3A molecular sieve is a kind of aluminosilicate crystal with uniform microporous structure, which is widely used in the production and drying of industrial ethanol, such as ethanol distillation and PSA ethanol purification. The following is an introduction to its principles, characteristics, advantages and other applications.
Application Principle
The pore size of 3A molecular sieve is about 3 angstroms, the diameter of water molecules is about 2.8 angstroms, and the diameter of ethanol molecules is greater than 4 angstroms. Therefore, 3A molecular sieve can selectively adsorb water molecules and let ethanol molecules pass through, thereby achieving the purpose of drying and dehydration. This selective adsorption is based on the difference in molecular size and utilizes the screening effect of molecular sieve.
Characteristics
3A molecular sieve has the characteristics of high selective adsorption and large adsorption capacity. It has strong selective adsorption for water and can preferentially adsorb a large amount of water in organic compounds such as ethanol, while the adsorption amount of ethanol is very small, which ensures the high efficiency of dehydration and high recovery rate of ethanol, and reduces the use and replacement frequency of molecular sieve. In addition, 3A molecular sieve adsorbent also has stable chemical properties, good acid and alkali resistance, and is not easy to react chemically with ethanol or other impurities during ethanol drying and dehydration, which ensures the service life and dehydration effect of the molecular sieve.
Other applications
In addition to solvent dehydration, 3A molecular sieve beads can also be used for gas drying. For example, air drying, it can prevent equipment corrosion by removing moisture from the air and improve the efficiency and purity of air separation. For the drying of petroleum cracking gas, 3A zeolite molecular sieve desiccant can effectively remove moisture and impurities in it, and improve qualified raw gas for subsequent processing. Natural gas drying, by adsorbing moisture in natural gas, zeolite 3A prevents the formation of hydrates during transportation and storage, clogging pipelines and equipment, and improves the calorific value and utilization efficiency of high natural gas.
