So where will we get those other products if the crude is not refined? We are still using those.
What I said is that it takes ~2 gals of crude to make 1 gal of petroleum. That is a fact.
Not a fact. If all we did was the following, we could not change the ratio of gasoline from crude.
Using only distillation, the first step of a refinery, the yields look like:
But in today's refineries, we have several post-distillation processes that allow us to vary the amount of gasoline produced from the crude oil. A catalytic cracker, for instance, uses the gasoil (heavy distillate) output from crude distillation as its feedstock and produces additional finished distillates (heating oil and diesel) and gasoline. A reforming unit produces higher octane components for gasoline from lower octane feedstock that was recovered in the distillation process. A coker uses the heaviest output of distillation, the residue or residuum, to produce a lighter feedstock for further processing, as well as petroleum coke. So in simplified terms, a modern refinery looks like:
By adjusting the amount of heavier products sent through the downstream processes, we can vary the ratio of gasoline produced from the same crude oil. There are limits to the process, but currently we change the above crude yields into:
