Such as; buying and operating a iron fired boiler and turbine-generator. I doubt that anyone makes one. And of course you need an industrial water treatment system for your feed water. And you will need a High Pressure Boiler Operator’s license to run your system.
Of course you also need the equipment to reduce your iron oxide back in to iron.
You probably also need a mill system that operates in a vacuum to turn your iron back in to a powder. It is very likely to clump up during the regeneration process.
Yes, the devil is in the details.
This entire idea is a solution looking for a problem.
CO2 is not a pollutant.
co2 is plant food
More devilish details here:
https://deepresource.wordpress.com/2018/11/04/iron-powder-as-a-fuel/
All that high pressure/temperature equipment is expensive. And the stationary engineers are costly.
Nice when needed for industrial applications.
But I just want to grind up an old Chevy to keep my house warm.
Perhaps a pulse combustion boiler with ~110F out?
Would match nicely with the radiant floor and panel emitters in my house.
OK, that stainless cyclone looked expensive!
But, my brother has a beater in his garage that could be had at zero cost!
Henry Bessmer invented a process for manufacture metal powder over a hundred years ago, can’t be that difficult!
A fantastic story in itself.
https://www.chemistryviews.org/details/ezine/11187437/Sir_Henrys_Secret_Pot_of_Gold__Part_2.html