Activated carbons were produced from coconut shells by chemical activation using H3PO4 (CAQ1) and ZnCl2 (CAQ2), and used as adsorbents for natural gas storage. CAQ1 presented a wider pore size distribution than CAQ2. Storage evaluations were made in a semi-pilot unit (0.54.0?MPa and 298313?K). According to the used reactant, at 313?K and 3.0?MPa, the adsorptive capacities were 0.060?g/g (CAQ2) and 0.092?g/g (CAQ1). The shortest storage time to charge the tank to 4.0?MPa was obtained by CAQ2 (3.1?min), compared to CAQ1 (3.4?min), due to its higher specific heat capacity. (C) 2011 Canadian Society for Chemical Engineering