Carbon Molecular Sieves (CMS) are used in PSA (pressure swing adsorption) Nitrogen gas generators. CMS also finds use in other separations like Hydrogen refinement from crude sources and also biogas refining.

We specifically referring to CMS for Nitrogen production. Carbon Molecular Sieve operates at a molecular level and under pressure separates oxygen from nitrogen when fed atmospheric air.

Carbon Molecular Sieves have a porous nano-structure which is arrived at after processing activated carbon as the raw material. The nano-pores capture the Oxygen molecule in compressed air when the CMS is subjected to pressure. This allows the balance Nitrogen, which is unable to be adsorbed, to be delivered as the product gas. Once the pores have been saturated with Oxygen, the CMS is de-pressurized back to atmospheric pressure and this allows the adsorbed Oxygen molecules to be released out as the exhaust.

The carbon molecular sieve (CMS) shelf time is about 3-5 years.

So, once you used it for 5years, you should consider the replacement.

Here are some additional things to consider…

Never enter a vessel that contains used molecular sieve.

During the unloading process the molecular sieve may have adsorbed chemical compounds.  These adsorbed chemicals may be desorbed again when the molecular sieve is exposed to open air, especially if humidity is high or the air is very moist.

These desorbed chemical compounds can create hazards if the desorbed chemical compounds are toxic.   The plant manager or operator has the responsibility to know what chemicals may have be desorbed in this manner and to know what precautions may be necessary to ensure everyone’s safety.