> The nanoparticles are not emitted in the atmosphere but captured in a HEPA filter.
If that's true, your point #3 is moot. And if the nano particles can be captured by a filter, maybe we could design filters specifically for iron oxide nano particles that would allow the nano particles to be extracted
> but I imagine it's actually more scalable and healthy to burn jet fuel and reproduce it from renewable powered carbon capture, where density is needed.
You're saying capture carbon from CO2 and turn it into kerosene? I tried googling around and everywhere I look it seems like this is currently way more difficult than renewable iron fuel (https://www.planet.veolia.com/en/how-produce-kerosene-co2).
Cherry-picking the fuel for jets example makes sense, since somehow we don´t expect aviation to transition completely to airscrews.
As for the disposal of HEPA filteres loaded with air-stable inorganics, that still is pollution, only the kind of waste you store safely, and if not give people cancer, but highly localized so.
If that's true, your point #3 is moot. And if the nano particles can be captured by a filter, maybe we could design filters specifically for iron oxide nano particles that would allow the nano particles to be extracted
> but I imagine it's actually more scalable and healthy to burn jet fuel and reproduce it from renewable powered carbon capture, where density is needed.
You're saying capture carbon from CO2 and turn it into kerosene? I tried googling around and everywhere I look it seems like this is currently way more difficult than renewable iron fuel (https://www.planet.veolia.com/en/how-produce-kerosene-co2).