Producing oxygen and fuel from Martian CO2


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New research suggests that the conditions on Mars are ideal for using its carbon dioxide to produce both oxygen and fuel for future manned missions.

Mars has excellent conditions for In-Situ Resource Utilisation (ISRU) by plasma. As well as its CO2 atmosphere, the cold surrounding atmosphere (on average about 210 Kelvin) may induce a stronger vibrational effect than that achievable on Earth. The low atmospheric temperature also works to slow the reaction, giving additional time for the separation of molecules.

Dr Guerra said: “The low temperature plasma decomposition method offers a twofold solution for a manned mission to Mars. Not only would it provide a stable, reliable supply of oxygen, but as source of fuel as well, as carbon monoxide has been proposed as to be used as a propellant mixture in rocket vehicles.

While achieving this kind of in-situ resource use is not trivial, it is essential if humans are going to settle colonies on Mars. This research seems to be a good start.

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24 comments

  • LocalFluff

    This doesn’t seem to be the method to be used by the MOXIE experiment on the Mars 2020 rover. MOXIE is a real ISRU experiment, the first ever to fly, I think. It replaces some science instrument and that makes scientists moan and groan about this payload mass being wasted for an 1800s experiment with a totally predictable outcome. But it’s all about psychology. There are “planetary protectionists” and such who need evidence in order to accept that Earth isn’t flat.

    And there’s this thing with there being about just the same amount of CO2 per cubic meter on Earth as on Mars. Still, I’ve never heard of anyone trying to “frak” natural gas out of thin air. It would certainly be helpful for getting away from Mars, but isn’t a very commercially viable foundation for a permanent settlement, is it? Considering the expense and risks of even getting there. Then the lesser insolation and the same CO2 in the atmosphere. Fuel production will obviously not be Mars’ strong point.

  • Tom Billings

    “It would certainly be helpful for getting away from Mars, but isn’t a very commercially viable foundation for a permanent settlement, is it?”

    That will depend on how viable the other sources of metha/LOx propellant are in the inner solar system. Most CC asteroids have carbonaceous material and water as well, but are not placed as close to Mars orbit , in their delta-vee transport needs, as is the martian surface. Of course, some believe, and I hope, that one of the martian moons, Phobos, may be a captured CC asteroid. If it is, then in the long term it will be the dominant supply of Methane and Oxygen anywhere near Mars orbit. IMHO, the dominant sale on Mars for many decades will be land, ….or cubic, if people are living in the lava tubes I expect them to occupy.

  • Mike Borgelt

    There’s water so you can make methane and oxygen from water and CO2 via the Sabatier process. There is WAY more CO2 per cubic meter of Martian atmosphere than in a cubic meter of Earth atmosphere.
    Both these processes require you to add energy. If solar isn’t your thing, nukes will work.
    Fuel production on Mars beats shipping it from Earth, that’s all it has to be better than.

  • Edward

    Mike Borgelt wrote: “Fuel production on Mars beats shipping it from Earth, that’s all it has to be better than.

    LocalFluff wrote: “Still, I’ve never heard of anyone trying to “frak” natural gas out of thin air.

    Natural gas is too inexpensive on Earth, but everything will take more resources on Mars. Production on Mars will be more expensive than on Earth but less expensive than shipping materials and products from Earth. Moving mass between the planets is expensive, so using resources local to Mars is important.

    A Martian colony should not be expected to sell goods to Earth as a source of income, but most likely it will make money by selling massless intellectual property, such as exploration data, useful chemical processes, better solar power collection methods, better insulation manufacturing (materials science information), better robotics software or configuration (due to the high cost of labor on Mars), etc. Doing everything more efficiently on Mars will become imperative on Mars and will have money-saving uses on Earth.

  • wodun

    Production on Mars will be more expensive than on Earth but less expensive than shipping materials and products from Earth.

    This really depends on how a Martian economy takes shape and at what point in development we look at. This is because the customers are on Mars not Earth, the price is what someone is willing and able to pay, and the development costs are sunk.

    There is a lot of other analysis that goes into it, like why would someone build a power plant when they don’t have a business case for profit and anyone initially setting up shop on Mars is going to be funded by Earth dollars and likely arrange for access to energy in advance. All of these considerations can/will change over time though.

    We can’t assume that everything on Mars will necessarily be more expensive. The same technology that lands 50 tons of equipment from Earth could land 50 tons of ore mined on an asteroid. But here again, it all depends on what stage of development we look at.

  • Edward

    wodun wrote: “We can’t assume that everything on Mars will necessarily be more expensive.

    Considering that the labor involved will have higher expenses, since housing will have to be airtight, environmentally controlled (heated, manufactured air, etc.), and radiation resistant, and since work not performed in an airtight building will have to be performed in an airtight, restrictive, time-limited EVA pressure suit, then I think Martian production costs are certain to be greater than on Earth. Transporting material from the mine to the point of use is likely to be more expensive, too, and for similar reasons.

    Paying back the Earth funding for initially setting up shop would likely take the form of doing exploration and research for Earth scientists. Rather than a few probes and rovers that produce a limited daily amount of science, real scientists can personally and quickly examine all the interesting points of a region, not just a rock here and a dirt clod there. There can be more and better science performed in person than by robot.

  • LocalFluff

    @Edward
    Where i live taxes cost more than the sum of all other expenses for each and every household. So there are substantial cost cuttings to be made by leaving Earth.

  • Dick Eagleson

    Fuel production will obviously not be Mars’ strong point.

    On the contrary, propellant production might end up being Mars’s only strong point. Propellant production from Deimosian and/or Phobosian material is problematical at present. But we know Mars has lots of water and an entire atmosphere of 98% CO2. Sabatier-ing both to produce methalox, electrolyzing the former to produce hydrolox and liquifying the waste gas stream from the Sabatier reactors to pull out liquid Argon would allow Mars to be a source of propellant mass for any and all the likely propellant options in use BEO a few decades hence.

  • LocalFluff

    @Dick
    Sure, the elements are there. It is doable. Looks like a good start. But it will be a pretty miserable economics to it. We don’t create rocket fuel out of thin air in dry deserts on Earth. We rather much drill kilometers deep under the ocean floor to get at some methane. And Solar power to feed it all is on Earth just used either for propaganda reasons or in isolated temporary emergencies. On Mars insolation is between 50% to 38% of that on Earth depending on season because of its eccentricity.

    So nuclear power is best for Mars. No need to care about any fallout either since the surface is irradiated anyway. Maybe a heavy element like Uranium is easier to mine on Mars thanks to its lower gravity?

  • Edward

    LocalFluff,
    You wrote: “But it will be a pretty miserable economics to it. We don’t create rocket fuel out of thin air in dry deserts on Earth.

    I have to side with Dick. The economics of bringing propellant from Earth to Mars is far worse. Just getting propellant from Earth to LEO costs a large delta V.

    Once again, I have to remind you that we get our natural gas and other fuels from much easier sources, which is why we don’t make it from the air (the air has the ingredients). Liquid oxygen propellant, however, is another matter. We get that out of thin air.

    The concept of making propellant from the atmosphere is not so far fetched, and right now making fuels from the Martian atmosphere is more likely and less expensive than getting it from wells on Mars. That may change if we find subterranean (subMartian?) pools of fuels on Mars. But we would still need an oxidizer, because Mars’ atmosphere is not as oxidizer rich as Earth’s.

    So nuclear power is best for Mars.

    Maybe so, as long as we are allowed to launch nuclear fuels from Earth until we find other sources around the solar system. The energy to mass ratio is pretty high, we know how to make reasonably efficient Rankine cycle power plants (>40%), and some of the waste heat can be used to heat the habitats and for several industrial processes.

    To paraphrase a Depression era song: nice power source if you can get it.

    However, Hillary Clinton and Barack Obama corruptly gave away 1/5 of the US uranium supply, so it isn’t clear how much uranium is leftover from other national needs to be available for Mars or space.

  • wayne

    interesting back-n-forth.

    Can anyone speak to using air-liquefaction techniques, on Mars?

    On Earth, we have to cool “air,” until it liquefies, and then use a cryogenic distillation process to separate the various gases. ( It is a relatively energy intensive process, but the low-cost way to mass produce the constituents of our own atmosphere.) And with relatively few moving parts, basically pumping & distillation columns. (low maintenance)

    Gas-chemistry is not my strong point, but I would think we could take advantage of the fact the Martian atmosphere is already very cold to begin with, at the pressure it is at.
    –concentrate the atmosphere and manipulate pressure & temperature to fractionate what you have.

    This plasma-technique intrigues me but I’m no engineer, but I always favor less complicated methods to accomplish something.

    “Digital-complex” is always nice, but analog-dumb, is often sufficient, especially In Space! (where ‘they’ claim, no one can hear you scream, and it is very cold…)

  • wodun

    Edward
    October 18, 2017 at 5:57 pm

    Considering that the labor involved will have higher expenses, since housing will have to be airtight, environmentally controlled (heated, manufactured air, etc.), and radiation resistant, and since work not performed in an airtight building will have to be performed in an airtight, restrictive, time-limited EVA pressure suit, then I think Martian production costs are certain to be greater than on Earth. Transporting material from the mine to the point of use is likely to be more expensive, too, and for similar reasons.

    Initially I would expect costs to be higher but higher than what? On Earth, we build many different types of buildings. You can build a tiny house for $30k or for $150k. You can get a manufactured home for $40k or build a similar sized house for $300k.

    On Mars, construction will be different. That doesn’t necessarily mean it has to be more expensive than building something on Earth. And we don’t know what form Martian habitats will take. I think building structures on Mars would be one of the easier ISRU problems to solve and is a much smaller problem than building heavy machinery, wiring, or light bulbs.

    Would preparing a cavern to hold a thousand people be cheaper than building a thousand individual residences above ground? Would the cavern option cost more than building a high rise in a major metropolis? No one can really say for sure right now. We don’t have enough information to figure out the costs.

    Even with BFR, we are decades away from any large scale presence on Mars, so much will change. During this time there wont just be advances in rocketry, propulsion, manufacturing, and ISRU but also a web of space based activities that will change the economic situation. Some of these activities can be predicted but others we can’t.

    I think asteroid mining could have a big impact on all of this. We are were we are now because of a confluence of events and conditions. Will there be ore returning from asteroids in thirty years just when large scale activity on Mars is beginning to take shape?

  • ken anthony

    A Martian colony should not be expected to sell goods to Earth as a source of income

    Once the new SpaceX ship is returning from mars it will be much cheaper to ship stuff to LEO from the surface of mars than from the surface of earth. Before we were limited by infrastructure. With Elon’s new ship we are not. The future is going to happen much faster than even the most optimistic of us thought.

    Elon may even decide to create a new version of his ship just to deliver a full shipload of fuel from mars to LEO in one shipload because the Delta-V is only about half.

  • wayne

    “Extraction of Oxygen from the Martian Atmosphere”
    2004, JPL
    https://ntrs.nasa.gov/search.jsp?R=20040196381
    “A mechanical process was designed for direct extraction of molecular oxygen from the martian atmosphere based on liquefaction of the majority component, CO2, followed by separation of the lower-boiling components.”
    “The conceptual design, termed ‘MARRS’ for Mars Atmosphere Resource Recovery System, was based on the NASA/JSC Mars Reference Mission (MRM) requirement for oxygen. This mission requires both liquid oxygen for propellant, and gaseous oxygen as a component of air for the mission crew. With single redundancy both for propellant and crew air, the oxygen requirement for the MRM is estimated at 5.8 kg/hr. The process thermal power needed is about 120 kW, which can be provided at 300-500 C. A lower-cost nuclear reactor made largely of stainless steel could serve as the heat source. The chief development needed for MARRS is an efficient atmospheric compression technology, all other steps being derived from conventional chemical engineering separations.”

  • wayne

    excuse for an obscure tangential cultural tidbit tie-in;

    “John Carter of Mars,” test reel clip
    Bob Clampett animation
    https://youtu.be/bTAlgZlqwnQ
    2:27
    Note the title “The Atmosphere Factories of Mars,” at the 1:51 mark.

    please proceed. (Mars is always a good Topic. I really don’t think we’re going any time real soon, but it is… fascinating.)

  • LocalFluff

    @ken anthony
    “Once the new SpaceX ship is returning from mars it will be much cheaper to ship stuff to LEO from the surface of mars than from the surface of earth”

    But, shipping what from Mars to LEO? There are no satellite factories on Mars. And it takes quite a bit of a global industry and infrastructure with millions of people to manufacture, for example, a pencil. CO2 in the air and a little water under the dry desert makes Sahara sound as oil rich as the Gulf states, when Mars enthusiasts describe it. Meanwhile people in Chad know not what you are talking about.
    https://ed.ted.com/on/8S6Mp7EP

  • Edward

    wodun,
    How many airlocks do you get with that $30k house on Earth? Does it include an oxygen generator? How about the energy needed for heating? My house has minimal radiation shielding, but a Martian habitat will need plenty.

    On the other hand, they may not need as many cans of Raid bug spray on Mars, but that isn’t much of a cost at my house.

    Now that you mention it, we will have to add in the higher cost of wiring and lighting the Martian habitats. Perhaps we should throw in furnishing them, too. If you think a couch is expensive here on Earth …

    Building structures may be an easier in situ resource utilization (ISRU) problem to solve, but we have already solved the materials problems on Earth in an inexpensive way. It will be relatively expensive on Mars for a long time, if not always.

    Will there be ore returning from asteroids in thirty years just when large scale activity on Mars is beginning to take shape?

    Transportation costs on Earth may seem pretty steep, but they are nothing compared to the fuel needed for the delta V accelerations transporting stuff around the solar system. Ore coming from the asteroids to Mars may be rather expensive, even if it is less expensive than transporting it from Earth.

    The problem being solved with ISRU is the expense of shipping all supplies and materials from Earth by making them with local Martian materials. Keep in mind that it costs almost 10 km/sec just to get to low Earth orbit (LEO) and a total of 12.6 km/sec just for Earth escape. More to get to Mars.
    http://i.imgur.com/SqdzxzF.png

    Ken Anthony,
    I expect that the Moon will be the source of fuels and materials sent to LEO. On the other hand, with SpaceX’s ship coming back anyway, maybe there will be some unique products from Mars.

  • LocalFluff

    Mars might have many more near mars asteroids than there are near Earth asteroids, since it is closer to the main asteroid belt. Mars’ moons might be captured asteroids. Phobos will disintegrate to a ring system already in ten or so million years (<1% of Mars existence). Maybe Mars regularly captures large asteroids like that.

    In any case, the Moons of Mars is the obvious next step in human space flight. Most of the technologies needed have already matured on the ISS. No landing system required. No set of surface habitat and equipment need to be developed. Simply a Bigalow and an special Deimos/Phobos module with airlocks for suitports and some kind of multi-person excursion vehicle and a robotic arm. This could definitely be completed within 7 years. In amazement, human kind will watch the crew float above a world out of the Le Petit Prince. Digging into the porous "ground" with their hands, creating dust clouds of shining white ice crystals from underneath the Sun baked dark surface. And when the crew quickly recovers home on Earth again after 26 months in microgravity, we can put the hypochondriac weightlessness scare aside for good. Those moons will of course be visited at some time, and since they are the easiest targets to reach in the Solar system, it is obvious that they will be the first.

  • LocalFluff

    Both moons of Mars were discovered by American Asaph Hall with the US Navy observatory in D.C. 140 years ago. That might help NASA get astronauts there. That Pluto was discovered by an American astronomer has been given quite some public attention in the latest years of planet definitions and New Horizons.

  • Edward

    LocalFluff wrote: “And when the crew quickly recovers home on Earth again after 26 months in microgravity

    We do not need to go to Mars to test this. We have the ISS right here, where we can perform this experiment with much more safety for the astronaut. That could “put the hypochondriac weightlessness scare aside for good” in less than three years from now.

    Do we really need to use near Mars asteroids if Mars has the material on or near its surface? It could be faster, easier, and cheaper to mine Mars rather than mine an asteroid and transport material to Mars’s surface. Exploring Mars’s surface for needed material may be faster, easier, and cheaper than exploring asteroid after asteroid for the same material then transporting that material through gravity wells.

  • Max

    We discussed where to land, and why, A few days ago.
    http://behindtheblack.com/behind-the-black/europes-trace-gas-orbiter-detects-clouds-over-martian-volcano/#comments
    I made the case for “near the north polar ice cap” for Raw materials, safety, fuel.
    Another reason has occurred to me, considering the need for power that solar cells cannot provide, plutonium batteries which remain hot for hundreds of years can solve the problem. A long with fuel tanks from the lander, we can create pressure system that will provide all the energy we need.
    I had mentioned using the heat from the batteries to carve out living quarters in the ice that can be pressurized and insulated with no dust or debris. I forgot to mention that heating up solid carbon dioxide inside of a closed system creates pressure which can be used to drive a generator…
    Wayne asked:
    “Can anyone speak to using air-liquefaction techniques, on Mars?
    On Earth, we have to cool “air,” until it liquefies, and then use a cryogenic distillation process to separate the various gases. ( It is a relatively energy intensive process, but the low-cost way to mass produce the constituents of our own atmosphere.) And with relatively few moving parts, basically pumping & distillation columns. (low maintenance)”

    Why compress carbon dioxide from the air when there is concentrated solid carbon dioxide ice miles thick? That seems to me a waste of energy to compress 7 mbar of pressure for a week, when you can shovel that much CO2 into a tank in 10 minutes.

    CO2 ice placed in a sealed container with hot nuclear batteries will become high pressure liquid. This hot liquid expanding into a gas through a turbine will drive pumps and generators. The CO2 exhaust is pure carbon dioxide and will refreeze on the ice cap or into a Mylar balloon enclosure exposed to atmospheric cold to refreeze to be reused. No pollution. Other gases will separate at different temperatures, as Wayne suggested, to be pumped out for further processing. Water will collect in the bottom of the container keeping the batteries cool until next heating cycle, or drained for other uses such as fuel, habitat radiant heat, human and greenhouse consumption. The cycle can be automated and repeated for as long as the batteries are hot.
    New long lasting solar lights with low energy consumption can grow food for the Martians to survive without relief supplies from earth. Providing oxygen, glucose, hydrocarbons, cellulose products for clothing and plastics for insulation, manufacturing, pharmaceuticals, chemicals, raw materials for 3D printing of components, tools, toys, leisure comforts.

    The biggest problem is locating a source of nitrogen. Hopefully there is nitrogen or ammonia frozen in the Polar ice as nitric acid.

    Worry about survival first, tragedy will dry up funds and dampen spirits for years.
    Movies showing big nuclear hot tubs surrounded by plants in clean pristine environment with children jumping through the air digging up meteorite fragments from the sand will have everyone wanting to vacation on Mars.

    Once manufacturing facilities are up and running, all-terrain vehicles, drilling platforms, heavy lift hydrogen Zepplin’s will be able to explore the planet with leisure. The volcano with all it’s volcanic tubes will still be there for one of you mad scientists to claim as his own… (Cue the derange laughter from the space pirate…)

  • wayne

    Max-
    Interesting stuff!

    Ref:
    “Why compress carbon dioxide from the [Martian] air…”

    My inquiry with that, would be to avoid having to physically mine solid CO2, until such time as we could do so efficiently, if ever.
    >Less moving parts overall to deal with initially, for liquefaction-type processes and the atmosphere is already, what 90% CO2? and liquefaction runs in-place, 24/7.

    (I’m just unclear on what aspects of temperature, volume, and pressure on Mar’s, inherently helps or hinders the reactions we need to drive. In the paper I referenced above, they talk of using “120kW/hour to yield 5-6 kg/hour of oxygen,” and a need for more “efficient atmospheric compression technology,” and that was 13 years ago.)

    Briefly skimmed some interesting technology recently, (in use) involving cryogenic air-liquefaction techniques, with specialized permeable-membranes, for Nitrogen extraction from the Earth’s atmosphere.
    Nitrogen on Mars is what– 1%? (in contrast to Earth with what, 75%?)–We do extract Argon from the Earth’s atmosphere via liquefaction, and that is at less than a 1% concentration.
    (What we don’t do, is extract gold from seawater on Earth. We could, but we don’t. Similar constraints (and opportunities) await us on the off-world colonies.)

    I’d not wedded to liquefaction by any means, just finding the simplest methods to do what we need to do, initially.

  • Max

    Wayne said,
    “I’d not wedded to liquefaction by any means, just finding the simplest methods to do what we need to do, initially.”

    Exactly! you outlined the problem nicely. There are solutions not involving any need for mining equipment. That’s the beauty of carbon dioxide, the heat source will evaporate the tunnels with very basic equipment. Once an air pressure lock is installed on an ice cave, the heat source will evaporate and build up pressure. 5 atm (75 pounds of pressure) is all that is needed to turn CO2 gas into a liquid. Drain into a storage bin where it is kept warm before it refreezes to the floor or walls.

    I was reading your NASA post above and they mentioned something similar to what I was trying to express. Evidently they already thought of this, NASA believed it to be a source of energy with extra energy left over. They said, and I quote,

    “The uncondensed gases are further compressed to 30 bar or more, and then cooled again to recover water as ice and to remove much of the remaining CO2. The final gaseous products consisting mostly of nitrogen, oxygen, and carbon monoxide are liquefied and purified by cryogenic distillation.”

    “The liquefied CO2 is expanded back to the low-pressure atmosphere with the addition of heat to recover a “majority of the compression energy” and to produce the needed mechanical work. Energy for the process is needed primarily as heat to drive the CO2-based expansion power system. When properly configured, “the extraction process can be a net producer of electricity.” !!!

    I could never have said it better. Being near a large source of carbon dioxide and water ice would just make it so much easier. The technology is no more complicated than the water wheel, or your local mechanics pneumatic system.
    Once the high pressure hot CO2 liquid has been through a turbine, the exhaust gas Is collected and condensed for reuse. Extracting more CO2 will not be necessary. None of this is possible without the plutonium battery heat source.

    I know that there’s a lot of talk about bigger Rockets (BFR) I am in love with the central fuel tank that was used with the space shuttle. Once emptied of their non-toxic fuel, they would make an excellent thick walled living space for a long journey. Two compartments, with built in ports and air lock with designed struts to join two or more together.
    Four solid rocket boosters placed on a large aluminum tank (without the space shuttle) should be able to reach orbit with most of the fuel left over to use for the thrust to get to Mars, then to land. Pump all the fuel into two large center tanks and place them in earths shadow Lagrange point to keep them cold. Convert the rest of the tanks in to human habitat with plenty a room for storage, equipment and supplies.
    If we think big, half dozen of these fuel tanks,the size of a 747 airplane fuselage, could be launched towards Mars like a space station that rotates for microgravity. It can be left in orbit, or returned to earth for another load of passengers. The Bigelow expanded compartments would be nice, but not safe in the solar wind.
    Perhaps I am getting ahead of myself…
    let your own imagination fill in the blank’s.

  • wayne

    Max-
    Good deal. I have a better visual image of what you propose.

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