Liquid metal catalyst quickly converts carbon dioxide into solid carbon:
Researchers at RMIT [(Royal Melbourne Institute of Technology)] have developed a new method for quickly converting carbon dioxide into solid carbon, which can be stored indefinitely or turned into useful materials. The technology works by bubbling CO2 up through a tube of liquid metal, and it's designed to be easy to integrate into the source of emissions.
[...] The RMIT team's new system uses liquid metal, specifically an alloy called Eutectic Gallium-Indium (EGaIn), which is heated to between 100 and 120 °C (212 and 248 °F). Then, carbon dioxide is injected into the mix, and as the bubbles rise, the CO2 molecules split into flakes of solid carbon. These float to the top, making it easy to collect the material.
The team says that the design of the system should be relatively easy to scale up and implement at the point of emission. The reaction occurs quickly and efficiently, and the heat required is also relatively low, and could be supplied by renewable sources. All of these are improvements on the team's earlier work, which required more hands-on steps.
[...] Solid carbon, on the other hand, is stable, and could be stored more or less indefinitely without risk of leakage. The team says this could be buried again, or, more promisingly, used for other industrial applications, such as making concrete.
The next steps for the team are to scale up the system to a modular prototype that's about the size of a shipping container.
Journal Reference:
Karma Zuraiqi, Ali Zavabeti, Jonathan Clarke-Hannaford, et al. Direct conversion of CO2 to solid carbon by Ga-based liquid metals, Energy & Environmental Science (DOI: 10.1039/D1EE03283F)
(Score: 2, Funny) by Anonymous Coward on Wednesday January 26 2022, @08:22PM
Save the planet, overclock your PC!
(Is there enough indium on Earth for this to be practical at industrial scale?)
(Score: -1, Troll) by Anonymous Coward on Wednesday January 26 2022, @08:26PM (23 children)
https://en.wikipedia.org/wiki/Soot [wikipedia.org]
We do not have science anymore. Everybody switched to scamming.
(Score: 4, Informative) by PinkyGigglebrain on Wednesday January 26 2022, @08:52PM (22 children)
its going to depend on how large the "scales" of carbon are. But even if it is the same size common soot is easy to capture and remove from the gas stream. Another factor is the result of this process is 100% pure carbon from gaseous CO2, not the partially combusted mix of common soot.
"Beware those who would deny you Knowledge, For in their hearts they dream themselves your Master."
(Score: 1, Interesting) by Anonymous Coward on Wednesday January 26 2022, @09:27PM (21 children)
Leave the gaseous CO2 to trees and other plants to handle. The tech is in use all around the globe for 450,000,000 years, no human intervention required.
If your faith absolutely forces you to rituals such as "burying carbon", take your pick of those trees and plants and study up on https://en.wikipedia.org/wiki/Carbonization [wikipedia.org] ; I hope some of the faithful do retain enough brain matter to be taught the 30,000 years old tech of making https://en.wikipedia.org/wiki/Charcoal [wikipedia.org]
(Score: 0) by Anonymous Coward on Wednesday January 26 2022, @09:55PM (1 child)
You don't seem to understand the FULL lifecycle of these plants and trees, do you?
(Score: 0, Troll) by Anonymous Coward on Wednesday January 26 2022, @10:20PM
You don't seem to understand written language, do you?
Once again, for the DENSE lefties: https://en.wikipedia.org/wiki/Charcoal [wikipedia.org]
(Score: 4, Interesting) by cmdrklarg on Wednesday January 26 2022, @10:06PM (8 children)
And what exactly do you think happens when said plants and trees stop growing and die? All the carbon that went into growing the plant now decomposes, releasing the CO2 back into the atmosphere.
Your dismissive attitude notwithstanding, your post is not completely useless. From your link, current charcoal production tends to be a dirty process that creates a lot of pollution and results in a lot of deforestation. If it can be regulated into something sustainable (replanting, using renewable energy in production, etc.) it could be useful for sequestration of CO2. I'm not certain about how well it would scale to be able to put a dent in the excess CO2 however.
The world is full of kings and queens who blind your eyes and steal your dreams.
(Score: -1, Troll) by Anonymous Coward on Wednesday January 26 2022, @10:38PM (1 child)
And what exactly do YOU think happens then? Some inane talking point comes true in defiance of all evidence?
Liar, liar, pants getting carbonized!
Here is some science for you to read: "Faster carbon accumulation in global forest soils" https://www.biorxiv.org/content/10.1101/149393v1 [biorxiv.org]
Ask your friendly search engine for "soil carbon accumulation", and next time please DO LEARN SOMETHING about the natural world you are pretending to "protect".
(Score: 2) by cmdrklarg on Thursday January 27 2022, @04:33PM
Being an antagonistic asshole will do little to help your case.
Soil carbon accumulation being a greater CO2 sink than previously thought is interesting. Unfortunately the atmospheric CO2 PPM is still rising, so it's not enough to offset.
We can't keep pulling already sequestered carbon out of the ground (oil, coal, natural gas) and expect the PPM to lower without a method to re-sequester it. This will likely require several methods being used in parallel.
The world is full of kings and queens who blind your eyes and steal your dreams.
(Score: -1, Troll) by Anonymous Coward on Wednesday January 26 2022, @10:56PM
Couple more things for a plucky humanities student to consider:
https://en.wikipedia.org/wiki/Coarse_woody_debris#Nutrient_cycling [wikipedia.org]
https://en.wikipedia.org/wiki/Humus#Stability [wikipedia.org]
See, what your gurus call "science" when indoctrinating you, and the old-style "study of the natural world based on facts learned through experiments and observation", have literally nothing in common.
(Score: 2) by PinkyGigglebrain on Thursday January 27 2022, @12:11AM
The carbon only gets released back if the plant decays, if it is converted into charcoal then the Carbon is locked. Using some fast growing high cellulose plant like Bamboo instead of slow growing trees it becomes more practical. Saving the planet is a big project no mater how you look at it.
"Beware those who would deny you Knowledge, For in their hearts they dream themselves your Master."
(Score: 2) by mcgrew on Thursday January 27 2022, @07:31PM (3 children)
...trees stop growing and die? All the carbon that went into growing the plant now decomposes, releasing the CO2 back into the atmosphere.
You mean like all the wood in my eighty year old house, or in the 300 year old courthouse in Cahokia, Illinois? Trees release CO2 when they burn, not any other kind of death. Or do termites and fungus shit CO2?
Impeach Donald Palpatine and his sidekick Elon Vader
(Score: 2) by cmdrklarg on Friday January 28 2022, @02:28PM (2 children)
If they're not maintained, yes they will rot.
The world is full of kings and queens who blind your eyes and steal your dreams.
(Score: 2) by mcgrew on Saturday January 29 2022, @04:57PM (1 child)
My house was built in the 1940s and since it was rented out for at least 20 years before I bought it, it was never well-maintained. But the wood hasn't rotted.
Impeach Donald Palpatine and his sidekick Elon Vader
(Score: 2) by cmdrklarg on Monday January 31 2022, @06:31PM
Was the house painted, or have siding installed? Those help protect from the elements. As long as the wood stays dry it should last a long time. Wood left out in the elements will rot over time. A couple of anecdotes from me:
On the farm where I grew up there are several buildings that are basically falling down or apart due to lack of maintenance.
There used to be a stump in my back yard from a dead tree that I had taken down 6 years ago. Last year the stump had rotted enough that I could pull it apart with my hands.
The world is full of kings and queens who blind your eyes and steal your dreams.
(Score: 5, Insightful) by PinkyGigglebrain on Thursday January 27 2022, @12:00AM (9 children)
You seem to be overlooking the fact that the whole reason we have a problem with the CO2 in the first place is that we have been taking carbon that was sequestered in the ground for the last 300,000,000 years and adding it back into the atmosphere.
Most of the coal that we've been burning the last 200 years formed formed in the Carboniferous period aprox 300 million years ago. During a time when plants figured out how to make a type of cellulose that didn't get broken down like it does today. At the time nothing had evolved yet that could break it down so the carbon in it was locked in. So as the CO2 was captured and sequestered by this new type of cellulose the Earth's atmosphere had a Oxygen content 30% higher than today. It was why insects of the time could grow to ridiculous size (dragonflys with 3ft wingspans) and forest fires was common. The charcoal left over from those fires is what eventually became the coal we've been digging up and putting back into the air.
We can't just rely on trees anymore. They suck as Carbon sinks now, they grow way too slowly and organisms have evolved to break down their cellulose so the carbon in the trees will just get released back into the atmosphere when the tree decays. Unless we started a huge program to grow and convert lots of high cellulose, fast growing plants like Bamboo and Hemp into charcoal and sinking it into some deep ocean trench somewhere we're not going to make a dent in the CO2 levels anytime soon.
"Beware those who would deny you Knowledge, For in their hearts they dream themselves your Master."
(Score: 0, Troll) by Anonymous Coward on Thursday January 27 2022, @12:39AM
Is that some enterprising people invented a new way to siphon $trillions of taxpayers money into private pockets.
Lignite coal begs to differ. ;) https://en.wikipedia.org/wiki/Lignite [wikipedia.org]
Said who? Saint Greta The Truant?
https://www.fast-growing-trees.com/pages/fastest-growing-trees [fast-growing-trees.com]
At least you do know of really fast growing things like bamboo.
https://en.wikipedia.org/wiki/Coarse_woody_debris#Nutrient_cycling [wikipedia.org]
A program to somehow magic into being gallium and indium in an equally huge amount, use said gallium to combine with some CO2 into gallium oxide and soot, then somehow magic said gallium oxide back into metallic gallium, surely would be much better. For robbing the naive citizenry blind, certainly so.
https://en.wikipedia.org/wiki/Pyrolytic_carbon [wikipedia.org]
https://en.wikipedia.org/wiki/Carbon_fibers [wikipedia.org]
Corollary: stacking bad science and unfounded beliefs ten layers deep does not compact the word compost into a diamond of truth. Learn more, be fooled less.
(Score: 0, Troll) by captain normal on Thursday January 27 2022, @01:52AM (1 child)
"...we have been taking carbon that was sequestered in the ground for the last 300,000,000 years and adding it back into the atmosphere."
Just wondering just who the "we" is you are talking about. Humans, nor our closest ancestors, have been around for 300 million years. That long ago there were some big lizards and pre -chickens stomping around the old terra firma. You are not one of the Lizard People are you?
The Musk/Trump interview appears to have been hacked, but not a DDOS hack...more like A Distributed Denial of Reality.
(Score: 3, Insightful) by mhajicek on Thursday January 27 2022, @06:37AM
Whoosh
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 1, Interesting) by Anonymous Coward on Thursday January 27 2022, @05:20AM (3 children)
That's a nice little fairy tale told by those who make a living out of climate change. In reality, the entire amount of carbon in the biosphere is laid down as limestone by shellfish every 10,000 years. If it wasn't for the carbon replenishment by volcanoes and oil seeps then life would have died out long ago.
In fact, limestone deposition tracks carbon production so well because life is carbon limited. Limestone is deposited until the CO2 drops to the point that plants and animals suffer from it's lack, either directly by plants failing or by inducing an ice age.
Humanity has made a sudden change to that rate though, and the biosphere is still ramping up to use the excess. Currently half of the "excess CO2" humans have produced has "disappeared". Oil is already past peak, and coal isn't that far behind, we won't get into serious trouble before we run out of them.
The big danger isn't CO2, but running out of fossil fuels before we have viable replacements.
(Score: 1) by pTamok on Thursday January 27 2022, @08:15AM (1 child)
Interesting story, especially if true.
I'm a lazy so-and-so: have you got links to good references backing up your statements? If so, I'd like to see them. A 10,000 year carbonate deposition cycle sounds...amazing.
We have not hit peak oil, or coal. As the price paid by people for oil or coal goes up with demand and/or scarcity, marginal reserves become more viable. Climate change mitigators seriously argue we should pay oil companies to leave oil in the ground, and there are huge untapped reserves: not least the Athabasca tar sands which "contain about 1.7 trillion barrels (270×109 m3) of bitumen in-place, comparable in magnitude to the world's total proven reserves of conventional petroleum." [Wikipedia]
Much as I'd like to believe what you are saying, there is a bit of a credibility gap for you to fill.
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @10:55AM
It's not so much a cycle as a stream. Volcanoes and oil seeps add carbon while limestone takes it away.
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @02:36PM
you can gladly have your "concret" made from "carbonese limestone".
i will continue to find "calcium-silicon" based limestone for my concret, thank you very much ...
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @10:17AM (1 child)
That all carbon sequestered by plants ends up in the atmosphere at their death is a gross misrepresentation. There are many paths which remove it from the atmosphere: Peat bogs, permafrost, anoxic lake sediments, marine clathrates, marine snow, wooden buildings, anoxic municipal dumps.
If we were to market plants as smart, adaptive, self-assembling, solar-powered cabon sequestration robots, then maybe people would care a bit more. Just add block chain and big data too that somehow...
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @02:42PM
"planto: it's what cows crave(tm)"...
(Score: 3, Informative) by JoeMerchant on Wednesday January 26 2022, @08:47PM (12 children)
At ~$6000 per pound [sigmaaldrich.com] (sure, cheaper sources will be found, maybe as low as $600 per pound), I'm guessing the it will be some time before we have ready supply of enough catalyst to actually apply it to the "easy targets" like gas fired power plants.
🌻🌻🌻 [google.com]
(Score: 4, Informative) by JoeMerchant on Wednesday January 26 2022, @08:50PM (1 child)
Maybe not...
Summary: During the 2011–2018 period, both production and demand quantities increased at an average CAGR of 3–5%, although production did not always increase in a straight line as it tends to anticipate or adjust to demand. In summary, virgin production increased from 500mt in 2011 to 700–800mt by 2018. The peak in production was actually reached in 2014, driven by an artificial demand created by the Fanya Exchange in China. Fanta was a scheme that induced the general public to buy indium metal by promising high annual returns and cash back. Chinese private investors ended up funding purchases of up to 3,600mt (or about five times the world annual primary demand). This demand fueled an increase in prices, which enabled a higher production output. The Fanya Exchange suspended operations in 2017, the managers have been indicted of crimes (fraudulent in nature), and the investors lost their investment (for now). The indium stock still exists in the hands of the curators and it has created a down-pressure on prices ever since; however, this can also be viewed as a safety stock of indium.
https://www.indium.com/technical-documents/whitepaper/availability-of-indium-and-gallium [indium.com]
🌻🌻🌻 [google.com]
(Score: 0, Offtopic) by Anonymous Coward on Wednesday January 26 2022, @11:47PM
I quit drinking Fanta when I learned there was indium in it. The corn syrup was bad enough!
(Score: 4, Touché) by drussell on Wednesday January 26 2022, @08:50PM
You aren't going to be buying industrial quantities of materials from a laboratory chemical supplier...
(Score: 3, Touché) by krishnoid on Wednesday January 26 2022, @09:46PM
Perfect! Finally, a way for cryptocurrency speculation to pay for its carbon footprint. Plus, since it converts it to solid carbon, they could even make the blocks in the shape of feet!
(Score: 3, Funny) by EvilSS on Wednesday January 26 2022, @10:45PM (7 children)
And don't get me started on what they charge for cocaine! Your drug dealer wishes he could get those prices. https://www.sigmaaldrich.com/US/en/product/sigma/c8912 [sigmaaldrich.com]
So don't use SigmaAldrich as a benchmark for how much anything costs, unless they are literally the only place you can get it.
(Score: 2) by krishnoid on Wednesday January 26 2022, @10:53PM (6 children)
I bet you can use it as a benchmark, just with a multiplicative factor. Hey, you might be able to mail them in a question and link to this article, asking what the costs would actually be per pound in industrial applications! I bet a bunch of nerds work there anyway and they'd be interested in looking it up when they're bored. At the least, it would work as blog fodder if they run a blog.
(Score: 3, Informative) by EvilSS on Wednesday January 26 2022, @11:40PM
Nah, they have so much margin built in that they don't need to reprice on fluctuations. The spot price could double and they could just leave it at $6K. Looking it up, it looks like it's around $360/kg: https://www.metal.com/Indium-Germanium-Gallium [metal.com] or higher depending on purity.
(Score: 3, Informative) by JoeMerchant on Thursday January 27 2022, @01:08AM (4 children)
No, he's right, the problem with using them as a benchmark is that they throw on a $50 "bottle charge."
I used them to get some specific long chain entangled Poly Acrylic Acid once, I think it was like $300, don't really remember it was part of a company project where we were traveling to sites to pay them $500 per hour to use their MRIs, so after the travel and tool machining costs etc. whatever the chemicals were was trivial, and we wanted something exactly repeatable. But, if you don't mind something close, an equivalent amount of ungraded long chain entangled PAA is available from horticultural suppliers for like $5.
Still, I wouldn't be surprised at all if the catalyst is $600 per pound - silver is about $400 per pound today, and the platinum they use in auto converters is $16,000. This "bubble your exhaust through the liquid metal" scheme sounds like it's going to need a lot more mass than the platinum in an automotive catalytic converter.
🌻🌻🌻 [google.com]
(Score: 2) by captain normal on Thursday January 27 2022, @02:01AM (3 children)
The best price I could find is $325.00 per 25 grams. So if it remains stable after having tons of CO2 bubbled through it, it might be a bargain.
https://www.sigmaaldrich.com/US/en/product/aldrich/495425 [sigmaaldrich.com]
The Musk/Trump interview appears to have been hacked, but not a DDOS hack...more like A Distributed Denial of Reality.
(Score: 2) by JoeMerchant on Thursday January 27 2022, @04:00AM (2 children)
Think about the torrent of CO2 leaving a gas fired electrical generation station. How many grams of liquid metal will be needed to "bubble" all that gas into even brief contact with some of the liquid catalyst? Then the carbon flakes collect on top, maybe they can work out a process whereby the carbon flakes blow off into a side-stream catcher.
I'm actually more curious about what becomes of the pure oxygen liberated in this process?
Also, that's quite a drop in chemical potential energy from CO2 to Cx + O2, I assume it will be chilling the catalyst - and the energy to keep the catalyst at catalyzing temperature has to come from somewhere...
🌻🌻🌻 [google.com]
(Score: 2) by FatPhil on Thursday January 27 2022, @12:25PM (1 child)
Uhuh - you read the crappy science journalism rather than the uni press release or the paper. This ain't a catalyst, it's a reagent. It emerges as an oxide, so would need to be reduced in post-processing to use again.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by JoeMerchant on Thursday January 27 2022, @01:06PM
Yeah, gathered that eventually.... although, if the reduction is part of the process then the net action is like a catalyst. Either way, you'll be giving up the energy gained by conversion of hydrocarbon to CO2, netting at best the hydrocarbon to water energy release (50-66% of the total, depending on your hydrocarbon).
🌻🌻🌻 [google.com]
(Score: 3, Insightful) by Rosco P. Coltrane on Wednesday January 26 2022, @08:56PM (12 children)
How energy efficient is it?
There are plenty of methods to turn CO2 into something else, but by definition, they all involve pouring energy into it. The process can require insane amounts of energy, or just enough - the latter of which then only makes sense if you convert CO2 using renewables.
(Score: 2, Insightful) by Anonymous Coward on Wednesday January 26 2022, @09:32PM (3 children)
Even the theoretical amount of energy required to separate the carbon from the oxygen is more than the energy released when the carbon-based fuel was burned in the first place. Want to remove all of the excess carbon dioxide in the atmosphere? That will require more energy than we ever got from all of that oil, coal and natural gas over the centuries. Fuel for thought.
(Score: 2) by Freeman on Wednesday January 26 2022, @09:52PM
Possibly doable with the advances in power generation that we've made. We didn't have Nuclear Power Plants 100 years ago. Solar and Wind energy farms are a thing. It may be doable over the long haul.
It's like with dieting. People expect to lose weight fast, but it took them years to pack on the weight. Seems nuts to expect to lose the weight fast and keep it off. Life style changes need to be made, if you want to lose weight. Even then, some people just can't, due to circumstances outside of their control.
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
(Score: 2) by maxwell demon on Wednesday January 26 2022, @10:00PM (1 child)
In particular, it will make no sense to equip the exhaust of a power plant with this device; the energy needed by the device will be greater than what the power plant delivers.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 1, Interesting) by Anonymous Coward on Thursday January 27 2022, @12:01AM
Not necessarily. Most of the energy in hydrocarbons comes from the hydrogen, not the carbon. That's why gasoline burns better than charcoal. Nobody cares about the released water, just the CO2.
(Score: 3, Informative) by Michael on Wednesday January 26 2022, @10:29PM (2 children)
The total reaction energy of the two successive bond breaking operations is 0.73 eV according to the paper.
That converts to 70 Kj/mol. CO2 is 44 g/mol. (Disclaimer, this is more chemistry than I actually know how to do.) So I suppose it takes 1.6 Kj to convert a gram. So 0.45 kWh per kg.
Also going to depend on how much energy it takes to pump the gas through, which the paper doesn't mention.
(Score: 3, Interesting) by Michael on Wednesday January 26 2022, @10:40PM (1 child)
Actually not sure any of that is relevant / makes sense.
Someone further down is saying it's not actually a catalyst, and you end up with left over gallium oxide. So most of the energy is going to go into gallium refining.
(Score: 1, Funny) by Anonymous Coward on Wednesday January 26 2022, @11:06PM
It is not supposed to make sense. It is supposed to siphon government money.
(Score: 2) by JoeMerchant on Thursday January 27 2022, @04:16AM (4 children)
That's my sticking point: the "relatively low" amounts of heat required to sustain the process... 806 kJ/mol for CO2, 498 kJ/mol for O2, CH4 is 415 kJ/mol per bond, H2O 461.5 kJ/mol... so CH4 + 2 O2 ~ CO2 + 2 H2O, 415*4 + 498*2 ~ 806 + 2*461.5 + ?, 2656 ~ 1729 + 927, 927 kJ liberated per mol of methane burned, but then we're going to turn around and suck out 806 - 498 = 308 kJ for the CO2 carbon capture process, 33% minimum.
Granted, if you want your power plant to not emit CO2, you've got to "pay for it" somehow, but if my 40 year old high school chemistry isn't too rusty, this means that what used to be a 10MW output power plant will need to sink at least 3.3MW into the carbon capture unit, and when you start throwing in the realities of inefficiencies, heat losses, etc. that's probably closer to a 50% hit on total plant output.
🌻🌻🌻 [google.com]
(Score: 2) by FatPhil on Thursday January 27 2022, @12:35PM (3 children)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by JoeMerchant on Thursday January 27 2022, @01:08PM (2 children)
It is unusual for industrial / utility scale processes to accept those kinds of efficiency drops without kicking, screaming, demanding taxpayer subsidies, etc.
🌻🌻🌻 [google.com]
(Score: 2) by FatPhil on Thursday January 27 2022, @03:24PM (1 child)
They build datacentres in Finland to reduce their cooling demands, for pity's sake.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by JoeMerchant on Thursday January 27 2022, @04:29PM
I'm talking about existing industries and utilities that have established methods of doing business. Changes like this will have strong negative impacts on their profit margins, shareholder value, etc. Yes, the changes should come, yes they're entirely doable from a technical standpoint (well, maybe not this GaIn thing, yet), but when you take a utility company with $500M in natural gas fired generators operating at such and such efficiency and you tell them that they're going to have to slap on $100M in stack scrubbers which will themselves mandate the buildout of another $300M in generation capacity to meet demand - they are just going to talk about doubling their charge rates to their customers (as it should be), and the customers themselves will be the ones screaming NO, NO, NO!!!!!!
🌻🌻🌻 [google.com]
(Score: 4, Interesting) by Swervin on Wednesday January 26 2022, @10:01PM (6 children)
I looked at the abstract for the paper, and they admitted that they're oxidizing the gallium. So at a minimum this requires another step where the oxygen is driven off of the gallium. Apparently there is Gallium(I) Oxide and Gallium(III) Oxide. Gallium(I) Oxide decomposes above 500C, and Wikipedia says Gallium(III) Oxide melts at 1900C which seems pretty resistant to letting go of that Oxygen.
(Score: 4, Informative) by Swervin on Wednesday January 26 2022, @10:07PM (1 child)
I looked into the supplemental materials they had and they explained what they're doing with the Gallium oxide:
The electroreduction of gallium oxide was carried out on glassy carbon, with an exposed area of 0.28 cm2. Linear sweep voltammetry measurements were performed using a CHI680 Amp Booster. Potentials were measured in an aqueous solution comprised of 1M H2SO4, against Ag/AgCl as a reference electrode, and with platinum wire as the counter electrode.
Not sure how electrically intensive this step is.
(Score: 4, Informative) by EvilSS on Wednesday January 26 2022, @11:30PM
And that's also where the idea of this being a catalyst is coming from. It sounds like they are shooting add the Gallium reduction into the system as a whole. So process CO2, then reduce the Ga and get it back into the CO2 stream. Also explains the talk of renewable energy. I was wondering why they needed that since they could most likely utilize waste heat from the combustion process they were pulling the CO2 from. 200c isn't crazy hot after all.
So yea, as is they have half a solution and we still don't know if it's practical yet. But interesting. Also should be reproducible for home chemists so that could be fun to dink around with.
(Score: 2) by Beryllium Sphere (r) on Wednesday January 26 2022, @10:20PM (2 children)
Where the very definition of a catalyst is a substance that does not participate in the reaction.
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @05:49AM
Technically a catalyst is the same at the end of the reaction as it was at the beginning. During intermediate steps it can combine with one or more reagents as long as a later reaction returns it.
In fact that is exactly how many catalysts work. Reactant A won't react with B. Add C and product C-A forms. C-A reacts with B displacing C. Final result is A-B plus C, but C was definitely reacting in the middle of all that.
(Score: 2) by FatPhil on Thursday January 27 2022, @12:37PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 4, Informative) by EvilSS on Wednesday January 26 2022, @11:12PM
(Score: 3, Interesting) by ElizabethGreene on Thursday January 27 2022, @02:26AM (7 children)
The obvious issues with this are:
1. Absorption of even trace amounts of the Gallium oxide onto/into the carbon waste product will kill the economics of the process.
2. Reducing the Gallium Oxide isn't sorted out yet.
I hope they are able to figure these out. I'm far more comfortable with the idea of storing bulk solid carbon than the current schemes for shoving down high-pressure gas and hoping nothing goes awry.
(Score: 2) by JoeMerchant on Thursday January 27 2022, @04:18AM (2 children)
>Absorption of even trace amounts of the Gallium oxide onto/into the carbon waste product will kill the economics of the process.
Not just the economics, but the ecologics - clean carbon is easy to use, even valuable. Gallium oxide contaminated carbon sounds like toxic waste to me.
🌻🌻🌻 [google.com]
(Score: 2) by ElizabethGreene on Thursday January 27 2022, @05:17PM (1 child)
My guess is that Gallium is expensive enough that they'd recover the adsorbed material from the carbon flakes, probably with an acid wash to bring it into a solution and then drying. The extra machinery and process wrapped around that make it expensive.
(Score: 2) by JoeMerchant on Thursday January 27 2022, @05:37PM
There's also a rather high inherent energy cost here, since CO2 is less energetic than C + O2, no matter how many steps you put in the process, there will be net energy input to break those bonds. It can be energy collected from "waste heat" - but I'd wager that for the cost of the machinery and maintenance to do this CO2 scrubbing you might convert that "waste heat" to quite a lot of useable energy other ways.
I believe anywhere from 33 to 50% of the energy derived from burning hydrocarbons comes from the breaking of the CH bond to form CO2, while the balance comes from the formation of H2O. So, we get to keep the H2O conversion energy, but there's no way to not lose the energy required to break the CO2.
Then we come to the fact that most hydrocarbons are still obtained from non-renewable sources, so whatever we clever-up around burning them without releasing CO2 is still a temporary solution that involved some rather nasty extraction processes that only get worse as the easily accessed natural resources are used up.
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(Score: 5, Interesting) by deimtee on Thursday January 27 2022, @06:02AM (3 children)
There's another problem. Their test apparatus used a pure CO2 stream mixed with Argon. That implies that they needed to remove all oxygen from the stream, probably because it would oxidize the gallium before the CO2 would. Isolating pure CO2 from an exhaust stream isn't cheap either.
Seriously, the cheapest and most effective carbon capture would be to plant trees and then build pyramids from the logs in the middle of a desert somewhere. Use something like Eucalyptus_cladocalyx [wikipedia.org], fast growing, water efficient, dense and rot resistant timber. Drop them in the middle of a desert and cover them with a layer of sand and they would still be there a thousand years later.
200 million years is actually quite a long time.
(Score: 2) by JoeMerchant on Thursday January 27 2022, @11:34AM
Step back (into the desert) 50km from the advancing edge of the Sahara and build a wood wall.
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(Score: 2) by ElizabethGreene on Thursday January 27 2022, @05:13PM (1 child)
I would be curious to know the partial pressure/concentration of oxygen in the flue gas from a natural gas or coal plant? I assumed, possibly incorrectly, that they'd be burning near stoichiometry, but that could be way off the mark.
(I am not an expert.) The trouble with plants for carbon capture at the emission sourceis scale. Sourcing a large fresh water supply and comparatively tiny amounts of fertilizer inputs near a power plant is reasonably doable. That's just logistics. The sheer volume of biomass required to uptake 900 pounds of CO2 per Megawatt hour * 800 MW average plant size =~ 3.5 tons of CO2 per hour is pretty jarring.
Back of the envelope:
Duckweed can grow at about a KG/m^2 and in perfect conditions double its biomass every day. We only run the system during daytime so sunshine is free = 12*3.5tons = 40 tons of CO2, *ASSUME* half of the biomass is carbon so we'll double that = 80 tons of duckweed = 8 hectares or 20 acres.
If you don't go for "at the source" capture and just plant a forest any old place that's convenient then it's a great solution.
Sidebar: I very much hope we figure out very large-scale renewable dirt-cheap carbon capture machinery. It's the easier of the two big-rock problems for terraforming Venus.
(Score: 0) by Anonymous Coward on Thursday January 27 2022, @09:59PM
If you burn at stoichiometry you'd maximise energy production, but you'd also produce significant amounts of very nasty CO. I would expect there to be enough of an excess of O2 to ensure complete combustion.
(Or air could be added to the exhaust to burn it, but CO to CO2 is exothermic. You might as well burn it in the furnace.)
(Score: 1, Insightful) by Anonymous Coward on Thursday January 27 2022, @10:21AM (1 child)
... and then you get the carbon, which you burn again to get some more energy, which you then bubble through this magic solution again, etc, etc.
Not gonna be useful peeps, at least not in the way you imagine it.
(Score: 2) by FatPhil on Thursday January 27 2022, @12:40PM
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