ISOTHERMAL AND ISOBARIC DESORPTION OF CARBON-DIOXIDE BY PURGE

Isothermal and isobaric desorption of carbon dioxide was experimentally evaluated by purging adsorbent columns saturated with pure carbon dioxide with pure hydrogen, nitrogen, and methane. Three different activated carbons and two zeolites were investigated as adsorbents. The effects of purge gas flow rate, system pressure and temperature, strength of carbon dioxide adsorption, and selectivity of adsorption between carbon dioxide and the purge gas on the desorption process were measured. Instantaneous local equilibrium between gas and adsorbed phases was established under the conditions of the experiments. An analytical mathematical model for isothermal and isobaric desorption of binary gas mixtures by purge was developed. It was demonstrated that the efficiency of desorption by purge can be increased by (1) lowering the desorption pressure, (2) increasing the adsorbent temperature, and (3) increasing the selectivity of adsorption of the purge gas over the desorbing component.