Patent ID: 6878657

Claim:
A process for the preparation of a molecular sieve adsorbent for the size/shape selective separation of air, which comprises (1) activating a commercially available zeolite A at a temperature in the range of from 350 to 450° C. to eliminate physically adsorbed water, for a period of time ranging from 3 to 6 hours; (2) cooling the activated zeolite in a desiccator under vacuum in the range of from 1×10 −2 to 1×10 −4 mm Hg; (3) treating the cooled zeolite with tetra alkyl ortho silicate dissolved in a dry solvent at a concentration ranging from 0.1 to 1.0 wt. %/volume for a specified period of time in the range of from 4 to 8 hours under continuous stirring; (4) recovering the solvent by conventional techniques for re-use; (5) drying the treated zeolite in air in static condition at an ambient temperature in the range of from 20 to 35° Celsius to provide a modified zeolite; (6) heating the modified zeolite to a temperature in the range of from 450 to 600° Celsius for a period of time ranging from 3 to 8 hours; and (7) cooling the zeolite at ambient temperature in static conditions to provide the molecular sieve adsorbent having a preferential oxygen adsorption selectivity over nitrogen and argon.