Re:Robotic 'trees' can turn CO2 into concrete
by raverbashing on Tuesday September 11, 2018 @08:20AM
(#17959011)
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/
Re:Robotic 'trees' can turn CO2 into concrete
by innocentfelon on Tuesday September 11, 2018 @10:25AM
(#17959975)
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.
Re:Robotic 'trees' can turn CO2 into concrete
by raverbashing on Tuesday September 11, 2018 @10:56AM
(#17960270)
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
by 08-15 on Tuesday September 11, 2018 @12:08PM
(#17960990)
But where does the Ca come from? Obviously not from limestone...
Re:Robotic 'trees' can turn CO2 into concrete
by liveoneggs on Tuesday September 11, 2018 @11:38AM
(#17960684)
so you're claiming this isn't a functional perpetual motion machine that (bonus) outputs useful building materials? come on
When you make cement, you heat up natural CaCO3 -> CaO + CO2. The heat itself also requires combustion, so more CO2.
Some cements have perhaps 10% CaCO3 added to their mix. It’s not so much desirable as cheap filler.
What the media fails to realize is pumping CO2 into curing cement reverses the CaO reaction. In other words, every CO2 molecule you capture releases 2 or more. You’d be better off using less CaO and more CaCO3 to begin with.