The oil refining process starts with a fractional distillation column. The problem with
crude oil is that it contains hundreds of different types of hydrocarbons all mixed
together. You have to separate the different types of hydrocarbons to have
anything useful. Fortunately there is an easy way to separate things, and this is
what oil refining is all about. Different hydrocarbon chain lengths all have progressively
higher boiling points, so they can all be separated by distillation.
This is what happens in an oil refinery - in one part of the process, crude oil is heated
and the different chains are pulled out by their vaporization temperatures. Each
different chain length has a different property that makes it useful in a different way.
To understand the diversity contained in crude oil, and to understand why refining
crude oil is so important in our society, that is the important part role of oil refining
machine.