How are the crude oil fractions separated?
A. Crude oil is physically separated by fractionation in atmospheric and vacuum distillation towers, into groups of hydrocarbon molecules with various boiling-point ranges, called fractions or cuts. Crude oil is heated and put into a distillation column. Different products can be recovered at different temperatures. The lighter products- LPG, naphtha, and straight run gasoline are recovered at the lowest temperatures. Middle distillates-jet fuel, kerosene and gas oil come next. The heavier fractions are separated under vacuum and may be reprocessed into lighter products.
