Molecular simulation of adsorption of short linear alkanes and their mixtures in silicalite

Configurational-bias Monte Carlo simulations in the grand-canonical ensemble are employed to compute adsorption isotherms of methane, ethane, propane, butane and binary mixtures of methane–ethane, methane–propane, ethane–propane, and methane–butane in the zeolite silicalite. Comparison of the simulation results with the limited expetiniental data available shows good agreement. For ethane at room temperature, a small inflection point in the isotherm was observed due to a surprising ordering of the ethane molecules in the zeolite. For the simulation of a methane–ethane mixture, at low pressure ethane is preferentially adsorbed, while at high pressures methane replaces ethane due to entropic effects.