Preparation of carbon molecular sieves for gas separations by modification of the pore sizes of activated carbons

Two activated carbons of different texture were modified by carbon deposition from the pyrolysis of benzene, in an attempt to obtain carbon molecular sieves of high adsorption capacity and selectivity for the separation of O2/N2 mixtures by pressure swing adsorption (PSA). The results show that these objectives can be attained when the carbon precursor has been activated only to a limited extent, and when carbon deposition is carried out in the proper kinetic regime.