Activated carbons with molecular sieve propeties

Carbon molecular sieves with micropore diameters of 0.41-0.54 nm were obtai ned by activation with water vapour to 6% burn-off of chars from oxidized b ituminous coals and semianthracite. A temperature of 750 degrees C and a fl ow rate of 100 mL.min(-1) of N-2 with a 12.4% of steam content were used. L ess developed microporosity was obtained from anthracite, that needed a 12% bum-off in order to obtain similar micropore development and size distribu tion. Activation temperature has an important influence in the development of microporosity of chars from anthracite. For chars from lo tv rank coals narrower micropore size distributions can be obtained by using in the activ ation a low stream flow rate.