APPLICATION FOCUS
PROVEN EXPERTISE IN AIR
SEPARATION
UNIT
APPLICATIONS
Air separation is used to divide atmospheric air into its primary components – nitrogen ( N 2 ), oxygen ( O 2 ), and argon ( Ar ).
The predominant method for this is the cryogenic distillation process , invented in 1910 , which results in high-quality , high-volume liquid and gaseous N 2 , O 2 , and Ar products .
This method is also the only process capable of producing the ultra-high-purity gases needed for semiconductor device fabrication , as well as the gases required for applications such as metal production , healthcare , industrial processes , and heat treatment .
First , the air is filtered and compressed to remove dust . The air is then purified , most commonly with a molecular sieve , to remove water vapor , carbon dioxide , and gaseous hydrocarbons .
Next , it is passed through an integrated heat exchanger , and cryogenically cooled to approximately -180 o C before being fed to a distillation column , which consists of a stack of two separate columns , for high pressure and lower pressure .
Here , the main gas components are separated into purified N 2 , O 2 , and an Ar stream , with pure gaseous N 2 drawn off from the top of the low-pressure column , and pure O 2 withdrawn from the bottom of the column .
Argon is enriched - to approximately 15 percent argon - in the middle part of the column , the socalled ‘ argon belly ’, and can be withdrawn from there and then further purified in the crude and pure argon columns .
As each product is distilled and purified , a portion is brought back to ambient temperatures in the heat exchangers , making the process more heatefficient . The final product can then be transported in gaseous form locally , via pipelines .
Liquified N 2 , O 2 , and Ar can be stored , or transported regionally by truck and large dewars directly to customers .
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