Interfacial tension and adsorption in the binary system ethanol and carbon dioxide: Experiments, molecular simulation and density gradient theory

Data on the interfacial tension and adsorption are reported for the binary mixture of ethanol + carbon dioxide (CO2) as well as for pure ethanol. The data are obtained from experiments, molecular dynamics (MD) simulations, and density gradient theory in combination with the PC-SAFT equation of state (DGT + PC-SAFT). Experimental data of the interfacial tension are reported for 8 temperatures between 303 K and 373 K and pressures up to 6 MPa. The experimental data are compared to results from MD simulations and from DGT + PC-SAFT for which pressures up to 12 MPa are considered. From the experimental data, the relative adsorption of CO2  is obtained via the Gibbs adsorption equation using the PC-SAFT equation of state. Data on the relative adsorption of CO2  is also determined both from MD and DGT + PC-SAFT. The three data sets show good agreement. There is a substantial enrichment of CO2  at the interface. This is consistently predicted both by MD and DGT + PC-SAFT. The work shows that both MD and DGT + PC-SAFT are well suited for detailed studies of interfacial properties and that the independent methods yield similar predictions for those interfacial properties which cannot be studied experimentally.