Cryogenic air separation processes rely on differences in boiling points to separate and purify products.
All cryogenic processes include these steps:
- Filtering and compressing air
- Removing contaminants, including water vapor and carbon dioxide (which would freeze in the process)
- Cooling the air to very low temperature through heat exchanger and refrigeration processes
- Distilling the partially-condensed air (at about -300˚F / -185˚C) to produce desired products
- Warming gaseous products and waste streams in heat exchangers that also cool the incoming air stream
Cryogenic processes are the most cost effective separation process for producing at high production rates and are capable of making the highest purity products.