Resumen de Fundamental aspects of supercritical gas adsorption
Fernando Vallejos Burgos, M. Tomonori Ohba, Katsumi Kaneko
Understanding of the explicit difference between supercritical gas and vapor is necessary for a better design of nanoporous materials for gas storage; we show the difference between supercritical gas and vapor with the van der Waals equation which leads to the critical point and the second virial coefficient. Detailed explanation on intermolecular interactions such as dispersion interaction and electrostatic interaction and the gas-solid interaction is given for enhancing the physical adsorption of supercritical gas by nanoporous materials. Plausible routes of quasi-vaporization for enhancement of supercritical gas adsorption on nanoporous materials are suggested. The effectiveness of the quasi-vaporization of supercritical gas with the strong interaction potential field of nanopores and the specific surface interaction is shown for supercritical nitric oxide, nitrogen and methane. The simple analytical method of supercritical gas adsorption isotherms with the aid of the quasi-vaporization can provide the quasi-saturated vapor pressure and isosteric heat of adsorption, being useful to design the better nanoporous materials for gas storage.
