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 ch arcoal was compared to charcoal produced during conventional, atmospheric c arbonization process. Steam activation of charcoal obtained by vacuum pyrol ysis yields an activated carbon with a higher surface area than by using ch arcoal produced during atmospheric carbonization process. This can be relat ed to the more open pore structure of the vacuum pyrolysis charcoal. Steam activation of the vacuum pyrolysis charcoal was studied at temperatures ran ging from 760 to 850 degreesC. Activated carbons with surface areas above 1 200 m(2)/g and micropore volumes above 0.40 cm(2)/g were obtained. Dependin g on the activation conditions, carbons with properties (surface area, pore volume, pore structure and methylene blue value) similar to commercial gra des were produced.