Adsorption of Nitrogen Oxides, Water Vapour and Ozone onto Activated Carbon

Abstract

Noxious gases and odours in cabin air are reduced by activated carbon filters. However, the adsorption process involved in cabin air filtration is very complex because of the large number of influencing parameters. Some important parameters are changes in the input concentrations and surrounding conditions. Furthermore, the presence of different substances leads to their mutual influence on the respective adsorption processes. The separation of nitrogen oxides is an especial focus of discussion in Germany at present because of decreasing ambient exposure limits. One part of the study presented herein deals with the binary adsorption of nitrogen dioxide in humid air at varying NO 2 input concentrations, relative humidity and temperature. In order to obtain more information about this process, after initial validation of the test procedure employed, breakthrough curves of NO 2 have been undertaken in the present study. In the second part of the study, the influence of a third adsorptive (ozone) on the adsorption of nitrogen dioxide has been investigated.