Molecular sieve adsorbents were developed to remove
water from liquids and gases more efficiently than the older silica
gel and alumina desiccants. Molecular sieves, because of their
crystalline composition, will yield virtually water-free products.
This feature makes molecular sieves particularly useful in
cryogenic operations where liquefaction of gases is required and
water must be eliminated to avoid freezing.
Molecular sieves offer adsorption selectivity based on molecular
size, molecular affinity for the sieve crystal surface, and shape
of the molecule. Molecular sieve systems are extremely simple to
use for reducing contaminants to nearly undetectable levels
compared to other technologies such as liquid separation
systems.
This, along with the higher efficiency compared to
other adsorption systems, has made molecular sieve systems a
popular engineering choice.