Molecular sieve is a kind of cubic crystal aluminosilicate compounds. Molecular sieve has the advantages of uniform porous structure, the diameter of the aperture size uniform, these holes to the adsorption of molecules smaller than the diameter of the cavity to the internal, and the polar molecules and unsaturated molecules has a preferential adsorption capacity, and are better able to different degrees, different saturation degree, molecular size and the boiling point of different molecules are separated, that is "screening" molecular, the so-called molecular sieve. Molecular sieve has the advantages of high adsorption capacity, high thermal stability, and so on, so that the molecular sieve is widely used.
Molecular sieve classification
3A molecular sieve
Chemical formula:, 1/3Na2O, Al2O3, 2SiO2, 9/2H2O, 2/3K2O
Silicon aluminum ratio: SiO2/ Al2O3 = 2
Effective aperture: about 3A
Application: mainly used for all kinds of liquids (such as ethanol dry, gas drying, dry methane gas, refrigerant drying, unsaturated hydrocarbon and pyrolysis gas, ethylene, acetylene, propylene, butadiene drying, alcohol and all kinds of solvent dehydration.
4A molecular sieves
Chemical formula: Al2O3, 2SiO2, Na2O, 9/2H2O
Silicon aluminum ratio: SiO2/ Al2O3 = 2
Effective aperture: about 4A
Application: mainly used for natural gas and chemical gas and liquid, refrigerants, pharmaceuticals, electronics and materials and volatile substances dry, purified argon, methane, ethane, propane separation.
5A molecular sieves
Chemical formula: 3/4CaO, 1/4Na2O, Al2O3, SiO2 2, 9/2H2O
Silicon aluminum ratio: SiO2/ Al2O3 = 2
Effective aperture: about 5A
Application: it is mainly used for the separation of the isomers of alkanes, oxygen and nitrogen separation, chemical industry, petroleum and natural gas, ammonia decomposition gas and other industrial gases and liquids.
13X molecular sieve
Chemical formula: Al2O3 2.45SiO2 6.OH2O Na2O
Application: industrial gas drying and purification, can also be used as a carrier. Purification of raw gas for air separation unit (simultaneous removal of H2O and CO2). Desulfurization of liquid hydrocarbons and natural petroleum gas (removal of hydrogen sulfide and thiol).