The purpose of using pressurized distillation in the distillation tower

The light and heavy components have relatively low volatility; by applying pressure, the temperature at the bottom of the tower is increased, thereby improving the efficiency of separating the light components at the top of the tower

For example, in oil distillation, since all the components to be separated have low boiling points and are even gaseous at room temperature, pressure-driven distillation is necessary

Most reactive distillation processes are also carried out under pressure

Distillation is advantageous for separation at low pressures, as the relative volatility is high. However, there are mainly two reasons for using pressure in industry: one is that pressure can reduce the requirement for low-temperature cooling at the top of the tower. For example, in the ethylene industry, the separation of methane from ethylene requires a temperature of -160 degrees at atmospheric pressure; however, by using distillation under a pressure of 35 kilograms per square centimeter, the temperature at the top of the distillation tower can be raised to -101 degrees. Another reason is related to process requirements; for example, the feed with high pressure enters the distillation tower, and the vapor at the top of the tower must not have too low a pressure in order to be sent to subsequent units. You should know that the cost of adding a compressor in between is very high

It is only related to physical properties and the processes involved in material intake and output; it has absolutely nothing to do with energy consumption. Those who don’t understand this should not reply needlessly.