Why is the pressure in the lower tower of the air separation equipment higher than that in the upper tower?

Why do the design, installation, and production of complete sets of air separation equipment require various parameters from the demand side?

The classical single column process is the first one to be used in industrial application. However, there are many disadvantages in the classical single column process. One is that oxygen and nitrogen cannot be produced simultaneously, and the other is that the oxygen extraction rate can only reach about 70%. There are two improvement schemes to solve the defects of classical single column process. One is the curren...