Zeolite molecular sieve 3A 4a 5a 13x is an alkali metal alumino silicate; it is the potassium/sodium/calcium/sodium form of the Type A/X crystal structure.
Molecular sieve 3A has an effective pore opening of 3 angstroms (0.3 nm). It is large enough to allow in moisure, but excludes moleculars such as unsatureated hydrocarbons which can potentially form polymers: and this maximises lifetime when dehydrating such molecules.
Molecular sieve 4A has an effective pore opening of 4 angstroms (0.4 nm). It will adsorb molecules with a kinetic diameter of less than 4 Angstrom and exclude those larger.
Molecular sieve 5A has an effective pore opening of 5 angstroms (0.5 nm). It will adsorb molecules with a kinetic diameter of less than 5 Angstrom and exclude those larger.
Molecular 13x will adsorb molecules with a kinetic diameter of less than 9 Angstrom (0.9 nm) and exclude those larger.
It also has the highest theoretical capacity of the common adsorbents and very good mass transfer rates. It can remove impurities too large to fit into a type A crystal and is commonly used to separate nitrogen from oxygen.
Typical Chemical Formula
0.45k2O ·0.55Na2O·Al2O3 ·2.SiO2· 4.5H2O(3A)
Na2O·Al2O3 ·2.SiO2· 4.5H2O (4A)
0.7 CaO . 0.3 Na2O . Al2O3 . 2 SiO2 . 4.5H2O(5A)
Na2O . Al2O3 . (2.8±0.2) SiO2 . (6~7)H2O(13x)
SiO2 : Al2O3 ≈2.6-3.0
1) Drying of unsatureated 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
|Item ||unit ||target |
|Shape || ||pellet ||ball |
|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 ||≥96 ||≥96 |
|Bulk density ||g/ml ||≥0.64 ||≥0.64 ||≥0.68 ||≥0.68 |
|Abrasion rate ||% ||≤0.20 ||≤0.25 ||≤0.10 ||≤0.10 |
|Crushing strength ||N/p ||≥45 ||≥60 ||≥30 ||≥70 |
|Water adsorption ||% ||≥20 ||≥20 ||≥20 ||≥20 |
|Packing water ||% ||≥15 ||≥15 ||≥15 ||≥15 |
By carton box, each box 30kg or 25kg, inside airtight bag.
Or 40kg/sealed iron drum, inside airtight bag.
Molecular sieve 3A 4a 5a 13x 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 molecular sieve 3a 4a 5a 13x, 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