Experimental Data of VLLE, and Dynamic Viscosity for Furfural + Undecane and Furfural + Pentane Systems and Their Application to Process Simulation

This work presents experimental data for liquid–liquid (LLE), vapor–liquid (VLE), and dynamic viscosity equilibria of the furfural + undecane and furfural + pentane mixtures at 85.25 kPa. Thermodynamic properties were measured across a broad range of temperatures and compositions using validated equipment with low expanded uncertainties: 0.21 K for VLE, 0.42 K for LLE, 0.12 K for viscosity temperature, and 0.177 mPa·s for viscosity (at 95% confidence level). The LLE, VLE, and VLLE data were modeled with a modified Peng–Robinson equation of state coupled with Huron-Vidal mixing rules and the NRTL model. Viscosity was modeled using a generalized logistic function and the Eyring-Wilson-Porter mixing rule. For the furfural + undecane system, average relative absolute deviations were 0.19% for LLE, 0.49% for VLE, and 3.67% for viscosity. For the furfural + pentane mixture, the VLLE deviation was 0.72%. A chemical process to produce undecane from furfural was also simulated, including aldol condensation, hydrocycloaddition, and hydrodeoxygenation reactions. A subsequent vapor–liquid–liquid separation followed by distillation was carried out using a rigorous stage-by-stage methodology in combination with the modified Peng–Robinson equation of state (EoS). The process achieved a 99.9% undecane recovery. The results provide a solid foundation for future research and industrial applications in biobased chemical production.