The historical root of chemistry is metallurgical, the creation of metals from ores. This process is called reduction of the ore, and the trick to doing it was discovered early on, to heat the ore as high as possible after mixing it with charcoal. The achievable final temperature at the time pretty much determined whether the locals were living in the copper, bronze or iron age. There are nice video demonstrations on line.
The charcoal is transformed into carbon monoxide or carbon dioxide depending on the conditions in the furnace. This is pretty much how most metals are produced today, except that instead of charcoal, coke is used.
2. Even electrolysis of bauxite (Al2O3) to aluminum requires using graphite electrodes, which, guess what, during the electrolysis process, are oxidized to CO2.
Which, in the usual Rabett Run way brings Eli to the point of all this. According to the EIA, 2012 production of coal is about 8.7 billion short tons. In real units that is 7.9 x 1012 kg or, if a bunny prefers 7.9 109 tonne.
The amount of metallurgical coke produced in 2012 was about 0.7 billion short tons, but given the wastage from coke production, 2/3 of a ton of coke is produced from a ton of coal. Multiplying, dividing and so forth (hopefully correctly, this comes out to about a billion short tons or 0.9 109 tonne.
Bottom line is that about 1/8th of the current coal mined is used for metal refining and this is still quite a bit, making it harder to reach zero CO2 emissions.
Eli apologizes for this Sunday sadness.