Molecular Simulation of Adsorption Processes. 1. Isothermal Stirred-tank Adsorber

Abstract

A new molecular simulation method is proposed to solve the governing equations  for a multicomponent, isothermal stirred-tank adsorber under equilibrium controlled conditions. The technique is formulated in the Gibbs ensemble, but is more appropriately viewed as a hybrid of a molecular simulation and continuum modeling. For the general case of an arbitrary multicomponent mixture, the total number of molecules of each species is allowed to fluctuate so that the ensemble average satisfies the macroscopic material balances to the adsorber. It is shown that if an analytical equation  of state for the fluid phase is known, the simulation procedure can be considerably simplified and acquires many characteristics of a Monte Carlo simulation conducted in the grand canonical ensemble. The technique is thoroughly validated and its usefulness is demonstrated through application to a gas separation problem encompassing the major steps of practical value to batch adsorption processes.

Keywords:

• Adsorption of fluids and fluid mixtures
• Molecular simulation method
• Isothermal stirred-tank adsorber
• Grand Canonical Monte Carlo (GCMC) method