3A Molecular Sieve

Molecular Sieve type 3A is an alkali metal alumino-silicate; it is the potassium form of the type A crystal structure. Type 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 maximizes lifetime when dehydrating such molecules.

Typical Chemical Formula

0.4K₂O 　0.6Na₂O　 Al₂O₃ 　2.OSiO₂ 　4.5H₂O

SiO₂ : Al₂O₃ ≈2

Regeneration

Molecular sieve Type 3A can be regenerated by either heating in the case of thermal swing processes; or by lowering the pressure in the case of pressure swing processes.
To remove moisture from a 3A molecular sieve, a temperature of 200-230°C is required. A properly regenerated molecular sieve can give moisture dew points below -100°C.
The outlet concentrations on a pressure swing process will depend on the gas present, and on the conditions of the process.

Attention
To avoid damp and pre-adsorption of organic before running, or must to be reactivated.