The main components  functions of molecular sieves are briefly introduced

Molecular sieves have synthetic aluminosilicate hydrate (zeolites)  natural zeolites. Its chemical formula is (m'2m) O · Al 2O 3 · xsio2 · yh2o, M ' m are k, Na  ca22, ba22  other monovalent  divalent cations. There are many uniform holes  well arranged holes in the structure. Molecular sieves with different pore sizes can separate molecules of different sizes  shapes. According to the molecular ratio of silica to alumina, the molecular sieves with different pore sizes were obtained. Its models are: 3A (potassium a), 4a (sodium a), 5A (calcium a), 10z (calcium z), 13z (sodium z), y (sodium y), mercerizing sodium, etc. It has high adsorption capacity, high selectivity  high temperature resistance. It is widely used in organic chemical industry, petrochemical industry  other fields.

The basic structure of the framework of molecular sieve is SiO4  alo4 tetrahedron. They combine with a common oxygen atom to form a three-dimensional network structure. This combination forms cavities  pores with molecular level  uniform pore size. Due to the different structures  forms of "cage" space pores, they are divided into "cage" space pores, such as α, β, γ, hexagonal columns  pumice.

Adsorption function: the adsorption of molecular sieve to the material comes  physical adsorption (van der Waals force). The crystal pore has strong polarity  Coulomb field,  has strong adsorption ability to polar molecules such as water  unsaturated molecules.

Screening function: the pore size distribution of molecular sieves is very uniform,  only materials smaller than the pore size can enter into the lattice.

Molecules of different substances are distinguished according to the order of priority  adsorption size, so they are appropriately called "molecular sieves".

Molecular sieves have strong hygroscopicity  can be used to purify gases. Avoid direct exposure to air during storage. Molecular sieves with long storage time  good hygroscopicity should be regenerated before use. Molecular sieves avoid oil  liquid water. Avoid contact with oil  liquid water during use. 4. The drying gases in industrial production include air, hydrogen, oxygen, nitrogen  argon.