Re:Robotic 'trees' can turn CO2 into concrete
by 6nf on Thursday September 13, 2018 @12:19AM
(#17975985)
Yea that's what I mean. It seems that cheap fast growing timber can be purchased for $20 per tonne. Dry timber is about 50% carbon and CO2 is about 30% carbon, so that means we can grow CO2 out of the atmosphere at a price of around $12 a tonne. We'll need to stack the wood somewhere but I don't think that will be terribly expensive.
Re:Robotic 'trees' can turn CO2 into concrete
by hodgesrm on Friday September 14, 2018 @12:40PM
(#17988698)
The problem we're seeing in the US West is that wood has an increasing tendency to burn up. For this to work at least where I live we need to reforest using species that grow fast and are also relatively fire-resistant.
It seems people have been thinking of the fire-resistant part for a while: http://blog.davey.com/2017/08/fireproof-landscapes-with-fire....
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.