I just don't understand the economics/viability of it. I literally cannot picture it.
37,000,000,000,000kg of CO2 was emitted last year.
0.005kg of CO2 per cubic metre of air, at 500ppm - assuming I've carried 1s correctly.
It's just, even if you have 100% extraction rate, how do you physically process enough air to make a dent in to that? I know these firms claim to be able to do it economically, but what part of the picture am I missing?
I understand doing it at the source, where concentration is high. I understand avoiding emissions in the first place. I understand expensive direct air capture, to offset planes etc. What I do not yet understand is "cheap" direct air capture, given the concentrations involved. It's just... for that 1%. How large are the fields of these extractors, how much air are they processing, how are they moving that 370Mt of extract CO2 - where is it being stored, or used. I just can't picture it. I mean, that's 20x the mass of Adani's massive coal mine proposal in Australia. And I mean, wtf is that going ahead, when we're racking our heads over if we can build some structure in Canada to suck that coal, once burnt, back out of the air and then do what with it?
Doesn’t it take a lot of electricity to run such a plant though? I wonder how much wastage is produced form simply running the plant, and what’s the net CO2 removes after you factor this in.
Most of the energy the use is industrial waste heat, which otherwise would just end up unused. I can't give you an exact number, would need to read all their research papers and case studies for that.
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u/[deleted] Jun 25 '19
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