Kinetic and equilibrium separation of Co and Co 2 by impregnated spherical carbons

Abstract

The surface of microporous spherical carbon was modified by nitric acid treatment and impregnation with Cu 2+ and Sn 2+ salts. The transport dynamics of CO 2 and CO were investigated by the batch-type frequency resonance method. High-pressure CO 2 and CO adsorption/desorption isotherms of the samples were measured gravimetrically in the pressure range 0–2 MPa (0–20,000 mbar), at 273, 291 and 298 K. The separation efficiency of the spherical carbon samples was evaluated on the basis of their kinetic and equilibrium performance. The high kinetic separation factor, 33, was attained, with the oxidized samples, demonstrating that oxidation enhances the interaction with CO 2. Cu impregnation influences only the Co kinetics, Sn while increases the response time by a factor of five for both gases. The equilibrium separation factor, defined by the isobaric ratio of the CO 2 and CO uptakes, varies between 2.8 and 8.5, and depends on the temperature and the pressure range applied.