molecular sieve

Introduction:
Molecular sieve 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 maximises lifetime when dehydrating such molecules.

Typical Chemical Formula:
0.*5 K2O . 0.*5 Na2O . Al2O3 . 2 SiO2 . 4.5H2O

Technical Parameter:

Typical Application:
 Drying of unsaturated hydrocarbons (e.g. ethylene, propylene, butadien)
 Cracked Gas Drying
 Drying of natural gas, if COS minimization is essential, or a minimum co-adsorption of hydrocarbons is required.
 Drying of highly polar compounds, such as methanol and ethanol
 Drying of liquid alcohol
 Static, (non-regenerative) dehydration of insulating glass units, whether air filled or gas-filled.
 Drying of refrigerants

Regeneration:
3A Molecular sieve 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 ******0°C is required. A properly regenerated molecular sieve can give moisture dew points below ***0°C.
The outlet concentrations on a pressure swing process will depend on the gas present, and on the conditions of the process.

Size:
Molecular Sieveare available in beads of **2 mm, (*0x*8 mesh) **3 mm, (8x*2 mesh) , 2.**5 mm, (4x8 mesh) and as powder, and in pellet 1.6, 3.2.