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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.
No sig today...
Nobody's going to bury coal. If we can make coal from CO2, we're going to burn it.
Converting CO2 into a usable or sequestered state is not a new process. It requires a very large amount of energy, but is essentially 100 year old technology. To suggest it "doesn't work" is incorrect, it "works" perfectly fine and has for decades. The basic chemistry goes back before the 20th century, and biology has obviously done this for a very long time. The problem is that none of this is economical. Economical carbon dioxide reduction would be a huge step toward stabilizing the climate and would make fossil fuels obsolete. This would be true even for high energy density needs like rocket and aviation fuel. (This is a bit of a fantasy, because "economical" is a very hard thing to pin down.)
So far, attempts to lower the cost have failed, and the part that needs the most help is the initial reduction of CO2. There are a lot of approaches to this, including engineering the enzyme RuBisCO (the main way biology reduces CO2), and looking for better chemical catalysts. The big deal with the paper here is demonstration of a better chemical catalyst.
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.
"Mr President, what we have here is a great new coal-based technology. Not only does it involve coal, it actually creates coal in the process. Now, the sooner you sign the bill, the sooner we can start building coal manufacturing plants. Yeah, you heard me. COAL MANUFACTURING PLANTS. How awesome is that? Other presidents settled for mining it, but you will be the president that made coal production a reality."