Activated carbon is a highly porous material characterized by an extremely elevated specific surface area. This structure allows activated carbon to capture and retain a large number of pollutant molecules through adsorption on its extended internal surface.
Thanks to this high specific surface area, activated carbon is capable of trapping molecules of other substances inside its pore network, lodging them on the internal surface. In practical terms, activated carbon is a material with very high adsorptive capacity and is widely used for filtration, purification, deodorization and decolourisation of fluids and gases.
Observed under a microscope, activated carbon appears as a complex system of interconnected pores that progressively decrease in size, effectively “trapping” pollutants present in air or fluids. This unique structure gives activated carbon a specific surface area of up to 2,500 m²/g, divided into:
- Macropores (> 500 Å)
- Mesopores (20–500 Å)
- Micropores (0–20 Å)
Types and adsorption capacity of activated carbon
Our company can offer you several types of carbon from dust to granular flakes:
- ACFINDPOR is the Brofind trademark for activated carbon dust. The high adsorption features, achieved by its extreme purity, make the product especially suitable for this application.
- ACFINDBIT corresponds to activated carbon in flakes of various grain sizes. Its high resistance makes it suitable for reactivation.
- ACFINDZ is activated carbon in small cylinders. It is available both in vegetable and mineral form. This type of carbon can also be regenerated with steam or gas.
Features of activated carbon
Activated carbon is used in a wide range of industrial and environmental applications, including:
- decolourisation, for example in the food industry;
- treatment of poisoning to adsorb toxins;
- treatment of industrial wastewaters;
- purification of water, for example in aqueducts;
- solvent recovery;
- support for catalysts;
- air handling (for example in cabin filters, to reduce outdoor-borne odour nuisances);
- elimination of antibiotics and fungicides in aquariums, after treatment of the intended duration (often from 2 to 4 weeks).
Regeneration
As pollutants accumulate on the surface of activated carbon, its adsorption capacity gradually decreases until it is completely exhausted. At this stage, activated carbon must either be replaced or regenerated to restore its adsorptive properties.
Regeneration of activated carbon can be carried out through several methods:
- chemical methods, either with chemical reactants which oxidise the adsorbed organic substances, or with solvents which extract them;
- steam or inert gas (normally nitrogen) stream at relatively high temperatures (150-220 C) for the desorption of the adsorbed volatile organic compounds (VOC);
- biological regeneration processes;
- thermal processes (reactivation), actuated by heating the material in controlled environment rotating furnaces (so as not to oxidise the carbon) up to a temperature of 800-900 °C, causing the pyrolysis of the absorbed substances.
This last method is the most effective, namely thermal reactivation at high temperatures (850-2500 °C), though it entails losing part of the processed carbon.
