What is a key difference between atmospheric distillation and vacuum distillation?

Vacuum distillation operates under reduced pressure, which is a fundamental aspect that distinguishes it from atmospheric distillation. In vacuum distillation, lowering the pressure decreases the boiling points of the components in the mixture, allowing for the separation of temperature-sensitive materials without decomposition. This technique is particularly essential for separating heavier fractions that may decompose at higher temperatures when subjected to atmospheric conditions.

Atmospheric distillation, on the other hand, operates at the natural atmospheric pressure and is primarily used to separate lighter fractions from crude oil. The inability to efficiently separate certain fractions at high temperatures makes vacuum distillation invaluable in processing more complex hydrocarbon mixtures.

This capability to operate at reduced pressures in vacuum distillation is crucial for handling specific feedstocks and desired products, especially in refining processes where maintaining product integrity is paramount.