They're referred to as micropores (small), mesopores (medium) and macropores (large). Pore Volume Distribution - Each type of carbon has its own unique distribution of pore sizes. Pore Radius - The mean (average) pore radius, often measured in angstroms, differs by activated carbon type. Total pore volume (T.P.V.) differs by raw material source and type of activation method. However, if the sizes of the molecules to be adsorbed are not a good match to the pore size, some of the pore volume will not be utilized. In general, the higher the pore volume, the higher the effectiveness. It is expressed in milliliters per gram (ml/g), volume in relation to weight. Total Pore Volume - Refers to all pore spaces inside a particle of activated carbon. In chemical activation, phosphoric acid is used to build up such a porous system at a lower temperature. The most common process is steam activation at around 1000☌ steam molecules selectively burn holes into the carbonized raw material, thus creating a multitude of pores inside the carbonaceous matrix.

It is in the activation process that this vast surface area is created.

The surface area of activated carbon is impressive, 500 to 1500 m2/g or even more a spoonful of activated carbon easily equates the surface area of a soccer field.

Surface Area - Generally, higher the internal surface area, higher the effectiveness of the carbon. Physical Adsorption - During this process, the adsorbates are held on the surface of the pore walls by weak forces of attraction known as Van Der Waals Forces or London dispersion forces.Ĭhemisorption - This involves relatively strong forces of attraction, actual chemical bonds between adsorbates and chemical complexes on the pore wall of the activated carbon. Typically 1 m3 of Activated Carbon with 0.3m3 of internal pores can adsorb 30m3 or more of a gas, even if present in low concentrations in a carrier. These molecules are then trapped within the carbon's internal pore structure by Van Der Waals Forces or other bonds of attraction and accumulate onto a solid surface. Adsorption occurs in pores slightly larger than the molecules that are being adsorbed, which is why it is very important to match the molecule you are trying to adsorb with the pore size of the activated carbon. The porosity of activated carbons offers a vast surface on which this adsorption can take place. AdsorptionĪdsorption is the attachment or adhesion of atoms, ions and molecules (adsorbates) from a gaseous, liquid or solution medium onto the surface of an adsorbent – activated carbon. This is the key to the performance of activated carbon. The intrinsic pore network in the lattice structure of activated carbons allows the removal of impurities from gaseous and liquid media through a mechanism referred to as adsorption. Chemical activation or High Temperature Steam Activation mechanisms are used in the production of activated carbons from these raw materials. The networks of pores in activated carbons are channels created within a rigid skeleton of disordered layers of carbon atoms, linked together by chemical bonds, stacked unevenly, creating a highly porous structure of nooks, crannies, cracks and crevices between the carbon layers.Īctivated carbons are manufactured from coconut shell, peat, hard and soft wood, lignite coal, bituminous coal, olive pits and various carbonaceous specialty materials. New to Activated Carbon Industry? You will find this is extremely helpful for you to get to know the basics of Activated CarbonĪctivated carbon is a carbonaceous, highly porous adsorptive medium that has a complex structure composed primarily of carbon atoms.

Activated carbon