Equilibrium Adsorption of Silica Gel vs RH

Silica Gel is the world’s most popular desiccant in a variety of industries, including pharmaceutical, medical devices, and defence. It has an excellent adsorption response throughout almost the entire relative humidity (RH) spectrum, and the highest overall capacity of commercial desiccants. The tool provided here allows you to determine the specific adsorption capacity of silica gel with respect to RH. Shown graphically in Figure 1. This can then be used to determine the mass of silica gel required for a given application. We note that while there will be small variations with temperature, the adsorption values are very stable for all typical temperatures.

For example, if you have a moisture load of 100mg at 10% RH, then given the adsorption of 8g moisture per 100g desiccant, then you need 100mg/0.08 = 1.25g of silica gel.