Isothermal Vapor–Liquid Equilibrium of Ethanol–Water Mixtures + Acetone–Ethanol Mixtures Inside Capillary Porous Plates

Abstract

Isothermal vapor-liquid equilibrium (VLE) of ethanol-water mixtures at different temperatures and the isothermal VLE of acetone-ethanol mixtures at 305.15 K were experimentally measured in three different macroporous plates: a 13.5-m pore diameter sintered stainless steel plate, a 30-m pore diameter porous carbon plate, and a 30-m pore diameter porous Teflon plate. The experimental results showed that the VLE of the ethanol-water system in the porous sintered stainless steel plate was dramatically altered, and the azeotropic point was shifted from ethanol mole fraction of 0.90 to Ͼ 0.99. However, there was no significant effect of this plate on the acetone-ethanol system. The effect of either the porous Teflon plate or the porous carbon plate on the VLE was insignificant for both systems. These results show that for substantial alteration of the VLE binary mixtures, two conditions are required: the liquid components must be of different polarity, and the porous plate should possess high polarization.

Experimental Study on the Criticality of a Methane/Ethane Mixture Confined in Nanoporous Media

“…For example, it has been experimentally proven that phase transition in confined space occurs isothermally at a lower pressure, or isobarically at a higher temperature, than that in the bulk phase. − Recently, the critical point of pure fluids in confined space has also been unambiguously demonstrated to locate at a lower temperature and pressure than that in bulk by us using an isochoric cooling method . Experimental studies on the phase behavior of confined mixtures, on the other hand, are relatively scarce in the literature, − not to mention the fact that their phase behavior in the critical region has never been experimentally explored, which, in turn, results in disagreement and conflicting conclusions about the pore critical point (PCP) of mixtures in confinement; PCP is defined as a point beyond which the condensation of confined fluids can no longer occur. Therefore, the purpose of this work is to verify its existence and demonstrate its shift from the bulk critical point.…”

Thermodynamic Study of the Role of Interface Curvature on Multicomponent Vapor–Liquid Phase Equilibrium

“…The Kelvin equation and its liquid–liquid and liquid–solid analogues describe capillary condensation, adsorption hysteresis, − nucleation, − and emulsion stability . Single-component systems have been extensively examined theoretically. − ,− Early experimental work − and more recent work − verified the Kelvin equation, with discrepancies observed for systems containing water. , Using certain capillary plates results in deviations from the Kelvin equation − due to molecular interactions between the liquid and the capillary walls, adsorption, or surface contamination . Closer experimental agreement was achieved by Shin and Simandl − for multicomponent mixtures.…”