In this contribution implications of using different rigorous thermodynamic models for the description of the liquid liquid equilibrium (LLE) appearing in an hydroformylation process of 1-dodecene in a decane/N,N-dimethylformamide thermomorphic solvent system are discussed. Besides a fully predictive G(E) model (UNIFAC Dortmund), a representative of cubic equations of state with mixing rules based on G(E)-models (SRK-MHV2 with nonrandom two liquid (NRTL)) and a representative of equations of state based on statistical associating fluid theory (heterosegmented PCP-SAFT) are evaluated. The influence of the chosen thermodynamic model on the simulated process-wide performance is quantified, and the simulation results are compared against published experimental data from a miniplant with full recycle. Special attention is given to equations of state approaches with fitted binary interaction parameters, since they allow a good correlation of available experimental data and are applicable to process-wide simulations under consideration of gaseous compounds. A short analysis regarding the computational effort related to the evaluation of the equation of state models is additionally provided. The obtained results show that both selected equation of state models, in conjunction with the parameters obtained in this contribution, have a good agreement with available phase equilibrium and miniplant experimental data. Hence, both approaches appear to be suitable for process design and optimization tasks. Taking a closer look SRK-MHV2 shows slightly better correlative capabilities with lower computational effort, although requiring a larger amount of binary interaction parameters. However, while phase equilibrium compositions are almost equally well described by both approaches, particular care should be taken when calculating volumetric properties. For the latter properties the heterosegrnented PCP-SAFT approach provides better results.