What are the advantages and disadvantages of vacuum distillation compared with atmospheric distillation?

Vacuum distillation is one of the common methods to separate purifiable organic compounds, especially for substances that have been thermally decomposed, oxidized or polymerized before reaching the boiling point in the process of atmospheric distillation.

Advantages: Under vacuum condition, the boiling point of the substance is reduced, which can reduce energy consumption and realize distillation conditions at lower temperature. Disadvantages: vacuum system is needed, which requires high pressure resistance of containers.

Extended data:

Because atmospheric distillation plays a connecting role in the process of crude oil distillation unit, to stabilize and operate atmospheric distillation well, pre-distillation is required to have stability and adaptability first. For example, the pre-distillation section should stabilize the fluctuation of crude oil flow and electric desalting operation, and prevent the large fluctuation of atmospheric distillation feed rate and properties, thus affecting the stability of atmospheric distillation operation and the quality of atmospheric side products.

The main processes of atmospheric distillation system are heating, distillation and stripping, and the main equipment includes heating furnace, atmospheric tower and stripping tower. The goal of atmospheric distillation operation is to improve fractionation accuracy and reduce energy consumption. The process operating conditions that affect these objectives mainly include temperature, pressure, reflux ratio, linear velocity of steam in the tower, steam blowing rate and liquid level at the bottom of the tower.

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