ISOTHERMAL AND ISOBARIC DESORPTION OF CARBON-DIOXIDE BY PURGE

Isothermal and isobaric desorption of carbon dioxide was experimentall y evaluated by purging adsorbent columns saturated with pure carbon di oxide with pure hydrogen, nitrogen, and methane. Three different activ ated carbons and two zeolites were investigated as adsorbents. The eff ects of purge gas flow rate, system pressure and temperature, strength of carbon dioxide adsorption, and selectivity of adsorption between c arbon dioxide and the purge gas on the desorption process were measure d. Instantaneous local equilibrium between gas and adsorbed phases was established under the conditions of the experiments. An analytical ma thematical model for isothermal and isobaric desorption of binary gas mixtures by purge was developed. It was demonstrated that the efficien cy of desorption by purge can be increased by (1) lowering the desorpt ion pressure, (2) increasing the adsorbent temperature, and (3) increa sing the selectivity of adsorption of the purge gas over the desorbing component.