How To Activate Molecular Sieve?

Why Do You Need to Activate a Molecular Sieve?

In the process of storage and transportation, a molecular sieve will absorb a small amount of water and carbon dioxide. Activation can ensure molecular sieve maximum adsorption capacity.

For a molecular sieve, activation means emptying the adsorbent to expose the surface, which can affect the adsorb of the reaction materials and shorten the reaction induction period.

What is a Molecular Sieve?

Molecular sieves adsorb different substances by their adsorption priority and aperture. It is an aluminosilicate microporous crystal.

Molecular sieves have four major uses and various types. According to different uses, different types of molecular sieves will be matched.

1. Industrial desiccant: It is mainly used for the use of equipment desiccant packs, deep drying of air compressor dryers, and the insulating glass process.

2. Oxygen production: Molecular sieves are the best choice for oxygen production. The concentration of oxygen production is 93-96%. The rate of oxygen production has different indicators according to the equipment.

3. Air separation equipment: Air separation equipment mainly separates rare gases in the air, such as helium, nitrogen, argon, etc…

4. Catalyst carriers: Molecular sieves have good carrying capacity due to their flourishing pores and high adsorption capacity. They can be used as carriers for various catalysts. At the same time, they have a good adsorption capacity for heavy metals, arsenides, and fluoride in water.

How to Activate Molecular Sieves?

The main purpose of activation is to improve their function and keep them dry and stable. Before molecular sieves can be used as a desiccant, they must be “activated” by removing all trace amounts of water and other volatile compounds. Place the molecular sieve in a large heat-resistant beaker or ceramic bowl. Place the beaker or bowl in the oven. Heat the molecular sieve at 300 to 320 degrees Celsius for at least 15 hours. Vacuum drying is a faster method that requires relatively lower temperatures. Prolonged heating is unnecessary but does not damage the molecular sieve. Remove the molecular sieve from the oven using heat-resistant gloves. If possible, cool the molecular sieve in a dryer.

Otherwise, let the beaker cool in the open air until it feels hot to the touch, then transfer the molecular sieve to an airtight container and close the lid.

This will keep them active for up to six months. To check whether the molecular sieves are active or not, you can hold them in your hand with gloves and add water. If they were fully active, the temperature would increase significantly, making it impossible to hold them even with gloves.

Safety equipment such as PPE kits, gloves, and safety glasses are recommended as the activation of a molecular sieve involves handling high temperatures and chemicals and associated risks.


A molecular sieve is the best desiccant on the market. For the highest quality, Naike Chemical is your best choice. Contact us and we will be happy to offer you our expertise.

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