Within the framework of the Collaborative Research Centre SFB/TR 63 InPROMPT, "Integrated chemical processes in liquid multiphase systems", a novel process concept for the hydroformylation of long chain alkenes to aldehydes in microemulsions is investigated and developed at the Berlin Institute of Technology (Technische Universitat Berlin), Germany. To start the hydroformylation reaction, a hydrophilic rhodium-ligand-complex is required. By applying a nonionic surfactant, a microemulsion system is formed and thus the hydrophilic catalyst is transported into the, hydrophobic alkene phase. Next to achieve a high conversion rate in the continuously stirred tank reactor, the separation of the valuable rhodium catalyst from the product phase poses a challenge. This separation is the crucial step for the technical and economic feasibility of the overall process concept and plant design. Owing to the lack of thermodynamic data for microemulsion mixtures, the design of the phase separation unit strongly depends on experimental results. Consequently, a systematic experimental approach has been developed to identify potential operating conditions and relevant design parameters. To classify and find these, a set of experimental set-ups have been investigated to characterize impact factor on the phase separation such as type of surfactant, different concentrations of surfactant, olefin, product, and water. With the information gained through the observations the relevant composition of the investigated mixture and the separation temperature are determined for the operating conditions. Finally, necessities with regards to plant and process design are revealed.