Adsorption of gas mixtures on solid surfaces, theory and computer simulation

A treatment of the thermodynamics of mixed gas adsorption is presented in which the gas-solid interface is three dimensional. Such a treatment yields an additional term as compared to two dimensional approaches. This additional term has significant consequences for the derivation of adsorbed solution theories, particularly at higher temperatures. Results are presented for a Grand Canonical Monte Carlo study of a model methane-ethane mixture in a carbonaceous slit pore. Comparison of single component and mixture results provides an unambiguous means of testing theories of adsorbed solutions and bears out the thermodynamic treatment presented in the previous section of the paper.