Molecular sieves are zeolites. Zeolites are crystalline three-dimensional aluminosilicates with cavities inside the crystal lattice. These cavities are connected by channels, the so-called pores. The pores have an exactly defined diameter which is the most important parameter for the application of zeolites. That means just molecules having a diameter smaller than the diameter of the pores reaching the cavities. Thereby an accurate separation (selectivity, molecular sieve effect) between absorbable and non-absorbable molecules is possible.
According to their pore Grade like 3A, 4A, 5A and 13X are available in Beads and Pellet Forms.
Yes, you can regenerate. There are some methods of Regeneration of Molecular Sieve include pressure change, heating and purging with a carrier gas or vacuum Pressure Swing Adsorption. Regeneration temperatures depend on Molecular Sieve type.
Life of Molecular Sieves is around 5-6 years. However, Molecular Sieves life is reduced by oil and any other impurities in the air. Therefore, it is essential to provide special pre-filters if lubricated air is used.