Molecular simulations have shown that the metal-organic framework Cu-BTC (Cu-3(BTC)(2)) is an interesting candidate for the separation of CO2 by adsorption. In this work, the first experimental binary and ternary adsorption data of CO2, CH4, and CO on the Cu-BTC are reported. These data are analyzed and compared with coadsorption models that are built from pure component isotherm data. Cu-BTC has a CO2/CH4 selectivity of similar to 8 and a high delta loading (=difference between adsorption capacity under conditions of adsorption and desorption) and therefore appears to be a good compromise between zeolites, with high selectivity for CO2, but low delta loadings, and activated carbons, with high delta loadings, but low selectivity, for pressure swing adsorption applications.