And that's the only byproduct of the entire business -- in goes the iron powder, and out comes energy in the form of heat and rust powder.
Although its specific energy is a relatively poor 1.4 kWh/kg, meaning that for a given amount of energy, iron powder will take up a little bit less space than gasoline but it'll be almost ten times heavier.
Researchers from TU Eindhoven have been developing iron powder as a practical fuel for the past several years, and last month they installed an iron powder heating system at a brewery in the Netherlands, which is turning all that stored up energy into beer.
[...] Philip de Goey, a professor of combustion technology at TU/e, told us that he hopes to be able to deploy 10 MW iron powder high-temperature heat systems for industry within the next four years, with 10 years to the first coal power plant conversion.
Since electricity can't efficiently produce the kind of heat required for many industrial applications (brewing included), iron powder is a viable zero-carbon option, with only rust left over.