Abstract:

On the basis of experimental data, double-Langmuir (DL) model was used to investigate the adsorption and separation of hydrogen and carbon dioxide in activated mesocarbon microbeads with high specific surface. Pure and binary adsorption isotherms of carbon dioxide and hydrogen (mole ratio is 1:9) in activated mesocarbon microbeads were measured using the high-precision intelligent gravimetric analyzer at temperature of 298, 273 and 268 K, and the pressure ranging from 0 to 1.8 MPa. In order to get adsorption amount of the single component of mixture gas, the DL model and the ideal adsorbed solution theory (IAST) were combined. The combined method can be applied to carbon dioxide and hydrogen binary systems perfectly. The calculated results indicated that the selectivity of carbon dioxide can reach 73.4 at 268 K and 1.7 MPa, which suggests that the activated mesocarbon microbead was an excellent candidate for the removal of carbon dioxide in hydrogen/carbon dioxide mixtures.

Key words: Activated mesocarbon microbeads, Hydrogen, Carbon dioxide, Adsorption selectivity, Double Langmuir model