Comparison of the Prices of Activated Powder and the Adsorption Characteristics of Activated Alumina

Molecular sieve manufacturers deal with a kind of aluminosilicate compound with a cubic lattice structure. Molecular sieves have a uniform microporous structure, and the diameters of their cavities are uniform. These cavities can adsorb molecules smaller than their diameters into the interior of the cavities, and they have a preferential adsorption capacity for polar molecules and unsaturated molecules. Therefore, they can separate molecules with different degrees of polarity, different degrees of saturation, different molecular sizes, and different boiling points, that is, they have the function of "screening" molecules, so they are called molecular sieves. Due to the advantages that molecular sieves have, such as high adsorption capacity and strong thermal stability, which other adsorbents do not possess, molecular sieves have been widely applied.

Molecular sieves have a very high affinity for high-polarity molecules such as H₂O, NH₃, H₂S, and CO₂. Especially for water, they still have a very high adsorption capacity under extremely harsh conditions such as low partial pressure (even below 133 Pa) or low concentration and high temperature (even above 100°C).

Comparison of the Adsorption Characteristics between Molecular Sieves and Activated Alumina:

Adsorption at Low Partial Pressure or Low Concentration: When the relative humidity is 30%, the water absorption capacity of molecular sieves is higher than that of silica gel and activated alumina. As the relative humidity decreases, the superiority of molecular sieves becomes more and more significant. While for silica gel and activated alumina, their adsorption capacity increases continuously with the increase of humidity, and when the relative humidity is very low, their adsorption capacity is very small.

High-temperature Adsorption: Molecular sieves are available high-temperature adsorbents. At 100°C and a relative humidity of 1.3%, molecular sieves can adsorb 15% of water by weight, which is 10 times the water absorption capacity of activated alumina under