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

  SiO2 : Al2O3 ≈2

 

Technical Parameter

Item	Unit	Technical data
Shape		Pellet		Sphere
Diameter	mm	1.5-1.7	3.0-3.3	1.7-2.5	3.0-5.0
Size ratio up to grade	%	≥98	≥98	≥98	≥98
Bulk density	g/ml	≥0.65	≥0.65	≥0.70	≥0.70
Wear ratio	%	≤0.20	≤0.25	≤0.10	≤0.10
Crushing strength	N	≥45/cm	≥60/cm	≥30/p	≥70/p
Static water adsorption	%	≥20	≥20	≥20	≥20
Ethylene adsorption	%	≤3.0	≤3.0	≤3.0	≤3.0
Water content, as shipped	%	≤1.5	≤1.5	≤1.5	≤1.5

 

 Size
 

Typical Application

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

 

 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.