High-performance silica gel for high moisture absorption and stable drying
PORESPHERE™ Macro B is an amorphous, open-pore desiccant with an exceptionally wide pore structure, designed for efficient moisture absorption even in high humidity. The combination of large pores and a diverse pore distribution allows this silica gel to facilitate rapid diffusion and
Versatile and highly effective
PORESPHERE™ Macro B is ideal for applications where fast and reliable drying is required – such as in high-flow process air systems, for protecting sensitive equipment, in laboratories, or for storing moisture-sensitive materials.
Since the material contains no color indicator, the moisture content is controlled via technical methods such as moisture measurement, dew point monitoring, or time- or volume-based regeneration cycles. Furthermore, PORESPHERE™ Macro B is thermally regenerable, enabling multiple reuses. This provides not only operational reliability but also a sustainable and economical solution.
Microstructure and pore structure of PORESPHERE™ Macro B
PORESPHERE™ Macro B is a synthetically produced, amorphous type B silica gel characterized by its highly porous macropore structure. The irregular network of silicon and oxygen atoms forms pores in the nanometer range (approx. 7.5 nm), resulting in a high pore volume and a large specific surface area of several hundred square meters per gram.
This structure enables uniform absorption of water vapor over a wide range of relative humidity. Therefore, PORESPHERE™ Macro B is particularly suitable for applications requiring consistent performance even under high humidity.
Thanks to its combination of macroporous structure, high pore volume and stable moisture absorption, the material is frequently used in chromatography, as a catalyst support, in drying processes under humid conditions and in other moisture-sensitive applications.
Adsorption behavior
The hydrophilic surface and large pores of PORESPHERE™ Macro B ensure efficient moisture absorption across a wide humidity range. The silica gel preferentially adsorbs water vapor while binding only minimally nonpolar molecules. This makes it ideally suited for processes requiring precise humidity control in humid environments.
Adsorption mechanism
Moisture adsorption occurs physically: water molecules are bound to the polar silanol groups on the surface by van der Waals forces and hydrogen bonds. The macropores of PORESPHERE™ Macro B enable effective adsorption even at higher humidity levels, while the large surface area and the abundance of free silanol groups ensure a high adsorption capacity.
Regeneration – reusable and energy-efficient
The adsorption process is completely reversible. Heating releases bound water molecules from the pores, allowing PORESPHERE™ Macro B to retain its performance in the long term.
- Optimal regeneration temperature: approx. 140 °C
- Temperatures below 100 °C lead to incomplete regeneration.
- Temperatures above 180 °C can impair the pore structure.
Since PORESPHERE™ Macro B is manufactured without a color indicator, there is no risk of degradation during regeneration.
Thermal regeneration with hot air or inert gas
Thermal regeneration can be achieved using hot air or inert gases such as nitrogen (N₂) or argon (Ar). During heating, the water molecules are released from the pores; a continuous gas flow prevents re-adsorption. The use of inert gas also prevents
Typical applications of this method include industrial drying systems, gas processing plants, and compressed air dryers. In dual-chamber dryers, alternating operation between drying and regeneration enables continuous, fail-safe performance.
Alternative regeneration methods
In addition to classic hot air regeneration, vacuum and microwave regeneration are also possible:
- Vacuum regeneration reduces the pressure in the adsorber bed and weakens the bond between water and the pore surface. This allows moisture to evaporate at lower temperatures – energy-efficient and gentle on materials, ideal for temperature-sensitive applications.
- Microwave or infrared regeneration uses radiant heat to selectively excite and evaporate water molecules. This method enables rapid regeneration with minimal energy loss and is particularly suitable for laboratory or high-tech applications.
However, for large-scale industrial processes, thermal regeneration with inert gas is usually the most efficient and economical solution.
