Aluminium is an electrolysis process, and does not need an organic fuel, just electricity. Copper mills work in general with gas, some with coal dust (if I'm correct). I could add oil or coal if you think it represents better the process. What do you think?

Well, at least it should use any energy source, so if coal dust is for copper mill let it use coal as well.

And as a replacement for the electricity the aluminium smelter uses (from 1850 on?) it could be oil, but oil is not available yet.
It could™ use "crude oil" but only until 1900 and for a lower efficiency and with "waste" as additional output... from 1900 on it uses oil and gets more output and no waste anymore - how about that?

I'll add coal for the copper mill. Feels right. But I'm not convinced about oil for the aluminium smelter. Electricity is not a thing in this game. Hmmm.. I'll let it rest for the moment, until a better solution presents itself. Thanks for the input, GordonDry. ;)