3 ms·
Speaking as a geophysicist who worked in the research end of the Australian mining industry, just the fracturing of rock itself already consumes a LOT of energy
by fghorow 3y ago
Speaking as a geophysicist who worked in the research end of the Australian mining industry, just the fracturing of rock itself already consumes a LOT of energy.
Thermodynamically, think of all the fracture surface area being created. If you ever studied fracture mechanics, it's essentially the same as requiring that the elastic potential energy being released by creation of new fracture surface needs to come via work from somewhere (Griffith theory).
I think this approach needs significant "lifecycle analysis" before it can be declared to be a net positive.
Just my two cents.
(Edit: typo.)
- crazygringo 3y agoBut if I'm understanding correctly, that's only a one-time cost. Then the already-fractured rocks are used (forever?) to absorb CO2, heat to release, and repeat. (Do they somehow lose that capacity over time?) But also this seems to be assuming that all the energy comes from renewables in the first place, including the energy for crushing the rocks...
- eppp 3y agoWe are also in need of sand for concrete. Can we not crush the rock until suitable for concrete and then entomb it in buildings and structures?
- ttyprintk 3y agoOlivine-supplemented cement actually absorbs CO2 in low-pH environments, healing cracks.
- tuatoru 3y agoThere's been quite a bit of work on enhanced weathering (google the phrase). Even powered by coal and diesel, it's entirely feasible at global scale, provided we are willing to blanket a fairly large area of sea with rock flour. Heirloom's approach, turn limestone into quicklime and then let the quicklime turn itself back into limestone, is different, and I don't know how the energy economics work out for it.
- MrVandemar 3y ago> provided we are willing to blanket a fairly large area of sea with rock flour That sounds like a different type of disaster.
- diogenes4 3y agoThe ocean is a very large place, and much of the floor is nearly barren of life (compared to coastal waters anyway, and certainly in terms of biomass). Furthermore benthic storms already cause a great deal of turbulence on the bottom; i don't think problems are obvious. Granted, i have similar concerns about efficiency, but we need any wins we can find.
- FreshStart 3y agoWater it. Freeze it? Sounds not very carbon intensive if done right?
- fooker 3y agoYeah, this strikes me as the kind of tech that becomes viable with unlimited free energy. If/when fusion becomes harnessed I think we can expect to see a large variety of impractical tech like this suddenly becoming mainstream.