3. What are some of the major applications for
zeolites?
Adsorption - Zeolites are used to adsorb
a variety of materials. This includes applications in drying,
purification, and separation. They can remove water to very
low partial pressures and are very effective desiccants, with
a capacity of up to more than 25% of their weight in water.
They can remove volatile organic chemicals from air streams,
separate isomers and mixtures of gases.
Catalysis - Zeolites can be shape-selective
catalysts either by transition state selectivity or by exclusion
of competing reactants on the basis of molecular diameter.
Zeolites can also be acid catalysts and can be used as supports
for active metals or reagents. They have also been used as
oxidation catalysts. The main industrial application areas
are: petroleum refining, synfuels production, and petrochemical
production. Synthetic zeolites are the most important catalysts
in petrochemical refineries.
Ion Exchange - The largest volume use
for zeolites is in detergent formulations where they have
replaced phosphates as water-softening agents. They do this
by exchanging the sodium in the zeolite for the calcium and
magnesium present in the water.
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