Measurement and correlation of phase equilibria for (water + aromatic hydrocarbon) binary mixtures at T = (573 to 623) K using microfluidic mixing

(Vapour + liquid) and (liquid + liquid) equilibria for (water + p-xylene) and (water + decalin) mixtures at T = (573 to 623) K were measured by a flow type apparatus with microfluidic system. The liquid–liquid slug flows in the microfluidic system were used for mixing of water and hydrocarbon due to high mass transfer between two liquid phases. The formations of the liquid–liquid slugs for (water + p-xylene) system were studied by changing the flow rate. The results of the liquid–liquid slug formations at hydrocarbon and water rich compositions were used for the measurements for (vapour + liquid) and (liquid + liquid) equilibria, respectively. It was found that the phase equilibria using the apparatus with the microfluidic system can be measured in a short residential time (1.6 to 3.2) min. The experimental results of the phase equilibria for (water + p-xylene) and (water + decalin) systems give that the regions of the (vapour + liquid) and (liquid + liquid) equilibria for both mixtures reduce with the increasing temperature. The mixture of (water + decalin) at T = (583 to 623) K forms the two phase regions of the (vapour + liquid) and (liquid + liquid) equilibria larger than those for (water + p-xylene) mixture. The experimental data of the phase equilibria obtained in this work were correlated with Peng–Robinson–Stryjek–Vera equation of state. The correlated results of the (liquid + liquid) equilibria for both systems represent the experimental data. For (vapour + liquid) equilibria, the results give the qualitative representations in the shape of the two phase region for both mixtures.

► Phase equilibria for (water + hydrocarbon) mixtures were measured by flow method.
► Liquid–liquid slugs in microtube were used for the mixing.
► The phase equilibria can be measured in short residential time.
► (Water + decalin) forms the two phase regions larger than (water + p-xylene) mixture.