The cryogenic distillation method is to first cool the air to liquefaction, and then selectively distill the components at different boiling temperatures. This process can produce high-purity gas with high energy consumption. The cryogenic separation process requires close integration of the heat exchanger and the separation tower to obtain good efficiency. All refrigeration energy is provided by the air compressor at the inlet of the device.
In order to achieve a lower rectification temperature, the air separation plant needs to use a throttling device to obtain the refrigeration capacity, that is, the isothermal throttling effect (Linde Liquefaction Cycle), or use an expander to obtain a large isentropic expansion refrigeration capacity (Clauter Liquefaction Cycle). ), the air is liquefied, and the cold equipment must be kept in an insulated enclosure (usually called a "cold box").
