A molecular sieve is a porous material with a uniform microporous structure, composed mainly of silicon, aluminum, and oxygen. Its crystal framework contains countless cavities and channels. Because the pore size is fixed and uniform, only molecules with diameters smaller than the pore openings can enter, while larger molecules are excluded. This enables selective separation of molecules.
Removal of Hydrogen Sulfide (H₂S)
Desulfurization-grade molecular sieves have surface cations, such as Na⁺ and Ca²⁺, that interact strongly via electrostatic forces with the polar H₂S molecule, firmly adsorbing it within the channels. Molecular sieves exhibit a much stronger adsorption capacity for H₂S than for CH₄ or CO₂, so they are widely used for deep desulfurization of natural gas, biogas, and refinery gas, reducing H₂S concentrations to very low levels.
Removal of Sulfur Dioxide (SO₂)
Similar to H₂S, the sulfur and oxygen atoms in SO₂ interact with cationic sites on the molecular sieve surface and are strongly adsorbed. Silver-exchanged (Ag⁺) modified molecular sieves show particularly high affinity and capacity for SO₂. They are commonly used for treating low-concentration SO₂ in tail gases or as a gas-purification step in fine-chemical processes. For high-concentration SO₂ flue gas from coal-fired power plants, however, limestone-gypsum wet flue gas desulfurization is more economical, while desulfurization-grade molecular sieves can be used downstream for polishing.
Shanghai Jiuzhou’s desulfurization-grade molecular sieves, with precise pore sizes, very high specific surface area, and tunable chemical properties, have become powerful and versatile materials for industrial exhaust-gas control.
Post time: Sep-08-2025