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Comment by josemanuel | Hacker News Reader

Will we ever be able to extract CO2 from the atmosphere by mimicking the process that goes on in trees? And perhaps speeding it up or increasing the density? Is that even feasible? Disclaimer I know very little about botany/biology/chemistry.. so if the question may be off.

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You already can, plant trees or other plants or use algae farms etc. Then sequester the carbon into something that will not decay quickly and release it back.

The problem is always scale, so any artificial mechanism that would mimic this would have to many orders of magnitude more efficient than using existing biological solutions to be viable as biological solutions are simpler and cheaper to do at any scale.

We can, but you have to supply energy to do it; and since we still burn carbon for energy, it's not worth extracting CO2 since if you've got the spare energy for that, it's far more efficient to simply burn less coal.

Having a thing that makes nice big carbon structures from atmospheric carbon would be nifty, though. People use wood for all sorts of things; being able to plop a "seed" some place and come back in a couple seasons and have a structure made from sunlight, ambient minerals, and co2 from the air -- would be super cool.

I still can't quite convince my kids or other people I mention it to -- hey -- this tree? Almost all of it comes from air and sunlight. I'm lucky to live near some really big, really old trees; they're quite obviously magical.

Yes, It really does boggle the mind when you realize that these large trees were mostly manufactured from air. Just a few trace elements sucked out of the ground added in.

So power it with wind or nuclear?

If you have x MWh of wind or nuclear, then using that for CO2 conversion to C is worthless and harmful, since the obvious alternative is to send the same MWh to consumers, replacing x MWh produced by current coal electricity plants, as that would reduce the CO2 emissions at least 2-3 times more than what you could capture with that energy. As long as there's at least a single "CO2 conversion machine" and at least a single coal plant, shutting down an equal quantity of both is a good deal for both environment and economy.

I mean, in practice there's a single pool of energy for each region and even those are connected in various ways (e.g. shipping of fuels), so "power A with X and B with Y" is just fiction, all energy consumption is powered with all energy generation, and the marginal consumption is (currently) fueled by fossil fuels, which vary how much is burnt based on how much consumption is not filled by nuclear/solar/wind.

It might make sense when you need the energy storage density. For example for jet fuel.

Quite a lot of people are researching this. For a Starting point, have a look at the 'harnessing plants' initiative at the Salk Institute:

https://www.salk.edu/harnessing-plants-initiative/

If the Netflix show Unstable is a reliable source, a hyperdense "biomass" or recaptured carbon cement is the future. ;) it's quite enjoyable - very silly.

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