Molecular sieve is a kind of material containing precise and single micro pores, which is used to adsorb gas or liquid. Small enough molecules can be adsorbed through the pores, while larger molecules cannot. Molecular sieves are often used as desiccants. A molecular sieve can absorb up to 22% of its own weight of water. Molecular sieves are often used in the petroleum industry, especially in the purification of gas. For example, silica gel molecular sieves are used to adsorb mercury in natural gas to avoid corrosion to aluminum pipelines and other liquefaction equipment.
Molecular sieves can be divided into silicon aluminum, phosphorus aluminum and heteroatoms according to the composition of skeleton elements. According to the size of holes, those with hole size less than 2nm, 2-50nm and greater than 50nm are called micropores, mesopores and macropores respectively.
It is widely used in many fields, such as microporous molecular sieve as the main catalytic raw material, adsorption separation material and ion exchange material, which plays an increasingly important role in petrochemical industry, fine chemical industry and daily chemical industry
