Combination of adsorption followed by ozone oxidation with pressure swing adsorption technology for the removal of VOCs from contaminated air streams

Abstract

This paper reports the application of adsorption followed by ozone oxidation in the pressure swing adsorption (PSA) process for the removal of VOCs from contaminated air streams. For that 13X molecular sieves and o-xylene selected as adsorbent and contaminant (one of the VOCs), respectively. The adsorption capacity of 13X molecular sieves for o-xylene is significantly increased from 0.6 to 2.8mmol/g with pressure from 0.5 to 5.0kg/cm2 and these values are relatively good compatible with the Freundlich isotherm model. The 13X molecular sieves are efficiently regenerated in 70min by ozone oxidation process at 25°C and the adsorbed o-xylene is significantly oxidized to the CO2. In four successive cycles of adsorption followed by ozone oxidation process, the adsorption efficiency of 13X molecular sieves is not affected (±5%). Further, the adsorption-ozone oxidation process embedded PSA system is operated continuously for 50h and there is no breakthrough observed in the fresh air. So that, the combination of adsorption followed by ozone oxidation with PSA process seems to be the better technology for the removal of VOCs from the contaminated air streams.