CO2 Adsorption Equilibria on 5A and 13X Molecular Sieves at Elevated Carrier GasPressures

摘要

An automated volumetric isotherm system capable of measuring adsorptionequilibria of trace levels of contaminants from 1 to 10,000 ppm in carrier gas up to 3.5 x 10(exp 6) Pa has been developed. The system is a modified version of the volumetric isotherm system previously published by Mahle, et al. The system is used to measure isotherm data for CO2, a typical contaminant in both separation and purification processes, adsorbed on two commercially available adsorbents, 5A molecular sieve and 13X molecular sieve. These data are measured in the presence of air at pressures of 1.0 x 10(exp 5) Pa, 5.0 x 10 to the 5th power Pa, 2.5 x 10(exp 6) Pa, and at temperatures of 278 K, 298 K, and 317 K. Results show that air adsorbed at elevated pressures reduces the amount of CO2 adsorbed at a given partial pressure and temperature for both adsorbents. The effect of adsorbed air on the CO2 loading is greater for 5A molecular sieve than for the 13X molecular