Progressively magnified views of an activated carbon granule

How Does ACE Work?

ACE is achieved by introducing granules of activated carbon into the enclosure.

Activated carbon can be produced from any organic material. The source material is first heated in an oxygen free environment, to prevent burning and to remove any volatile components. The carbon is then activated by additional heating in a controlled environment of oxygen and steam.

We can see from the magnified images (figure 1) that the surface of activated carbon contains a multiplicity of cavern-like pores. In fact these pores penetrate deep into the material and there are more than a million-fold range of pore sizes, from visible cracks to holes of molecular dimensions. Porosity is what distinguishes activated carbon from other carbon materials, and gives it amazing versatility.

Intermolecular attractions in these pores result in adsorption forces. Carbon adsorption forces work like gravity, but on a molecular scale. The pore size distribution is normally classified into macropores, mesopores (collectively known as ‘transport pores’) and micropores (figure 2). It is in the latter - also known as adsorption pores - that the key process of adsorption takes place.

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