This study focuses upon the supercritical CO2 extraction of oil seed rape (Brassica napus) and the energy consumption associated with it in two different scales (1 Land 2 x 16 L). Experiments were carried out to determine the influence of pressure, temperature and flow rate on the extraction yield. The yield varied from 37 to 97% of the one for n-heptane. The energy consumption in both extraction plants allowed an analysis of the different components involved in the extraction process, namely pumping, heating and cooling. This energy consumption was analysed depending on the amount of CO2 used, so the calculations can be extrapolated to any supercritical fluid extraction process undertaken in those plants. In the particular case of the supercritical extraction of oil seed rape, the best conditions in our experimental range were achieved at 55 MPa and 35 degrees C, yielding 100.3 g of oil per kWh. This yield was comparable to that obtained in the pilot plant of 97.4g oil/kWh. An accurate energetic evaluation of the extraction process at different scales has provided further evidence to encourage the change to supercritical fluid extraction as an economically viable industrial process. (C) 2015 Elsevier B.V. All rights reserved.

The objective of this study was the preparation of supercritical (SCE), conventional hydrodistilled (HDE) and organic solvent (OSE) extracts from two Iberian Lavandula luisieri populations (A and B) to study their chemical composition and their insect antifeedant properties against Spodoptera littoralis and Myzus persicae. HDE and SCE extracts had different chemical compositions and insect antifeedant effects, extracts from population A being more effective. Compounds 5-hydroxymethyl-2,3,4,4-tetramethylcyclopent-2-en-1-one (6) and (2,2,3,4-tetramethyl-5-oxocyclopent-3-en-1-yl)-methyl acetate (7)were the major components of the SCE fractions of both populations. The supercritical technique (SFE) improved the extraction of 6, 7, oxo-cadinol (8), hexadecanoic acid and several not identified compounds with respect to HDE. SCE extracts also exhibited increased antifeedant effects against S. littoralis and the aphid M. persicae (A-SCE). The biological effects of the active extracts cannot be accounted for those of their individual major components, suggesting additive or synergistic effects.

The aim of this study is to develop a method and to determine by means of isothermal microcalorimetry the activity of supercritical extracts obtained from growth-controlled wormwood (Artemisia absinthium L.) over Spodoptera littoralis L. (S. littoralis), a polyphagous pest of the Mediterranean crops. In order to achieve this goal, a three-step microcalorimetric method has been developed to insure the quality of the measurements and the validity of the results. Once optimized, different extracts of wormwood obtained by means of supercritical fluid extraction and by traditional methods have been used to investigate their effects over S. littoralis. The microcalorimetric method serves as a tool to complement other bioassays found in the literature. Several extracts from supercritical extractions with solvent density ranging from 485.5 to 819.5 kg m−3 have been tested. The influence of an entrainer addition to the supercritical fluid has also been investigated. The traditional extracts were obtained by hydrodistillation and organic Soxhlet extraction. The supercritical extracts were more efficient against S. littoralis than the traditionally obtained extracts.

A comparison between traditional extraction techniques (hydrodistillation and organic solvent extraction) and supercritical fluid extraction was made for two different populations and crops of Artemisia absinthium L., cultivated in the field and aeroponically. The composition of the extracts, volatile and non volatile oils, was analyzed by GC–MS and HPLC–DAD, respectively. The antifeedant and phytotoxic activity of the extracts was tested on insect pests (Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi) and plants (Lactuca sativa and Lolium perenne). The supercritical extracts exhibited stronger antifeedant effects than the traditional ones (up to 8 times more active) with moderate selective phytotoxic effects on L. perenne root growth (<50% inhibition).

A useful encapsulation methodology has been developed to fabricate α-tocopheryl acetate-zeolite Y microcapsules. These new microcapsules have been applied to obtain special textile polyamide fibers. The presence of α-tocopheryl acetate in both microcapsules and special fibers has been qualitatively and quantitatively determined using various techniques such as thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), and high performance liquid chromatography (HPLC). Two different techniques to extract the α-tocopheryl acetate encapsulated in both microcapsules and special fibers have been compared: liquid−liquid extraction, that gives the best results under the studied conditions, and supercritical CO2 extraction, which is useful when there are mass transfer limitations as in the case of the special fibers. Mechanical properties of the fiber do not significantly change when they are fabricated with zeolite Y microcapsules. Finally, fabrics knitted with yarns of α-tocopheryl acetate-zeolite Y microc...

A measuring device, based on the vibrating tube principle, for measuring P rho T data is described. The device was checked against the recommended literature values of the 1-hexanol + n-hexane binary system within the temperature and pressure ranges (278.15 to 313.15) K and (0.1 to 20) MPa. The relative deviations between experimental and bibliographic densities are lower than 0.2 %. After the validation, the original mixture 1,8-cineole + ethanol was studied in the ranges (283.15 to 313.15) K and (0.1 to 20) MPa. The isothermal compressibility, the isobaric thermal expansion, and the excess molar volume were derived from the experimental density data, revealing that a volume contraction occurs for this binary system. Four different equations of state, Peng-Robinson, Sako-Wu-Prausnitz, Statistical Associating Fluid Theory (SAFT), and Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT), were applied to predict the volumetric behavior of the ethanolic mixture. The best predictions were achieved with the PC-SAFT equation of state.