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Regarding iced methane, Wikipedia gives the freezing point as 91 K, -182 C. I'm pretty sure Mars never gets this cold (In fact, I'm entirely sure; Air temperature on Mars has a lower limit represented by the freezing part of CO2, around 195 K (-78 C)).
Methane clathrate is fine, but why not use Methanol? It's no harder to produce than Methane, and is liquid at any conceivable Martian pressure. As an oxidizer, I like NO2 as the one that's easiest to make.
It's not so efficient to make chemical fuels, though (Maybe 30-40% efficient going from electricity?) so I would say they would only be used for long term storage. For overnight storage I think flywheels are a better option, assuming that they are oriented parallel to the planet's axis of rotation so that they can store power for a relatively long time. We could be looking at more like 80% efficient energy storage over a night.
-Josh
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I am thinking that compressed gas is a temporary method and that we should be saving it as just as much water as possible if we are not making fuels.
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I think water will be something that well actually have a relative abundance of, seeing as its fairly easy to make/obtain and purify and once we locate a suitable reserve there will no reason to be sparing with it.
-Josh
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The topic of superheating pressurized co2 has been in recent descusions for making of energy from the natural solar cycle to aid in heating via concentrating the energy on the container that holds the co2..
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scCO2 is good but how about chemical reduction of carbon dioxide by hydrogen from water splitting to oxalic acid that is a solid. From ethylene glycol, glycolaldehyde, glyoxal, glycolic acid, glyoxylic acid, oxalic acid to two molecules of carbon dioxide, there are six choices of oxidation to be utilized.
Notable is glyoxylic acid whose salt glyoxylate could be an participant in photosynthetic carbon fixation in greenhouses. So there may be a chance of combining biotechnology and chemical technology at a facility to make fuel and plant food.
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What chemical compound is a good working fluid?
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old ideas not really just a new way to look at things
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Can carbon dioxide on Mars be compressed by waste heat, chemical energy or infrared? If so, the energy storage is a way of energy conversation. Then can the compressed carbon dioxide react on catalyst to form carbon monoxide and oxygen? Oxygen is consumed by humans on settlement and in greenhouses. The carbon monoxide is the main reducing agent and can be pressurized to supercritical state for greater reaction rate. Even if industrial accident happens, can leaked carbon monoxide escape the Mars on its own?
On the other hand, humans on Mars are likely wearing suits with gas mask for gas mixture with oxygen. Ozone can also be mass produced and released into the Martian atmosphere for an artificial ozone layer. Carbon monoxide that float to the layer is going to become carbon dioxide again. Oxygen, carbon dioxide are known that they cannot escape Mars on their own. Can carbon monoxide?
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CO2 can be split into CO and O or C and O2 using frequency and pulse width tuned UV lasers in conjunction with molecular sieves and pumps as a form of energy storage. Efficient? Probably not, but it's simple to use. You can run a combustion engine, even a rocket engine, off of CO and O2. Isp with good chamber pressure is not too shabby, either. Solid Oxide Fuel Cells can also run on CO. If you intend to use the atmosphere for other stuff anyway, then you may as well stretch what you get to the limit of available technology. There will be lots of uses for stainless steel cylinders for storage of various gases, so we may as well have CO2-powered air tools for maintenance.
The newer battery powered tools are quite good, but for durability and longevity well-maintained air tools are still pretty hard to beat. Perhaps super capacitors with energy densities approaching current Lithium-ion batteries would change that. However, air tools require no electronics of any kind to function and that's a useful feature in its own right. I do think that we should keep compressed gas cylinders in unpressurized environments. If something ruptures, it's not the end of the world. Hand tools could be used inside and half-way intelligent fastener design would minimize the number of tools required.
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For the Human power (HP) vehicles back up I was trying to focus on what the energy required for a single person for the life support needs for a compact system. I am also wondering in HP compression pumping of the atmosphere would or would not be possible to do and at what level of co2 could we collect.
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https://www.engineeringtoolbox.com/hors … _1363.html
https://www.livescience.com/4955-compre … uture.html
air is compressed to around 1,000 psi (or 70 times atmospheric pressure), which raises its temperature to more than 600 degrees Celsius (1,100 degrees Fahrenheit). This is far too hot to pump underground, so the air is cooled to about 50 degrees Celsius (120 degrees Fahrenheit).
Unfortunately, the air must be reheated on release in order to turn a turbine. This extra reheating energy (usually provided by burning natural gas) means CAES has a relatively low efficiency of about 50 percent: for every kilowatt-hour of energy going in, only 0.5 kilowatt-hour of energy can be taken out.
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For SpaceNut ...
Thanks for #36 above, and for the quote regarding increase of temperature of air as it is compressed.
For anyone who might know the answer .... I cannot (at this point) see/understand why the hot air (600 Celsius) cannot be pumped underground? To my way of thinking, the Earth will happily absorb that tiny bit of thermal energy if it is not distributed rapidly (at the speed of sound) through the already compressed gas in the reservoir. Or has the author of the piece quoted simply made a mistake?
In an area not far from where I live, natural gas was routinely pumped into underground reservoirs to prepare for winter demand in a nearby city. I understand that practice is continued today, albeit with much smaller machines to perform the compression. To my knowledge, no cooling was performed before the gas was injected into the underground reservoir.
(th)
Last edited by tahanson43206 (2019-04-01 18:07:33)
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The heat is within the compressing of the gas to which its transferred to the chamber its in as well as to the gas but once it exits to the storage it them pass the heat to the chamber or tank to which will contain it.
The gas that is in storage still has the water with in it but we must do another step before pass it onto that storage which is to cool the gas back to zero degrees so as to freeze out the water. Once the gas is pushed out the temporary tank it is warmed and the water is removed.
The gas when it cools will have less pressure with in the temporary tank as well as for when it gets to the permanent storage as well.
With a dual propellant we can mix the Lco and Lo2 to make the rocket move. The tanks would be pressurized and most likely heated to keep the pressure rising as the volume of gas is used.
https://en.wikipedia.org/wiki/Gas_expansion
https://physics.info/pressure-volume/
https://www.engineeringtoolbox.com/comp … d_605.html
https://www.quora.com/What-is-the-volum … ent-of-gas
http://scipp.ucsc.edu/~schumm/ph6/hw_sol_w11/hw4.pdf
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This is also a cold gas topic in that we are compressing co2 to make use of for power generation. We can heat or use solar concentrated or nuclear heat sources to aid in the compression.
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For the Human power (HP) vehicles back up I was trying to focus on what the energy required for a single person for the life support needs for a compact system. I am also wondering in HP compression pumping of the atmosphere would or would not be possible to do and at what level of co2 could we collect.
Well, let us say in a gym at a human settlement, the HP can be stored in flyweels that is connected to exercising machines. The rotational energy in flyweels powers lysis of carbon dioxide or water to oxygen. Essentially, more humans on the settlement, more oxygen are generated. The hydrogen or carbon monoxide generated are compressed as compressed gas energy storage or as starting materials for hydrocarbons by Fischer-Tropsch reaction that also consumes the stored energy, at a factory location away from the human residence. Propene and Propane are made and delivered as a liquid in PVC pipes which is a topic of another thread. http://newmars.com/forums/viewtopic.php?id=7509
The flyweels can be installed in HP vehicles.
My point is that carbon dioxide is a chemical. If it is compressed for energy storage, let us budget the process so some CO2 is also converted to useful chemicals when energy production at human settlements exceeds demand.
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I agree as we need to do more than make oxygen or fuels from expending energy to gather co2 from mars thin air as the energy has been spent and if we vent any waste products we are burning much needed energy for the future..
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When humans expend energy they use more oxygen and make more CO2. Making oxygen with the energy expended is not going to counter this increase, given the inefficiency of all devices including muscles. 2nd law applies everywhere to everything.
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https://www.nasa.gov/centers/johnson/pd … 70-407.pdf
Astronaut Health and Performance
https://www.quora.com/What-is-the-longe … e-to-Earth
Still looking for the number of exercise hours but in the second article its 2 hrs every day but the types of equipment to do the exercises on are quite a few in both articles.
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Automated control of a solar microgrid-powered air compressor for use in a small-scale compressed air energy storage system
https://calhoun.nps.edu/bitstream/handl … sAllowed=y
For mars I would put to work a few compressors in parellel in order to get volume and then use a single compressor for the final tank storage.
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Any gas follows a law P V = n R T where P = pressure (pascals) V = volume (m^3), n is the number of moles (44g for CO2), R is a constant 8.3145 J/(mol K) and T is the absolute (kelvin ) temperature. Alternatively 44g of CO2 occupies 24 litres at room temperature/pressure. The volume decreases linearly with pressure and increases linearly with absolute temperature.
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At typical Martian temperatures, CO2 is far beneath its critical temperature.
https://en.m.wikipedia.org/wiki/File:Ca … iagram.svg
This implies that very little compressor work is needed to condense it into liquid.
https://en.m.wikipedia.org/wiki/Compressibility_factor
Last edited by Calliban (2019-11-22 18:11:12)
"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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Surface Temperature. Martian average temperature is roughly 210 degrees Kelvin (-55 degrees Celsius), with a high temperature of 3,000 degrees Kelvin (27 degrees Celsius) and a low temperature of 140 degrees Kelvin (-133 degrees Celsius).
For Mars the atmospheric air pressure is only 7.5 mb so while we satisfy the temperature we are factor of 900 plus times to thin to get to be liquid. So if you want a cubic meter of liquid you are going to compress that same volume a total of 900 plus times to get to it.
Now saving a batch of frost into a chamber and heating the internal pressure will rise but its still not a cubic meter of a volume. Its just a means to allow pressure to work as the energy source to make motion as its vented. So if we want fast we will need to shade the chamber until the sun is up and use concentrated heat from reflection. Once vented the chamber is placed into shade once more and opened to allow more frost to form inside the chamber.
Now the vented gas can go into the next chamber to get more work out of it once cooled while waiting for the next day.
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Using mountains for long-term energy storage
Mountain Gravity Energy Storage, constitutes of building cranes on the edge of a steep mountain with enough reach to transport sand (or gravel) from a storage site located at the bottom to a storage site at the top.
A motor/generator moves storage vessels filled with sand from the bottom to the top, similar to a ski lift. During this process, potential energy is stored. Electricity is generated by lowering sand from the upper storage site back to the bottom.
If there are river streams on the mountain, the MGES system can be combined with hydropower, where the water would be used to fill the storage vessels in periods of high availability instead of the sand or gravel, thus generating energy. MGES systems have the benefit that the water could be added at any height of the system, thereby increasing the possibility of catching water from different heights in the mountain, which is not possible in conventional hydropower.
"One of the benefits of this system is that sand is cheap and, unlike water, it does not evaporate - so you never lose potential energy and it can be reused innumerable times. This makes it particularly interesting for dry regions," notes Hunt. "Additionally, PHS plants are limited to a height difference of 1,200 meters, due to very high hydraulic pressures.
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Can the lower storage site be connected to a Parabolic antenna that received microwave from solar panel in Mars Orbits or Phobos?
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