RESUMEN
The separation of Jatropha curcas oil from azeotropes of ethyl alcohol-n-hexane and isopropyl alcohol-n-hexane using ceramic membranes with different cutoffs (5, 10 and 20â kDa) is presented. The mass ratios of oil:azeotropes (O:S) studied were 1:3 for feeding pressures of 0.1, 0.2 and 0.3â MPa, and 1:1 for the feeding pressure of 0.1â MPa. Isopropyl alcohol was the best solvent for the membranes conditioning to permeate n-hexane (240â kg/m2â h). In the separation of J. curcas oil and azeotropes of solvents, both membranes showed oil retention and total flux decreases with time. Overall, the lowest decrease in the retentions was reached in the 5â kDa membrane, while the lowest decrease in the total flux was reached in the 20â kDa. In the separation of oil and ethyl alcohol-n-hexane azeotrope, the best retention at 60â min of the process was equal to 17.3â wt% in the 20â kDa membrane at 0.3â MPa and O:S ratio equalled to 1:3. In this condition, the total permeate flux was 17.5â kg/m2â h. Different retentions and permeabilities are provided when changing the O:S ratio, the feeding pressure and the molecular weight cutoff of membranes.
Asunto(s)
Cerámica/química , Fraccionamiento Químico/métodos , Jatropha/química , Aceites de Plantas/aislamiento & purificación , Solventes/química , 2-Propanol/química , Hexanos/química , Membranas Artificiales , Aceites de Plantas/químicaRESUMEN
This work investigates the extraction process of safflower oil using pressurized ethanol, and compares the chemical composition obtained (in terms of fatty acids) with other extraction techniques. Soxhlet and Ultrasound showed maximum global yield of 36.53% and 30.41%, respectively (70°C and 240min). PLE presented maximum global yields of 25.62% (3mLmin(-1)), 19.94% (2mLmin(-1)) and 12.37% (1mLmin(-1)) at 40°C, 100bar and 60min. Palmitic acid showed the lower concentration in all experimental conditions (from 5.70% to 7.17%); Stearic and Linoleic acid presented intermediate concentrations (from 2.93% to 25.09% and 14.09% to 19.06%, respectively); Oleic acid showed higher composition (from 55.12% to 83.26%). Differences between percentages of fatty acids, depending on method were observed. Results may be applied to maximize global yields and select fatty acids, reducing the energetic costs and process time.