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Robotic 'trees' can turn CO2 into concrete

engadget.com

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Re: Robotic 'trees' can turn CO2 into concrete

#51

Post by hendryau »

konschubert wrote: post #48
hendryau wrote: post #35

If only someone would invent something that could be stuck into the ground that would just suck CO2 out of the air. Hmmm...

... and never release it again, unlike trees.

It doesn't need to be stored forever. As trees die and are farmed, they are replaced by new ones. Large forests in conjunction with reduced CO2 emission and renewables is the best answer to climate change, not some band-aid to mask the problem.

Land usage is abysmal, and there's a lot of waste. Stop cutting down trees and stop urban sprawl.

As a side effect we might just be able to stop a mass extinction due to loss of habitat.

Re: Robotic 'trees' can turn CO2 into concrete

#52

Post by tomatotomato37 »

village-idiot wrote: post #25
ValleyOfTheMtns wrote: post #23

Earlier quoted context omitted.

I think all these comments about wood eventually releasing the carbon back into the atmosphere are missing the point. We don't need to capture it forever, we just need to get the ratio between carbon output and input under control in the next couple of decades. That should give us enough time to come up with longer term and sustainable ways of our planet... until we encounter the next problem, and so on. "Solutions"…

You could also just bury it. That’s effectively putting coal back into the ground.

Building with it is a lot more effective as there's economic incentive in preventing it from decaying back to base elements

Re: Robotic 'trees' can turn CO2 into concrete

#53

Post by bluGill »

Maakuth wrote: post #34
ValleyOfTheMtns wrote: post #23

Earlier quoted context omitted.

I think all these comments about wood eventually releasing the carbon back into the atmosphere are missing the point. We don't need to capture it forever, we just need to get the ratio between carbon output and input under control in the next couple of decades. That should give us enough time to come up with longer term and sustainable ways of our planet... until we encounter the next problem, and so on. "Solutions"…

And if we could forest up some places where there's no forest at the moment, a large fraction of that carbon would be tied up there basically as long as that forest stays up.

For the most part we have been doing that for decades. The US has a lot more forests now that 100 years ago (the height of logging).

It is hard to know for sure, but there is reason to believe we have more trees than even 1000 years ago. We are not allowing forest fires to clean out the dead trees which allows them to build up. This is a negative, regular forest fires burn colder and leave a lot of charcoal in the soil, while the less regular forest fires burn hotter and so release that carbon back into the atmosphere.

Re: Robotic 'trees' can turn CO2 into concrete

#54

Post by czbond »

bluGill wrote: post #53
Maakuth wrote: post #34

Earlier quoted context omitted.

And if we could forest up some places where there's no forest at the moment, a large fraction of that carbon would be tied up there basically as long as that forest stays up.

For the most part we have been doing that for decades. The US has a lot more forests now that 100 years ago (the height of logging). It is hard to know for sure, but there is reason to believe we have more trees than even 1000 years ago. We are not allowing forest fires to clean out the dead trees which allows them to build up. This is a negative, regular forest fires burn colder and leave a lot of charcoal in the so…

So I didn't believe this statement (eg: more trees than 100 years ago), bc I'm the skeptical sort. You're right though. I looked at "US Forest Resource Facts..." page 8 and the numbers are higher for millions of acres across different types. https://www.fia.fs.fed.us/library/brochures/docs/2012/Forest...

Re: Robotic 'trees' can turn CO2 into concrete

#55

Post by village-idiot »

tomatotomato37 wrote: post #52
village-idiot wrote: post #25

Earlier quoted context omitted.

You could also just bury it. That’s effectively putting coal back into the ground.

Building with it is a lot more effective as there's economic incentive in preventing it from decaying back to base elements

Good point.

Re: Robotic 'trees' can turn CO2 into concrete

#56

Post by raverbashing »

innocentfelon wrote: post #49
raverbashing wrote: post #33

Earlier quoted context omitted.

Read the page of the company doing it, that's not exactly what they're doing (which you correctly point out it would be pointless) - http://www.blueplanet-ltd.com/

I read it again, twice. That is exactly what they’re doing. Their starting material is CO2-source cement, not some natural “rock”. Counterexamples are substantially more helpful than downvotes.

It seems they're not replacing the quicklime, but the gravel. The left column is confusing, the right column is better.

> A rock particle is coated with our synthetic limestone, forming a carbon-sequestering coating that is 44% by mass CO2.

That's where the CO2 goes, not in curing the CaO

Re: Robotic 'trees' can turn CO2 into concrete

#57

Post by czbond »

Gustomaximus wrote: post #29
dithering wrote: post #20

Earlier quoted context omitted.

There's got to be something that grows faster, and is easier to sequestrate, than trees. Bamboo, maybe? Seaweed? Algae? Dry it off in salt pans and dump it in the deep, cold ocean? That's just dumping more carbon into one of our natural sinks, I think, rather than trying to create a new artificial sink. Even just using it as fertilizer has got to be an improvement over using inorganic fertilizers.

Iron fertilization https://en.wikipedia.org/wiki/Iron_fertilization

Thank you for posting this - the link is very interesting.

Re: Robotic 'trees' can turn CO2 into concrete

#58

Post by stronglikedan »

xupybd wrote: post #38

“Climate change is killing our planet“ I wouldn’t go that far. Sure it’s making it less hospitable for us and much of the complex life here. But life will go on without us.

I guess you're being downvoted for pedantry, because your statements are accurate.

Re: Robotic 'trees' can turn CO2 into concrete

#59

Post by DanBC »

Cthulhu_ wrote: post #39
chii wrote: post #15

Earlier quoted context omitted.

but wood burns so much more dirtier than coal, and leaves much more uncombusted remains that then have to clean. The problem is energy (or lack thereof) - and so why not solve it directly by adding ever larger sources of renewables, which eventually will becomes enough that there's no need to burn any fossil fuels!

Is that so? Even when ground fine and with enough oxygen? For local heating, I heard good things about the efficiency and cleanliness of wood pellet heaters.

Did you hear those things from either people trying to sell you a wood pellet burner, or people who've just spent a lot of money money on a wood pellet burner?

Re: Robotic 'trees' can turn CO2 into concrete

#60

Post by hodgesrm »

6nf wrote: post #2

Every time one of these articles come up I wonder about the price per tonne of CO2 removed by simply growing wood and not burning it. I'm not really sure what that price is, but it seems to be around $20-$40 per tonne? Does anyone have a more accurate number?

Taking your estimated numbers it's interesting to add that cost to the price of fuel and see where it gets you. A gallon of gasoline on average produces about 20 pounds of C02, so 100 gallons gives a ton of CO2.

You can then calculate the cost of adding capture to gas prices.

* At $200 per ton gas prices increase $2 per gallon.

* At $100 the increase is $1 per gallon.

* At $40 the increase is $0.40.

* At $20 the increase is $0.20.

It looks as if we need to get numbers into the low tens of dollars for this to be feasible on a widespread basis.

The numbers are optimistic since they don't cover the CO2 from refining and transport. That seems to be around $2 but it's somewhat hard to get accurate values.

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