Kinetic Simulation of Adsorption Isotherms

The possibilities of calculating adsorption equilibria by simulating a set of kinetic stages of sorption and desorption are considered. An approach is proposed in which an adsorption isotherm is obtained by scanning the concentration of the adsorbed substance in a simulation program as a linear function of time. The principal possibility of obtaining the adsorption isotherms of five types out of the six approved by IUPAC (except for the multistage one of type VI) is shown. To obtain undistorted adsorption isotherms, it is necessary and sufficient to use a scanning step larger than the time constant for establishing the adsorption equilibrium. It is shown that the polymolecular Brunauer-Emmett-Teller adsorption isotherm can be simulated with high accuracy using a simple kinetic scheme.