Activated carbon is a carbonaceous adsorbent with a high internal porosity, and hence a large internal surface area. Commercial activated carbon grades have an internal surface area of 500 up to 1500 m²/g. Related to the type of application, two major product groups exist:

• Powdered activated carbon; particle size 1-150 micron
• Granular activated carbon (granulated or extruded), particle size in the 0.5-4 mm range

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:

• Macropores (above 50 nm diameter)
• Mesopores (2-50 nm diameter)
• Micropores (under 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 (SEM). 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.

Now you can imagine that Norit offers over 150 different activated carbon grades.

For any further information, please fill in the questionnaire or contact the nearest Norit sales office or agent.