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Removing CO2 From the Air Efficiently
Canadian scientists have created a device that efficiently removes CO2 from the atmosphere. "The proposed air capture system differs from existing carbon capture and storage technology ... while CCS involves installing equipment at, say, a coal-fired power plant to capture CO2 produced during the coal-burning process, ... air capture machines will be able to literally remove the CO2 present in ambient air everywhere. [The team used] ... a custom-built tower to capture CO2 directly from the air while requiring less than 100 kilowatt-hours of electricity per tonne of carbon dioxide."
This may be Bad Math, but... The article says, "The tower unit was able to capture the equivalent of approximately 20 tonnes per year of CO2 on a single square metre of scrubbing material -- which amounts to the average level of emissions produced by one person each year in North America." A page I dug up claims a single tree removes "on average 50 pounds (22 kg) of carbon dioxide annually over 40 years."
The scrubber sounds pretty effective. No waiting for it to grow, and it's more space-efficient, which is good for cities and industrialized areas.
This may be Bad Math, but... The article says, "The tower unit was able to capture the equivalent of approximately 20 tonnes per year of CO2 on a single square metre of scrubbing material -- which amounts to the average level of emissions produced by one person each year in North America." A page I dug up [carbonify.com] claims a single tree removes "on average 50 pounds (22 kg) of carbon dioxide annually over 40 years."
The scrubber sounds pretty effective. No waiting for it to grow, and it's more space-efficient, which is good for cities and industrialized areas.
Yep, and we only ned 450,000,000 of them to keep up with the carbon output of the denizens of North America.
It's not clear from the wording whether that includes the output of North American industry, or just the habits of individuals.
This extraction of CO2 from the atmosphere is all well and good, but are there any reliable and cost-effective ways to store it or dispose of it?
And now the catch ... while this tower is beyond inefficient :
Coal produces 2.117 pounds per kwh.
= 0.000960255047 tonne per kwh.
= 1041 kwh per tonne Co2
This needs about 10% of that power, combined with some 15% transmission loss, and the fact that this is a lower bound over time (obviously if we lower athmospheric co2 this cost will raise).
That means we need 23% or about 1/4th of total energy to merely break even. Petroleum and gas aren't that much better, and aren't feasible over even the medium term anymore. To actually make a difference we'd need 50% of all energy produced, which means our generating capacity needs to rise by 100% (and not 50% because if we raise it by 50% we'd have 1.5 times the energy which would be divided into 0.75 for carbon nonsense and 0.75 for us. So we'd need 200% of the energy making it 1 unit for us, and 1 unit for co2 nonsense).
That's not exactly good news, is it ? It gets worse.
Trees are much worse in efficiency than this. Yes, they do produce their own energy. They're however 2% efficient solar panels (so in reality a tree presents lost energy, in that a solar panel could have been standing where the tree stood and produce about 20 TIMES more energy, making these towers more efficient even if trees were 100% efficient chemical machines, since that would only give them 5% of the efficiency of the solar panels).
Well trees do about 650 kg per tree per year. Needless to say this is beyond pitiful. Using solar panels to power a tower like this would replace a forest in about 100 square meters. Combine this with the need to double generating capacity in order to make the towers work and you'll see exactly where this would be going in the real world.
Yes, but nature already has a robust way of dealing with it's own carbon sink. Having tons of liquified CO2 sitting around does not sound like a long term solution. While it's a clever technological fix, it does not solve the fundamental problem Kind of like puting ice on a febrile patient instead of giving them antibiotics to kill the infection.
..........FULL STOP.
They are, the only downside is that the oceans are gradually becoming acidic (carbonic acid) from all that CO2 being produced.
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