Adsorption of light hydrocarbons on HMS type mesoporous silica

Equilibrium adsorption isotherms for light hydrocarbons namely, ethane, ethylene, acetylene, propane, and propylene have been measured on hexagonal mesoporous silica (HMS)-type mesoporous silica. The measured data are analyzed using Langmuir-Freundlich adsorption isotherm model. The adsorption capacity for C-2 and C-3 olefins are found to be higher than for corresponding alkanes. Further, uptake of acetylene is observed to be more comparable to ethylene. The isosteric heats of adsorption for ethylene are marginally higher than ethane but those observed for propylene are found to be significantly higher than for propane. The isosteric heats observed for propylene are found to be comparable with those reported for pi-complexation based systems. Such a trend has in turn suggested a higher affinity of HMS framework for propylene over propane. (C) 2003 Elsevier Inc. All rights reserved.