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Author Topic: is it possible to electrolyse CO2?  (Read 8045 times)

Offline Graham_Potter

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is it possible to electrolyse CO2?
« on: 23/10/2008 11:24:49 »
Graham_Potter asked the Naked Scientists:
 
In a recent newbielink:http://www.thenakedscientists.com/HTML/podcasts/show/2008.08.03/ [nonactive], they talked of storing carbon dioxide under ground as there is too much about.

As carbon dioxide is CO2, is there no way we have of splitting it into its components carbon and oxygen in the same way that passing an electric current through water (H2O) produces hydrogen and oxygen? Is there no CO2 converter or have plants cracked something humans can't?

Graham Potter
Cambridge
England

What do you think?


 

lyner

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is it possible to electrolyse CO2?
« Reply #1 on: 27/10/2008 17:05:11 »
What would be the point?
A lot of energy would be required to 'decompose' the CO2. This would negate the energy which was obtained from burning the original Carbon.  You'd need to get that energy from somewhere else.
It's a downhill process, I'm afraid. The same applies to splitting water to get hydrogen and oxygen. There's no such thing as a free lunch.

Of course plants have 'cracked it'. They use the energy in sunlight to produce their food - which is what we eat and the plants use. We'd not be here if it weren't for the plants.
« Last Edit: 27/10/2008 17:09:05 by sophiecentaur »
 

Offline Bored chemist

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is it possible to electrolyse CO2?
« Reply #2 on: 27/10/2008 18:25:55 »
Incidemtally, the simple answer is no. Liquid CO2 doesn't conduct and CO2 in solution in water acts as a weak acid- the products at the electrodes are H2 and O2.
You might be able to do this in some strange solvent, but I doubt it.

The only reason I can think of to do this would be if (big if) we were able to get a massive source of cheap energy and use it to strip CO2 from the air to reduce the greenhouse effect.
 

lyner

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is it possible to electrolyse CO2?
« Reply #3 on: 28/10/2008 10:59:06 »
How about at high temperatures, sY, with very high voltages applied directly to the CO2?
 

Offline Bored chemist

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is it possible to electrolyse CO2?
« Reply #4 on: 28/10/2008 18:36:36 »
Very high voltages are not a feature of electrolysis.
 

lyner

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is it possible to electrolyse CO2?
« Reply #5 on: 28/10/2008 19:49:09 »
Oh. Fair enough. I suppose you need to form ions for it to happen.
 

Offline Graham_Potter

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is it possible to electrolyse CO2?
« Reply #6 on: 02/11/2008 11:12:03 »
Ok people thanks for your attempts to answer the question but you all seem hung up on electrolysis, The question was not about changing CO2 to its elements by electricity but by any means known to man, If you missed the programme the speaker was referring to storing CO2 underground deep underground and at that depth it would stay in liquid form due to depth and pressure, thatís what he said, This was to reduce the amount of CO2 in the atmosphere and hence reduce the green house effect. So I thought why store it canít we convert it. Oxygen which is what seems to be lacking in this world
 

Offline Bored chemist

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is it possible to electrolyse CO2?
« Reply #7 on: 02/11/2008 14:28:24 »
Ok people thanks for your attempts to answer the question but you all seem hung up on electrolysis,
That may have been something to do with the title of the thread.
We don't have a shortage of oxygen, we have a shortage of (easily used, nicely packaged) energy.
 

Offline srobert

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is it possible to electrolyse CO2?
« Reply #8 on: 11/11/2008 19:46:03 »
Ok people thanks for your attempts to answer the question but you all seem hung up on electrolysis, The question was not about changing CO2 to its elements by electricity but by any means known to man, If you missed the programme the speaker was referring to storing CO2 underground deep underground and at that depth it would stay in liquid form due to depth and pressure, that’s what he said, This was to reduce the amount of CO2 in the atmosphere and hence reduce the green house effect. So I thought why store it can’t we convert it. Oxygen which is what seems to be lacking in this world

Yes you can.To link this thread to another on here, burning magnesium in a CO2 atmosphere will seperate the carbon  and oxygen as the magnesium is more reactive than the carbon. Of course the you're left with Ganesium oxide not free oxygen.
 

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is it possible to electrolyse CO2?
« Reply #8 on: 11/11/2008 19:46:03 »

 

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