Modification of pore size in activated carbon by polymer deposition and its effects on molecular sieve selectivity

The separation of air for nitrogen production can be carried out by pressur e-swing-adsorption over a carbon molecular sieve. The separation is kinetic ally controlled, since the equilibrium adsorption of both oxygen and nitrog en is very similar, but the adsorption kinetics for oxygen is faster than f or nitrogen. Several methods to prepare carbon molecular sieves are reporte d. In this work, we synthesized a carbon molecular sieve from a commercial activated carbon. After deposition of polyfurfuryl alcohol, these materials were subjected to carbonization at 800 degreesC under an inert atmosphere. All the microporous materials were characterized by analysis of kinetics a nd equilibrium adsorption data. The molecular sieve performance was assesse d by the O-2/N-2 uptake ratio. The material prepared by two depositions has characteristics similar to those of commercial CMS. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.