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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 °C. 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.

The surface energy of thermal and furnace carbon blacks was determined by inverse gas chromatography (IGC) at infinite dilution. In general, the specific surface energy decreases with decreasing carbon black specific surface area. However, there is also an influence of the concentration of impurities during the carbon black production. The surface energy decreases with decreasing concentration of impurities. The carbon black surface and bulk chemistry was studied by electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectroscopy (SIMS) and Raman spectroscopy. Scanning tunnelling microscopy (STM) was used for characterization of the surface morphology. Thermal grades of carbon black produced from high purity natural gas feedstock do not contain fewer surface functional groups than the other grades. No correlation between the concentration and nature of the oxygen and sulphur surface groups and the carbon black surface energy was found. Instead, a correlation between the surface energy and the polyaromatic character of the carbon black surface exists. Both increased in the order: thermal blacks from high purity natural gas feedstock < thermal black from oil feedstock < furnace blacks. The increase of the surface energy might be related to the formation of active sites which are formed upon removal of non-carbon elements during the carbon black formation. There was no principal difference in the surface morphology of thermal blacks from high purity gas feedstock and other blacks.