Introduction :
Molecular Sieve 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 maximises lifetime when dehydrating such molecules.
Typical Chemical Formula
0.45 K2O . 0.55 Na2O . Al2O3 . 2 SiO2 . 4.5H2O SiO2 : Al2O3 ≈2
Technical Parameter
| Item | Unit | Technical data | |||
| Shape | Pellet | Pellet | |||
| 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 |
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
Molecular sieve 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.
Size 3A - Zeolites are available in beads of 1-2 mm, (10x18 mesh) 2-3 mm, (8x12 mesh) , 2.5-5 mm, (4x8 mesh) and as powder, and in pellet 1.6”, 3.2”.
Attention
To avoid damp and pre-adsorption of organic before running, or must to be reactivated.
