Molecular sieve usually means zeolite molecular sieve, it is crystalline, highly porous materials, which belongs to the class of aluminosilicates.
The crystals of molecular sieve are characterized by a three-dimensional pore system, with pores of precisely defined diameter. This diameter is in the dimension of the size of molecules such as water, CO2 and H2S. The pores can be adjusted to precisely determined uniform openings allowing for molecules smaller than its pore diameter to be adsorbed while excluding larger molecules, hence the name “molecular sieve”.
Molecular sieve has a special selective adsorption and ion exchange properties, and widely used to dehydration of gas and solvent in insulating glass, automobile air-actuated braking system, refrigeration equipment, industrial gas making, painting & coating, petrochemical industry, etc.
A 4 X 8 mesh bead is normally used in gasphase applications, while the 8X12 bead is common in liquidphase applications.