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Used tires were pyrolyzed in a nitrogen-purged 3 kg static bed, batch reactor. The char was subsequently activated in an equimolar mixture of either steam and nitrogen or carbon dioxide and nitrogen. Activation was a two-stage process, with an initial more rapid gasification of carbonized rubber deposits followed by less rapid gasification of carbon black. The activation energy in steam was 201 kJ mol -1 . The burnoff achieved by carbon dioxide under otherwise identical conditions to that of steam was on average 72% of that found when steam was used. The reactivity of acid-demineralized char in steam was around 22% less than that of raw char. It was suggested that calcium ions in the raw tire char catalyzed the gasification reactions. The tire pyrolysis temperature had an unclear influence on the rate of activation of the derived chars. The influence of particle size on the rate of activation was also investigated, and the results are discussed in terms of ash content and distribution. The outflow gas composition and gross calorific value of the gas were also determined in relation to activation conditions. BET surface areas of the derived activated carbons reached a maximum of 640 m 2 g -1 .

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