Non-invasive quantification of phase equilibria of ternary mixtures composed of carbon dioxide, organic solvent and water

•Development and characterization of a flexible Raman sensor.•Introduction of a straight forward spectra evaluation procedure.•Non-invasive determination of mixture composition.•Composition quantification in ternary systems.

Raman spectra of ternary mixtures of unknown composition are processed to extract the content of the compounds in the mixture. The evaluation method of the ternary mixtures is based on a previous calibration of binary mixtures. The applicability of the method is demonstrated by measuring the vapour liquid equilibria of the ternary system carbon dioxide, ethyl acetate and water at 8.5 MPa and 310 K and providing them in a triangle diagram. The advantages of the used flexible Raman sensor in comparison to conventional techniques for the determination of phase equilibria are discussed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide