Originally Posted by
jantar99
Technically, fuel molecules have not been synthesized at the refinery, but separated from different kinds of molecules.
I'd suggest that you research what a hydrocracker is, what it does, and what percentage of kerosene is straight-run distilled vs what percentage is cracked. A hydrocracker does not simply separate crude oil into it's various weight fractions. It synthesizes short-chain hydrocarbons such as kerosene from longer chain hydrocarbons. It creates new molecules from older molecules. For bonus points, look into the sulphur content of straight-run kerosene vs cracked kerosene, and compare that to the specification limits for Jet-A, and you will understand why Jet-A is mostly produced from cracked kerosene feedstock.