Molecular sieve is an artificially synthesized hydrated aluminosilicate (zeolite) or natural zeolite with the function of screening molecules. Its chemical formula is (M′₂M)O·Al₂O₃·xSiO₂·yH₂O. It has many pores with uniform pore sizes and neatly arranged pores in its structure. Molecular sieves of different pore sizes can separate molecules of different sizes and shapes.

Molecular sieves have many excellent properties. Its adsorption capacity is high, and it can effectively adsorb molecules in gases and liquids; it has strong selectivity and can accurately separate according to the size of the molecule; it is resistant to high temperatures and can maintain stable performance under high temperature environments. In the fields of organic chemicals and petrochemicals, it is an excellent adsorbent for gas dehydration, which can efficiently remove moisture from gas and improve gas quality. In terms of exhaust gas purification, molecular sieves are also receiving increasing attention, which can adsorb and decompose harmful substances in the exhaust gas and reduce environmental pollution.

There are many types of molecular sieve, such as 3A (potassium A), 4A (sodium A), 5A (calcium A), etc. Different models are suitable for different application scenarios. With the continuous advancement of science and technology, the performance of molecular sieves will continue to improve, and the application fields will be further expanded, making greater contributions to the development of modern industry.