Mass transport properties in quaternary Systems at elevated pressures

In the context of the energy transition, processes related to storage and utilization of CO₂ and H₂ as well as fluid mixtures containing natural gas are gaining relevance. These processes take place at elevated pressure for which determining the respective phase equilibria as well as system properties like the interfacial tension and mass transfer is challenging. Experimental and theoretical investigations are carried out using the model systems “water – n-dodecane – n-butanol – CH₄” as well as “water – n-dodecane – n-butanol – CO₂”, representing systems that are of high scientific interest since from literature it is known that two of the transferring compounds, n-butanol and CO₂, are enriched at the interface. For the first time, two quaternary systems are investigated systematically in this project, i.e. all relevant thermodynamic properties are determined, also of all binary and ternary subsystems. Further, new experimental procedures are employed to systematically investigate the mass transfer that include the implementation of results from the thermodynamic modelling that on its turn is delivering a thermodynamically consistent approach based on PCP-SAFT. In combination with the density gradient theory (DGT), interfacial properties can be calculated. The final objective of this project is to develop a thermodynamically consistent model for determining the mass transfer in multiphase systems at elevated pressures. Further, the data base on fluid mixture properties is extended and new experimental methods are provided.