> The company spreads crushed basalt on small farms in India and Africa. The silica-rich volcanic rock improves the quality of the soil for the crops but also helps remove carbon dioxide from the air. It does this by reacting with dissolved CO2 in the soil’s water, turning it into bicarbonate ions and preventing it from returning to the atmosphere
> Carbon dioxide in the air dissolves into rainwater, forming carbonic acid. As rocks are worn away (or weathered) by this slightly acidic water, silicate minerals in the rock dissolve. This releases calcium, magnesium, and other positively charged ions called cations. These cations react with carbonic acid in the water, forming bicarbonate ions.
Here is a dumb question: Would the basalt capture CO2 more effectively if released into the atmosphere or into rain storms?
AFAIK cationic calcium, et. al., combine with dissolved CO2 forming carbonates which having low water solubility eventually precipitate out of solution. Area with "hard water" often have issues with buildup of scale in water pipes. The scale is mainly calcium carbonate and sulfate.
This is normally a gradual process requiring ample moisture. Releasing finely ground rock into the air wouldn't likely be effective. For one thing, such dispersal would be rather dilute. IOW the dispersion wouldn't reliably react with CO3 ions before settling out of the air. Another consideration is the salicaceous content of the rock being a potential health hazard.
The original idea of adding crushed rock to water-containing soil is logically the best way for the project to accomplish its goals.
> Would the basalt capture CO2 more effectively if released into the atmosphere or into rain storms?
Guess: it would do so more quickly, but not necessarily more effectively in the long run to the extent it balances the energy required to loft it. (Even if it's all green. You could just that energy to grind and distribute more basalt to the ground.)
You’d need to, at the very least, make it into a powder or it would just fall to the ground anyway. That, in turn, would require you to crush basalt, which is pretty tough and, importantly, energy intensive. And you wouldn’t have any agricultural benefits either.
You can still do both things but if the primary goal is to capture carbon my question is if it would capture more if released in the atmosphere (by planes or similar).
You'd want to crush it much more finely for it to have a chance to actually capture anything while in the air, requiring more energy input and causing breathing hazards due to the fine particulates, not to mention staining everything it rains on with the fine basalt.
You could release it extremely high such that it stays suspended a bit longer, but then you'd waste even more energy getting it up there.
I've been wondering for a while now about the viability of asteroid/lunar mining that involves returning the payload of rare earth minerals or titanium in flying wing shaped return vehicles that are wrapped in some sort of mineral that ablates in the atmosphere while absorbing CO2 like this stuff does.
The idea is that we could both eliminate the Earth based pollution associated with mining while sequestering co2 previously emitted by terrestrial mining at the same time.
> The company spreads crushed basalt on small farms in India and Africa. The silica-rich volcanic rock improves the quality of the soil for the crops but also helps remove carbon dioxide from the air. It does this by reacting with dissolved CO2 in the soil’s water, turning it into bicarbonate ions and preventing it from returning to the atmosphere
> Carbon dioxide in the air dissolves into rainwater, forming carbonic acid. As rocks are worn away (or weathered) by this slightly acidic water, silicate minerals in the rock dissolve. This releases calcium, magnesium, and other positively charged ions called cations. These cations react with carbonic acid in the water, forming bicarbonate ions.
Here is a dumb question: Would the basalt capture CO2 more effectively if released into the atmosphere or into rain storms?
AFAIK cationic calcium, et. al., combine with dissolved CO2 forming carbonates which having low water solubility eventually precipitate out of solution. Area with "hard water" often have issues with buildup of scale in water pipes. The scale is mainly calcium carbonate and sulfate.
This is normally a gradual process requiring ample moisture. Releasing finely ground rock into the air wouldn't likely be effective. For one thing, such dispersal would be rather dilute. IOW the dispersion wouldn't reliably react with CO3 ions before settling out of the air. Another consideration is the salicaceous content of the rock being a potential health hazard.
The original idea of adding crushed rock to water-containing soil is logically the best way for the project to accomplish its goals.
> Would the basalt capture CO2 more effectively if released into the atmosphere or into rain storms?
Guess: it would do so more quickly, but not necessarily more effectively in the long run to the extent it balances the energy required to loft it. (Even if it's all green. You could just that energy to grind and distribute more basalt to the ground.)
You’d need to, at the very least, make it into a powder or it would just fall to the ground anyway. That, in turn, would require you to crush basalt, which is pretty tough and, importantly, energy intensive. And you wouldn’t have any agricultural benefits either.
They're already crushing it here though?
You can still do both things but if the primary goal is to capture carbon my question is if it would capture more if released in the atmosphere (by planes or similar).
You'd want to crush it much more finely for it to have a chance to actually capture anything while in the air, requiring more energy input and causing breathing hazards due to the fine particulates, not to mention staining everything it rains on with the fine basalt.
You could release it extremely high such that it stays suspended a bit longer, but then you'd waste even more energy getting it up there.
I've been wondering for a while now about the viability of asteroid/lunar mining that involves returning the payload of rare earth minerals or titanium in flying wing shaped return vehicles that are wrapped in some sort of mineral that ablates in the atmosphere while absorbing CO2 like this stuff does.
The idea is that we could both eliminate the Earth based pollution associated with mining while sequestering co2 previously emitted by terrestrial mining at the same time.
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