Specification for the design of piping for small air separation unit

In the operation of the air separation unit, the superheat of the expanded air sent to the upper column is a key parameter affecting the stability of distillation conditions and product purity. The fluctuation of superheat will directly change the gas-liquid load and mass transfer efficiency of the upper column, and then affect the distillation effect and energy consumption of the unit. If the superheat of the expanded air is too high, the gas entering the upper tower will carry a large amount of excess heat, which will significantly increase the gas phase temperature in the tower and aggravate the consumption of cooling capacity in the tower. This will lead to the decrease of reflux ratio in the distillation section of the upper column, insufficient gas-liquid two-phase contact, and poor mass transfer and heat transfer efficiency. At the same time, the increase of superheated gas will raise the rising gas flow in the tower and destroy the balance of distillation conditions, resulting

Why only cryogenic air separation equipment can be selected for large industrial gas?