Carbon pellets have been prepared from powdered Eucaliptus globulus charcoal, by mixing with an organic binder followed by a thermal treatment in carbon dioxide. The obtained materials have been characterised by N2 and CO2 adsorption and temperature-programmed decomposition of surface complexes. Their properties as carbon molecular sieves (CMS) have been evaluated by measuring the adsorption kinetics of CO2 and CH4 at room temperature. It has been found that, under the experimental conditions used, the adsorption selectivity is controlled by the methane adsorption rate, and this selectivity is higher for the CMS obtained at high temperature (870 °C), with a high heating rate and short activation time.
Keywords
Carbon molecular sieves; Charcoal; CO2/CH4 separation; Selectivity