Activated carbon is a carbonaceous adsorbent with a high internal porosity, and hence a large internal surface area. The manufacturing and activation process and the basic raw materials used have a determining influence on the adsorptive capacity of activated carbon products in use. Raw material may be charcoal, bituminous coal, wood, coconut shells, olive stones, fruit stones, peat etc.

Commercial activated carbon grades have an internal surface area of 500 up to 1500 m2/g. Related to the type of application, three major product groups exist: Powdered activated carbon; particle size 1-150 μm Granular activated carbon, particle size 0.5-4 mm Extruded activated carbon, partilce size 0.8-4 mm A proper activated carbon has a number of unique characteristics: a large internal surface area, dedicated (surface) chemical properties and good accessibility of internal pores. According to IUPAC definitions three groups of pores are distinguished

There are mainly five types of activated carbon. Each is better suited to a certain application than another, and here are the main forms of activated carbon you will come across.

• Powdered Activated Carbon
• Granulated Activated Carbon
•  Pelletized Activated Carbon
•  Impregnated Activated Carbon
•  Catalytic Activated Carbon

Macropores (>50 nm diameter) Mesopores (2-50 nm diameter) Micropores (< 2 nm diameter) Micropores generally contribute to the major part of the internal surface area. Macro and mesopores can generally be regarded as the highways into the carbon particle, and are crucial for kinetics. Macropores can be visualised using scanning electron microscopy. The pore size distribution is highly important for the practical application; the best fit depends on the compounds of interest, the matrix (gas, liquid) and treatment conditions. The desired pore structure of an activated carbon product is attained by combining the right raw material and activation conditions.