellow ambient temperatures.  However, a refrigeration system is required to do this.  If there is sufficient insulation, the heat gain can be quite small and the refrigeration system will also be minimum.   
 
It is likely that all the nitrogen obtain through atmospheric processing will become part of the colony atmosphere, at least in the early stages.  So large scale storage is not an immediate problem.  In all cases nitrogen can be stored at lower pressures when cooled bellow ambient temperatures.  However, a refrigeration system is required to do this.  If there is sufficient insulation, the heat gain can be quite small and the refrigeration system will also be minimum.   

Revision as of 10:01, 18 April 2019

N 7
 
Nitrogen

Abundance: 2.7%

Nitrogen (chemical symbol: N7) is the most abundant atmospheric element in the Earth's atmosphere, making up 78% of the total atmospheric gas. Mars, however, has less nitrogen in it's atmosphere, only 3% of the total atmospheric gas. This relative scarcity of nitrogen will cause an expense for colonists on Mars as the existing atmosphere must be processed to separate out CO2. As the CO2 is required for propellant production, the concentration of Nitrogen to breathable levels becomes part of the propellant production cycle.

Producing in-situ nitrogen is a rather straightforward operation in which the cooling needed to liquefy the carbon dioxide is mainly provided by evaporating the liquid carbon dioxide after the nitrogen has been removed. Likewise the power for compressing the carbon dioxide is partially provided by expanding the output waste through a turbine with a common shaft with the compressor. however some energy is required to offset system losses, and the CO2 may not always be expanded as it will normally be used to produce propellant.


The "nitrogen cycle" is an essential terrestrial process that produces organic compounds intrinsic to life on Earth. "Fixing" by lightning strikes or bacterial processes combine atmospheric nitrogen with other elements (such as hydrogen, producing ammonia) producing organic compounds required for plants (sustaining growth and used in photosynthesis), thereby supporting ecosystems. Nitrogen can be found in amino acids, proteins and DNA, making it an essential component of life as we know it.

Storage

Nitrogen from atmospheric processing will probably be used immediately to create the settlement atmosphere. If any excess nitrogen is produced it can be stored in some form of containment, or pressure vessel. The boiling point of nitrogen is -195.79 °C at atmospheric pressure. Unless the nitrogen is actively cooled by a refrigeration system, it will eventually heat up to ambient temperatures and the pressure will increase. If the nitrogen is obtained though CO2 compression to 520 kPa (about 5 atmosphere, or 75 psi) it can remain a liquid if cooled to about -170°C. To keep the nitrogen liquid at a room temperature of 23°C requires a pressure of about 1500 kPa (220 psi). This can be easily maintained in small pressure vessels but requires extremely strong and heavy vessels in large volumes.

It is likely that all the nitrogen obtain through atmospheric processing will become part of the colony atmosphere, at least in the early stages. So large scale storage is not an immediate problem. In all cases nitrogen can be stored at lower pressures when cooled bellow ambient temperatures. However, a refrigeration system is required to do this. If there is sufficient insulation, the heat gain can be quite small and the refrigeration system will also be minimum.

The surface temperature of Mars aids for refrigeration as the average global temperature is approximately -63°C. So the storage location for liquid nitrogen would not be inside habitats (where the average temperature should be as close to 23 °C as possible), but outside, on the cooler surface. Or preferably underground in pressure vessels. This section reflects the personal position of Ioneill

Uses

  • Settlement atmosphere (main usage).
  • Fertilizer when transformed into ammonia as part of the nitrogen cycle.
  • Inert gas for certain industrial processes.
  • Explosives component (nitrates).
  • May be used to prepare dead bodies prior to disposal. Freezing bodies with liquid nitrogen and then powdering the remains (through vibration) may be a viable means to reuse valuable biomass (in greenhouses etc.).

External links