(320aw) Iteration Function Method for Mixture Adsorption Calculations

Adsorption equilibrium models are essential in optimizing coalbed methane (CBM) production and CO2 sequestration processes. Although several frameworks are available for describing adsorption phenomenon, two-dimensional (2-D) equations of state (EOSs) offer distinct advantages in modeling supercritical, high-pressure adsorption systems.

Our previous studies involving high-pressure mixture adsorption have indicated the inadequacy of the simultaneous solution calculation scheme, which requires the knowledge of experimental gas-phase compositions. An iteration function method (IFM) for mixtures adsorption equilibrium calculations has been developed for 2-D EOS, and the robustness of the proposed method is evaluated.

Analysis of the results involving many supercritical adsorption systems indicate that the new IFM algorithm is effective in performing equilibrium mixture adsorption calculations based on feed compositions. Further, use of a formulation equivalent to the Rice-Racford VLE iteration function, where the molar adsorption ratio is the iteration variable, leads to frequent adsorption calculation failures.