A Theoretical Model to Simulate Supercritical Fluid Extraction: Application to the Extraction of Terpenes by Supercritical Carbon Dioxide (original) (raw)
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Supercritical Fluid Extraction on Semibatch Mode for the Removal of Terpene in Citrus Oil
Industrial & Engineering Chemistry Research, 1996
Supercritical carbon dioxide extraction of a mixture of limonene and linalool was carried out with a rectification column in the semibatch operation mode. For the simple semibatch extraction where the column was controlled at the uniform temperature without an internal reflux, the Rayleigh equation, developed for the simple batch distillation, was applied to express the dynamic extraction behavior. In this paper the Peng-Robinson equation of state was used to estimate the ternary phase equilibria. The semibatch extraction with internal reflux induced by a temperature gradient of the rectification column increased the separation selectivity. The internal reflux ratio was calculated by the measurement of the extraction rates at the top and bottom of the column, and it was 7.6 for the column having a temperature gradient from 313 K at the bottom to 333 K at the top at 8.8 MPa. Behavior in the rectification column was discussed by means of estimated physical properties.
Supercritical carbon dioxide extraction of essential oils:: Modeling and simulation
Chemical engineering science, 1998
In this study, the supercritical carbon dioxide extraction of essential oils from plants which contain secretory ducts as essential oil reservoirs was investigated and modelled. Supercritical carbon dioxide extraction of essential oils from Asteraceae family species, marigold and chamomile, indicated that particle size had no significant influence on the extraction rate in two outermost cases: fine milled plant material and plant material cut to particle length of 5 mm. This confirmed previously reported phenomenon that in some cases particle size had no influence on the rate of supercritical extraction process. In order to explain this behavior, the mathematical model which took into consideration the phenomena occurring on the secretory duct scale, was developed and applied to simulate experimental data of marigold and chamomile supercritical carbon dioxide extraction. Proposed model was also applied to the literature experimental data of fennel fruit supercritical fluid extraction where the same phenomenon had been observed. To obtain information regarding secretory structure, scanning electron microscopy investigation of the plant material was performed. Very good agreement of the model results and experimental data in the case of different plant species, extraction conditions and particle sizes, confirmed the basic hypothesis of the model.
2007
In this study, the supercritical carbon dioxide extraction of essential oils from plants which contain secretory ducts as essential oil reservoirs was investigated and modelled. Supercritical carbon dioxide extraction of essential oils from Asteraceae family species, marigold and chamomile, indicated that particle size had no significant influence on the extraction rate in two outermost cases: fine milled plant material and plant material cut to particle length of 5 mm. This confirmed previously reported phenomenon that in some cases particle size had no influence on the rate of supercritical extraction process. In order to explain this behavior, the mathematical model which took into consideration the phenomena occurring on the secretory duct scale, was developed and applied to simulate experimental data of marigold and chamomile supercritical carbon dioxide extraction. Proposed model was also applied to the literature experimental data of fennel fruit supercritical fluid extraction where the same phenomenon had been observed. To obtain information regarding secretory structure, scanning electron microscopy investigation of the plant material was performed. Very good agreement of the model results and experimental data in the case of different plant species, extraction conditions and particle sizes, confirmed the basic hypothesis of the model.
The Journal of Supercritical Fluids, 2011
Supercritical fluid extraction is an interesting alternative for the fractionation of essential oils, in order to obtain concentrates or compounds of interest. This technique requires information about the distribution of the components of the mixture between the phases present at different conditions of pressure, temperature and composition. In this work equilibrium information of three bioactive essential oils (Salvia officinalis, Mentha piperita and Tagetes minuta oil) with near-critical and supercritical carbon dioxide is measured using a dynamic apparatus in the range of 313-323 K and 60-120 bar. The distribution of monoterpenes, oxygenated terpenes and sesquiterpenes in the extract phase is determined by gas chromatography in order to explore the best operating conditions for the separation of the fractions or compounds with higher biocidal activity. Predictive calculations are performed using the group contribution equation of state (GC-EOS) and compared with the experimental data.
An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological 10551 properties, which is present in the oils from thyme and winter savory. On the other hand, the modeling of our data on supercritical extraction of volatile oil from pennyroyal is discussed using Sovová's models. These models have been applied successfully to the other volatile oil extractions. Furthermore, other experimental studies involving supercritical CO 2 carried out in our laboratories are also mentioned.
Molecules, 2012
An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological OPEN ACCESS Molecules 2012, 17 10551
Extraction of Clove and Vetiver Oils with Supercritical Carbon Dioxide: Modeling and Simulation
The Open Chemical Engineering Journal, 2007
The kinetics of supercritical fluid extraction (SFE) of clove and vetiver oils using carbon dioxide as solvent was studied, in order to establish an efficient method to predict extraction curves on large scale. The mass transfer model of Sovová was used to adjust the experimental SFE data, which were obtained at 100 bar and 35 °C for clove and 200 bar and 40 °C for vetiver, using extraction columns of different geometry and solvent flow rates. Some other process parameters, such as bed density and porosity, solvent to feed ratio and solvent velocity were kept constant from one experiment to another, in order to verify if the mass transfer coefficients adjusted by the model varied. The results show that the model of Sovová was able to predict an overall extraction curve for clove from data obtained with twenty times less raw material, since the mass transfer coefficients remained the same and the predicted curves were similar to the observed ones. For vetiver, the simulation was not as effective, probably due to the effects of transport properties on the process.
Mathematical modelling of supercritical CO2 extraction of volatile oils from aromatic plants
Chemical Engineering Science, 2010
The modelling of the experimental data of the extraction of the volatile oil from six aromatic plants (coriander, fennel, savoury, winter savoury, cotton lavender and thyme) was performed using five mathematical models, based on differential mass balances. In all cases the extraction was internal diffusion controlled and the internal mass transfer coefficient (k s ) have been found to change with pressure, temperature and particle size. For fennel, savoury and cotton lavender, the external mass transfer and the equilibrium phase also influenced the second extraction period, since k s changed with the tested flow rates.
2012
An overview of the studies carried out in our laboratories on supercritical fluid extraction (SFE) of volatile oils from seven aromatic plants: pennyroyal (Mentha pulegium L.), fennel seeds (Foeniculum vulgare Mill.), coriander (Coriandrum sativum L.), savory (Satureja fruticosa Béguinot), winter savory (Satureja montana L.), cotton lavender (Santolina chamaecyparisus) and thyme (Thymus vulgaris), is presented. A flow apparatus with a 1 L extractor and two 0.27 L separators was built to perform studies at temperatures ranging from 298 to 353 K and pressures up to 30.0 MPa. The best compromise between yield and composition compared with hydrodistillation (HD) was achieved selecting the optimum experimental conditions of extraction and fractionation. The major differences between HD and SFE oils is the presence of a small percentage of cuticular waxes and the relative amount of thymoquinone, an oxygenated monoterpene with important biological
Ethane as an alternative solvent for supercritical extraction of orange peel oils
Journal of Supercritical Fluids, 2008
The objective of this study was to investigate the superiority of ethane in comparison to CO 2 as a supercritical extraction solvent for deterpenating citrus oils. A rigorous computer code was developed that optimized extraction column operating conditions to minimize solvent recirculation. The SRK equation of state was used as the thermodynamic model after globally optimizing its adjustable binary interaction parameters to a combination of different literature data sets consisting of binary isothermal P-x, y, ternary constant composition P-T, and ternary isothermal isobaric x-y data. An investigation of the effects of different process variables on the degree of extraction revealed complicated and interconnected relations among the variables and extraction efficiencies. However, since the process of deterpenation, in particular, benefits from higher solubility more than from higher selectivity, increases in temperature, pressure, solvent-to-feed ratio, and reflux rate all seem to favor the separation.