I looked and I couldn’t find a use of the term “Ölchemie”, however I am pretty sure that for all other oils, there were never enough chemical processes to have a need in finding a name for a branch of the chemical industry, as for “Petrochemie”. But yes, per the Etymologie link that I looked at, “Petrochemie” comes from greek “petros” for rock, and “ol” for oil - technically (and the article mentioned the same) it should be “Petrolchemie” which makes it closer to the “Alchemy” joke the previous commenter was making :)
Unfortunately this is only fun, not fact. The actual word is “Petrochemie”.
Does that term apply to just petroleum based oils or does it include essential oils extracted from plants, herbs, etc?
I looked and I couldn’t find a use of the term “Ölchemie”, however I am pretty sure that for all other oils, there were never enough chemical processes to have a need in finding a name for a branch of the chemical industry, as for “Petrochemie”. But yes, per the Etymologie link that I looked at, “Petrochemie” comes from greek “petros” for rock, and “ol” for oil - technically (and the article mentioned the same) it should be “Petrolchemie” which makes it closer to the “Alchemy” joke the previous commenter was making :)