PREPARATION AND CHARACTERIZATION OF ACTIVATED CARBONS FROM ANTHRACITE

A single-step pyrolysis/activation was used to produce activated carbo ns from a Pennsylvania anthracite. Steam was employed as the principal activation agent, although some experiments were carried out using ai r activation prior to the reaction with steam. Activated carbons produ ced from two different particle size ranges of the starting anthracite (1-3 mm and <1 mm) showed relatively high N2 BET surface areas depend ing on the pyrolysis/activation conditions. The highest BET surface ar ea carbon (720 m2/g) was obtained from the anthracite with particle si ze <1 mm. The particle size of the starting anthracite was found to be the most important variable which affects the adsorption properties o f the resulting carbons. The initial reaction of the anthracite with a ir leads to an increase in the solid yields with comparable adsorption parameters for the steam activated anthracite with highest N2 surface area produced at treatment temperature of 850-degrees-C for 6 h from fine particles. Microscopic examination of activated carbons showed a highly anisotropic attack of steam on the active edges of anthracite p articles. This preferential attack produced highly asymmetrical needle like particles. Air activation results in more isotropic activation of the anthracite surfaces.