New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#26 2020-01-28 22:20:00

kbd512
Administrator
Registered: 2015-01-02
Posts: 3,982

Re: Carbon Monoxide - a way to power Mars?

Even if the rockets end up being heavier as a result, from an energy input perspective LOX/LCO still looks like a much better deal to me if energy and resource input per unit of output thrust produced is taken into consideration.  We already know that we can obtain as much CO2 as we need and this propellant combination is very simple to make, requiring no new technology development.  Unless humans will be breathing the atmosphere outside the rocket without pressure suits, which will never happen, or the propellant lines intrude into the pressurized compartment of the vehicle, which shouldn't happen given proper design, then this is also one of the most benign realistic propellant combinations available.

Offline

#27 2020-01-29 04:03:32

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 642

Re: Carbon Monoxide - a way to power Mars?

kbd512 wrote:

Even if the rockets end up being heavier as a result, from an energy input perspective LOX/LCO still looks like a much better deal to me if energy and resource input per unit of output thrust produced is taken into consideration.  We already know that we can obtain as much CO2 as we need and this propellant combination is very simple to make, requiring no new technology development.  Unless humans will be breathing the atmosphere outside the rocket without pressure suits, which will never happen, or the propellant lines intrude into the pressurized compartment of the vehicle, which shouldn't happen given proper design, then this is also one of the most benign realistic propellant combinations available.

Agreed.  If the production can be carried out thermochemically, using nuclear or solar heat, then LOX/LCO becomes even more attractive as a propellant.

https://www.frontiersin.org/articles/10 … 00601/full

It would be difficult to develop nuclear fuel with an operating temperature of 1500C.  A pebble bed could probably reach those temperatures and could run on natural uranium.  Maybe a pressurised sodium reactor using unclad UO2 fuel.  Now there's a scary thought :-)

Last edited by Calliban (2020-01-29 04:20:37)


Interested in space science, engineering and technology.

Offline

#28 2020-01-29 08:25:57

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For Calliban re #27

Thanks for the link to the paper about use of Cerium to facilitate production of Carbon Monoxide.  I didn't read every word, but I read enough to understand that this was a significant effort by a number of researchers with a considerable financial investment.  Along the way I picked up the mention of the use of electric furnace technology to provide the needed temperatures.

Your suggestion of a fission power plant as the underlying mechanism to produce CO on Mars, and the normal operating temperature well under what is required, leads me to wonder if the existing temperature can be used to generate electricity in sufficient quantity and force to yield a useful amount of CO for propulsion.

I understand that efficiency falls with each stage of energy conversion, but I'd like to point out that Uranium decaying naturally has an efficiency of zero.

If humans can achieve a net efficiency of 5%, given a resource that would otherwise go to waste, I would count that as a good day, on Earth or Mars.

Can you (would you) estimate the net efficiency achievable by using a practical nuclear fission plant to create CO?

A related question is what size of fission plant is needed to produce enough CO to lift a reasonable payload to Mars Low Orbit?

NASA is contemplating a sample return mission from Mars.  They'll need a way to lift the sample from the surface.  The vehicle to achieve that might be worth considering for the estimate.   

Google found a question/answer pair about decomposition of CO2.  The first discovery (for me) was that the ration of CO to CO2 changes over a wide range of temperatures.  There was a StackExchange answer with plenty of math for those who might be interested.

The math answer included a branch to this link: https://chemistry.stackexchange.com/que … down-to-co

Heating CO2 at atmospheric pressure:
At 1000K it is still essentially all CO2.
At 2000K: 98% CO2, 1.4% CO, 0.7% O2
At 3000K: 44% CO2, 36% CO, 16% O2, 4% O
At 5000K: 50% CO, 50% O
only at even higher temperature does significant atomic C appear (9% at 6000K).

The "atmospheric pressure" is most likely to be Earth sea level.

From the point of view of how production of CO would actually work in an industrial setting, I'm wondering how the CO would be separated from the mixture.

Now I'll have to go back to the Cerium paper to see what temperatures they were using. 

Edit #2 ... the answer appears to be that at 1500 C, the Cerium material is able to deliver CO as a part of the gas flow.

Edit #3 ... from https://www.theunitconverter.com/celsiu … elvin.html

1500 Celsius (°C) = 1773.15 Kelvin (K)

If I am following the discussion correctly, at 1773 Kelvin, there would be (about) 1% free CO in a mixture which began as all CO2.

(th)

Last edited by tahanson43206 (2020-01-29 13:12:48)

Offline

#29 2020-01-29 19:48:25

kbd512
Administrator
Registered: 2015-01-02
Posts: 3,982

Re: Carbon Monoxide - a way to power Mars?

tahanson43206,

CO would probably be separated from other gases the way we've been doing it:

Molecular Sieve 5A and 13X - Packed GC Columns for Permanent Gas Separations

Edit:

However, this also looks very promising because the researchers were able to accurately predict CO output using a mathematical model:

Converting carbon dioxide to carbon monoxide using water, electricity

Last edited by kbd512 (2020-01-29 20:04:43)

Offline

#30 2020-01-29 21:22:04

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 20,902

Re: Carbon Monoxide - a way to power Mars?

Other gasses would be cooled out of the mixture as we compress the air into a chamber for use.
If you have co2 we can use the system which is going to be fully tested in mars conditions.
I got thinking about using o3 with the co with regards to temperature of reaction and then what we would get from the reaction.

Offline

#31 2020-01-29 21:36:14

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For kbd512 re #29

Thank you for those two links!

The first seems applicable when CO is already present.  I'm certainly open to correction on that point.

The second is (as you say, very promising) because it is able to make CO, and (as nearly as I can tell) it does so at modest temperatures.

The ceramic method found by Calliban seems appropriate for an industrial scale CO manufacturing operation, such as would (presumably) be needed for creating large quantities of fuel and oxidizer for Mars launches.  Calliban appeared (as I read the post) to be leaning toward using nuclear fission as a reliable source of power to drive the process.  My impression is that an electric furnace would be needed to achieve the temperatures where CO is freed up by thermal activity, so the nuclear plant would create the electric current through a heat-to-mechanical-energy process of some kind.  NASA is working on the Stirling engine method for their low power reactor, but I'm not sure how scalable that approach would be.

On the other hand, if the catalyst mediated conversion process can be scaled up, perhaps electricity from a fission reactor can deliver needed quantities of CO and oxygen without the high temperatures of the ceramic process.

(th)

Last edited by tahanson43206 (2020-01-29 21:40:01)

Offline

#32 2020-02-11 11:42:28

elderflower
Member
Registered: 2016-06-19
Posts: 1,262

Re: Carbon Monoxide - a way to power Mars?

CO is a cryogenic gas with physical properties similar to O2 or N2. Storage is therefore not very difficult. It is a usable fuel gas with O2. Specific impulse in a rocket is limited because of its relatively low heat of combustion (2CO +O2 >2CO2) but could be a useful energy source for surface equipment or for a hopper or flying machine on Mars.

Offline

#33 2020-12-30 19:57:54

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For SpaceNut ... thanks for bringing this topic back into view ...

I am bemused that we covered so much of this ground so recently ....

It is a good fit for the IC engine on Mars topic.

I ** was ** intrigued to see that Louis led off with a proposal to concentrate CO and O2 from the atmosphere of Mars instead of just making CO/O2 from CO2.

If there was a comparison of the energy required to accumulate a Kg of CO and the corresponding quantity of O2 by compression, and the corresponding amount of energy to make a Kg of CO and the corresponding quantity of O2 by electrolysis, I didn't see it.

I ** did ** see a description of the process of splitting CO2, and my recollection is that the process requires a high temperature and the services of a catalyst.

Another detail I did not see in Louis' original presentation was an answer to the question of how Louis would separate CO2 (and other gases) from the atmosphere while selecting for CO and O2.

This topic is about Carbon Monoxide (I'm reminding myself) ....

It would not be out of order for someone to contribute posts with those two procedures and the energy costs for each, if someone has the time, energy and motivation to build up the value of this topic.

It is one thing to enjoy a discussion about a technology.  It is quite another thing to accumulate knowledge in an organized form so that a future reader can print out instructions to do ** something **.

In this case, it would be helpful for a future Mars settler to call up this archive and find a concise list of materials and procedures to make CO/O2 using Louis' method (compression after filtering) or to make it using electrolysis after filtering.

In both cases, the desired products must be separated during production and kept separate for as long as needed.  As Louis pointed out, the "as needed" could be up to four years.

(th).

Offline

#34 2020-12-30 20:21:02

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 20,902

Re: Carbon Monoxide - a way to power Mars?

Mars has trace amounts of co and o2 in the atmosphere so its going to be a long time to get to much at all. It would be a waste of energy to just let it go back out to mars atmospheric pressures as it would require even more energy to obtain it back if we wanted to make use of it later.

We know that the critical first steps are to draw mars air in and start the process of dust removal and processing it to its components. That will take time and lots of energy to do even that amount of work due to the pressure that mars has and just how far we need to cool and pressurize it to get anything worth while.

Once in a stored form we need to maintain that level without boiloff so as to be able to use the most of what we have gathered.

Offline

#35 2020-12-30 21:18:14

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For SpaceNut re #34

The points you've made in this post are good ones, and you've made similar or the same points in the IC engine topic.

The exhaust from an iC engine would be pure CO2, contaminated by a bit of lubricant collected from the walls of the pistons after they are exposed by retreating piston rings.  The problem that needs to be addressed is how to collect the exhaust without detracting from the power output of the engine.

The goal of collecting the exhaust is laudable, but if all the energy produced by the engine is consumed by collecting the exhaust and packing it into storage containers, there's little point to the exercise.

If an engine is designed to produce 1000 horsepower to the crankshaft without any obstruction of exhaust gases to the outside, how much power will be consumed collecting and compressing the exhaust?

On Earth, we do not collect the exhaust from any hydrocarbon engines (that I know of).  I ** do ** recall reading that ** steam ** has been collected and reused in steam engines, but steam in that context is a working fluid, NOT the fuel burned in the firebox.  There is no effort to collect the exhaust from the firebox.

Likewise, I am not aware of any installation of a fixed burner system on Earth that collects exhaust .... examples include the home furnace ... I can't think of any examples of a home furnace or fireplace that collects the exhaust.

Your idea clearly has merit because of the special circumstances of Mars, but if an engineering team is asked to think up a way to achieve the objective without consuming power produced by the engine itself, they are going to be challenged.

You are pretty good at finding information on the Internet, so if there is an installation anywhere on Earth that collects the exhaust from a hydrocarbon engine, you'd be able to find it.  I won't hold you to it though, because it may not exist.

(th)

Offline

#36 2020-12-30 21:37:33

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 20,902

Re: Carbon Monoxide - a way to power Mars?

A balloon or espansion tank where the pressure is lowered and moved to a higher pressure later by pumps once cooled is how you do not restrict the engines exhaust from reducing the power output from the engine.

Exhaust cars on earth can use a co2 pump in the exhaust gas recirculating system to feed it back into the engine to burn the unburned gasoline that it contains it comes out of the catalytic convertors to provide it back into the reburn process. This system also makes use of what is called the oxygen sensor that provides a voltage to determine if the fuel is being burn correctly in the engine.

Offline

#37 2020-12-30 21:40:54

Void
Member
Registered: 2011-12-29
Posts: 3,632

Re: Carbon Monoxide - a way to power Mars?

Perhaps my intrusion may be tolerated.

If not, then never mind.

I have for a long time hoped to get the tiny amounts of CO and O2 out of the atmosphere for a useful purpose.  I believe that there is about twice as much Oxygen as Carbon Monoxide.  I won't bother about previous attempts to come up with a notion that might work effectively, except that Antius, as I recall seemed to think that it could be done Cryogenically and with centfifuges.

As it happens, I have been pondering it again in the last couple of weeks.

Specifically you might look to Adsorption/Desorption.   In this case I am thinking about the Carbon Monoxide.   You may look as to how that is used to remove Carbon Monoxide from Syngas.

Keeping in mind that if you could effectively get CO from the atmosphere, it would be like having a Coal Seam, but instead of having to mine a solid, you would be working with fluids.

I will attempt to fish up some references, then I will suggest some things that might be done with the CO, if it proves possible.  Lets call this one a start:
https://pubs.rsc.org/en/content/article … ivAbstract

My notion is that you would want to extract the CO, and then process the bulk remainder.   I have thought about trying to get the Oxygen with Hemoglobin, but of course CO would clog the Hemoglobin as it is far more reactive to CO than Oxygen.  But if you got the CO out first, then perhaps something could be attempted to mimic what organisms that use Hemoglobin might do.  However, I am most interested in the CO at this time.

My idea is to try to extract those two trace gasses, and then to feed the remainder into a bioreactor that is anaerobic, and adding Hydrogen to the mix, then you could enable Methanogens to absorb the CO2 and H2 and create Methane and biomass.

Of course having Methane, then it makes you wonder what you want the CO for.

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

Uses:
https://en.wikipedia.org/wiki/Carbon_monoxide#Uses

To produce Hydrogen from water to use in a bioreactor, the side product would be Oxygen.  So, it becomes less desirable to chase down the trace O2 in the atmosphere of Mars.

So, there is a lot to juggle around in consideration of what may be of use and maybe be practicle.

Of course CO can be used in processing metals, but of course Hydrogen might be useful as well.

So, I just dropped off this clump of my latest studies of the matter.

Done.

Last edited by Void (2020-12-30 21:56:10)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

Offline

#38 2020-12-31 08:27:21

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For Void re Post #37

Thanks for adding the valuable reminder that CO might be removed from Mars atmosphere (and isolated for use):

Specifically you might look to Adsorption/Desorption.   In this case I am thinking about the Carbon Monoxide.   You may look as to how that is used to remove Carbon Monoxide from Syngas.

In another place in the forum (perhaps this topic) Louis suggested collecting CO from the atmosphere of Mars, but the suggestion was not accompanied by a method Louis would use to accomplish that.  Your post contains what appears to be a method that might work, but I haven't studied the source material you suggested, so I'm not sure.

(th)

Offline

#39 2020-12-31 09:46:59

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,932

Re: Carbon Monoxide - a way to power Mars?

An easier recovery source for CO is from the MOXIE system, since CO is the byproduct of O2 from CO2.

2 CO2-------MOXIE------> O2 + 2CO is the reaction.

The energy released in the reverse reaction is not very much. This seems to be grasping at straws when Nuclear is so much more efficient and with higher power outputs by multiple orders of magnitude. Building the needed infrastructure to support this process is a total waste of resources better put to construction of other things.

Offline

#40 2020-12-31 10:11:16

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For Oldfart1939 re #39

Thank you for your substantial contribution to this topic, and thus to the IC topic!

Human teams are going to employ a great variety of technologies on Mars, to try to compete successfully with their peer groups trying other things.

What I have in mind for the CO initiative, is a way-of-doing-things that will last for hundreds of years after all the other higher technology approaches are lost in the mists of time.  The technology employed ** must ** survive the transition from the first settlers whose brains are packed with knowledge to the children who come along.  I am betting on a simple, reliable technology well suited for Mars that can be mastered by students at the high school level.

Even a "simple" CO based infrastructure will require heavy investment in education for it to become sustainable if contact with Earth drops for some reason.

For one thing (trying to stay on topic) the machinery needed to produce and then to use CO must be manufactured on Mars, and the technology to do ** that ** is non-trivial.  I am hoping that 3D Printing will be able to shoulder the greater part of that burden, because it should be easier to embody knowledge in 3D Printer software than into the brains of the students.

However, all that said, thanks again for your valuable contribution here!

(th)

Offline

#41 2020-12-31 10:24:19

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 20,902

Re: Carbon Monoxide - a way to power Mars?

One bit of knowledge still yet to find is "what If" the performance of Moxie for a 1 Bar co2 input to the machine for efficiency of the device for other applications.

As far as creating co2 we have known about bio reactors for ages in which they put out ch4 or methane to burn with oxygen to make all that you can...

Offline

#42 2020-12-31 10:45:15

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For SpaceNut re #41 ...

Thanks for the reminder that input to MOXIE is compressed to 1 Bar.  Energy is required for that operation.  There are filters in the flow to remove solids floating in the mix.  Those filters may be cleanable ... I don't recall at the moment.  I'm assuming they are not in this first test.

There's a ** lot ** riding with that experiment!

(th)

Offline

#43 2020-12-31 11:15:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 20,902

Re: Carbon Monoxide - a way to power Mars?

No its not at 1 bar and I proposed a what if to see what it could do.....moxie topic has a link in the engine topic...

Offline

#44 2020-12-31 12:15:49

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 4,707

Re: Carbon Monoxide - a way to power Mars?

For SpaceNut .... Thanks for the follow up in #43

I found an earlier reference (in the archive per your suggestion) .... Input to the MOXIE is boosted from 7 torr to 700 torr

So you are right that the current design does not operate at a full Bar ... here are the conversion figures:

Per Google:

New Year's Eve 2020
how many torr in a bar

About 8,160,000 results (0.46 seconds)

Pressure: 1 Bar = 750.062 Torr

The MOXIE spiral pump will deliver just ** under ** 1 Bar to the intake.

(th)

Offline

#45 2020-12-31 12:26:03

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 20,902

Re: Carbon Monoxide - a way to power Mars?

Which is also where the density of mars air comes in that only a small volume is moved by the spiral pump that gets compressed to the near value and why we need to proof of concept to work so that Nasa will then move upward to greater volumes.

Offline

#46 2020-12-31 16:25:05

kbd512
Administrator
Registered: 2015-01-02
Posts: 3,982

Re: Carbon Monoxide - a way to power Mars?

Oldfart1939,

Some of us want an on-demand energy store that does not use precious water and is completely reversible, meaning the combustion byproduct is exactly what we sucked out of the atmosphere to begin with.  The SCCO2 gas turbine is a closed loop machine, so it negates the need to procure or re-use a lot more CO2 to act as a working fluid, and we already have working examples of zeolite beds that can capture 90% of the exhaust of a diesel for a 7% payload performance penalty in an Earth-bound cargo delivery van.  Despite the weight penalty for carrying the extra mass of a zeolite bed to absorb the CO2 from the diesel or gas turbine's exhaust (from the combustor can that blow torches the working fluid inside the gas turbine's closed SCCO2 loop, in the case of the SCCO2 turbine), we can tolerate that kind of weight increase a lot more than a battery's linear weight increase for providing equivalent power output for an equivalent length of time.

The ultimate suitability of one solution over another will depend upon use case.  We're never going to capture the exhaust from a rocket engine, so we'll have to make an entirely new batch of LOX/LCO from scratch and incur the substantial energy penalty of doing that, rather than starting with roughly 90% of the CO2 we originally had to collect in order to power the bulldozer in that example.  The 7% mass penalty for a bulldozer that moves at modest speeds and does need some weight to push regolith around is less extreme than trying to travel several hundred kilometers under battery power, in a durable but heavy tracked off-road vehicle.  We can't make up for the order of magnitude greater energy density of the LOX/LCO versus Lithium-ion batteries, merely by piling more batteries atop said vehicle, so we're either going to have drastically limited range or very heavy vehicles that are mostly batteries by weight and volume, rather than payload, which happens to be the same basic problem that low-Isp chemical propellants pose in the context of the rocket equation.

Beyond that, a lot of what I'm proposing relies upon having some nuclear power as a type of "seed corn power" to build either larger reactors if they become available, or solar thermal power, which also has the benefit of the ability to store heat in molten salts from indigenous sources.  Anyway, just as there are appropriate and inappropriate uses of technology here on Earth, the same will apply on Mars.  This was always about, what is the "least mass and energy intensive for a specific use case", not what do we dream about having available.  Everything under discussion relates to practical technologies that we have a good grasp on, meaning real-world working examples that function as advertised.

Offline

#47 2021-01-12 00:07:02

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 642

Re: Carbon Monoxide - a way to power Mars?

An alternative to CO would be solid carbon.  Produce solid carbon slugs, which can be stored in a trailer or rack.  These are loaded into a combustor that produces CO which is subsequently burned in the S-CO2 engine.  It is added complexity, but it means that the fuel can be stored without need for a pressure vessel.

Given that solar panels are 20% efficient and the production of methane and oxygen is only 5-8% efficient, it may end up being more efficient to grow algae in transparent panels.  This can then be dehydrated and compressed into fuel slugs.  Hybrid rockets could use dried algae compressed with some sort of binder.


Interested in space science, engineering and technology.

Offline

#48 2021-01-12 00:18:04

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 642

Re: Carbon Monoxide - a way to power Mars?

kbd512 wrote:

.

Beyond that, a lot of what I'm proposing relies upon having some nuclear power as a type of "seed corn power" to build either larger reactors if they become available, or solar thermal power, which also has the benefit of the ability to store heat in molten salts from indigenous sources.  Anyway, just as there are appropriate and inappropriate uses of technology here on Earth, the same will apply on Mars.  This was always about, what is the "least mass and energy intensive for a specific use case", not what do we dream about having available.  Everything under discussion relates to practical technologies that we have a good grasp on, meaning real-world working examples that function as advertised.

In the past, I have looked into reactor types that could be built using entirely native Martian resources with minimal manufacturing capabilities.  If we have access to enriched uranium from Earth, building a reactor on Mars becomes dramatically easier and the best early choice would be a low temperature boiling water reactor.  If we are forced to rely on natural uranium on Mars, building a reactor is much more difficult.  The only practical option is then graphite moderated reactors, most likely using water cooling as in RBMK.  CO2 as a coolant is also possible, but would require big steel heat exchangers.  Building a reactor that is both safe and has affordable capital cost using natural uranium fuel is a very significant design challenge.  There are reasons why the Soviets chose to develop RBMK technology, knowing the inherent instability problems that it presents.

Last edited by Calliban (2021-01-12 00:21:19)


Interested in space science, engineering and technology.

Offline

Board footer

Powered by FluxBB