Activated carbon produced from charcoal obtained by vacuum pyrolysis of softwood bark residues

Vacuum pyrolysis of softwood bark residues yields besides oil, charcoal as second valuable product. The activation behavior of the vacuum pyrolysis charcoal was compared to charcoal produced during conventional, atmospheric carbonization process. Steam activation of charcoal obtained by vacuum pyrolysis yields an activated carbon with a higher surface area than by using charcoal produced during atmospheric carbonization process. This can be related to the more open pore structure of the vacuum pyrolysis charcoal. Steam activation of the vacuum pyrolysis charcoal was studied at temperatures ranging from 760 to 850 degreesC. Activated carbons with surface areas above 1200 m(2)/g and micropore volumes above 0.40 cm(2)/g were obtained. Depending on the activation conditions, carbons with properties (surface area, pore volume, pore structure and methylene blue value) similar to commercial grades were produced.