Numerical modeling and evaluation of solid-liquid extraction with pressurized hot water extraction applied to Robinia Pseudoacacia wood
Résumé
Computational Fluid Dynamics (CFD) simulation was used to study the solid-liquid extraction of Robinia Pseudoacacia wood by pressurized hot water extraction (PHWE). The proposed model couples momentum and mass transfer, including the extraction kinetics. The model is based on transport species and flow in a porous medium. The results show that the extraction of the two main flavonoids, Dihydrorobinetin (DHR) and Robinetin (Rob), increased with increasing temperature up to 120 °C, with values of 46.85±1.44 and 6.84±0.42 mg/gdB, respectively. However, at higher temperatures, these flavonoids degraded. Additionally, the exhaustive extraction cycle, ranging from 80 to 160 °C, was found to be less effective when compared to extraction at 120 °C.The kinetic parameters were included in the CFD simulation. As a result, a good agreement between the results of CFD simulation and experimental data was found with R2 > 0.97. The model predicts the temperature distribution inside the reactor during the pre-heating period, the evolution of the DHR and Rob concentrations at the reactor outlet, and the effect of degradation at high extraction temperatures.