Heats of water adsorption on microporous carbons from nitrogen and methanecarriers

Simultaneous determinations in the flow adsorption microcalorimeter of the amounts and heats of adsorptions designed to discover to what extent the ad sorption of water vapour on a heterogeneous carbon and a carbon molecular s ieve is influenced by the presence of nitrogen and methane at atmospheric p ressures and how the differential heats of displacement of these gases by w ater change with its increasing uptake. The work revealed that the adsorpti on of water is strongly influenced by the nature of the carrier gas from wh ich the adsorption takes place. Water uptake from methane is much greater t han that from nitrogen, but its heats of adsorption are much lower. For bot h carrier gases the differential heats of water adsorption at low surface c overages on the carbon with the wider range of pore diameters greatly excee ds the heats of water vapour condensation at room temperatures. (C) 2001 El sevier Science Ltd. All rights reserved.