(347l) Multi-Normal Energy Distribution Model for Correlating Single Gas Adsorption Isotherms for Carbon Dioxide, Methane, Ethane, Ethylene, Propane and Propylene on 5A Zeolite
A new multi-normal energy distribution (MNED) model was developed for correlating single gas equilibrium adsorption isotherms with any number of NED functions. This new model utilizes the single process Langmuir model in the integrand of the adsorption integral equation, along with the MNED function. The MNED model was correlated with experimental single gas isotherm data for CO2, CH4, C2H6, C2H4, C3H8 and C3H6 on 5A zeolite at 25, 50 and 75 oC and up to 110 kPa using one, two and three ND functions. For comparison, the same data were also correlated with the single, dual and three process Langmuir (SPL, DPL and TPL) models. All these models incorporated a temperature dependence on the saturation loading capacity that provided a better correlation. The goodness of the fit in each case was based on a specially defined weighed sum of log-error function. The single gas correlations of the isotherms, along with the corresponding isosteric heats of adsorption, from all these models will be presented and discussed.