Activated alumina as a desiccant works by a process called adsorption where it removes water from the air by trapping the water molecules when air is passing through the desiccant chamber. It is used for a wide range of adsorbent and catalyst applications including the adsorption of catalysts in polyethylene production, in hydrogen peroxide production, as a selective adsorbent for many chemicals including arsenic, fluoride and sulfur removal
from gas streams. Air dryer desiccant releases the trapped water at heated temperature of ~200°C , there by regenerating itself.