Description

Introduction 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 maximises lifetime when dehydrating such molecules. Typical Chemical Formula 0.*5 K2O . 0.*5 Na2O . Al2O3 . 2 SiO2 . 4.5H2O Typical Application Drying of unsaturated hydrocarbons (***** 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 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 ******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 3A - Zeolites are 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”.