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#126 2021-12-10 20:16:22

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
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Re: Mars Water regolith soils 1 foot depth only

steam boiler energy input requirement to temperature

https://www4.eere.energy.gov/manufactur … superSteam
Steam System Modeler Tool (SSMT)

https://www.engineeringtoolbox.com/stea … d_437.html

https://www.engineeringtoolbox.com/boil … _1115.html

https://www.csemag.com/articles/getting … ign-right/

https://www.power-eng.com/coal/steam-ge … ency/#gref
Steam Generator Efficiency

https://power.mhi.com/products/conventional

Under normal atmospheric pressure [0.101 MPa], water boils at 100ºC. As pressure increases, the boiling temperature of water also increases. When the pressure is increased to 22.12 MPa, and at a temperature of 374ºC, water does not boil but is directly converted into steam. This is called the critical point, and the pressure above this critical point is called supercritical pressure. Supercritical pressure with a temperature equal to or more than 593ºC is called ultra-supercritical pressure.

https://en.wikipedia.org/wiki/Steam-ele … er_station

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#127 2021-12-12 15:41:49

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

Without ground proof of how hard the soils are during the day to night cycle we may need to give a soil preheat coil loop to this monster contraption to make sure that we do not break the digging section due to the ground being so hard.

I would think that its needs to be a meter by 2 meters to fit in from on an arm that could be lowered and raised as needed so long as we do not need it. The flow of maybe liquid co2 or glycol or other working fluids might be what we would want in the coil of tubing which is mounted to a heat reflector set to send it to the ground. I will probably need a bypass value as well for when we do not need it and heat storage tank.

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#128 2021-12-20 08:47:41

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

Caliban wrote:

On Mars, we must inject large amounts of heat into the ground to melt permafrost.  To do this, we need at least 500KJ of heat per kg water, to first heat the ice from -60°C to 0°C, melt the ice and warm the water to ~10°C.  I say 'at least' because the ice will be mixed with other solids that will absorb heat and some heat will escape into surrounding materials.  We must then desalinate the liberated water.  So we are probably looking at around 1MJ of energy per kg of water, most of which is in the form of heat.  That works out to be nearly 300kWh of energy per m3 of water - which is around 50x more energy than is needed for desalination of water on Earth.

How does these target values match up with the tray baking to liberate water to a 5 minute duration at 500'C?
Unlike earth the salts are an advantage for electrolysis as we are not intending to drink it and we would be using a sabatier to make drinkable water.

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#129 2021-12-20 09:22:36

Calliban
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Re: Mars Water regolith soils 1 foot depth only

Baking soil to 500°C will consume a lot more energy per unit water, as most of the mass heated is not water.  But why do we need to do that anyway?  You could get most of the water out by heating to 30°C at typical Martian pressures.

I don't honestly know if you can put untreated salty water into an electrolysis cell.  Most electrolysis is carried out in alkaline water.  Could the membranes, anode and cathode be damaged by lack of chemistry control?  Not sure.  If you are evaporating the water from the dirt it isn't an issue anyhow as your water is distilled.

What I was talking about in the other thread is bulk water supply for an eventual base.  Water for propellants production, industrial uses, agriculture and hotel use.  For those sorts of loads, we are going to need tonnes of water per capita.  We can only meet those sorts of requirements through bulk mining.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#130 2021-12-21 21:12:38

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

So testing of the bake cycle release of moisture as steam will require sensors to automate the process rather than a strict time for a given temperature. So tray contents will be IR sensor evaluated while in the cycle to watch for temperature changes.

I am thinking that each unit will be outfitted with Mars weather reporting equipment similar to that which is being used on the rovers which has been found to be very robust to limit development.

The Mars Environmental Dynamics Analyzer (MEDA) is an instrument on board the Mars 2020 Perseverance rover that will characterize the dust size and morphology, as well as surface weather

We will monitor mars https://en.wikipedia.org/wiki/Climate_of_Mars for dust storms and more to ensure success.

We will most likely want a mast camera and possible ground radar to watch the diggers path for large rocks that would cause damage to the unit.

We will also want a neutron detector unit to give measurement of water content that the path contains before gathering to place into the chamber for baking as a means to measure expectations.

The unit will also carry communications equipment not only RF radio but networking computer interface.

kbd512 wrote:

The frequency of transmission plays a major role in the quantity of data that can be transmitted per unit time and an IR laser's frequency is far above radio frequency ranges.  There are various other ways to pack more data into a carrier signal per unit time, but increasing the frequency is generally how we do it when using radios.  That's why 5G cellular communications operate at higher frequencies than 4G, for example.

Radio frequency communications are generally either focused / directional or unfocused / omni-directional.  The focused signals can transmit more data per unit time because more of the electromagnetic radiation arrives at the receiving end than with omni-directional antennas, improving the signal-to-noise ratio (strength of the signal) and lowering the transmitter power requirements, but that also requires precise alignment of the transmitter with the receiver over extended ranges, essentially a line-of-sight system as a result, just like lasers.

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#131 2022-01-23 17:49:54

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

https://www.greenenergytimes.org/2021/1 … l-warming/

Ice can exist at 0°C (32°F), and if no energy is going into it, it does not melt. Water can exist at the same temperature, and if no energy is being extracted, it does not freeze. There seems to be some sort of balancing act going on here. How does that work?

A calorie (as used in physical sciences) is the amount of energy required to raise one gram of water by 1°C. The amount of energy it takes to melt a gram of ice at 0°C into water at 0°C, without changing the temperature, turns out to be about 80 calories. If you measure the amount of heat it takes to convert a given volume of ice into water, without raising the temperature, and then apply the same amount of heat to the water, you will raise its temperature to about 80°C (176°F). It takes a lot of heat to melt ice.

So to liberate the ice water from the soil which is estimated as being 9kg for a meter square at 1/2 meter depth is why the temperature must be brought up fast to bake it out of the soil. As most of the heat is not used to get the water but to raise the temperature of the soil to allow for the small amount of ice to vaporize.

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#132 2022-01-28 20:23:45

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

tahanson43206 wrote:

This post is to thank Void for another outstanding discovery!

http://newmars.com/forums/viewtopic.php … 16#p190616

The post at the link above contains a link to, and snippet from, an article about the comparative efficiency of use of microwaves to soften soil containing frozen water.  While the method may not be productive if water is not present, the results indicate effectiveness up to 140 times greater than conductive heating.

It seems to me this research shows a way forward for numerous proposals for Mars settlement activity involving water.

A heat engine (eg a nuclear fission reactor) can produce electricity to generate microwaves, while dumping waste heat into regolith to maintain it's own stable operation.  While the dumping process is inefficient (compared to microwave heating) the energy released ** should ** be 100% captured by humans using the process on Mars. 

For SpaceNut re Top Layer of Regolith Water Harvest equipment .... Please continue development of your important (to me for sure) work on the first meter problem.  You left off with a plan to use scrapers and scoops to collect regolith so that water mechanically bound to the materials could be released.  It may turn out that use of microwaves to soften the soil before scooping would permit greater productivity for a given amount of fission reactor energy in your system.

(th)

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#133 2022-01-28 20:24:57

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

GW Johnson wrote:

The microwave idea is a good way to thaw frozen regolith.  As for harvesting the water content of the frozen regolith,  there is a maximum of 10 kg (10 L) of water harvestable for every single percent of water content in a metric ton of regolith.  And just what is that water content,  3-4%?  30-40 L max per ton processed?  You gotta do a lot more to that ton than just scoop it up. 

And that assumes all your harvesting processes are 100% efficient (which they will NOT be).  Tons to move and process for only liters of water does not sound very promising to me as a viable resource.  I guess it's better than no resource at all,  but I think drilling into buried glaciers would yield orders of magnitude more water for a whole lot less effort.  Steam down the pipe,  water comes back up.  Coaxially-nested pipes make this a continuous process.

GW

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#134 2022-01-28 20:43:22

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

I had been thinking about how hard the ground might be and until its been tested as a prototype in a ground level condition simulating mars we might be over designing for the what if but if we find that its needed the levels required is more than 6Kw of microwave energy to penetrate into the ground that might be frozen. We are just trying to defrost it but not release the water from it.

Microwave Thawing of Frozen Soil abstract


On earth they place a blanket over the area which is something for mars which seems not possible. Another is to place a hot box heated by propane not likely as well.
https://www.thawground.com/

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#135 2022-03-05 20:00:29

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

Test of the baking was already done we just need it on a larger scale
Where is the water on Mars?

The regolith in these samples were heated in an oven to 500C°. This caused water, initially frozen inside of the regolith, to be ejected in its gaseous state. This caused the weight of the regolith to decrease by 1%. Thus, when the amount of water contained in these samples was measured, the regolith must have been 1% water and 99% other stuff. But the regolith measured in these samples was exceptionally dry and lost a lot of water content during the time interval when the regolith was extracted and stored before being cooked to 500C°. We think that the average regolith on Mars is more like 3% water.

extracting+water+from+Mars%27+regolith.jpg?format=750w


One technique used by that group of Martian pioneers to extract water from the regolith would likely be the following: a dump truck would dump regolith onto a conveyor belt (see illustration above); the conveyor belt then transports the regolith to an oven powered by a 100KWe (kilowat-electric) reactor. The oven would cook the regolith to 500C°, hot enough to release water from that regolith in its gaseous state. The water vapor would then be collected in a condenser and subsequently stored inside of large containers. But not all of the power generated by the reactor would get converted into electricity to power the oven; the overwhelming majority of this power would get converted into waste heat. This waste heat could be used to cook additional regolith and used to extract even more water. Such a system could extract 14,000 kg/day of liquid water.

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#136 2022-03-12 14:43:16

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

“The project, supported through ESA’s Technology Development Element, will include the initial design of a large scale reactor device to periodically extract oxygen from soil, what we term ‘oxygen farming’. Solar UV irradiation will then replenish their oxygen supply within a matter of hours. The estimate is that a 1.2 hectare (3 acre) area would yield enough oxygen to keep a single astronaut alive.”


https://www.esa.int/Enabling_Support/Sp … en_farming

Viking’s ‘Labeled Release’ experiment applied micro-nutrient liquid to a Martian soil sample, which released copious amounts of oxygen in response. Some authorities interpreted this result as evidence of microbial life on Mars – except that even after the sample was sterilised with 160°C heat this oxygen production continued. Meanwhile other Viking experiments found no traces of organic chemicals.

Reactive_oxygen_species_detector_concept_pillars.jpg

https://www.esa.int/ESA_Multimedia/Imag … or_concept


so we now have a bonus with the heating but I need to find something that indicates how much is released.

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#137 2022-03-12 18:30:54

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

Perchlorate Radiolysis on Mars and the Origin of Martian Soil Reactivity

If mars has this much rock at the sites to which we are looking to turn into water we may need to alter the digging method

nasa-mars-rover-perseverance.jpg?fit=1064,598

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#138 2022-03-18 18:22:12

SpaceNut
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Re: Mars Water regolith soils 1 foot depth only

I am in awe with regards to the quantity of fuel required for an every other mission cycle for the Large ships dead head mass of 5000 mT.
Its not going to be done with soil water for sure even with a 52 month to get it done in. In fact that is also quite a bit of Co2 as well.

The issue then for a starship support is how much cargo can we land to build up capability for fuel creation but can we live on mars for that long?

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