A QUALITATIVE-ANALYSIS OF THE EFFECTS OF WATER-VAPOR ON MULTICOMPONENT VAPOR-PHASE CARBON ADSORPTION

The effects of water vapor on binary vapor adsorption of toluene and m ethylene chloride by activated carbon were investigated on a bench-sca le experimental system. Three levels of relative humidity (1 5, 65 and 90 percent) in conjunction with different concentrations of individua l adsorbates (from 400 to 1200 ppmv) were tested by tracing the breakt hrough curves of each adsorbate eluted from a fixed-bed adsorber. The adsorption capacities of the activated carbon tested.for each adsorbat e under the various conditions were obtained from calculations based o n area integration of the breakthrough curves. It was found that with increasing relative humidity, the shape of breakthrough curves was asy mmetrically distorted and the width of the breakthrough curves was bro adened for toluene and steepened for methylene chloride. The adsorptio n capacities for both toluene and methylene chloride were decreased wi th the increase of relative humidity. The magnitude of the effect of w ater vapor is greater at the lower toluene concentration and at the hi gher concentration of methylene chloride. The mechanisms of water vapo r influence on the process of multicomponent vapor adsorption are disc ussed.