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Direct air capture: our technology to capture CO₂

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Re: Direct air capture: our technology to capture CO₂

#21

Post by usrusr »

thx-2718 wrote: post #3

"Our plants require less land than other techniques. E.g., on a land area of 0.42 acres, our Orca plant can remove 4,000 tons of CO₂ from the air every year, which is almost 1,000 times more effective than trees. The same land would host around 220 trees with an estimated capacity of 22kg each" How much land, in solar panels for example, is required to power this? Also what's the carbon waste that this generates? Is…

And the land for the solar panels that substitute the energy you'd harvest from the trees while turning them into highly concentrated CO2 for storage. And the land for the batteries you'd have to add to achieve the same dispatchability as the burn trees (or faster-growing plants!) and work on that CO2 alternative. DAC is a joke.

Re: Direct air capture: our technology to capture CO₂

#22

Post by fwlr »

Their subscription page is currently offering a rate of about $1.35 USD per kg of CO2 removed, and they promise to complete your order within 6 years. It’s nice to have some hard numbers on end-stage or “gold standard” CO2 offset (no doubt there are cheaper carbon credit options but this directly solves the hardest problem, CO2 that’s diffused into the atmosphere.

Re: Direct air capture: our technology to capture CO₂

#23

Post by A_D_E_P_T »

themanmaran wrote: post #5
thx-2718 wrote: post #3

"Our plants require less land than other techniques. E.g., on a land area of 0.42 acres, our Orca plant can remove 4,000 tons of CO₂ from the air every year, which is almost 1,000 times more effective than trees. The same land would host around 220 trees with an estimated capacity of 22kg each" How much land, in solar panels for example, is required to power this? Also what's the carbon waste that this generates? Is…

> Also what's the carbon waste that this generates? Is there a synergistic use for it? I've wondered the same about these carbon capture plants. Is this literally just elemental carbon in some kind of dust/sand at the end of the day? Could this be a raw material input for carbon fiber production?

Elemental carbon is a valuable industrial material -- and even low-quality carbon, like "carbon black" soot, ain't cheap!

Nah, separating carbon from oxygen in CO2 and CO is too expensive and energetically demanding.

To simplify things a little bit, what they do here is inject CO2 into water at high pressure, which results in highly acidic H2CO3. They then pump H2CO3 into basalt rock, which chemically reacts with the acid -- in fact, it is partially dissolved. Then there's a second stage reaction between the partially-dissolved basalt and the remnant HCO3-, and it recrystallizes as carbonate minerals, e.g. FeCO3 or CaCO3.

So they're turning CO2 into a liquid acid, and then injecting it into rock where it reacts with basalt and crystallizes as carbonates.

Re: Direct air capture: our technology to capture CO₂

#24

Post by usrusr »

shipman05 wrote: post #10
thx-2718 wrote: post #3

"Our plants require less land than other techniques. E.g., on a land area of 0.42 acres, our Orca plant can remove 4,000 tons of CO₂ from the air every year, which is almost 1,000 times more effective than trees. The same land would host around 220 trees with an estimated capacity of 22kg each" How much land, in solar panels for example, is required to power this? Also what's the carbon waste that this generates? Is…

> How much land, in solar panels for example, is required to power this? It says "The CO₂ can then be safely and permanently stored underground by our storage partners — Carbfix in Iceland." So my assumption was that the collectors are located there as well and using Iceland's abundant geothermal electricity.

In other words: it definitely will not scale.

Re: Direct air capture: our technology to capture CO₂

#25

Post by lom »

The article says that the plant can remove 4000 tons of co2 per year. If you look up what’s the equivalent of that, just under 900 average vehicles less on the road per year.

Or the equivalent co2 savings of building one wind turbine to replace polluting forms of energy production.

What a joke.

Re: Direct air capture: our technology to capture CO₂

#26

Post by bradleyjg »

samatman wrote: post #19
bradleyjg wrote: post #12

Earlier quoted context omitted.

It’s hard for me to believe that the answer isn’t biological given the whole self replication thing.

The Industrial Revolution is a history of various industrial processes outcompeting biology within a narrow boundary. Cars pull more than any horse, trains as well, an airplane flies faster and with much more cargo than any bird, and the industrial production of nitrogen is faster than bat guano. CO2 fixation might also follow this curve, in fact, as a technology in isolation that's what I would bet on. Economics asi…

As a technology in isolation, sure. But something like iron seeding, assuming it works, would be orders of magnitude cheaper because most of the work is being done by algae and they don’t have to be paid.

I don’t think horses are particularly similar, but nitrogen fixation in the fertilize vs crop rotation case gets closer.

Re: Direct air capture: our technology to capture CO₂

#27

Post by michaelt »

kmeisthax wrote: post #6

Lots of information about land usage, not so much about power usage beyond "it'll run on renewables". I imagine their cost benefit analysis boils down to "governments will pay for it to not die", which sounds rather optimistic.

They can also get cash from big oil and car companies, who will offer this to regulators as an argument to let them keep polluting.

For this application it doesn’t matter if it works or not.

Re: Direct air capture: our technology to capture CO₂

#29

Post by rtpg »

lom wrote: post #25

The article says that the plant can remove 4000 tons of co2 per year. If you look up what’s the equivalent of that, just under 900 average vehicles less on the road per year. Or the equivalent co2 savings of building one wind turbine to replace polluting forms of energy production. What a joke.

If the vehicle numbers were a _bit_ better, there might be an idea behind forcing car companies to build one for each couple thousand vehicles it puts out into the world. But 900... yeesh.

Re: Direct air capture: our technology to capture CO₂

#30

Post by yodelshady »

thx-2718 wrote: post #3

"Our plants require less land than other techniques. E.g., on a land area of 0.42 acres, our Orca plant can remove 4,000 tons of CO₂ from the air every year, which is almost 1,000 times more effective than trees. The same land would host around 220 trees with an estimated capacity of 22kg each" How much land, in solar panels for example, is required to power this? Also what's the carbon waste that this generates? Is…

It's such an easy, relevant question to ask that it boggles the mind that investors don't have their own engineers to ask it. I know you're money people not tech, but how do you know you're not being ripped off if you can't check figures that basic?

Anyway, apparently 3 MWh/tonne is a not-unrealistic claim, so they're only demanding 1.5 MW (on average, though if solar-powered it would make sense to oversize) and a km2 of solar panels could reasonably generate 50-100 MW on average (this is conservative for most places, though not for Iceland). A km2 of tress, by their calculations, gets 1,000 tonnes, so DAC comes out ahead, although you're right to observe that trees do have a synergistic use for the carbon they capture.

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