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#51 2018-12-10 20:51:53

knightdepaix
Member
Registered: 2014-07-07
Posts: 186

Re: Mobile Energy Storage in a Mars Colony

Well, I am not thinking about a fuel but a liquid that stores energy, that is similar to a molten salt on Earth. Methyl formate can be broken down into two molecules each of carbon monoxide and hydrogen. The hydrogen and carbon monoxide can be used to make methanol, as JoshNH4H expressed.

JoshNH4H wrote:

Methyl formate is an option, sure.  If we're going that route though I would think we might go for Methanol.  Methanol is produced by reacting H2 with CO over a zinc catalyst at elevated temperature and pressure.

Or formaldehyde can be made. This compound has many uses. Formic acid can be also be made.
https://pubs.acs.org/doi/abs/10.1021/ac … ng.6b00837

From formaldehyde, ribose the 5-carbon sugar can be made
https://en.wikipedia.org/wiki/Formose_reaction

Or acetic acid from isomerizing methyl formate.

Given acetic and formic acid, the acetic formic anhydride could be made, which is an isomer of pyruvic acid.

So in my humble opinion, methyl formate is the precursor of all these chemical reactions, either endergonic or exergonic. The liquid itself that stores energy shall be made readily from local material, stores both kinetic and chemical energies and exists in the three phases like water on Earth. I believe methyl formate can be made from methane and carbon dioxide, both of which are available; methyl formate can be broken down into two molecules each of carbon monoxide and hydrogen. Wasted energy that causes temperature change in methyl formate during energy storage can be used to generate on demand the suitable chemical compound to save energy that could have been lost to the environment.

In sum, a list of formaldehyde, methanol, formic acid and acetic acid feeds chemical preparation of more complex compounds. Another list of ribose and pyruvic acid feeds biotech preparation of carbohydrates and nucleic acids, if phosphorus and nitrogen are also available on Mars.

Last edited by knightdepaix (2018-12-11 23:18:23)

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#52 2018-12-11 05:06:01

louis
Member
From: UK
Registered: 2008-03-24
Posts: 4,565

Re: Mobile Energy Storage in a Mars Colony

I don't think there is a problem with energy storage on Mars from a pragmatic point of view, although this is something that should be kept under review.

The simplest approach I think is a combination of:

- Lithium batteries
- Methane and oygen
- Well insulated hot water.

A Mars Mission of 500 tonnes cargo could easily afford  50 tonnes of electric batteries in various forms, including rover batteries.

At 300 whs per kg, that would provide 15,000 KwHs of emergency stored power. That would provide about 6Kws steady over 100 sols or 12kws steady over 50 sols.

The BFR Starship will of course land with a store of methane and oxygen.

A 5000 KWhs per sol 10,000 sq metre PV system even in the worst dust storm (10% of normal insolation - the worst I have ever seen in reality was around 20% but such figures last for only a few sols) would produce a minimum of 500 KWhs per sol.  That would keep the batteries topped up. Some of that could also be converted into methane-oxygen production, also adding to your energy storage.

For exploration purposes, we need mini solar powered battery packs that can be left along trails, where rovers can recharge. Alternatively we could have rovers powered by methane but I think PV power.  Rover could also have PV "canopies" and trailers  that could  substantially slow down their battery depletion.

Last edited by louis (2018-12-11 05:19:21)


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#53 2018-12-11 17:54:08

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,049

Re: Mobile Energy Storage in a Mars Colony

void wrote:

https://en.wikipedia.org/wiki/Atmosphere_of_Mars

Carbon dioxide  95.97%
Argon               1.93%
Nitrogen            1.89%
Oxygen             0.146%
Carbon monoxide 0.0557%

Louis, What knightdepaix & JoshNH4H are trying to get at void has already flagged as important in the next quote happens to be what remains after processing the atmosphere and that would make that wasted energy used if you do not store or change it into something useful.

void wrote:

You can correct me on my rough math.  Excessive precision here is likely not warranted.
With the above numbers, if you could eliminate the CO2, and be left with everything else, I estimate that that multiplies the amount of each by ~25 times.

Argon          48.25%
Nitrogen       47.25%
Oxygen         3.65%
Carbon monoxide  1.3925%

Since we are making fuel in methane as ch4 the we are also havesting what water we can get and if we use the hydrogen with nitrogen we get amonia and we can get possibly bleach from percolates from the soil and so on...

We could make aromatic smells of all sorts and that will please many...

These are all long term energy savings.

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#54 2018-12-12 00:59:02

knightdepaix
Member
Registered: 2014-07-07
Posts: 186

Re: Mobile Energy Storage in a Mars Colony

louis wrote:

The simplest approach I think is a combination of:
- Lithium batteries
- Methane and oygen
- Well insulated hot water.

SpaceNut wrote:

Louis, What knightdepaix & JoshNH4H are trying to get at void has already flagged as important in the next quote happens to be what remains after processing the atmosphere and that would make that wasted energy used if you do not store or change it into something useful.

Thank you for the complement and compliment. My change to Louis' approach would be
sodium ion, potassium ion or super-iron batteries
https://en.wikipedia.org/wiki/Sodium-ion_battery
https://en.wikipedia.org/wiki/Potassium-ion_battery
https://en.wikipedia.org/wiki/Super-iron_battery

methane and carbon dioxide to make acetic acid
https://cfpub.epa.gov/ncer_abstracts/in … stract/358
Electrolytic decarboxylation of acetic acid gives ethane. Note that water splitting still has not been used. So these conversion can take place a chemical facility near a drilled well of methane. Water and carbon could be made from reacting methane and carbon dioxide. ethanol and acetic acid give ethyl acetate. carbon, methane and hydrogen could be cracked to give hydrocarbons including ethene. The hydrolysis of ethene gives ethanol.

RickSmith wrote:

MARS DATA:

Natural temperature of space craft at Mars Orbit: 5° C
Natural temperature of space craft at Earth Orbit: -47° C
(These values can be raised or lowered by the surface texture and color.)

(Since Mars spends more than 1/2 of its time further from the sun than the semi-major axis, Robert Zubrin suggests an average value of 500 W/m^2 which is easy to remember.)

On the surface, the thin dusty atmosphere reduces the above values by about 100 to 200 W/^2. 

Average Temperature: -63° C or 215K
Highest Equatorial Temperature: 20° C or 293K
Coldest (South) Polar Temperature: -132° C or 141 K

The Blackbody temperature for Mars is: -67° C or 211K   
(For Comparison, the Blackbody temperature of: Venus 11° C or 283 K. Earth -23° C or 249K.  Ceres is -136° C or 137K. Callisto is -178° C or 95K.)

References:
"Moons and Planets" by W.K. Hartmann
"Entering Space" by Robert Zubrin
Wikipedia
"Mars: A Warmer Wetter Planet" by J. S. Kargel
"Terraforming" by M. Fogg

http://www.oemvacuumpump.com/boiling-po … calculator
Acetic acid boils at 22° C on Mars, ethanol -19° C and Ethyl acetate boils at -28° C on Mars. Esters would be a convenient choice and the corresponding acid and alcohol are saved for heated situation. The conversion is simply hydrolysis with water. All 3 compounds are of low toxicity to human settlers.

Any of the esters mentioned (methyl and ethyl, formate and acetate) are liquids on Mars.  Could they be working fluids -- energy storage for example -- on Martian automobiles and aircrafts? Heat exchangers would still be needed. The leftover wasted heat in these working fluids is used to convert on demand the desired amount to another compound. (as SpaceNut noted).

For examples,
1) After hydrolysis, could wasted heat help convert acetic acid to methanol and carbon monoxide (JoshNH4H wanted), ethanol to ethene? Both latter compounds can be very useful starting materials for a chemical or biotech facility on the human settlement.

2) Carbon monoxide, ethene and water can be reacted to give propionic acid.

IanM wrote:

Now that you mention it, I was thinking about oxidizing the Carbon present in Propionic Acid into sugar (coupled with the reduction of the sulfates in regolith into elemental sulfur) that would then be fermented into CO2 as a terraformation method. The reactions, and net overall reaction, with Propionic Acid would be:

SO4^2-(s) + 4C2H5COOH(l) -> 2C6H12O6(s) + S(s) (Chemosynthesis courtesy of Sulfate-reducing bacteria)
C6H12O6(s) -> 2CO2(g) + 2C2H5OH(l) (Fermentation, courtesy probably of yeast)
SO4^2-(s) + 4C2H5COOH(l) -> 4CO2(g) + 4C2H5OH(l) + S(s) (Overall reaction)

Woulld the sulfate-reducing bacteria also work well on perchlorate to give chloride? Human settlers need inorganic and organic chlorides.

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#55 2018-12-14 20:24:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,049

Re: Mobile Energy Storage in a Mars Colony

Simular to the super Iron battery is the https://en.wikipedia.org/wiki/Nickel–iron_battery otherwise known as the Edison Battery.
Insitu batteries creation will be one of the early business actions that benefit the colony whether we are going with solar or with nuclear as there will always be a need to correct for surge power requirements.

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