Browsing by Author "Loughlin, K. F."

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    Sorption of Ethylene, Propylene and Cyclopropane in 5A Zeolite: Analysis of Equilibrium Isotherms
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (10), 1972) Derrah, R. I.; Loughlin, K. F.; Ruthven, D. M.
    Experimental equilibrium isotherms are presented for the sorption of light unsaturated hydrocarbons in type A zeolite. The data are analyzed according to the extended potential theory of Dubinin and also by the use of a simple statistical model isotherm. Henry constants and heats and entropies of sorption are calculated and compared with the values previously obtained for the light paraffins. It is shown that the relatively stronger adsorption of the olefins, in comparison with the corresponding paraffins, is almost entirely attributable to the greater energy of sorption arising from specific electrostatic interactions. Under comparable conditions the entropies of sorption of paraffins and olefins arc very similar.
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    Sorption of Light Paraffins in Type-A Zeolites: Analysis and Interpretation of Equilibrium Isotherms
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (2), 1972) Ruthven, D. M.; Loughlin, K. F.
    Equilibrium data for the sorption of light paraffins in 4A and 5A zeolites are interpreted in terms of a simple idealized model isotherm. Henry’s law constants and isosteric heats of sorption, calculated from the model, agree well with published experimental values and (for CH4) with the values calculated theoretically. The observed increase in the isosteric heat of sorption with sorbate concentration arises primarily from the effect of sorbate-sorbate repulsion (finite size of sorbate molecules) and, for the systems considered, the effect of sorbate-sorbate attraction is relatively minor. Entropies of sorption are calculated and compared with the values for ideal Langmuir adsorption and the limitations of the Langmuir plot as a method of extracting Henry's law constants and saturation concentrations from experimental equilibrium data are discussed.