an experimental study of adsorption breakthrough curves for co2/ch4 separation in a fixed bed of nanoporous shaped copper trimesate metal organic framework

copper trimesate (cu-btc) mof has been pointed out as a promising adsorbent for separating carbon dioxide from methane. however, mof’s need to be shaped prior to their use in packed bed adsorbers in order to reduce pressure drop; on the other hand, the production of mechanically resistant shaped bodies reduces their adsorption performance. in this work, cu-btc tablets provided by basf are evaluated to perform co2/ch4 separation through adsorption. the adsorption capacity of pure carbon dioxide from methane was measured in a magnetic suspension balance between temperatures of 308 and 373 k up to a pressure of 700 kpa. the evaluated material presents higher adsorption capacity than previously studied shaped samples with a carbon dioxide and methane adsorption capacity up to 3.07 and 0.63 mol/kg at 100 kpa and 308 k respectively. moreover, the experimental data were fitted with the langmuir model. isosteric heats of adsorption were obtained to be 22.8 and 15.1 kj/mol for co2 and ch4 on cu-btc tablets respectively, which indicates a strong adsorption of carbon dioxide on these adsorbents. also, single and binary breakthrough curves were measured in the same temperature range and atmospheric pressure by using cu-btc tablets as the adsorbent. the preferential adsorption capacity of co2 on nanoporous copper trimesate (cu-btc) indicates that this material can be used for methane purification from natural gas.