It should be blatantly obvious just from basic thermodynamics that carbon capture cannot ever possibly be cheaper than not burning the fossil fuels in the first place.
Thermodynamics tells us it takes exactly as much to put the carbon back in as you got out of it by taking it out. So best case scenario we double the price of energy (which also means increasing the price of everything by a lot due to production costs increasing with higher energy costs) and capture as much carbon as we release.
However this is the real world and in the real world processes aren’t 100% efficient. Even a hyper efficient combustion engine is only like 40% efficient in converting the stored energy into a usable form. Our carbon capture techniques suck hard at the moment, but say we improve the tech. That means in the real world we would need to increase energy costs by 4-6 times. Which probably means increasing the pricing of everything by a factor of 10.
That shows just how unsustainable our current consume heavy economy actually is. And that is assuming we have a way of capturing carbon out of the atmosphere in a way that’s both efficient and long term. And do this in time before the processes we’ve set into motion spiral out of control.
And like you say, it puts into perspective how big of a win not releasing the carbon is.
Thermodynamics tells us it takes exactly as much to put the carbon back in as you got out of it by taking it out.
Thermo says it takes at least as much energy to put the carbon back in. If the process is done in a reversible way (reversible in the thermo sense), it would take exactly as much energy. And since real-world spontaneous processes are never reversible, it will always have energy lost.
I know you said down below that energy is lost, but I’m just saying that from a physics POV, there is not a possible way that reactions can ever be done in a reversible way, so it’s not like there’s even a possible theoretical world where you could approach 100% efficiency.
By definition, you will always pay the heat tax to the second law of thermodynamics.
To be extremely pedantic, operations on physical systems can be performed and perfectly reversed without loss of energy, but you couldn’t ever extract anything anywhere along the way - not even direct evidence that it happened. Our models predict that this happens literally all the time in quantum mechanics.
Edit: fun fact: this prediction is actually central to what makes quantum computers work.
Caveat: it’s been a few weeks since I read up on this so I’m fuzzy.
It’s also worth noting we will need carbon capture to actually keep catastrophic global warming from occurring. Even if we cut emissions to 0 by 2035 we’re blowing past 1.5C and maybe even 2 as I recall.
Doesn’t mean that we can fix the climate with CC, but we can’t fix it without.
There’s nothing thermodynamically wrong with burning methane, releasing the water, and putting the CO2 back underground. Sequestration does not require un-oxidizing the carbon.
Though if we’re going to bury harmful waste underground, nuclear power reduces the quantity of waste by a factor of a million.
There’s nothing thermodynamically wrong with burning methane, releasing the water, and putting the CO2 back underground. Sequestration does not require un-oxidizing the carbon.
Maaaaybe if the CO2 is captured at the point source of the methane burner. But if you’ve already let it disperse into the atmosphere, forget about it ever making sense to try to compensate for that huge increase in entropy by collecting and re-concentrating it.
No, definitely not cheaper. Also not a viable alternative to not burning.
That said, we’re probably going to need it eventually to try to undo even a small amount of the damage we’ve done
Problem is that it’s not being used to undo the damage - it’s being used to justify doing more.
Solar - even with batteries is significantly cheaper under almost any circumstances… Location, scale, photovoltaics vs thermal - it only tends to affect how much cheaper. Wind is cheaper too, but less so on average.
Funny how pulling power out of thin air is cheaper and better than digging it out of the ground, shipping it all over the place and burning it.
I do wonder if it could be beneficial for the case of excess solar/wind/etc production. Obviously, renewable infrastructure, storage capacity, and efficient transfer should be prioritized, but I can see there being a place for carbon capture, as long as it’s not to the detriment of something better.
Edit: but i do totally agree with you that using fossil fuels to power carbon capture is completely idiotic and makes no sense
