Most practical applications of adsorption technology for gas separation and purification deal with multicomponent feed gas mixtures. The key input variables for the design and optimization of such separation processes are the multicomponent gas adsorption equilibria, kinetics, and isosteric heats. Recent advances in the measurement of these properties for multicomponent systems by macroscopic methods are discussed. The isothermal isotope exchange technique for measurement of multicomponent gas equilibria and kinetics, and micro-calorimetry for direct measurement of component isosteric heats from gas mixtures are recommended.