Definition of Activated Carbon

Process Principles

As its name indicates, the carbon must be "activated" and this generates the release of sites that subsequently allow it to be added to molecules, ions or atoms, allowing the elimination of toxins. In addition, it is observed that it is a versatile compound since it can be in contact with both gases as with liquids to purify them. In that case, the solid (activated carbon) is called adsorbent while the substance to be retained is called adsorbate.

To be "activated", the carbon must undergo thermal or chemical processes that are capable of forming pores on the surface, which gives it its adsorption capacity. If the treatment is thermal, the coal is subjected to high temperatures causing the oxidation of the compound for its channeling and subsequent formation of pores, in general, the addition of steam or nitrogen is required and a control in the process to prevent it from being reduced the

efficiency of the process losing carbon. On the other hand, if the process is chemical, it seeks to break the bonds between cellulose chains, later it is carbonized at temperatures lower than thermal activation and finally it is cleaned.

Not any substance that has carbon can be activated, it is necessary that the bonds between atoms relatively weak so that they are capable of trapping molecules of the fluid with which they come into contact Contact. That is, between the carbon and the fluid molecules there will be intermolecular London forces, this gives it the skill of reversibility. Then you get to the conclusion that adsorption is a reversible process, so much so that when carbon occupies all its active sites it is exhausted and must undergo a desorption process to continue being used. This process cleans the sites occupied by activated carbon impurities, leaving them free for a new purification cycle.

As is well known, like attracts like, so activated carbon is a good adsorbent for covalent-type molecules, since, For example, if ionic compounds were adsorbed, they would strongly polarize the bond so as to take electrons from the carbon atoms. carbon.

Based on this, highly ordered carbonaceous compounds with forces of attraction more intense are difficult to activate to generate pores, the less the order of the structure and the less hard the material, the easier it will be to generate pores in it.

Examples of the use of activated carbon

Thanks to its versatility, it has countless uses, from medicinal to even in water treatment. The latter is one of the main uses since it has managed to make water purification processes profitable and make them much more efficient. In this case, activated carbon is responsible for retaining fats, oils, organic matter, fungi, bacteria, viruses, pesticides and even active chlorine. Many of these substances are responsible for giving the water a taste and smell, which is why this filter is crucial in processing. So much so that, for example, reverse osmosis equipment usually has a double pass through activated carbon filters, a previous step before entering the reverse osmosis membrane and a subsequent step, to culminate with its purification.

In the case of air, for its deodorization it is also used in spaces that store volatile organic solvents such as in recirculation systems.

In stores we find it in the form of pellets or powder, the latter is used in water purification while cylindrical pellets, thanks to their lower pressure drop, are often used in the treatment of gases.

Likewise, activated carbon has tax a fashion in the field of health. There are those who affirm its benefits in the stomach and skin. For example, many people carry activated charcoal tablets in their wallet since it is indicated as a treatment for stomach upset and diarrhoea. In addition, it is considered a supplement to kidney function in detoxification since a reduction in intestinal inflammation has been observed in people with chronic kidney diseases.

On the other hand, thanks to its bleaching properties, it is often recommended for tooth whitening and for “skin care” type routines.

Themes in Activated Carbon