Science Buddies: "Ask an Expert"

Does anyone know how zeolite is properly activated in order to take advantage of its adsorption capabilities? In addition, are a zeolite's adsorption abilities affected by the pressure of a gas?

Thank You

Hi,

Activation of zeolites for what purpose?

The usual techniques is to heat them quite hot, often under vacuum, to drive off water or adsorbed gases. But the techniques vary depending on the use to which you wish to put the zeolites. Here are some references:

http://books.google.com/books?id=DmPr4R ... ion&f=true

http://www.absorcare.net/desiccant/quic ... iccant.htm

http://www.scientific.net/AMR.178.3

http://www.freepatentsonline.com/4524140.html

http://books.google.com/books?id=UsLE2X ... ion&f=true

http://books.google.com/books?id=iIi08k ... on&f=false

I hopr this helps you find the answer you need. Please note that you can probably borrow any of the books referenced above by contacting a reference librarian at your local city library and asking about interlibrary loans or InterLink (which my local city library uses to facilitate borrowing books from university libraries). These services are free and often quite fast, and therefore extremely useful to those of us on limited budgets!

Best regards,

Barrett L Tomlinson

The purpose of the zeolite is to adsorb water vapor, ideally releasing heat in the form of the heat of adsorption. Based on research, the activation obviously requires heat. Does it require that the zeolite be in a vacuum as well?

Hi,

I have no definitive information other than the references you have already been given. I doubt that a vacuum is absolutely necessary, though it may speed up the activation process considerably. What is crucial is that the zeolite be maintained in an absolutely dry state as it is cooled from the activation temperature, as the water can be easily reabsorbed into the zeolite from water vapor. This means you want to flush the zeolite with bone dry gas before cooling if you do not heat in a vacuum.

Good luck!

Barrett L Tomlinson