Scale Supercritical Fluid Extraction Research Articles

Development of encapsulated sage extract powder: Inter-comparison with commercially available powder for physical properties and metabolites composition

Encapsulated Salvia officinalis L. powder (SESP) was developed from extract obtained by supercritical fluid extraction (SFE), and it was compared with commercial sage powder of hydro-distillation extract (HESP). The optimised conditions of 30 MPa at 50 °C for laboratory scale SFE extraction were found to generate the highest yield at 40.96 ± 0.84%. The conditions were later applied in the upscaled extraction, which yielded about 30.10 ± 1.33% extract. Large particle size distribution at 118.46 ± 6.63 µm for SESP was notified as compared to 66.80 ± 1.50 µm for HESP. Outcomes of crystallographic analysis demonstrated that abundant metabolites from various groups existed in both powders. About 25 and 43 metabolites were identified by Gas Chromatography-Mass Spectrometry (GC–MS) in HESP and SESP, respectively. In HESP, organic acids were found to be the major group identified, while terpenoids were the largest group found in SESP.

Recovery of uranium and plutonium from pyrochemical salt matrix using supercritical fluid extraction

Pyrochemical reprocessing of spent nuclear fuel involves use of molten salts for the separation of actinides from fission products. Salt waste arising from this process contains residual actinides along with fission products. In the present study, extraction of residual uranium and plutonium from pyrochemical salt matrices was investigated using supercritical fluid extraction (SFE) technique. Supercritical carbon dioxide (SCCO2) containing various ligands was examined to recover actinides from salt matrix with minimum generation of secondary liquid waste. Influence of ligand, salt matrix, temperature, pressure, co-solvent and HNO3 concentration was examined for efficient recovery of actinides. Among the ligands employed in present study, SCCO2 containing trioctylmethylammonium chloride resulted in better recovery of actinides. The recovery of uranium from salt matrix was also demonstrated using semi-preparative scale SFE facility. This study is first of its kind for recovery of actinides from pyrochemical salts using SFE.

Pressure control of a continuous pilot scale supercritical fluid extraction (SFE) process

Pressure control for a pilot scale continuous supercritical fluid extraction (SFE) process, has been developed for consistent extractions, overall efficiency and process safety reasons. The Internal-Model-Control (IMC) framework (specifically Skogestad’s IMC method) was employed for the design of a Proportional-Integral (PI) controller using both the actual pilot process and a hydrodynamic model of the process. Controller performance was assessed for set point changes and disturbance rejection. The best controllers lead to limited overshoot (less than 1 MPa), a response time of 200 s (within ±1% of set point) and little oscillatory behaviour. The design and performance results of the controllers generated using the hydrodynamic model were consistent with those of the actual process. Tests at alternate pressure conditions confirmed that the controller design and performance is pressure dependent owing to the nonlinear character of SFE processes.

Inverse supercritical fluid extraction as a sample preparation method for the analysis of the nanoparticle content in sunscreen agents

We demonstrate the use of inverse supercritical carbon dioxide (scCO2) extraction as a novel method of sample preparation for the analysis of complex nanoparticle-containing samples, in our case a model sunscreen agent with titanium dioxide nanoparticles. The sample was prepared for analysis in a simplified process using a lab scale supercritical fluid extraction system. The residual material was easily dispersed in an aqueous solution and analyzed by Asymmetrical Flow Field-Flow Fractionation (AF4) hyphenated with UV- and Multi-Angle Light Scattering detection. The obtained results allowed an unambiguous determination of the presence of nanoparticles within the sample, with almost no background from the matrix itself, and showed that the size distribution of the nanoparticles is essentially maintained. These results are especially relevant in view of recently introduced regulatory requirements concerning the labeling of nanoparticle-containing products. The novel sample preparation method is potentially applicable to commercial sunscreens or other emulsion-based cosmetic products and has important ecological advantages over currently used sample preparation techniques involving organic solvents.

Production of phenolic and glucosinolate extracts from rocket salad by supercritical fluid extraction: Process design and cost benefits analysis

A profitability analysis of a large scale supercritical fluid extraction (SFE) process to obtain natural extracts from rocket salad is presented in this work. An industrial-scale SFE plant is designed using process simulation techniques based on experimental data. Afterward, the effect of operative parameters on the process costs is evaluated. At the optimum conditions, the economic and financial analysis is performed, and the influence of the price of rocket salad on the price of the natural extract is assessed. Results indicate that the raw materials account for 67% of the total production costs. The proposed industrial application could be economically viable with a pay-back period of 10years if the price of the rocket salad extract is larger than 21.9US$kg−1, considering the current wholesale price in the market, or 17.0US$kg−1 if using non-saleable rocket salad. Both scenarios make the process economically sustainable and competitive with the current price of natural extracts obtained by extraction with organic solvents.

Supercritical CO2 extraction of Eucalyptus leaves oil and comparison with Soxhlet extraction and hydro-distillation methods

Oils were extracted from the leaves of Eucalyptus loxophleba ssp. lissophloia, also known as oil Mallee, using a laboratory scale supercritical fluid extraction (SFE) system using CO2. The effect of temperature (40–80°C), pressure (10–50MPa) and extraction time (30–150min) on the oil yield was investigated using a central composite design method to determine the significance and interactions of these parameters. The results showed that pressure had the most significant enhancing effect on the oil yield, while temperature and time showed a lesser impact. There was also pronounced interaction between temperature and pressure and their combined effect on the yield was such that the oil yield increased with increasing temperature at high pressures but decreased at low pressures. For comparison, the Eucalyptus leaves were also extracted with Soxhlet extraction, using two different solvents, and hydro-distillation methods. In the Soxhlet extraction, the solvent type had a more significant effect on the oil yield than the extraction time. Overall, the Soxhlet extraction produced the highest oil yield while hydro-distillation the lowest among the three methods. The SFE yield was up to 4.78%, comparable in magnitude to that of the hexane Soxhlet extraction of 7.9%. The chemical compositions of the extracted oils were analysed using a gas chromatography-mass spectrometer (GC–MS). The dominant component identified in the Eucalyptus oil was 1,8-cineole. The chemical compositions of the extracts were quite different for the three extraction methods. The oil extracted by hydro-distillation contained only volatile compounds while the oil from the SFE and Soxhlet contained both volatile and higher molecular weight compounds. The effect of the addition of ethanol as a modifier at concentrations from 5w% to 15w% on the supercritical fluid extraction of Eucalyptus leaves oil was also investigated. The ethanol addition was shown to increase the efficiency of oil extraction from Eucalyptus leaves and the oil yield increased with increasing ethanol concentrations.

An experimental investigation into the solubility of Moringa oleifera oil in supercritical carbon dioxide

The solubility of Moringa oleifera oil in supercritical CO2 was investigated using a laboratory scale supercritical fluid extraction system operating at temperatures from 333K to 373K and pressures from 20 to 50MPa. The oil solubility was found to be between 0.64 and 12.68 (g/kgCO2). The results showed that the solubility increased with increasing pressure under isothermal conditions. However, the effect of temperature showed different trends depending on the pressures. To generalise the experimental results, four models were employed to correlate the solubility data, including the Peng–Robinson equation of state and three density based models, namely, the Chrastil, del Valle and Aguilera, Adachi and Lu models. While all four models correlated the experimental data very well, the del Valle and Aguilera model showed the best fit. The Peng–Robinson equation of state enabled a thermodynamic explanation of the observed experimental trends of the variations in the M. oleifera oil solubility in supercritical CO2.

Recovery of Uranium and Plutonium from Waste Matrices Using Supercritical Fluid Extraction

Supercritical fluid extraction (SFE) of plutonium in its nitrate form from actual waste, i.e. plutonium bearing cellulose matrix was demonstrated using 0.1 litre capacity extraction vessel. Complete recovery of plutonium was demonstrated using modified supercritical carbon dioxide (Sc-CO2), i.e. Sc-CO2 containing octylphenyl-N, N-diisobutyl-carbamoyl- methylphosphine oxide (φCMPO). Near complete recovery of uranium was demonstrated from simulated waste matri- ces, i.e. uranium bearing teflon, glass and cellulose matrices using preparative scale SFE, i.e. from 1 litre capacity ex- traction vessel. The recovery of uranium was established using Sc-CO2 modified with acetyl acetone.

PRELIMINARY INVESTIGATION OF GALLIC ACID EXTRACTION FROM JATROPHA CURCAS LINN. LEAVES USING SUPERCRITICAL CARBON DIOXIDE WITH METHANOL CO‐SOLVENT

ABSTRACTThe leaves of Jatropha curcas Linn. contain antioxidant, anticancer and anti‐HIV compounds. This research investigated the extraction of the phenolic compound, gallic acid (GA), from Jatropha curcas Linn. leaves using supercritical carbon dioxide (SCCO2) and methanol co‐solvent. The SCCO2 pilot plant extractor, which was 10 times the capacity of a lab scale unit, was designed and built by our research group using a hydraulic pump instead of high pressure pump. The operating pressure was varied from 20 to 40 MPa; the temperature was varied from 40 to 60C; the particle size was varied from 10 to 40 mesh and the modifier concentration was varied from 0 to 70% (v/v) aqueous methanol. An orthogonal L9 (3)4 experimental design was applied to determine the optimal extracting condition and the effect of the parameters. The largest extraction yield from the experiment was 75.39 mg/kg dry weight of leaves at 40 MPa, 50C and 10–16 mesh particles using a 70% (v/v) methanol modifier. However, from the analysis of L9 (3)4, the optimal operating conditions were at 20 MPa, 50C and 10–16 mesh particles using a 70% (v/v) methanol modifier. It was found that temperature, particle size and modifier concentration had a statistically significant influence (at 85% confidence level) on the GA extraction yield. The fact that pressure was not found to be statistically significant is possibly due to the difficulty in controlling pressure in the pilot plant.PRACTICAL APPLICATIONSA pilot plant scale supercritical fluid extraction unit, which was 10 times the size of typical laboratory units, was designed and built in our lab using a low cost hydraulic pump to replace a high pressure pump. The pilot plant was able to reasonably extract gallic acid from the leaves of Jatropha curcas Linn. Preliminary experiments resulted in an optimal set of operating conditions which can be used as a starting point in future work. The system will eventually be instrumented and controlled to access operating data as well as maintain the operation of the extractor at desired set‐points. The advantage of using SCCO2 for the extraction is to achieve pure quality product. Gallic acid, which is one of the phenolic compounds in physic nut leaves, is characterized by various properties such as anti‐inflammatory, antimutagenic, anticancer, antioxidant and antiviral agent.

Triterpenes in traditional and supercritical-fluid extracts ofMorus albaleaf and stem bark

Summary Our objectives were to establish a GC method capable of quantitative analysis of terpenoids without derivatisation and to examine the amount of β-sitosterol extracted from Morus alba L. leaf and stem bark by use of traditional organic solvent extraction and supercritical-fluid extraction (SFE). To measure β-sitosterol content without derivatization, GC-FID was used with 5-α-cholestan-3-one as internal standard. To identify terpenoid constituents, GC-MS was used; β-sitosterol, phytol, lanost-7-en-3-on, α-amyrin, β-amyrin, and lupeol were identified. We established that for Morus leaf the best SFE method for β-sitosterol was pilot scale SFE; the β-sitosterol content of this extract was higher than that of the hexane solvent extract. Among analytical SFE conditions, 200 bar for 90 min and 300 bar for 60 min resulted in extraction of the most β-sitosterol. For mulberry stem bark, solvent extraction with hexane and SFE at 400 bar and 40°C for 60 min proved the best methods.

Determination of Extractability of Pine Bark Using Supercritical CO2 Extraction and Different Solvents: Optimization and Prediction

Bark from Pinus brutia was extracted with supercritical fluid extraction (SFE), using CO(2), at various extraction conditions both at laboratory and at pilot scale. Optimized parameters were 200 bar, 60 degrees C, and 3% ethanol at a solvent/feed ratio of 30. Additionally, the pine bark was sonicated (1 h at 50 degrees C) by different solvents (n-hexane, dichloromethane, ethyl acetate, and ethanol) to investigate the correlation between the different extraction setups and to obtain information on SFE up-scaling possibilities. Analyzed by HPLC, 7.2% of (-)-catechin was extractable at laboratory scale, and 58.4% (800 bar) and 47.8% (200 bar), both with modifiers, at pilot scale. By sonication with ethanol, 46.8% of (-)-catechin and almost 100% of (-)-epicatechin and (-)-catechin gallate were extracted. Ethyl acetate extract revealed high correlations with the laboratory scale SFE (r = 0.98) and also pilot scale SFE runs at 200 (r = 0.99) and 800 bar (r = 0.98) without modifiers.

A Fully Continuous Supercritical Fluid Extraction System for Contaminated Soil

AbstractA fully continuous lab scale supercritical fluid extraction system has been designed, built and tested. The system continuously pumps carbon dioxide under supercritical conditions and soil slurry into a counter‐current contacting column. Delhi Loamy Sand, spiked with approximately 10 mg/g of naphthalene, was used as the testing soil. The soil slurry ranged from 0.0028 g dry soil per g slurry to 0.072 g/g. The operating temperature was 43°C and the operating pressure was 7.7 MPa. Near steady state, fully continuous flow was achieved with runs lasting as long as 2 h. All carbon dioxide samples contained measurable quantities of naphthalene and the measured mass transfer coefficients were as high as 4.6×10−4 s−1.

Comparison of supercritical fluid and Soxhlet extractions for the quantification of hydrocarbons from Euphorbia macroclada

This study compares conventional Soxhlet extraction and analytical scale supercritical fluid extraction (SFE) for their yields in extracting of hydrocarbons from arid-land plant Euphorbia macroclada. The plant material was firstly sequentially extracted with supercritical carbon dioxide, modified with 10% methanol (v/v) in the optimum conditions that is a pressure of 400 atm and a temperature of 50 °C and then it was sonicated in methylene chloride for an additional 4 h. E. macroclada was secondly extracted by using a Soxhlet apparatus at 30 °C for 8 h in methylene chloride. The validated SFE was then compared to the extraction yield of E. macroclada with a Soxhlet extraction by using the Student’s t-test at the 95% confidence level. All of extracts were fractionated with silica-gel in a glass column to get better hydrocarbon yields. Thus, the highest hydrocarbons yield from E. macroclada was achieved with SFE (5.8%) when it compared with Soxhlet extractions (1.1%). Gas chromatography (GC) analysis was performed to determine the quantitative hydrocarbons from plant material. The greatest quantitative hydrocarbon recovery from GC was obtained by supercritical carbon dioxide extract (0.6 mg g −1).

Remediation of polychlorinated biphenyl contaminated soils/sediments by supercritical fluid extraction

AbstractStudies of polychlorinated biphenyl (PCB) desorption from soils have been conducted in a laboratory scale supercritical fluid extraction (SEF) unit to provide information for soil remediation. The results demonstrate the effectiveness of SFE as a promising technology for the clean up of PCB contaminated soils/sediments. After 30 minutes of extraction at 40°Cand 100 atm, more than 86% of PCBs in real world Hudson River sediment and 92% in St. Lawrence River sediment were removed. The extraction of PCBs from spiked samples showed even higher efficiencies. Various effects such as temperature, pressure, cosolvent, sample water content, and soil/sediment type on PCB desorption have been investigated. The sample water content and the presence of cosolvent were shown to be the most important factors affecting desorption of PCBs. The results show that PCBs in real world samples are more tightly bound than in spiked samples. The desorption behavior of individual PCB congeners in various samples has been investigated. The results demonstrate no relative accumulation of the most environmentally threatening PCB congeners throughout the extraction process.

Analysis of extracts fromcedrela toona (meliaceae) by on-line and off-line supercritical fluid extraction-capillary gas chromatography

A quantitative comparison between off-line supercritical fluid extraction (SFE) and a classical solvent extraction of a limonoid compound is discussed. A two-level three factor factorial analysis was used to optimize the variables, pressure, temperature, and the length of extraction time. By a statistical analysis of variance on the preliminary data collected, pressure and temperature were the significant variables influencing the yields of the limonoid cedrelone from the ground wood of Cedrela toona (Meliaceae). The cedrelone in the extracts was analyzed by capillary gas chromatography with flame ionization and mass spectrometric detection. On-line combination of micro-SFE with gas chromatography (SFE-GC) was also performed on the wood and bark to show the applicability of the technique in the analysis of semi-volatile components in natural products. Results for on-line and off-line SFE-GC were comparable and indicated that the on-line studies could be used to predict results obtainable from large scale SFE. © 1996 John Wiley & Sons, Inc.