Synthesis of carbon molecular sieves by activation and coke deposition

Abstract

Carbon molecular sieves were synthesized from indigenous bituminous coal and coconut shell. After preliminary treatment, these materials were subjected to steam or carbon dioxide activation in the range 500–900 °C. In other experiments the raw materials were partly air-oxidized at ~200 °C, mixed with binder and extruded to cylindrical pellets, which were subjected to coke deposition by cracking of methane in the range 750–780 °C for 5–14 min. All the products were characterized by analysis of kinetic and equilibrium adsorption data. The molecular sieve performance was judged by the O 2 N 2 uptake ratio. The best carbon molecular sieves, obtained by methane cracking at 780 °C at a flow of 100 ml min −1 had an uptake ratio of 2.667.