A new model for calculating the adsorption equilibrium constant of water vapor in micropores of activated carbon

•A new model for calculating equilibrium constant of micropore adsorption.•This model contains only a few number of parameters.•It well predicts water adsorption on different kinds of activated carbon.•An universal thermodynamic criteria for water adsorption on activated carbon.

A new model for calculating the adsorption equilibrium constant of water vapor in the micropores of activated carbon was established, the mechanism of which is based on the penetration of water clusters into micropores. Two kinds of carbon materials with significantly different pore and surface structures were prepared for water vapor adsorption, and the adsorption experiments were conducted in different conditions to test the accuracy of the new model. The new model was also applicable to water adsorption on bituminous-based activated carbon. Furthermore, being able to calculate the values for enthalpy of activation and entropy of activation, the new model can provide universal thermodynamic criteria for the water adsorption on activated carbon.

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