Oil Extraction from Castor Cake Using Ethanol: Kinetics and Thermodynamics

Abstract

In this study, the kinetics and thermodynamics of oil extraction from castor cake using ethanol were investigated. Castor cake had a total oil content of 14.78 ± 0.12% in mass and the average particle diameter was 0.446 mm. Oil extractions were carried out in a stirred batch extractor system at various temperatures (20, 30, 40, and 55 °C). The fit of three different kinetic models to the experimental data was tested, with a modified Fick’s Law model being the most appropriate to describe the extraction kinetics (r 2 ≥ 0.960 and ARE ≤ 3.25%). Effective diffusion coefficients were determined, ranging from 4.52 × 10–13 m2 s–1 at 20 °C to 5.60 × 10–13 m2 s–1 at 55 °C. Change in Gibbs’ free energy (ΔG°) was determined to be negative (−4.55 kJ mol–1 at 20 °C to −6.56 kJ mol–1 at 55 °C), while changes in enthalpy (ΔH°) and entropy (ΔS°) were positive (12.27 kJ mol–1 and 57.41 J mol–1 K–1, respectively).

Influence of microwave irradiation on kinetics and thermodynamics of extraction of flavonoids from Phyllanthus emblica

“…A positive value of the change in entropy (∆S°) implies an increase in disorder of the system (Amarante et al, 2014). A negative value for the change in Gibbs free energy (∆G°) implies spontaneity of the process.…”

“…The microwave-assisted extraction process is endothermic and spontaneous, as evident from the positive and negative values for ΔH° and ΔG° respectively (Table 8). The increase in entropy due to extraction is attributed to solute transfer from the solid phase to the liquid phase (Amarante et al, 2014). With an increase in temperature, the degree of spontaneity of the MAE increases, leading to favourable extraction at elevated temperatures.…”

Microwave assisted extraction of flavonoids from Terminalia bellerica: Study of kinetics and thermodynamics

“…The positive value of the change in enthalpy (DH°) indicates that the MAE of flavonoids from T. bellerica is endothermic. The positive value of the change in entropy (DS°) indicates the increase in disorder of the solid-liquid extraction system due to the solute transfer from more ordered solid phase to the less ordered liquid phase [30].…”

“…These include models based on first order and second order behaviour [24,25], modified Fick's law [26] and other empirical models [27][28][29]. The study on thermodynamic parameters of extraction helps in determining the spontaneity of extraction process [30].…”

Effects of compression ratio on variation of stresses and residual oil of cake in pressing process of castor beans and its curve fitting

“…It is also used in novel applications in polymer industry as raw material for the production of a number of chemicals notably sebacic acid, undecylenic acid, and nylon-11 [4]. When used as a less expensive vegetable oils as feedstock in the production of biodiesel, the resulting fuel is superior for cold winters due to its exceptionally low cloud and pour points [5].…”