TY - JOUR

T1 - Interfacial tension in water/n-decane/naphthenic acid systems predicted by a combined COSMO-RS theory and pendant drop experimental study

AU - Olesen, Kristian B.

AU - Pedersen, Anne-Sofie Dahl

AU - Nikolajsen, Lasse V.

AU - Andersson, Martin P.

AU - Sølling, Theis Ivan

AU - Sauer, Stephan P. A.

AU - Mikkelsen, Kurt Valentin

PY - 2020/9/23

Y1 - 2020/9/23

N2 - The interfacial tension of systems containing water, n-decane, and model naphthenic acids were investigated using a predictive model based on COSMO-RS theory and experimental pendant drop measurements. Five naphthenic acid homologues that are considered to be representative of surfactants inherent to crude oil were dissolved in n-decane at equal concentrations. The interfacial tensions of the five systems at an acid concentration of 1.66 mol% relative to n-decane were experimentally determined to be 27-30 mN/m. The interfacial tensions of the five different acid-decane phases against water were also predicted using density functional theory (DFT) calculations and COSMO-RS theory. The accuracy of the predictions was very good as confirmed through pendant drop measurements of the interfacial tension. The mean-absolute deviation between experimental and predicted values was 2.6 mN/m thus demonstrating the high predictive power of COSMO-RS theory for calculating the interfacial tension at oil-water interfaces in the presence of surface-active compounds.

AB - The interfacial tension of systems containing water, n-decane, and model naphthenic acids were investigated using a predictive model based on COSMO-RS theory and experimental pendant drop measurements. Five naphthenic acid homologues that are considered to be representative of surfactants inherent to crude oil were dissolved in n-decane at equal concentrations. The interfacial tensions of the five systems at an acid concentration of 1.66 mol% relative to n-decane were experimentally determined to be 27-30 mN/m. The interfacial tensions of the five different acid-decane phases against water were also predicted using density functional theory (DFT) calculations and COSMO-RS theory. The accuracy of the predictions was very good as confirmed through pendant drop measurements of the interfacial tension. The mean-absolute deviation between experimental and predicted values was 2.6 mN/m thus demonstrating the high predictive power of COSMO-RS theory for calculating the interfacial tension at oil-water interfaces in the presence of surface-active compounds.

U2 - 10.1080/00268976.2020.1764645

DO - 10.1080/00268976.2020.1764645

M3 - Journal article

VL - 118

JO - Molecular Physics

JF - Molecular Physics

SN - 0026-8976

IS - 18

M1 - e1764645

ER -