Phase equilibria and interfacial properties of selected methane + n-alkane binary mixtures

Experimental determination, theoretical modeling, and molecular simulation have been combined to describe the bulk phase equilibria (i.e., pressure, liquid, vapor saturated mass densities) interfacial properties concentration, adsorption, tension) for methane + n-decane, n-dodecane, n-tetradecane n-hexadecane binary mixtures at 344.15 K in a pressure range between 0.1 30 MPa. determinations are carried out using apparatus that includes high-pressure vibrating tube densimeter pendant drop tensiometer. The approach is based on van der Waals gradient theory coupled Statistical Associating Fluid Theory of Variable Range employing Mie potential (SAFT-VR-Mie) equation state, where fluids described as Coarse Grained (CG) atoms. Molecular dynamics same systems CG reported. three approaches able indepen independently predict equilibrium properties, showing very good agreement amongst themselves. For conditions studied here, density increases; liquid tensions decrease increases, with fixed temperature increase n-alkane chain length increases. It observed adsorbed along region, whereas n-alkanes (n-decane, n-tetradecane, n-hexadecane) do not exhibit surface activity. relative Gibbs adsorption increases significantly until it reaches maximum denoting saturation limit. also only slightly n-alkane.