Which process is used to separate crude oil into its fractions?

The process used to separate crude oil into its fractions is fractional distillation. Crude oil is a complex mixture of hydrocarbons with varying boiling points. During fractional distillation, the crude oil is heated in a distillation column, where it vaporizes and then condenses at different heights within the column, depending on the temperature.

As the vapor rises through the column, it cools down, allowing components with higher boiling points to condense back into liquid form and be collected. Those with lower boiling points remain in the vapor state longer and ascend higher in the column, where they eventually condense at lower temperatures. This method effectively separates the crude oil into its various fractions, such as gasoline, kerosene, diesel, and heavier oils, each of which can be tapped off at different points in the distillation column.

Fractional distillation is particularly suitable for this purpose because it leverages the differences in boiling points among the various components of crude oil, which is not something that can be accomplished with methods like filtration or evaporation. Filtration, for instance, is primarily used to separate solids from liquids, while evaporation involves converting a liquid to a gas, but it does not separate different components based on their boiling points.