Aqueous-organic and aqueous-vapor interfacial phenomena for three phase systems containing CO₂, CH₄, n-butanol, n-dodecane and H₂O at saturation conditions

A fundamental understanding of the interfacial properties at elevated pressure is essential for processes in the context of the energy transition, such as the storage of CO₂, H₂ or CH₄. Systems in such processes have traces of impurities. This work aims to systematically investigate these multi-component systems through simplified vapor-liquid-liquid systems comprising H₂O, (n-butanol or n-dodecane), and (CO₂ or CH₄). The model systems are theoretically investigated using the density gradient theory and the PCP-SAFT. The interfacial tension and saturated phase density of the model systems are experimentally measured by the pendant drop and the oscillating tube method, respectively. Good agreement between the theoretical and experimental results is found. It was found that the pure and binary systems of these mixtures can be described well by the introduced model, delivering high quality predictions.