(608b) Diffusion of CO2 and N2 in 5A Pellets Measured Using the Adsorption Differential Volumetric Apparatus

Mass transport of pure CO₂ and N₂ in commercial 5A pellets are reported at different temperatures and pressures from 0.1-0.2 kPa to near atmospheric pressure. The experiments are performed on small sample masses (3 pellets), but even in these conditions isothermal conditions can only be achieved at the lowest pressures. The data will be used to show the transition with pressure from isothermal diffusion to combined heat and mass transfer and finally to fully heat limited cases.

Both systems are macropore diffusion controlled and for CO₂ below 293 K there is evidence of a contribution of surface diffusion.