3 ms·
What’s the added co2 cost of grinding rocks and transporting them to farms?
by fractal618 6y ago
What’s the added co2 cost of grinding rocks and transporting them to farms?
- gnicholas 6y agoThere are apparently already stockpiles of basalt dust, though if this were done at a global scale we might need to grind more. I assume the authors accounted for the carbon footprint of distribution, since this was peer-reviewed and published in Nature.
- sacred_numbers 6y agoGrinding rocks to 200 mesh (74 microns) takes about 20 Kwh per ton. Using 100% coal electricity that would lead to 20 kg CO2. Transporting a ton of cargo by truck 200 km creates about 22 kg of CO2. Basalt seems to remove less CO2 per ton than other minerals, but I'm guessing it would still be more than 100 kg CO2 removed per ton of basalt (perhaps much more). Olivine (see Project Vesta) and serpentine are quite efficient; they remove about 1.2 tons of CO2 per ton. Basalt is extremely common, though, so it might win out in some circumstances.