The adsorption uptake curves of CO 2 , CO, N 2 and CH 4 on zeolite LiX and activated carbon were measured using a volumetric method at 293, 308 and 323 K and pressure up to 100 kPa. The experimental uptake curves were correlated with a non-isothermal kinetic model because the adsorption kinetics was controlled by heat generation and transfer, and an isothermal model showed large deviation from experimental uptake. The adsorption rates of the gases on zeolite LiX and activated carbon were affected by the isosteric heat of adsorption, heat transfer rate and adsorption affinity. At the same pressure and temperature, the sequence of effective diffusion time constants was CO 2 ( CO \ N 2 \ CH 4 for zeolite LiX and CO 2 ( CH 4 B N 2 \ CO for activated carbon. The adsorption rate of CO showed the largest difference between the two adsorbents. Effective diffusion time constants (D/R 2 ) for all cases were provided, which depended on pressure and temperature.Keywords Activated carbon Á Zeolite LiX Á Adsorption kinetics Á Heat of adsorption Á Non-isothermal model List of symbols a External surface area divided by the volume of the adsorbent (m -1 ) c p Concentration in the particle (mol kg -1 ) C s Heat capacity of the sample (J g -1 K -1 ) D/R 2 Effective diffusion time constant (s -1 ) D Diffusivity (m 2 s -1 ) D c /r c Micropore diffusion time constant (s -1 ) D p /R p Effective macropore diffusion time constant (s -1 ) hOverall heat transfer coefficient (J m -1 s -1 K -1 ) K Henry constant (-) P Pressure (kPa) Q Adsorbed amount (mol kg -1 ) Q st Isosteric heat of adsorption (kJ mol -1 ) R Ideal gas constant (J mol -1 K -1 ) R 2 Coefficient of determination (R 2 ) (-) T Time (s) T Temperature (K) V g Volume occupied by the gas (m 3 ) V s Volume occupied by the adsorbent (m 3 ) a Dimensionless parameter defined by nonisothermal model (-) bDimensionless parameter defined by nonisothermal model (-) q s Density of the adsorbent (g m -3 )