Molecular sieve manufacturer talks about when molecular sieves can be used as adsorbents

In general, the adsorption dryer uses activated alumina as the adsorbent, but activated alumina also has its shortcomings, in this case, it is necessary to use molecular sieve as the adsorbent. molecular sieve manufacturer talks about under what circumstances molecular sieves are used as adsorbents.

Molecular sieve is an excellent adsorbent. It has a larger surface area than alumina, and its surface area and pore size are very uniform, and it has good adsorption selectivity. Large adsorption capacity (activated alumina and silica gel have large adsorption capacity only when the water vapor pressure is high), therefore, molecular sieves are used for deep dehydration and drying of compressed air.

However, molecular sieves can not be used as adsorbents in any case, and it also has its own shortcomings: first, the adsorption capacity of molecular sieves for gases with large water content is not better than that of silica gel and alumina; secondly, the desorption temperature of molecular sieves High energy consumption for regeneration, easy to retain water; third, molecular sieve has low mechanical strength, easy to break and pulverize under pressure, long-term use can increase the bulk density by 20%, which increases the resistance of the adsorption bed; fourth, the molecular sieve has a high resistance to liquid water droplets The resistance is poor, and it is easy to powder and deteriorate when it encounters liquid water droplets. Therefore, when dealing with compressed air with high water content, the compressed air should be pre-dried with adsorbents such as silica gel and alumina, and the remaining moisture should be treated with molecular sieve, which not only ensures the requirement of deep drying, but also avoids Molecular sieves have the disadvantages of low adsorption capacity, easy failure, and frequent regeneration and replacement when the moisture content is high.