Molecular Sieve Grade Comparison

Seven grades leave our plant. The difference that matters is pore size — it decides which molecules get in and which stay out, and that single number picks the grade for you. Use this table to shortlist, then open the grade page for the full specification and its TDS.

Grade Pore Adsorbs Kept out Where it is used
3A 3 Å Water Ethane and larger molecules Insulating glass, ethanol dehydration, refrigerant drying
4A 4 Å Water, methanol, ethanol, H₂S Propane and larger molecules Compressed air drying, packaging desiccant, general gas drying
5A 5 Å Water, CO₂, normal paraffins Branched and cyclic hydrocarbons Air separation, PSA hydrogen, n-paraffin separation
13X 10 Å Water, CO₂, H₂S, aromatics, mercaptans — Gas sweetening, air pre-purification
13X APG 10 Å CO₂ and water with no co-adsorption of N₂/O₂ Nitrogen, oxygen Cryogenic air separation pre-purification
Li-LSX Li-exchanged X Nitrogen (high selectivity) — PSA / VPSA oxygen
Carbon molecular sieve Kinetic 3–5 Å Oxygen (faster than nitrogen) — PSA nitrogen generation
Pore sizes are nominal. Grade selection should be checked against your gas composition, pressure and regeneration temperature — send us the duty and we will confirm the grade.

How to choose in three questions

1. What has to come out?

Water only → 3A or 4A. Water plus CO₂ → 13X. Nitrogen from air → carbon molecular sieve or Li-LSX.

2. What must stay in?

If a valuable molecule must not be adsorbed, pick the pore just below its diameter — that is why insulating glass uses 3A and not 4A.

3. How will you regenerate it?

Temperature-swing beds use 3A/4A/5A/13X. PSA and VPSA plants use Li-LSX or carbon molecular sieve, which regenerate on pressure release, not heat.

Regeneration temperature by grade

Grade Typical regeneration temperature Regeneration method
3A / 4A / 5A 200–315 °C Temperature swing with dry purge gas
13X / 13X APG 250–315 °C Temperature swing with dry purge gas
Li-LSX Pressure release PSA / VPSA cycle, no heater
Carbon molecular sieve Pressure release PSA cycle, no heater
Typical ranges for guidance. The confirmed figure for the batch is on its TDS.

Documents: every grade ships with a certificate of analysis. Typical TDS and SDS are available before you order.

Bar chart comparing 3A, 4A, 5A and 13X molecular sieve pore openings with the kinetic diameter of water, CO2, nitrogen and other common molecules
Bar chart comparing 3A, 4A, 5A and 13X molecular sieve pore openings with the kinetic diameter of water, CO2, nitrogen and other common molecules
Table mapping common industrial applications to the recommended molecular sieve grade, from insulating glass 3A to carbon molecular sieve for nitrogen generation
Table mapping common industrial applications to the recommended molecular sieve grade, from insulating glass 3A to carbon molecular sieve for nitrogen generation

The four families side by side

3A, 4A and 13X beads from our current production.

Zeolite molecular sieve 3A 4A and 13X beads in laboratory bottles
Zeolite molecular sieve 3A 4A and 13X beads in laboratory bottles
3A molecular sieve beads for dehydration in ethanol and natural gas service
3A molecular sieve beads for dehydration in ethanol and natural gas service
13X molecular sieve beads for CO2 and moisture removal in air separation
13X molecular sieve beads for CO2 and moisture removal in air separation

Not sure which grade fits your plant?

Send the gas or liquid composition, flow, pressure and temperature. Our engineers confirm the grade and the bed size, and quote factory-direct.

Send your duty conditions