Description: 4A molecular sieve material is great for removing water moisture and smelly sulfur compounds from liquefied and gaseous hydrocarbons such as butane and propane. The “A” in 4A stands for a unit of measurement called an angstrom. Molecular sieve beads have microporous holes of precise and uniform size that are measured in angstoms. An angstrom is equal to one ten-billionth of a meter or 0.1 nanometers. Molecules small enough to pass through the 4A pores are adsorbed by the media while larger molecules are forced to pass around it. It is different from a common filter in that it operates on a molecular level and traps the adsorbed substance. For instance, a water molecule may be small enough to pass through the pores while larger hydrocarbon molecules are not, so water is forced into the pores which act as a trap for the penetrating water molecules, which are retained within the pores. Due to these properties, molecular sieves are often used as filter drier desiccants. 4A molecular sieve media can adsorb water up to 21% of its own weight. In other words, the saturation point for one kilogram (2.2 lbs.) of 4A media is potentially up to 210 grams of adsorbed material.
Bead Size: Circular beads with 4×8 mesh. 4×8 mesh is preferred over 8×12 mesh in gasphase applications because 4×8 is less restrictive and allows for higher flow rates.
Weight: Sold prepackaged in sealed 1 Kg / 2.2 Lbs. bags
Regeneration: 4A molecular sieve zeolite can be regenerated and reused by applying heat at a temperature of 450°F to the bead bed. Regeneration allows sieve beads to release the water moisture and other compounds that were adsorbed. While the sieves bind much water, they also hold some solvent and you don’t want to heat the beads very hot with a lot of solvent present, since this can be a fire hazard. Regeneration is most easily and safely accomplished by pouring the beads onto a cookie sheet in a shallow layer (not more than a few cm deep) and placing the sheet into a vacuum oven at full vacuum (-29.5″Hg) for at least one hour to purge any residual flammables prior to applying additional heat. After one hour has passed, release the vacuum and purge your vacuum oven. Next, pull another hard vacuum and set the oven temperature to 450°F. Allow the beads to remain in the vacuum oven at that temperature for around two hours to fully regenerate. The final step is to remove the cookie sheet from the oven and gently blow off any dust accumulation present on the beads before pouring them back into the canister from which they came.
Storage: Always store 4A zeolite in an air-tight container until ready for use to avoid unintended moisture adsorption from the surrounding air. If you are storing your 4A zeolite in a canister purchased from us, make sure the ball valves on either end of the canister are closed.
Additional Info: The table below lists some common molecules and their critical diameters. Keep in mind that anything smaller than 4.0 angstoms will be adsorbed by the 4A zeolite, anything larger will not be adsorbed.
|Molecule||Critical Diameter (Angstrom)|