Why there is so little carbon in Earth crust?

[Czcibor]

In the galaxy carbon is on 4th place (after hydrogen, helium and oxygen)

In Earth crust it has respectable 15th place.

Hydrogen, helium, neon - they are on to the top galaxy popularity list, but are too light to be kept by our planet in proportional amount. Quite a few elements in Earth crust (oxygen, silica, iron) have roughly the place that one would expect from their galaxy prevalence. However, carbon does not follow this logic.

Why it is so rare on Earth comparing its prevalence in other places?

 

[Whovian]

silica,

*Silicon

Anyway, my best guess would be that the crust has about the same percentage of Carbon as the galaxy, but most of it is concentrated in carbon-based life forms.

 

[eachus]

Because carbon is soluble in iron. When the hot new Earth was fractionating into crust, mantle, and core, much of the carbon would have ended up in the core. If you ever saw the blow of a Bessemer converter, you would know how much carbon loves molten iron.

I don't think there have been any Bessemer process steelmakers for almost fifty years. The major problem with Bessemer converters compared to basic oxygen furnaces (BOF) or open hearth furnaces was the short time of the blow. You couldn't change the process--or the charge once started. Of course, it is much easier to control air pollution with a BOF Once the gasses are cooled (in a heat exchanger to preheat the fuel or oxygen) the major component is CO2.

I'm sure there must be an online movie of a Bessemer converter in operation, but it is a waste of time. Anyone who lived within say 20 miles of a Bessemer converter (or twelve) can tell you they lit up the night sky like it was day. Closer in, tinted goggles are recommended. In daytime the converter will put out more light than the sun. (Locally of course.) A good cameraman will compensate for this, but that just means it looks like the sun went out.