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Scientists Turn CO2 'Back Into Coal' In Breakthrough Experiment (independent.co.uk)
"Scientists have managed to turn CO2 from a gas back into solid 'coal'," reports The Independent, "in a breakthrough which could potentially help remove the greenhouse gas from the atmosphere."
Long-time Slashdot reader bbsguru shared their report:
The research team led by RMIT University in Melbourne, Australia, developed a new technique using a liquid metal electrolysis method which efficiently converts CO2 from a gas into solid particles of carbon. Published in the journal Nature Communications, the authors say their technology offers an alternative pathway for "safely and permanently" removing CO2 from the atmosphere....
RMIT researcher Dr Torben Daeneke said: "While we can't literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock...." Lead author, Dr Dorna Esrafilzadeh said the carbon produced by the technique could also be used as an electrode.
"A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles," she said. "The process also produces synthetic fuel as a by-product, which could also have industrial applications."
More coverage from Fast Company, Science magazine, and the CBC.
RMIT researcher Dr Torben Daeneke said: "While we can't literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock...." Lead author, Dr Dorna Esrafilzadeh said the carbon produced by the technique could also be used as an electrode.
"A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles," she said. "The process also produces synthetic fuel as a by-product, which could also have industrial applications."
More coverage from Fast Company, Science magazine, and the CBC.
I wonder if it needs energy to do this, an amount of energy greater then the energy produced by burning it in the first place?
If so, why not just use that energy instead? Cut out the middle man.
I read through the paper when the article appeared in the firehose.
Yes, this method uses electrochemical decomposition to change CO2 into various forms of carbon. It essentially undoes the action of burning, and for that you have to replace the energy you got out when the carbon was originally burned.
CO2 is very stable and difficult to decompose - typical methods are inefficient. There are metal catalysts such as Cerium that bring the efficiency up nearer to the Faraday limit, but they tend to get oxidized during the process.
The paper talks about dissolving Cerium metal nanoparticles in molten Gallium at largely room temperature and using that as one electrode in electrochemical deposition against CO2 dissolved in dimethylformamide. The by products are carbon "chunks" that float on the surface of the mixture, and the Cerium is not oxidized because the liquid Gallium is an oxygen-free environment.
So to remove CO2 from the atmosphere you would need an awful lot of energy - the equivalent of all the energy we got from burning the CO2 in the first place. Possibly frickin' huge tracts of solar panels in an area that gets a lot of sun and little human use (Sahara desert, Utah salt flats, or similar) could capture CO2 in an automated process.
(For scale: A square of solar panels 20 miles on a side, working automated for about 100 years would be in the ball-park for reducing CO2 levels to pre-industrialized levels. With a lot of unknowns in the estimate.)
An unrelated question: Can anyone point me to a reference that tells how soluble Nitrogen is in dimethylformamide? I wanted to compare this to the solubility of CO2, and couldn't find that info anywhere.
Please post if you either a) have that information, or b) have a link that has it.
You could literally just flood depleted coal mines with the stuff and leave it.
. . . and what's even more . . . we can hire unemployed coal miners to bury it!
Clearly a win-win on all fronts!
"I used to be a coal miner . . . now I am a coal bury-er!"
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
Actually you can. You burn the trees without oxygen (or very little) and route the resulting gases into your engine.
Really need a truck rather then a car though in Germany during the war, there were even motorcycles equipped to burn wood gas. It's also fairly efficient (need about 1.5 times the fuel compared to gasoline) and clean burning.
Wiki has an article worth reading, https://en.wikipedia.org/wiki/...
https://en.wikipedia.org/wiki/Inverted_totalitarianism
Yeah, but then you raise the oxygen levels, and everybody spontaneously combusts!
The amount we are capable of changing the atmosphere composition is surprisingly small. The current makeup of the atmosphere is:
.4%
Nitrogen: 79%
Oxygen: 21%
Water vapor:
Carbon dioxide: 0.04%
Look how little CO2 there is in the atmosphere. After 200 years of pumping CO2 into the atmosphere, burning as much coal and oil as we can find, the change is smaller than a rounding error in the overall composition of the atmosphere. If we did the same thing with oxygen for decades, trying to put as much oxygen into the atmosphere as we can, after decades we'd still have 21% Oxygen in the atmosphere.
Humanity's capability to change the atmospheric composition is remarkably small (remember that when people talk about geoengineering Mars). The only reason Global Warming is even a thing is because CO2 has an outsized effect on a certain important part of the light spectrum.
"First they came for the slanderers and i said nothing."
Solar and wind power facilities often have a lot of excess output because they aren't able to tune supply to accommodate demand. Using some of that spare power to produce coal seems like a good idea. You can also use it for energy storage. It will be more or less pure carbon without the other toxic things in coal, so burning it again is clean and CO2 neutral. If you set up a solar plant with this process and a coal-fired power plant, you can use carbon for energy storage to even out peaks and troughs in load and sequester any leftover carbon.
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