[datenhorst]

This article reads like metric ton of BS but sadly I don't understand enough about the substance to be able to tell reliably.

1) I thought the reason cement production is bad for the environment because CO2 is released from the calcium during the process, not because fossil fuels are using for the heating of the oven.

2) So they're solving the problem by pointing the mirrors directly at the oven or how does that work? I don't really get why the temperature generated is important otherwise.

3) There's also storage of the energy batteries mentioned, how exactly does that work? Sounds like a contradiction to 2)

[jsilence]

The CO2 expelled from the Calcium Carbonate is quite pure compared to CO2 from combustion which usually contains nitrous oxides. This makes it suitable for capture and liquification and thn for example as a gasous fertilizer in greenhouses. A heat exchanger can recuperate a good chunk of the residual heat and pipe that to the air intake for the gas burners that are used to heat the furnaces.

Not saying every cement plant is doing this. But it is possible and makes sense.

Focussing solar power to the furnace would eliminate a sensible usage of the residual heat within the process itself.