Activation of molecular sieve in plastic-shell carrier gas purifier
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The gas chromatograph and the carrier gas purifier have plastic housings. Now, it is planned to remove the molecular sieve and silica gel from these devices and place them on stainless steel trays in an electrically heated forced-air dryer for thermal activation. The activation temperature for molecular sieve is 250 degrees, while that for silica gel is 120 degrees. It is intended to reinstall the materials in the purifiers once the temperature drops to 60 degrees. I’m wondering whether the molecular sieve will absorb gases again and become ineffective after cooling down following drying.
This post was last edited by qugd on 2016-7-29 at 12:33. Such an old post was actually brought back to light. It is generally not recommended to use plastic materials for making carrier gas purifiers, but if it has already been used, there is little choice but to make do with it. Whether it is molecular sieve or silica gel, after drying and activation, it should first be placed in a container containing desiccant before cooling. Once cooled to room temperature, the molecular sieve or silica gel is then placed into the carrier gas purifier in a dry environment, and the cover or sealing element of the purifier should be sealed as soon as possible. Personally, I recommend that the carrier gas purification tank be made of stainless steel, as it offers better pressure and temperature resistance compared to plastic materials, and it is also capable of holding the newly regenerated hot activated carbon and molecular sieves.