Molecular Sieve 3A is a kind of molecular sieve (alkali metal alumino-silicate) whose aperture is 3A. Sometimes, it is also called 3A zeolite molecular sieve. It is the potassium form of the type A crystal structure. Molecular sieve 3A has an effective pore opening of about 3 angstroms (0.3nm). This is large enough to allow in moisture, but excludes molecules such as unsaturated hydrocarbons which can potentially form polymers; and this maximises lifetime when dehydrating such molecules. Molecular sieves 3A are the necessary desiccant in petroleum and chemical industries for refining oil, polymerization, and chemical gas-liquid depth drying.
