Gas Purification: Molecular Sieve & Copper Catalyst
A molecular sieve traps water, and a copper catalyst traps oxygen—together, they keep the inert gas atmosphere in your glovebox clean. We explain how this works and when filters need to be refilled or regenerated.
Gas purification is at the heart of every glovebox. It ensures that oxygen (O₂) and moisture (H₂O) are continuously maintained at very low levels—often below 1 ppm. Without proper gas purification, the concentration of these substances inside the box rises, and materials sensitive to air or moisture can no longer be handled safely.
How Gas Purification Works
During operation, the protective gas is continuously circulated through a purification column. Two materials work together within it:
- Molecular sieve – binds moisture (H₂O) from the atmosphere.
- Copper catalyst—binds residual oxygen (O₂).
Both materials become saturated over time. They are regenerated using a forming gas (usually a nitrogen/hydrogen mixture) and are then ready for reuse. Only when their capacity begins to decline after many cycles is the packing replaced.
Solvent filter with activated carbon
If solvents are used in the box, a solvent filter is often installed as well. It is filled with activated carbon and captures solvent vapors before they reach the gas purification system and damage the catalyst. Activated carbon is a consumable and is replaced regularly.
When to regenerate filters, when to refill?
- Rising O₂/H₂O values despite a sealed box are the first sign of saturated or declining gas purification.
- Regeneration is the normal, recurring process—automated in most systems.
- Refilling the molecular sieve and copper catalyst becomes necessary when regeneration no longer sufficiently lowers the levels.
- Activated carbon in the solvent filter is replaced depending on solvent usage.
Consumables & Refills
Molecular sieves, copper catalysts, and activated carbon are standard consumables—as are gloves and gaskets. We supply the appropriate materials from various manufacturers and, upon request, handle refilling as well as sensor calibration. You can find an overview of our consumables and accessories on the Glovebox Accessories & Consumables page. If gas purification is part of your regular support services, our KeT Care 360 maintenance contract is the right solution.
Gas Purification: Frequently Asked Questions
What is the difference between a molecular sieve and a copper catalyst?
The molecular sieve absorbs moisture (H₂O), and the copper catalyst absorbs oxygen (O₂). Both work together in the purification column and are regenerated regularly.
What is the purpose of the activated carbon in the glove box?
Activated carbon is used in the solvent filter. It captures solvent vapors before they reach the exhaust gas purification system and damage the catalytic converter. It is replaced depending on solvent usage.
Do you supply molecular sieves, copper catalysts, and activated carbon?
Yes. We supply consumables from various manufacturers and, upon request, will fill the filters and calibrate the sensors. Just ask us.
Is filter media or packing required?
Tell us the manufacturer and model of your glove box—we’ll supply the appropriate molecular sieve, copper catalyst, and activated carbon, pre-filled upon request.
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