NONISOTHERMAL ADSORPTION OF NITROGEN-CARBON DIOXIDE MIXTURE IN A FIXED-BED OF ZEOLITE-X

The binary adsorption of nitrogen and carbon dioxide on zeolite-X was investigated. The adsorption equilibria of pure and binary systems wer e measured by static methods. In the binary system the equilibrium sel ectivitY Of CO2 over N2 was very high: about 525 at a CO2 mole fractio n of 0.14 and a temperature of 15-degrees-C. Consequently, N2 can be c onsidered as inert when its mole fraction is less than 0.8. The ideal adsorbed-solution theory (IAST) predicted quite well the. binary equil ibrium data, while the extended Langmuir isotherm showed a great devia tion. The dynamics of fixed-bed adsorption Of CO2-N2 gas mixture (CO2 14.86 mole percent) was analyzed by the cell model under non-isotherma l conditions, incorporated with binary adsorption equilibria, mass and heat transfer resistances and variation of gas velocity in the bed. T he concentration and temperature history curves were determined and co mpared with the theoretical results. This cell-model with IAST predict ed well the dynamic behavior of the adsorption bed.