Comparison of Adsorption Isotherm Models for Methane and Carbon Dioxide Adsorption onto Activated Carbon

Abstract

Modeling and simulation of an adsorption-based gas separation process require accurately measured gas adsorption isotherms and isotherm model fittings. In this study, adsorption equilibria data of pure Methane (CH4) and Carbon Dioxide (CO2) onto activated carbon adsorbent (Calgon Co.) were extracted from the literature. Each experimental isotherm was correlated by the Simple Langmuir (SL), Dual Process Langmuir (DPL), Three Process Langmuir (TPL), Toth, and the Unilan models and the deviations were evaluated. Other than SL, all four models showed very good agreement with the experimental data. The fitting parameters for all models presented in this article can be used for any type of adsorption-based separation modeling which includes the BPL-activated carbon and analyzed gases.