Silica Gel White

Amorphous Silica with a High Capacity Isotherm

SorbiTech Silica Gel White is the standard non indicating grade. SorbiTech manufactures it from sodium silicate by acid precipitation, controlled gel ripening, washing, and drying, which delivers a developed pore network of 650 to 800 m²/g and a water capacity above 30 percent of its own weight at 80 percent relative humidity.

The isotherm is steepest at moderate humidity, which is the working range of most compressed air dryers and packaged goods desiccation duties. This is what makes silica gel the most economical desiccant for these applications, where activated alumina would deliver lower outlet humidity but at higher capital cost.

Compressed Air Drying

In a heatless desiccant air dryer the bed is sized for an outlet pressure dew point between minus 20 °C and minus 40 °C, which serves the majority of pneumatic instrument and process air duties. SorbiTech builds the dryer to ASME and CE with twin towers running on a 5 to 10 minute pressure swing cycle, and the SorbiTech Silica Gel White carries the duty for 3 to 5 years before requiring replacement.

For sites needing deeper drying or for fast cycling heatless duty, SorbiTech AA-201 activated alumina is the recommended alternative.

Packaged Goods and OEM Sachets

Outside compressed air, the largest single use of SorbiTech Silica Gel White is OEM packaged goods desiccation. The desiccant is supplied as small Tyvek or paper sachets in 0.5 g to 100 g sizes, packed into electronics, pharmaceuticals, packaged food, leather goods, and marine cargo to hold the relative humidity below the spoilage threshold during shipment and storage.

Regeneration and Service

A spent bed is regenerated thermally at 120 to 180 °C in air or under low vacuum, which removes the captured water and restores the gel to the dry state. The crystalline structure tolerates several thousand regeneration cycles before mechanical attrition forces a replacement.

Forms and Supply

Manufactured to ISO 9001:2015 as 2 to 5 mm beads, 3 to 8 mm beads, or 0.5 to 2 mm fine grade. Standard bulk packaging is 25 kg drums or 500 kg big bags. OEM sachet supply is matched to the customer packaging line and ships in case quantities. The non indicating white grade is the SorbiTech default for compressed air dryers; see the activated alumina drying grade alternative, the parent silica gel family, and the industrial gas sector.