Mass Transfer of Binary Mixtures of Oxygen and Argon in a Carbon Molecular Sieve

Abstract

Transport of binary O2/Ar gas mixtures in a carbon molecular sieve (CMS) has been studied using concentration-swing frequency response. The rate data for this binary gas system are described well by the transport models (surface barrier for Ar and surface barrier plus micropore diffusion for O2) and parameters that were found to govern transport of the respective pure gases on the same CMS. These results suggest that transport of O2 is not impeded by the presence of Ar. However, the experimental data do not rule out the possibility of some enhancement of the O2 transport rate. Furthermore, O2 and Ar isotherms on this CMS were observed to be linear in the region over which frequency response experiments were performed, suggesting that the micropore diffusion component of O2 transport behavior is unaffected by the presence of Ar. Because transport of Ar in this CMS is much slower than O2, the dynamic response of this system owes the majority of its character to O2 adsorption, and the effect of O2 on Ar transport remains hidden.