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Intergalacticdespot t1_j6811q7 wrote

Reply to comment by mmmmmmBacon12345 in ELI5: why can't we use electricity to kill microorganisms in small amount of water ? by FreshT3ch

Can we hit co2 with electricity and split it into carbon and oxygen? Seems like that would be a way to reduce CO2 emissions. But not sure how efficient it is or would be. Probably would need some economies of scale to make it viable in the long term. I'm assuming. Both carbon and oxygen have industrial uses so should theoretically count as useful resources. At least at any reasonable scale.

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Chromotron t1_j682dm1 wrote

We could. It would be horribly inefficient, taking way more than other methods, and most importantly, the current methods of power generation would produce way more CO2 than this destroys. And to make it work at all you would need to remove the CO2 from air to get a tank full of it; at which point you could just sequester it, store it underground, or whatever else works and takes much less energy.

Both carbon and oxygen are way easier to get differently, even if energy were free it would not be worth it.

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LowerEntropy t1_j682w1d wrote

You are talking about photosynthesis. That's were all our fossil fuels come from.

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CharsOwnRX-78-2 t1_j685sog wrote

I mean we could do all that.

Or we could just let plants do it for us

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Black_Moons t1_j68dtok wrote

If you take carbon and oxygen, burn them to produce CO2, any process you use to get back carbon and oxygen is by definition going to take as much or more energy then you got from burning it.

Chemical bonds all have a certain energy associated with forming and destroying them that must be paid (or released)

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Busterwasmycat t1_j68m4ql wrote

throw in some water and make sugars. About the same idea as photosynthesis. Of course, electricity-driven reactions don't tend to be all that controlled and there is a lot of competition by other reactions, so costly and inefficient is probably a good description. It is why we don't already do that.

Just making carbon would be a fool's game, because the carbon would want to react back with any free oxygen as soon as it could. generally as a big fire. Sure, we can deal with elemental carbon in lots of ways (it doesn't generally spontaneously combust) but you would have to do something with all that carbon. And, of course, there is the question of how you make the electricity in the first place, ideally not from burning coal or inefficiencies would mean you release more CO2 than you break apart/recover.

But yeah, at least it is an idea. Thinking and coming up with ideas is usually a good thing. Most ideas turn out to have more problems than they solve, but occasionally a good one comes up, so don't stop, don't get discouraged that your idea isn't practical. Hardly alone with that.

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