Utilizing transient breakthroughs for evaluating the potential of Kureha carbon for CO₂ capture

The commercial Kureha carbon was used as adsorbent for the selective adsorption of CO2 over N2 and CH4. The single-component isotherms are reported at pressures up to 2500 kPa and at 298, 310 and 323 K. The Langmuir–Freundlich model appropriately describes the adsorption equilibrium data over the whole range of conditions. The extracted isosteric heat of adsorption of CO2 on Kureha carbon is significantly lower than those on zeolite NaX and some metal–organic frameworks that are considered to be promising candidates for CO2 capture; this implies that the cost of regeneration with Kureha carbon can be potentially lower. The selective separations of two mixtures CO2/CH4 and CO2/N2 on Kureha carbon were experimentally investigated by a breakthrough-column technique. The simulations of transient breakthroughs for CO2/CH4 and CO2/N2 mixtures agree reasonably well with the experimental data. The breakthrough simulations also indicate that the separation performance is not significantly influenced by intra-particle diffusion resistances. Furthermore, the ideal adsorbed solution theory calculations are found to satisfactorily predict the experimentally observed separation performance. The investigations lead to the conclusion that Kureha carbon has a significant potential for CO2 uptake from flue gas mixtures