Redistribution of a mixture of organic vapours inside an activated carbon filter

X-ray tomography in a combination with gas chromatography was used for a qualitative and quantitative analysis of the redistribution of mixtures of organic vapours inside an activated carbon filter during a defined period of storage. In this study CCl4 and n-heptane were used. X-ray tomography was shown to be capable to differentiate between the different adsorbed organic vapours and to follow their movement inside the filter. In this way the roll-up effect was visualised in situ. Gas Chromatography was used to monitor all possible losses of adsorbed species from the carbon bed and for determining the composition of the adsorbed phase along the filter depth, allowing for an independent validation of the X-ray tomographic results. The information gathered through these experiments could be useful for evaluating the lifetime of carbon filters and to gain a thorough understanding of the adsorption processes taking place under static conditions.