The process of gas separation, purification or purification belongs to the same concept in physical essence, which is to change mixture into pure substance. The principle of gas separation is to use the properties of mixture to achieve local separation of mixture through condensation or evaporation process. Partial condensation is suitable for the situation that the boiling points of the components in the mixture are quite different. If the boiling points of the components are close, it is difficult to achieve the separation requirements by using the partial condensation method. At this time, the gas separation needs distillation, and the combination of multiple partial evaporation and partial condensation becomes the distillation process. The distillation process can separate oxygen and nitrogen from the air.
