Adsorption, Separation, and Phase Transitions of Fluids in Micropores.
Abstract
Mean-field density-functional theories and computer simulation methods have been applied to pure and mixed Lennard-Jones fluids, modeled on hydrocarbons and noble gases, in slitlike and cylindrical pores, modeled primarily on porous carbon. The fluid density profiles, adsorption and separation properties, and capillary phase transitions have been calculated. Calculations cover micropores and some mesopores, a wide range of temperatures and bulk pressures. For pure fluids, emphasis has been placed on supercritical adsorption and its application to gas storage. For mixtures, we focused on layering transitions at low temperatures, capillary condensation at subcritical temperatures, and separation phenomena at supercritical conditions. A nonlocal mean-field density-functional theory for pure fluids has been used to describe the correct density variations in pores. The accuracy of the prediction has been improved significantly by using a temperature dependent hard-sphere diameter. A non-local theory has been developed for binary mixtures. It describes the behavior of mixtures near a solid surface or confined in pores in quite good agreement with computer simulation.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1991
- Bibcode:
- 1991PhDT........84T
- Keywords:
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- Engineering: Chemical; Chemistry: Physical; Physics: Molecular