Experimental and Modeling Investigation of Supercritical Extraction of Mannitol from Olive Leaves

Abstract

The experimental feasibility of mannitol extraction from olive leaves using supercritical carbon dioxide was investigated. The experimental data indicated that increasing the pressure from 200 to 350 bar and decreasing the temperature from 80 to 40°C resulted in an enhancement of the extraction yield and reduced the partition coefficient significantly. In addition, increasing the extraction time from 10 to 90 min increased the extraction yield, while further increases up to 180 min did not cause any further change. Ethanol was utilized as an entrainer and the maximum extraction yield was obtained using 20 % of ethanol. Moreover, modeling of the supercritical fluid extraction was carried out with the relevant mass transfer mechanisms involved in the supercritical and solid phases, and the appropriate numerical method of finite difference. The numerical results show that the model with three adjustable parameters is capable of predicting the experimental data very well.

Response Surface Optimization of Essential Oil and Diosgenin Extraction from Tribulus terrestris via Supercritical Fluid Technology

“…Carbon dioxide is heated before entering the extraction column by using a coil preheater (6) that is placed in a Jasco oven (10). The system pressure is controlled and monitored by a Jasco back-pressure regulator (11) and a high-pressure pump [17]. At the effluent of the backpressure regulator, a restrictor heater (12) increases the temperature of the exit solution stream up to 80°C in order to prevent a possible serious safety problem caused by the JouleThompson effect that may result in freezing of CO 2 .…”

“…The yields of essential oil and diosgenin were measured gravimetrically [17] and determined to be 17.38 wt-% and 23.59 mg/g dry T. terrestris fruits, respectively, which were taken as 100 % for calculating the SC-CO 2 extraction recovery.…”

Subcritical Water Extraction of Gingerol From Zingiber Officinale

“…In the subcritical region, water has several unique properties that are namely its disproportionately high boiling point for its mass, a high dielectric constant and high polarity. 10,14,15 As the temperatures rise in the subcritical water region, the permittivity of the water, the viscosity and the surface tension significantly decrease, while the diffusion rate increases. 14 In consequence, more polar target materials with high solubility in water at ambient conditions are extracted most efficiently at lower…”

Response Surface Optimization of Biodiesel Production via Catalytic Transesterification of Fatty Acids

“…Among the existing methods, supercritical solvents, especially supercritical carbon dioxide (SC-CO 2 ), has attracted attention because of nonsolvent residues, availability in high purity, and nonflammable nature. SC-CO 2 was applied for oil extraction from different solid matrices such as Boraginaceae [30], lavender [31], olive leaves [32], evening primrose [33], and grain sorghum [34].…”