Activated Alumina Desiccant, under specific operating and regeneration conditions, achieves a drying depth below -70°C of the dew point temperature. This product can be used as a defluorination agent for high-fluoride drinking water (with a large defluorination capacity), a defluorination agent for recycled alkanes in alkylbenzene production, an acid-regeneration agent for transformer oil, and for drying in oxygen production, textile, and electronics industries. It is also suitable for drying of automatic instruments' air, and as a desiccant and purifier in industries such as chemical fertilizer and petrochemical drying, where the dew point can reach -40°C. In air separation, the dew point can reach -55°C. It is a desiccant for微量 depth drying and is highly suitable for non-heat regeneration systems.