mSORB® 3A Molecular Sieve

3A molecular sieve is the potassium form of the type A zeolite crystal. Exchanging potassium into the framework narrows the pore opening to a nominal 3 angstroms, which admits water while excluding most larger molecules, among them methanol, ethanol, carbon dioxide, hydrogen sulfide, and hydrocarbons. mSORB 3A is supplied as spherical beads with high crush strength and mass transfer efficiency for repeated adsorption cycles, and a spent bed can typically be regenerated by heating.

Chemical Formula: K₁₂[(AlO₂)₁₂(SiO₂)₁₂]·nH₂O

Typical Applications

• Drying ethanol, methanol, and other polar liquids without adsorbing the liquid itself
• Drying unsaturated hydrocarbon and reactive gas streams where co-adsorption must be avoided
• Fuel ethanol dehydration, with the mSORB 3A EDG grade built for cyclic ethanol service
• Natural gas dehydration, with the mSORB 3A-NG grade built to limit co-adsorption of CO₂, H₂S, and heavier hydrocarbons

Sizes

mSORB 3A is supplied as beads in 4x8 and 8x12 mesh, in bulk. Other sizes and forms are quoted on request.

Frequently Asked Questions

What is 3A molecular sieve?

3A molecular sieve is a synthetic zeolite, also written zeolite 3A: the potassium form of the type A crystal, with a nominal pore opening of 3 angstroms. The number gives the nominal pore size in angstroms and the letter the crystal type. Water enters the pore and is held; molecules larger than the opening pass by.

How does 3A differ from 4A?

Both are type A zeolites. 3A is the potassium form and 4A molecular sieve the sodium form, and the potassium ion narrows the pore from a nominal 4 angstroms to 3. So 3A adsorbs water while excluding molecules that 4A takes in, among them methanol, ethanol, and carbon dioxide. 4A is typically the general-purpose choice where light co-adsorption is acceptable; 3A is typically specified where it is not. The family page compares the four standard types.

Is 3A used for drying solvents?

Yes. Because the pore excludes the solvent molecule, 3A typically dries polar solvents such as ethanol and methanol without adsorbing the solvent itself. Both bead sizes are used; size selection typically trades pressure drop against mass transfer rate, and Interra Global reviews the service conditions when called on.

How is 3A regenerated?

Thermally, with a dry purge gas carrying the desorbed water out of the bed. The applicable conditions for each grade are given on its product data sheet.

What is the water capacity of 3A?

The typical properties table on this page gives the equilibrium water capacity at the stated humidity and temperature. Capacity in service depends on the stream's water content, temperature, and cycle design, and Interra Global reviews service conditions when called on.