Hi, around 20km away from where I live there is a coal powerplant. The “smoke” coming out of the chimney is dense and white, which suggests that it’s just steam, and for all I know steam doesn’t pollute. There is no darker smoke around the powerplant, it doesn’t even smell like it’s coal burning there. Where does all the smoke go?
In: Chemistry
The big cloud you see is steam coming from the cooling circuit in the plant. Coal power plants work by boiling water and using the resulting steam to turn a turbine, but the whole system works best if you use expensive, purified water in the boilers and then have a different stream of water that’s just pulled in from a nearby river or ocean to condense the steam coming out of the turbine back into water so you can boil it again.
They install “Scrubbers” in the smoke stacks. They the smoke out of the air, and capture it in what basically amounts to a massive filter. The chemical process used actually allows them to retrieve a recyclable form of gypsum from the filters, which gets turned into dry-wall for home building.
Basically go look at the air-intake filter for your house’s HVAC system. The filter is a scrubber, and the dust is “smoke”.
Coal plants are required in many countries to have traps in their chimneys to filter out most of the ash ([“fly ash”](https://en.wikipedia.org/wiki/Fly_ash)) they emit. This was (and is) a major source of pollution in places without such laws.
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