The performance of regenerated desiccants depends on their type and regeneration method. Generally, silica gel desiccants retain the best performance after regeneration, while other types, such as calcium chloride and quicklime, are difficult to regenerate, with limited or no performance recovery.
Silica Gel Dessert: Best Regeneration Performance, Can Be Recycled Multiple Times
Silica gel is currently the only common type of desiccant with highly efficient and reversible regeneration capabilities. It physically adsorbs moisture, and upon heating, it desorbs and restores its original structure.
Performance Retention Rate After Regeneration: Heating at 120–150℃ for 2–4 hours can restore over 95% of the initial moisture absorption capacity.
Lifespan Limitation: After repeated regeneration 3–5 times, the moisture absorption efficiency will decrease by approximately 35%. It is recommended to control the frequency of regeneration.
Color Indicator Function: Color-changing silica gel (e.g., blue/orange) turns pink or green after absorbing moisture and returns to its original color after regeneration, making it easy to determine its status.
Advantages: Non-toxic, stable, reusable, suitable for both home and industrial applications.
Calcium Chloride Dessert: Theoretically regenerable, but practically difficult to achieve. Calcium chloride has extremely strong hygroscopic capacity (up to 300%–500% of its own weight), but after absorbing water, it forms hydrates or a gel-like solution, requiring high-temperature evaporation for regeneration.
Industrial Regeneration: Can be achieved through high-temperature evaporation and crystallization, but this is energy-intensive and requires sophisticated equipment, making it unsuitable for home use.
Post-Regeneration Performance: Repeated regeneration can easily lead to structural damage, a significant decrease in hygroscopicity, and residual chloride ions may corrode equipment.
Environmental Risks: Improperly treated waste liquid may cause increased soil and water salinity.