Predicting the extraction yield of nimbin from neem seeds in supercritical CO_2 using group contribution methods, equations of state and a shrinking core extraction model

摘要

The purpose of this paper is to present the predicted extraction of nimbin from neem seeds using supercritical CO_2 when only the molecule structure of nimbin is known. Group contribution methods (GCM) were used to estimate pure component properties, equations of state (EoS) to estimate the pressure/volume/temperature (PVT) behaviour and fugacity coefficient of solute in the solute-solvent mixture. Transport properties were estimated using available correlations and a shrinking core model was used to predict the extraction yield. The model predictions were compared with experimental data; the effect of CO_2 flow rate (0.24-1.24 mL/min), temperature (308-333 K), pressure (10-26 MPa), particle size (0.575-1.850 mm) and weight of neem kernel powder (1.0-2.5 g) were investigated. The predicted results were found to agree well with the measured results and the model was able to explain the presence of optimum yields that were observed experimentally.