INFLUENCE OF AIR HUMIDITY ON THE ADSORPTION OF N-BUTANE ONTO ACTIVE CARBONS

Increasingly, the entrance air of car passenger space is purified from petrol hydrocarbons through adsorption onto active carbons in thin-la yer filters. In this publication some active carbons are characterized by fixed-bed adsorption measurements of 80 ppm n-butane with three di fferent air humidity levels; the variation of butane capacity is discu ssed in terms of water vapour and nitrogen adsorption isotherms on the same carbons. With 70% relative humidity, an excess concentration of butane concentration over the inlet is observed because of displacemen t by water.