Engineers are developing new ways to convert greenhouse gases to fuel
uc.edu
uc.edu
Article claims:
> Known as the “Sabatier reaction” from the late French chemist Paul Sabatier, it’s a process the International Space Station uses to scrub the carbon dioxide from air the astronauts breathe and generate rocket fuel to keep the station in high orbit.
Reality:
We just shipped a new CO2 scrubber a few months ago
https://www.nasa.gov/centers/marshall/news/releases/2021/mar...
For LONG space missions or colonies
https://www.eni.com/en-IT/scientific-research/space-free-co2...
The ISS is constantly falling back to earth. It maintains its orbit with thrusters on the Zvezda module or a visiting spacecraft boosts it higher
Zeolite is a mineral, you get a bunch of small pellets of it in a bed, and run air over it while cooling it. The CO2 (and H2O) stick to it while everything else goes over it. Once you're at capacity you vent it to space and heat it, the CO2 (and H2O) leave the bed (into space) and recharge it for the next cycle. Repeat forever.
The consumables here are the small amount of gasses sent overboard, and energy, nothing else.
(And you use multiple of these beds because capturing CO2 is exothermic, and venting CO2 is endothermic, so you want to run a heat exchanger between the two beds in opposite cycles to minimize energy usage)
"Once you're at capacity you vent it to space and heat it, [...]"
I thought oxygen was used fast enough to make resupply impractical, but perhaps there are in fact gigantic tanks of O2 under immense pressure somewhere aboard the ISS.
The ISS is constantly losing gas, I believe that the primary source of new O2 is actually electrolysis of water, not pressurized tanks, but that they do also have pressurized tanks as a backup.
A person breathes out roughly 1kg of CO2/day, and it follows you breathe in about the same amount of O2, not an impossible amount of mass to resupply.
which is crazy low if you put it in perspective and see that (gas powered) cars release about 0.2 kg of CO2 ... per kilometer.
There's a reason all the old buildings in big cities are elevated a few steps above street level...
So... Only about one chocolate bar per km.
Also ... CO² is bad ... but at least is non-toxic compared to some of the other side products.
https://www.bts.gov/statistical-products/surveys/national-ho...
I've heard that you mostly love weight by breath, and wondered what was the actual limit. Thanks for that info.
Also... this is a typical number for a typical lifestyle, I believe it can vary substantially if you exercise a lot.
Also... I know nothing about wait loss, but surely a lot of the mass is in water?
The numbers are in the right ballpark.
Not really. Yes, you loose water (and its weight) when you e.g. sweat a lot when exercising, but it gets replaced when you drink. More generally your body keeps the amount of water more or less at the same level through intake (drinking, but also water in food), urinating and sweating. There are short-term variations, but besides exceptional circumstances on a day-to-day basis the amount of water in your body should be pretty constant.
Real weight loss is through loss of muscles (not preferable) or loss of fat.
I haven't followed the new bed system though, I'd be very interested to know if it was using a different molecular sieve (and somewhat surprised if they are).
While it does talk about applications with respect to carbon capture, if we consume the fuel byproduct, presumably we just end up with co2 in the atmosphere?
> “In the future we’ll develop other catalysts that can produce more products,” said Zhang, a doctoral student in chemical engineering.
So I guess if we produce products which sequester carbon then maybe that would be useful, but this is purely speculative.
The old title really was egregiously bad. @dang, can we get it fixed?
If it replaces some amount of fossil fuel, it could still be useful. I'm guessing the efficiency isn't great, though.
The process would still be great news if true, as it could be a carbon-neutral source of hydrocarbon fuel for applications that are hard to electrify, like aviation.
But yes offsetting CO2 produced due to energy is a waste.
If we get into a deficit, we just get some rocks and convert them.
Anthropogenic Chemical Carbon Cycle for a Sustainable Future [0]
How to Make Carbon-Neutral Gasoline Out of Thin Air [1]
[0] https://pubs.acs.org/doi/abs/10.1021/ja202642y#
[1] https://nymag.com/intelligencer/2021/05/how-to-make-carbon-n...
The biggest challenge with renewables always cited is storage. Cabrin neutral feul like this could potentially be a good storage medium.
There's more than enough solar energy hitting the Earth's surface to supply all our power needs, the challenge is capturing, storing, and distributing this power.
After all, fossil fuels are just captured solar energy.
Storage isn't the only problem, and I mentioned this in my comment: weather patterns are changing in unpredicable ways. Building more weather-dependent power sources is stupid when we already have a great solution.
Since the climate change mention has turned out to be baity in its own right, I took that bit out above.
It's necessary to compare the two things:
1 - we drill out more fossil fuels and burn it
2 - we convert atmospheric CO2 to fuels and burn it
#2 is theoretically infinite and CO2 levels never increase. #1 is very finite and the longer we do it the higher CO2 levels increase.
Every way of replacing natural gas with some other source of methane - be it the sabatier process or biogas/biomethane - has this problem. It can only be a climate solution if you can bring leaks down close to zero, which is very challenging.
It also makes one wonder whether e-methane is really such a good idea or whether you'd rather look at other chemicals like ammonia or methanol.
This was one of the reasons behind the recent scandal where "blue hydrogen" had been found to be very dirty.
Essentially it would be almost infinitely easier to reverse all climate change on earth than to make another planet livable but it is in theory possible.
So, if we'd actually capture and burned the gas, there would be little to worry about. Especially considering we'd be getting less of it out of the ground in fossil form.
[1]: https://www.google.com/search?q=38.6+million+miles+*+3+feet%...
p = 1e5
l = 38.6e9 * 1.61
A = 0.27871
R_m = 8.3141
M_CO2 = 12 + 16 * 2
R = R_m / (M_CO2 / 1000)
T = 273.15
V = l * A
m = p * V / (R * T)
f"{m:_}"
'33_558_455_134.769554'We've known how to convert CO2 into fuel since the end of the 19th century.
It can run 24/7.
Little running costs?
No one complaining about NIMBYISM.
Though in the long term, it might be useful to do what you propose to produce carbon neutral hydrocarbon fuel for things that need exceptional energy density. Like air travel or space launch vehicles.
Yes that's what I had in mind - thanks.
I do remain sceptical that electric cars will save us. If everyone buys an electric car, and then plugs them in the evening to charge - I'm not sure the grid will cope very well. IMHO there is still a valid case for running cars, trucks and trains on hydrocarbons.
If you have a short commute, you might also not care how fully charged your car is as long as it is enough. So you may specify that you want a state of charge of 50-80% at the end of the day, and the grid can decide when to charge your car. It won't be enough to smooth out all the fluctuations in renewable generation, but it surely will help.
10 million cars (~20% of the cars existing in Germany) attempting to charge is at least 10 GW of load that can be shed when necessary, and significantly more than that in load that you can sink when there is excess power (I'm assuming each car needs to charge e.g. 10 kWh over 10 hours). Wikipedia says the total Regelleistung (operating reserve?) in Germany is 12.5 GW (7 GW in one direction, 5.5 in the other) and that this is responsible for 40% of the cost of the grid fees.
But another problem is that road construction itself is a huge cause of greenhouse gas emissions and isn't solved at all by electric cars. Only fewer and lighter cars would make things better. Personally I think electric scooters could replace a fair bit of car travel. The little sit down ones are sufficient to get you around for most trips and carry a bags worth of stuff.
Nuclear power is currently more expensive per kWh than renewables. This could potentially change if we were to build many identical plants, which would be viable with this strategy. By building it somewhere far from civilization, lower safety standards could also become acceptable, lowering cost further.
But in order for this to pay off, you'd need an absolutely massive investment, and I suspect nobody wants to take that risk. Building 100 nuclear power plants will be cheaper than building one per plant but still more expensive in absolute numbers, and each plant is already a many-billion project. So for this to work, you'd likely need someone to commit hundreds of billions, and most likely all upfront/at the same time to actually reap the cost benefits for the nuclear plants. And the technology to actually make use of the power isn't there yet.
OTOH, with solar and wind, you can build a plant at basically any scale. A lot of small projects is much easier to make happen than one absolutely gargantuan one.
From the article: The Martian atmosphere is composed almost entirely of carbon dioxide.
For Mars, the process being inefficient, expensive, slow etc. isn't necessarily a big hurdle as it competes with shipping fuel all the way from Earth, while on Earth, it has to compete with a lot of easily available alternatives.
For anyone who has been scouring the web to learn about carbon removal and wants all the best stuff in one place, check out the 5-week AirMiners Boot Up http://bootup.airminers.org
BTW people can access all the Boot Up content on your own on the "Content" menu: https://bootup.airminers.org/meeting-1
Is there a way to invest into the space through some form of managed fund? I have no way of evaluating the economics of any of the companies, but would like to park some of my money by investing in this sector (both hoping for an at-least-comparable-to-market return and wanting to support the development of the technology, while being OK with accepting extra risk - basically, I'm willing to donate to carbon capture and sequestration in the form of accepting a worse point than other investments on the risk/reward curve).
The more we do it the cheaper it'll get.
What about pulling it right where it's mostly produced (heavy polluting factories or electricity generators).
Then you need to secure a source of hydrogen. Over 90% of industrial hydrogen comes from steam reforming which emits CO2. So you'd need to build out massive electrolysis plants, and power these plants with carbon-free energy.
Finally you'd need to run the Sabatier process, which also needs energy.
It's much, much easier to drive down emissions by just reducing the CO2 released in the first place.
The Sabatier reaction seems to needs heat.
Burning organic anything makes water and CO2, amongst the most stable (read lower energy) chemicals in the world. If you want to break one of those up, you need to increase entropy some other way, and unless we're talking solar, wind, or nuclear energy, you're going to have to make more water and CO2 (burn more coal) to do it.
While that's a pretty expensive way of carbon capture, it does seem to work.
The question is of course how much energy it costs. It's probably quite a lot. Meaning that turning CO2 into methane is probably not a very efficient process. I.e. not a great use of clean energy.
Even in a world in which heavier-than-air flight is sharply curtailed, there's still an exeptionally strong case to be made for marine transport as the most efficient mode huamns have ever developed, in moving mass a given distance with a given energy input (ton-miles/gallon or tonne-km/litre as you prefer).
Large, long-distance, high-capacity aircraft will require some sort of liquid fuel. Hydrocarbons have high density by both volume and mass, are well-understood, are remarkably non-toxic and non-volatile (for fuels), and have excellent handling and storage characteristics.
Marine shipping has similar constraints. Wind might re-emerge as a partial contributor. Solar might aid in auxiliary electrical systems. But a big slow marine deisel or turbine remains a hugely efficient prime mover. Solid fuels (e.g., pelletised wood waste) is an option, but is still strongly inferior to liquid fuels.
Even for rail, electrification of heavy freight is a challenge, all the more so with elevation gain and loss, and when travelling far from infrastructure. Yes, much European freight rail is electrified, but it operates at a much smaller scale and through far more developed regions than US and Canadian railways. The need to electrify an entire route also poses challenges (though rail does somewhat lend itself to incremental enhancement).
Electric rocketry is a whole 'nother challenge. Very long extension cords, maybe? Is Musk working on those?
Don't get me wrong, producing fuel from atmospheric CO2 is still wonderful news.
But you know what they produce? Methane. And methane is what? It is A FUEL. And what we do with fuel? We BURN it. Once you burn methane you get the CO2 back, for net ZERO effect on the atmosphere.
The only way this works to help the climate is if you can use thus produced methane to remove need for mining actual gas. Unfortunately (or fortunately), we are already on the way to reduce a lot of mining for energy by replacing it with electricity. So according to Amdahal's law, the benefit is also going to be small.
Producing and burying methane clathrate is still impractical and would be very risky, because they can get resurfaced and then methane is hundreds of times more potent as warming agent than CO2.
You are better off just pumping the CO2 down there, instead, and arranging for it to turn into rock.
The solution can never be to remedy surface-level GHG. The sources need to remain buried and replaced by true renewables. Anything else is just an afterthought, patching what's already too little too late. Almost all fossil-based material that made it to the surface will end up contributing to GHG.
The carbon capture startup founder of Carbon Engineering talks about how he got this wrong, and how they switched their plans from using nuclear to solar. Here's a talk from two years ago on this:
https://www.youtube.com/watch?v=sYopOt9siLg
Note that many disagree with his optimism on the carbon capture side of things, but the solar is generally accepted by technologists.
> Right now we have excess green energy that we just throw away. We can store this excess renewable energy in chemicals.
The idea is that it can be used to store excess energy from green sources
[0] https://medium.com/climate-conscious/nuclear-powered-carbon-...
What are the benefits and risks from just bleeding spare methane into the atmosphere after any refueling reservoirs are topped off? I'd think it'd be useful in raising temperatures on the planet, though that's only one terraforming component.
(I'm very dangerously not an expert on this)
There is a replacement, now, for SF6, for use in power stations and wind turbines. Now the SF6 in use needs to be pumped out and disposed of safely, and SF6 actually banned. And, we have to persuade China to replace theirs too.
Source? This does not match what https://en.wikipedia.org/wiki/IPCC_list_of_greenhouse_gases says.
In my naive mind, Methane seems like the it could be a good candidate for removal from atmosphere: If you could just get it to react with oxygen, it turns into water and the much less harmful CO2, so you don't have to sequester anything, and the reaction is exothermic i.e. it already "wants to happen"... we would "only" need an effective yet cheap catalyst to make it happen at low temperatures.
"the collective contribution of [SF6] and similar man-made halogenated gases has reached about 10 percent as of year 2020". But reading more closely, it seems the SF6 by itself is much less. The rest, I guess, must be CFCs and HFCs.
https://gml.noaa.gov/aggi/aggi.fig3.png
Those 10% are almost all CFC, then the next largest component is HCFCs and then HFCs, where SF6 is included. On the graph subtitle it's explained that SF6 is about 13% of the HFCs component.
Anyway, that's a large change from the last data I've found.
It is worthy of note that the process that is described is exactly the one that Elon Musk was already planning to use on Mars. This is exactly why finding water on Mars is critical to his plans, and is also why Starship is designed to run on methane-oxygen. (Starship will be the second methane rocket ever. And the first, Starhopper, used the same raptor engine.)
It is also worth pointing out that producing methane here on Earth for use around Earth is not particularly helpful. Methane is hard to store and is a better greenhouse gas than carbon dioxide. Then if you use it for a rocket, you put that carbon dioxide back in the atmosphere. We benefit a bit from the shade provided by the water vapor so it isn't quite net neutral, but it is pretty close.
> It is also worth pointing out that producing methane here on Earth for use around Earth is not particularly helpful. Methane is hard to store and is a better greenhouse gas than carbon dioxide.
Couldn't we run the methane through one of those electric generators used in farming for cows' feces ? I honestly don't know how efficient these processes are, not an expert by any means.
You get back the co2 and the energy you expended to make methane in the first place.
What we really need is capture and store CO2, not capture and release again...
[1] https://phys.org/news/2021-09-metals-supercharge-method-carb...
berkeley.edu (where "University of CA" is a subtitle), ucla.edu, ucdavis.edu, etc.
Also, Berkeley was the first real UC campus.
I think Berkeley has its own bare domain because their name was registered before the UC naming conventions were established. I'm pretty sure it was the first or second name registered. https://bind9.readthedocs.io/en/v9_16_5/history.html
Not sure of that, though- in the old HOSTS.TXT predating DNS, UC Berkeley was called UCB, and the server ucbvax became ucbvax.berkeley.edu.
I think it's funny now they teach classes at Berkeley about stuff (DNS, nuclear energy) and the research was done just 30-70 years ago right on the same spot!
No, just no, full stop. They way forward is electrification of everything, using only carbon-neutral energy, renewables &nuclear. No hydrogen, no methane, no electric to fuel, let's not do these physical stupidities to keep dying industries alive.
Now, if the carbon remains captured and the energy for capturing is renewable, we are in business. I'm not aware that is done on a meaningful scale yet though.
Indeed, that's their goal, the issue is that currently we emit a lot so even making the fuel close to neutral (minus production inefficiencies) is already a huge progress. Going negative isn't for tomorrow unfortunately.
These things are not contradictory. We can build out more renewable electricity supply, replace with electric cars, and generate carbon neutral fuel all at the same time. You are underestimating how long and difficult the ICE replacement is going to take. It's not like a single organization can just wave a wand and all gas cars would be replaced over night.
And it will be driven solely by better economics.
You get two cars. A shiny new electric one running in (Central) Europe, and that same old stinky ICE one running in Eastern Europe, Asia or Africa.
The poorer countries will enjoy an influx and thus price decrease of valuable cars and happily drive them for decades to come.
The problem of course is that the planet doesn't care. Europe got cleaner but the planet got worse. Whereas Europe can outsource its dirty issues (waste, emissions, ...), the planet cannot. It stops there and we all lose.
I think the vast introduction of and blind focus on e-mobility is a mistake. Other areas are much more significant sources for GHG (industry, heating, A/C).
But, unless gasoline and diesel drastically drop in price, you are running towards an economic wall, since it's exactly people from Africa and former soviet territories that are the most sensitive to fuel economy and high maintenance costs. Meanwhile, electrics drastically drop in price, since they simpler and cheaper to produce.
The extra few years European cars will see in Africa is just the long tail of the ICE car in Europe, not some fundamental shift. If those would not be available, Africans would purchase cheap new Chinese ICE or other low cost brands. A visit to Eastern Europe will convince you that some 50% of cars are newly purchased cheap brands like Dacia-Renault, Mitsubishi Colt, Chevrolet Spark, often stripped down versions made specifically for these markets and priced at something like 10.000€.
These will have an even lower life expectancy than the typical 20-40.000€ western car, and will be in need for replacing.
I know it is a long shot: it is not yet competitive, there are still very few electrolyzers but some part of the world such as Europe seems pretty committed to try to make it work.
This is about space exploration. Literally it is about how to make fuel on Mars so that we can make the round trip without having to deliver fuel so we can make it back.
And, sorry, but there is no way with current technology to launch significant payloads into space using electric.
Ammonia seems to strike the right balance: https://www.ammoniaenergy.org/articles/zero-emission-aircraf...
But ammonia is probably a better choice for fueling trains and ships than for aircraft.
We may reasonably expect production of the needed aerogel-insulated LH2 tankage to be mature by then.
Gaseous H2 at the extreme pressure people try to use is a much greater nuisance.
The conditions for storage of LH2 and demands on materials in contact with LH2 are much harder than for e.g. methane.
It won't work in all of those situations since hydrogen is so hard to manage, but there are a number of applications where batteries are not the right answer yet. Battery weight is going to scale close to linearly with capacity, hydrogen tank weight should not.
Trains and ships, and maybe trucks, will do better with ammonia. The tanks are bigger, but those have room, and existing engines can burn ammonia with just changes to plumbing.
It seems like there isn't even a conspiracy, it's just a combination of poor choices, greed, and new technology. Solar is great, but often it's more expensive than just consuming grid power or has unpredictable payoffs. Wind has a lot of upfront costs. Massive batteries are just starting to roll out. Energy companies are trying to keep prices low in the short-term and keep things reliable, so they mostly use cheap and plentiful fuel. Consumers without a lot of money can't put the capital down for a new car, so they buy used or cheap. It happens that most used/cheap cars use petrol-based fuel. Additionally, car companies have a product that sells, why risk that or their reputation?
Finally, you have the government deciding policy based on much more than just the environment.
Perhaps this will create a better storage mechanism, but addressing getting to carbon neutrality feels very dreary.
It would be like expecting people who dump their industrial waste upstream in a river to be corrected by market forces - the market will probably choose that people don’t care about the down river people as long as they get their goods slightly cheaper.
Also a wrinkle in a pure market based solution is that the US substantially subsidizes fossil fuels because I think the 70’s taught politicians that fuel price shocks will get them voted out immediately. https://www.eesi.org/papers/view/fact-sheet-fossil-fuel-subs...
> I think most people believe there are more dire issues that need fixing and funding.
No, they're stuck in a shitty system that doesn't allow them to price resources according to their externalities. People aren't going to opt to pay more for fossil fuels than they have to because it would require a critical mass of buy-in. The only solution is taxation, but that doesn't work either because the system offers no safety nets and gasoline suddenly jumping to $20/gallon (which is what it should cost now) would be financially devastating to citizens.
Markets work great at lower populations, and now we're beginning to see their failure modes when population has skyrocketed and rampant resource consumption causes existential damage. Everyone knows it's a problem, but there's no systemic way of solving it.
We're now at a point in humanity where supply and demand alone are insufficient mechanisms to organize an economy.
I feel like this is the crux of your problem. People and governments have multiple priorities to balance
The impossible part is we have yet to discover a density/cost comparison to hydrocarbons.
No one is going to “switch” to something that isn’t as good as the existing option. Couple this with “but electric cars!” that often are still just coal powered.
Plastics, military, actual logistics, China, we’re going to burn every drop of oil. We all better hope someone is working on sequestering options!
It's a bunch of smaller decisions that are hampered by new technology and lack of economies of scale, among many other compounding factors that result in poor consumer/business/utility/government choices (for the environment). I think sequestering may be an important part of that, but it's still new technology.