Determination of critical properties of pure and multi-component mixtures using a “dynamic–synthetic” apparatus

In this work, we use an efficient and reliable “dynamic–synthetic” method for the measurement of critical properties of a variety of pure compounds, binary mixtures, and one ternary mixture. The critical phenomenon is observed via the critical opalescence in a view cell, which withstands conditions up to 543 K and 20 MPa. Excellent agreements were obtained between the measured pure compounds’ properties and those listed in recent databases. Among the pure compounds measured, several refrigerants less well described in open literature (C3F6, C3F6O, R365mfc) have been compared with conventional predictive models. The critical profiles of associating, azeotropic systems ethanol + n-alkanes (C4–C8) are presented, as well as the critical surfaces for the ternary system n-pentane + ethanol + n-hexane. We present forms of the Cibulka and Singh's equation suitable for correlating ternary critical properties.

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