How a Molecular Sieve Works

THINGS TO KNOW WHEN PURCHASING MOLECULAR SIEVES

Molecular sieves are used commercially to purify gas streams and as desiccants to remove water or reduce humidity. This article focuses chiefly on what you need to know when buying a desiccant dryer, although the basic principles may apply to other applications as well.

How a Molecular Sieve Works

The material used in an industrial molecular sieve has small uniform pores. When other substances come in contact with the molecular sieve, the molecules that are the right size to fit in the pores will be adsorbed. The molecules that are too large to fit will not. Molecular sieves function at the microscopic level, therefore their sizes are measured in angstroms. Pore sizes 3Å and 4Å will adsorb water while larges sizes remove larger hydrocarbons.