Live data from Hacker News

Robotic 'trees' can turn CO2 into concrete

engadget.com

11–20 of 125 posts

Re: Robotic 'trees' can turn CO2 into concrete

#11
post #6
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?

If the purpose is carbon sequestration, you'll have to include the cost of storing that wood. Indefinitely. Won't be cheap.

Burn them for their energy and keep more coal in the ground seems like a good first step.

Re: Robotic 'trees' can turn CO2 into concrete

#12
post #8

Earlier quoted context omitted.

You'll also need to store it in a way that does not release the wood's CO2 back to the atmosphere by biodegradation.

If you turn it into charcoal you keep most of the carbon locked up in a non-biodegradable form.

If you use it to build homes you provide shelter for more people.

Re: Robotic 'trees' can turn CO2 into concrete

#13
post #12
post #8

Earlier quoted context omitted.

If you turn it into charcoal you keep most of the carbon locked up in a non-biodegradable form.

If you use it to build homes you provide shelter for more people.

Building houses is great, but if you're growing the trees in order to sequestrate carbon, you'd better be reasonably sure a decent proportion of the wood doesn't release it's carbon within the next fifty years. I don't live in a country where wood is a major building material, but I'm imagining that most wood that goes into building gets discarded within a few decades and ends up decomposing or being burnt.

Re: Robotic 'trees' can turn CO2 into concrete

#14
post #6

Earlier quoted context omitted.

If the purpose is carbon sequestration, you'll have to include the cost of storing that wood. Indefinitely. Won't be cheap.

You could sell it, maybe trick people into doing stuff with it, like making buildings or durable goods.

This was interesting: https://www.ted.com/talks/michael_green_why_we_should_build_...

Re: Robotic 'trees' can turn CO2 into concrete

#15
post #11
post #6

Earlier quoted context omitted.

If the purpose is carbon sequestration, you'll have to include the cost of storing that wood. Indefinitely. Won't be cheap.

Burn them for their energy and keep more coal in the ground seems like a good first step.

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!

Re: Robotic 'trees' can turn CO2 into concrete

#16
post #6
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?

If the purpose is carbon sequestration, you'll have to include the cost of storing that wood. Indefinitely. Won't be cheap.

We can bury it until it becomes oil again.

Re: Robotic 'trees' can turn CO2 into concrete

#17
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?

For comparison. A ton of CO2 is roughly the equivalent of a London-NYC roundtrip in the economy class. https://calculator.carbonfootprint.com/calculator.aspx?tab=3

Re: Robotic 'trees' can turn CO2 into concrete

#18
post #6
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?

If the purpose is carbon sequestration, you'll have to include the cost of storing that wood. Indefinitely. Won't be cheap.

Doesn’t a forest tie up the carbon in live trees? A mature forest will be more or less carbon neural but a certain amount of carbon won’t be available to the atmosphere.

Re: Robotic 'trees' can turn CO2 into concrete

#19
post #13
post #12

Earlier quoted context omitted.

If you use it to build homes you provide shelter for more people.

Building houses is great, but if you're growing the trees in order to sequestrate carbon , you'd better be reasonably sure a decent proportion of the wood doesn't release it's carbon within the next fifty years. I don't live in a country where wood is a major building material, but I'm imagining that most wood that goes into building gets discarded within a few decades and ends up decomposing or being burnt.

and wood doesn't make for a building material that can go higher than a few stories.

Re: Robotic 'trees' can turn CO2 into concrete

#20
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?

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.

Post reply on HN