T-, D- and c-optimum designs for BET and GAB adsorption isotherms

Adsorption phenomena are described using the relationship between the equilibrium pressure of the gas and the amount adsorbed at constant temperature, known as adsorption isotherm. The Brunauer–Emmett–Teller (BET) model and the extension known as Guggenheim–Anderson–de Boer (GAB) model are widely used. The modelling of the adsorption phenomena in many chemical and industrial processes is proved to be of great interest. Consequently, a correct selection of the isotherm model and a correct estimation of the parameters are crucial tasks.The first objective to characterize the adsorption phenomena is to choose which of the models will best fit the data. T-optimum designs have been obtained in order to discriminate between both models. Once the model has been selected the correct estimation of the parameters is crucial. D- and c-optimality criteria are used in this work. Optimum designs are references, which allow the experimenter to measure the efficiency of any experimental design compared to the optimum.