Development, characterization and exploitation of a spectro-optical method for the simultaneous measurement of composition and density of the coexisting phases of vapor/liquid-equilibria at elevated temperature and pressure

• Applicant: Professor Dr.-Ing. Andreas Bräuer
• Subject Area: Chemical and Thermal Process Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546754490

The objective of the project is the development of a non-invasive optical measurement technique for the simultaneous determination of the densities and compositions of saturated vapor and liquid phases of binary and ternary vapor/liquid-equilibria (VLEs) at elevated pressures and temperatures (up to 25 MPa and 650 K). Due to the availability of reference data (density and composition) at few elevated pressures and temperatures from literature, the binary systems will be composed of organic solvent (ethanol, acetone, ethyl acetate) plus CO2 and the ternary mixtures will additionally include water. These mixtures are also relevant for the aerogel-related research of the applicant. The objective will be reached by combining a self-engineered Raman spectroscopy technique (already existing and established) for composition measurements with a to-be-developed light barrier technique for the measurement of the volume flow rates of the two coexisting phases in a pressure and temperature resistant microfluidic glass capillary. The densities of the phases are then deduced from their compositions (obtained via Raman) and their volume flow rates (obtained via light-barrier technique). The performance of the developed measurement technique will be characterized against systems, whose vapor/liquid-equilibria are well-known, and the developed measurement technique will then be utilized for the generation of composition and density data couples of other systems at elevated pressure and temperature conditions, for which such data couples are non-existing but demanded, for example in aerogel research.

• DFG Programme: Research Grants