Computational Fluid Dynamics (CFD) modeling of static maceration in view to optimize continuous flow extractions of robinetin and dihydrorobinetin from Robinia pseudoacacia wood

Abstract

Computational Fluid Dynamics (CFD) modeling was used to study solid-liquid extraction applied to Robinia pseudoacacia. Experimental and simulation studies on maceration and continuous flow extractions were performed at various solid-solvent ratios and flow rates. To validate the CFD modeling results, parameters such as diffusivity or diffusion coefficient and kinetic parameter of the extracts were estimated from experimental kinetic data. A good agreement was found between the CFD model and the experimental data. The mass diffusivity of the extracts in the liquid phase was 1.7 × 10−7 m2/s (R2=0.985) and 1.8 × 10−7 m2/s (R2=0.992) for dihydrorobinetin (DHR) and robinetin (Rob). Moreover, the phase change coefficient was 1.2 × 10−4 and 1.6 × 10−4 1/s for DHR and Rob, respectively. In addition, static maceration was combined with continuous flow extraction. The optimal condition was 213 min of static maceration followed by a flow of 1 mL/min for 465 min to obtain yields of 45.18 and 6.64 mg/g DHR and Rob, respectively.