active carbon are complex products which are difficult to classify on the basis of their behaviour, surface characteristics and other fundamental criteria. However, some broad classification is made for general purposes based on their size, preparation methods, and industrial applications.
active carbon is available in many forms, which are each ideal for different applications. Common forms of activated carbon include:
Powdered active carbon (PAC), which consists of crushed or ground carbon particles with an average diameter between 0.15 mm and 0.25 mm. Powder active carbon has a large internal surface with small diffusion distance, which makes it applicable for filtering liquid and gas.
Granulated active carbon (GAC), whose particles are typically larger than powder active carbon particles. Granular active carbon is useful for water purification and can also be found in deodorization products.
Pelletized activated carbon, which consists of extruded cylinders of active carbon particles with diameters ranging from 0.8 to 5 mm. These pellets are mainly used for gas phase applications such as removing volatile organic compounds and odor control.