In news- Air India flights began transporting ‘zeolite’, from Rome, that is an essential component imported by the DRDO for oxygen generation.
- Zeolite, also called molecular sieve, are microporous crystalline solid of aluminium silicate that have small openings of fixed size to trap large molecules, while allowing small molecules to pass through.
- Atmospheric air contains 78 % nitrogen and about 20 % oxygen and zeolite adsorbs or traps nitrogen onto its surface.
- Zeolite is used in the Medical Oxygen Plant (MOP) technology, developed by DRDO for on‐board oxygen generation on aircraft like Tejas.
- The MOP utilizes Pressure Swing Adsorption (PSA) technique and Molecular Sieve (Zeolite) technology to generate oxygen directly from atmospheric air.
- This technology will be useful to provide oxygen supply during the pandemic in hospitals in urban and rural areas.
Zeolites occur naturally as well as man made. They are very stable solid with a high melting point of 1000 degree Celcius. They do not undergo oxidation in the presence of air. They are insoluble in water or other inorganic solvents. They do not have any harmful environmental effects though skin contact or inhalation might have a carcinogenic effect.
Application of Zeolites-
- Zeolites are widely used as ion-exchange beds in domestic and commercial water purification, softening.
- They have the potential of providing precise and specific separation of gases, including the removal of H2O, CO2, and SO2 from low-grade natural gas streams.
- Zeolites help silver naturally emit light, which may compete with fluorescent lights or LEDs.
- Zeolites have used advanced nuclear-waste reprocessing methods, where their micro-porous ability is used to remove fission products from the waste.
- Used to thermochemically store solar heat harvested from solar thermal collectors.
- In agriculture, clinoptilolite (a naturally occurring zeolite) is used as a soil treatment. It provides a source of slowly released potassium.
- Clinoptilolite has also been added to chicken food- the absorption of water and ammonia by the zeolite made the birds’ droppings drier and less odoriferous, hence easier to handle.
- Pet stores market zeolites for use as filter additives in aquaria.