(323a) Single Gas Multi-Normal Energy Distribution Models for Predicting Mixed Gas Adsorption Equilibria from Non-Uniform Heterogeneous Extended Langmuir and Hias Models
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 parameters from the MNED model were then used to predict mixed gas adsorption equilibria of binary and ternary experimental data for both perfect positive and perfect negative correlations from two models that both utilize the cumulative MNED function obtained from the single gas correlations. The first model uses the extended Langmuir model in the integrand of the simplified adsorption integral equation, along with the cumulative MNED function, formulating a non-uniform heterogeneous extended Langmuir (NUHEL) model. The second model is the heterogeneous ideal adsorption solution (HIAS) theory. The experimental data used in this study was the single, binary and ternary adsorption equilibria for CO2, H2S and C3H8 on H-Modernite from Talu and Zwiebel [AIChE 32, 1263 (1986)]. The single gas correlations from the MNED model will be presented and contrasted against the dual and three process Langmuir (DPL and TPL) models, now referred to as the multi-process Langmuir (MPL) model. Then, the binary and ternary predictions from the NUHEL and HIAS models will be presented and contrasted against those from the MPL model. It suffices to state at this point that all three mixed gas models predict correctly that CO2 and H2S correlate in a perfect positive fashion, with both of these gases correlating in a perfect negative fashion with C3H8. The accuracy of the three mixed gas models, along with their ease of use, will be discussed.