Activated carbon can be prepared from a variety of raw materials. The most frequently used precursors for activated carbons are wood and its residues, nut shells, fruit stones and agriculture residues. A raw material with a high bulk density and a low content of volatiles such as nut shells and fruit stones is appropriate to produce mechanically strong granular activated carbon with a high adsorption capacity. In North Europe, however, these raw materials are either non-available or available in insufficient amounts. Therefore, it is proposed in this study to obtain mechanically strong granular activated carbon by physical activation with superheated steam under a self-generated atmosphere from hydrothermally treated and pelletized grey alder (Alnus incana (L.) Moench) wood.
The influence of the moisture content before pelletization in the range 4-12 wt% on the mechanical properties and the developed porous structure of the obtained carbons was studied. The mechanical and surface properties of activated carbons depend on the combined effect of the conditions employed. If microporous high density sorbents are necessary, the pelletization with the moisture content 6-10 wt% is preferable.
Keywords: Lignocellulosic sources, hydrothermal treatment, pelletization, carbonization, activated carbon
Authors
Rizhikovs J.
Department of Technological Research, Latvian State Institute of Wood Chemistry, Riga, Latvia
Zandersons J.
Department of Technological Research, Latvian State Institute of Wood Chemistry, Riga, Latvia
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