Adsorption – its operating principle is comparable to a cream pie thrown in one’s face.helsa’s honeycomb-shaped ceramic activated carbon filters are used as odour killers in extractor hoods among other applications.Activated carbon granulate, ready for further processing.Activated carbon can also be used to treat foams and non-wovens: helsa Sorbexx GS filter media.
15.10.2018 helsapedia

helsa ABCs

A as in activated carbon

Have you ever tried activated charcoal ice cream? Or a black smoothie? What about whitening your teeth with activated charcoal toothpaste?

Lately it seems like activated charcoal (also called activated carbon) is everywhere you look. Is it actually a miracle aid or just a clever advertising ploy? A healthy portion of scepticism is warranted; after all, there’s no reason to believe all the hype, is there?

Even we can’t tell you whether black facial masks will revolutionize your skincare regimen or charcoal smoothies will boost your health.

But what we can say – as the helsa experts – is what activated carbon actually can do and the application areas where its properties truly shine.


How to make activated carbon from a coconut shell

Before you can hold activated carbon in your hands, it must go through two processing steps:
1. Carbonization and 2. Activation

The source materials are always raw materials that already contain a great deal of carbon such as timber, peat, brown coal, the seeds and pits of fruits, coconut shells and similar natural products. During “pyrolysis”, heating materials in the absence of oxygen, all non-carbon compounds evaporate in the first step. What remains is a pitch black, shrunken piece of coal.

Activated carbon is finally “activated” in the second step, “activation”, made possible chemically or through the use of steam. What happens during the process: A winding labyrinth is created with extremely fine pores and cracks, which then form the inner surface of the coal. Imagine a network of caves infinitely branching off into different directions, with entrances growing ever smaller and more narrow. A sponge is another apt comparison: Large, medium, fine and the finest possible pores join together to form the carbon skeleton.

What makes this so interesting:

Its structure gives activated carbon an enormous inner surface, namely one that can reach anywhere from 500 to 1500 m2/g. Or, to put it another way: A teaspoonful could contain the entire surface of a football field! Incredible, isn’t it?

And that brings us to what activated carbon does best.


Ingenious operating principle

Activated carbon binds undesirable substances. It performs this job quite well because it has so much space to do it (remember the labyrinth?).

Even the tiniest particles of pollutant gases or odours that flow through this labyrinth are trapped in the pores. The magic word here is “adsorption” – the attraction of a gas or liquid to the surface of a solid. Imagine someone throwing a cream pie in your face: A lot of it is going to stick, isn’t it? This is precisely how adsorption works. ;-)

In concrete terms this means that activated carbon can bind odours and pollutants and “take them out of circulation”.


A clean affair

Activated carbon is used due to its adsorptive properties for exhaust and air purification, drinking water purification, groundwater remediation, in the field of medicine and much more.

At helsa we use it to manufacture filter media for air purification in buildings, industrial plants or cars, as well as for medical and cooking applications.



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