04/20/2026
Crude oil does not come out of the ground as ready fuel, it has to be split and rebuilt inside a refinery. The first step is heating crude and sending it into an atmospheric distillation tower, where temperature differences separate it into layers. The lightest parts like gases and gasoline rise to the top, middle products like kerosene and diesel form in the middle, and heavy oils and residue stay near the bottom. That first split is only the beginning because most crude naturally contains too much heavy material and not enough high value fuel. Refineries send the heavier parts through vacuum distillation and then processes like cracking and hydrocracking to break large molecules into smaller ones, while reforming upgrades fuel quality. In the end, one 42 gallon barrel typically becomes gasoline, diesel, jet fuel, chemicals, lubricants, and heavy products like fuel oil and bitumen, with the exact output depending on the crude type and how advanced the refinery is.