Effect of Allelochemicals of Chinese-fir root extracted by supercritical CO_2 extraction on Chinese fir

Allelochemicals of Chinese-fir root was extracted by technology ofsupercritical CO_2 extraction under orthogonal experiment design, and it was used to analyzeallelopathic activity of Chinese-fir through bioassay of seed germination. The results showed thatas to the available rate of allelochemicals, the pressure and temperature of extraction were themost important factors. The allelochemicals of Chinese-fir root extracted by pure CO_2 and ethanolmixed with CO_2 have different allelopathic activities to seed germination, and the allelochemicalsextracted by ethanol mixed with CO_2 had stronger inhibitory effects on seed germination than thatextracted by pure CO_2.

A Comparative Study on Chemical Composition of Supercritical CO_2 Extraction Products in Peels of Trichosanthes kirilowii Maxim. from Changqing District

[Objective] This study aimed to investigate the differences in chemical composition of supercritical CO2 extraction products in peels of Trichosanthes kirilowii Maxim. from Changqing district. [Method] Supercritical fluidextraction （SFE） and GCMS method were applied to determine and analyze the chemical components of the extracts in peels of three strains of Trichosanthes kirilowii Maxim. [Result] The chemical components of supercritical CO2 extraction products in peels of three strains of Trichosanthes kirilowii Maxim. varied., and the number of chemical components with normalized percentage content higher than 1% was 5, 7 and 8, respectively. There are 14 kinds of common components, and the relative content of hexadecanoic acid was the highest. [Conclusion] Supercritical CO2 extracts in peels of different strains of Trichosanthes kirilowii Maxim. contain different chemical components, providing scientific basis for breeding excellent varieties and the development and utilization of Trichosanthes kirilowii Maxim.

Experimental and Simulating Study of Supercritical CO_2 Extraction of Ginger Essential Oil

An experimental setup for separating ginger essential oil by supercritical fluid extraction is established. The effects of the extraction pressure, temperature, CO2 flow rate and particle size of raw material on the extraction rate are investigated, and the optimum process conditions of supercritical CO2 extraction are determined. A mathematical simulation model is established based on the mass conservation in differential units of extraction bed. The total mass transfer driving force and the equilibrium absorption constant are evaluated by the linear driving force theory. The results from numerical simulation agree well with the experimental data.

Extraction of betulin from bark of Betula platyphylla by supercritical carbon dioxide extraction

Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO2 extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extrac-tion conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 C. The velocity of flow of liquid CO2 was at 10 kg/h. The pressure and tem-perature in separation vessel were at 5.5 Mpa and 50 C, respectively.

Extraction of Heavy Metals from Solid Material by Supercritical CO_2

Extraction of heavy metal ions from solid matrix by means of an incorporation of chelating agents with supercritical carbon dioxide（scCO2） was investigated experimentally. Four commercially available chelating agents, diethylammonium diethyldithiocarbamate（Et2NH2DDC）, trifluoroacetylacetone（TFA）, hexafluoroacetylacetone（HFA） and thenoyltrifluoroacetone（TTA） were tested. The extraction experiments were conducted at 50 °C and 1.39×107― 2.80×107 Pa. According to the experimental results, for the extraction of Cu2＋, all the chelating agents investigated here are effective. For other metal ions, such as Pb2＋, Ni2＋ and Cd2＋, Et2NH2DDC exhibited a better extraction result, while other chelating agents were less effective. This investigation is expected to provide a tentative evaluation on the scCO2-based metal extraction from solid media.

Effect of Allelochemicals of Chinese-fir root extracted by supercritical CO2 extraction on Chinese fir

Allelochemicals of Chinese-fir root was extracted by technology of supercritical CO2 extraction under orthogonal experiment design, and it was used to analyze allelopathic activity of Chinese-fir through bioassay of seed germination. The results showed that as to the available rate of allelochemicals, the pressure and temperature of extraction were the most important factors. The allelochemicals of Chinese-fir root extracted by pure CO2 and ethanol mixed with CO2 have different allelopathic activities to seed germination, and the allelochemicals extracted by ethanol mixed with CO2 had stronger inhibitory effects on seed germination than that extracted by pure CO2.

Measurement and Correlation of the Solubility of Ligusticum Chuanxiong oil in Supercritical CO_2

Extraction of the Ligusticum Chuanxiong oil with supercritical CO2 （SC-CO2） was investigated at the temperatures ranging from 55℃ to 70℃ and pressure from 25 MPa to 35 MPa. The mass of Ligusticum Chuanxiong oil extracted increased with pressure at constant temperature. The initial slope of the extraction was considered as the solubility of oil in SC-CO2. Chrastil equation was used to correlate the solubility data of Ligusticum Chuanxiong oil. An improved Chrastil equation was also presented and was employed to correlate the solubility data, The correlation results show that the values of the average absolute relative deviation are 5.94% and 3.33% respectively, indicating the improved version has better correlation accuracy than that of Chrastil equation.

Dynamic analysis of heat extraction rate by supercritical carbon dioxide in fractured rock mass based on a thermal-hydraulic-mechanics coupled model

Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.

Kinetics of Reactive Extraction of Nd from Nd2O3 with TBP-HNO3 Complex in Supercritical Carbon Dioxide

The process based on supercritical fluid extraction for reprocessing of the spent nuclear fuel has some remarkable advantages over the plutonium-uranium extraction(PUREX) process.Especially,it can minimize the generation of secondary waste.Dynamic reactive extraction of neodymium oxide(Nd2O3) in supercritical carbon dioxide(SC-CO2) containing tri-n-butyl phosphate-nitric acid(TBP-HNO3) complex was investigated.Temperature showed a positive effect on the extraction efficiency,while pressure showed a negative effect when the unsaturated TBP-HNO3 complex was employed for the dynamic reactive extraction of Nd2O3 in SC-CO2.Both temperature and pressure effects indicated that the kinetic process of the reactive extraction was controlled by the chemical reaction.A kinetic model was proposed to describe the extraction process.

Isolation of Organochlorine Pesticide from Ginseng with Supercritical CO_2

The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1 × 10^-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.

MICROPOROUS PVDF-HFP-BASED POLYMER MEMBRANES FORMED FROM SUPERCRITICAL CO_2 INDUCED PHASE SEPARATION

Microporous poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)membranes following supercritical CO_2 induced phase separation process were prepared using four solvents.The solid electrolytes of PVDF-HFP were formed by microporous PVDF-HFP membranes filled and swollen by a liquid electrolyte.The effect of the solvents on the morphology and structure,electrolyte absorptions and lithium ionic conductivity of the activated membranes were investigated.It was approved that all the membrane had the similar...

Polymerization of Styrene in Supercritical CO_2-swollenPoly(ethylene terephthlate)

Polystyrene/Poly(ethylene terephthlate) (PET) blends have been prepared by theheterogeneous free-radical polymerization of styrene within supercritical carbon dioxide-swollenPET substrates. Composition of the blends and the average molecular weight of polystyrene inthe blends can be controlled by equilibration time and reaction condition.

Pressure Effect on the Local Composition SurroundingEthyl Acetoacetate in Supercritical CO_2 - Ethanol Mixture

The keto-enol tautomerization of ethyl acetoacetate (EAA) in supercritical CO2-ethanol mixture has been investigated at 308.15 K and at different pressures using UV-Visspectroscopy. A method for calculating the local composition about EAA has been developed based on the relationship between the equilibrium constant and dielectric property of the mixing solvent. The results indicate that the local concentration of ethanol surrounding EAA is much higher than that in the bulk.

Supercritical fluid extraction of useful compounds from sage

A qualitative analysis of supercritical fluid extraction (SFE) of the medically useful compound, sage (Salvia officinalis) is presented in this study. Carbon dioxide was used as a supercritical solvent. Effects of operating conditions such as temperature, pressure, and extraction time were investigated. The effect of addition of cosolvents was also studied. The extracted useful compounds were identified and analyzed using GC-MS chromatography. The analysis of the extract obtained by SFE showed certain significant major compounds that are considered medically important. These major compounds are 1R-.alpha.-Pinene, D-Limonene, l-Camphene, and b-Pinene, and Eucalyptol. Although, there was no consistent trend with respect to the effect of the studied parameters on the composition of the extract, the selectivity of these major compounds are dependant on the operating conditions, manily the operating pressure. An increase in the pressure resulted in an increase in herb extraction yield;this is true for certain group of extracts, while the inverse is also true for other group of compounds. The effect of certain cosolvents on the extractability of sage showed a significant improvement of the yield of some particular constituents of sage.

Supercritical Fluid Carbon Dioxide in the Extraction of Lanolin and Its Alcohol

The use of supercritical fluid carbon dioxide (SFCO2) in extraction of lanolin and its alcohol is superior to the conventional solvent extraction method. Its distinctive advantages include high extractive ratio, nontoxic and nonflammable solvents, and minimal by -product pollution. The resulting refined lanolin and its alcohol have light color and little odor, and can be used as raw materials for high grade cosmetic products.

Influence of Modifier in Supercritical CO₂on Qualitative and Quantitative Extraction Results of <i>Eucalyptus</i>Ecential Oil

A supercritical CO2 extraction behavior of Eucalyptus oil was investigated under different conditions of pressure, temperature and time with or without cosolvent. The pressure range was from 8 to 25 MPa, temperature from 35 to 55&deg;C and CO2 flow rate from 10 to 26 g/min. For 1,8-cineole the appropriate extracting pressure was 15 MPa and temperature was 45&deg;C. When CO2 flow rate was 18 g/min, it was benefit to extract the other three substances (limonene, p-cymene and γ-terpinene, respectively) except 1,8-cineole. Prolonging extraction time could not obviously increase the extract concentration, but the extract yield would increase. The results also indicated that ethanol as a modifier could improve extraction velocity and extraction concentration.

Optimization of Supercritical CO_(2) Extraction of Curcumin by Response Surface Methodology and Its Antioxidant Activity

[Objectives]This study was conducted to establish a mathematical model for supercritical CO_(2) extraction of curcumin.[Methods]With ginger as the experimental raw material,a quadratic polynomial mathematical model of the yield of curcumin extracted by supercritical CO_(2) was established by response surface methodology(RSM).The validity of the mathematical model was verified,and the effects of extraction temperature(60-70℃),pressure(30-50 MPa)and time(70-90 min)on curcumin yield were analyzed.[Results]According to the model,the process parameters were optimized.Taking curcumin yield as the index,the optimal process conditions for supercritical CO_(2) extraction obtained were:temperature 62.6℃,pressure 37.7 MPa,time 82.9 min,under which the yield of curcumin was as high as 7.34%.Under the optimal extraction conditions,curcumin had a certain reducing capacity,and showed strong scavenging capacities to·OH,O_(2)^(-)·and DPPH,and its IC_(50) values were 9.40,9.03 and 8.04 mg/ml,respectively.Therefore,it is feasible to extract curcumin from ginger using supercritical CO_(2).[Conclusions]This study provides a theoretical basis for the development and utilization of curcumin.

Supercritical Fluid Extraction of Uncrushed Jordanian Olives

Announcement from Editorial Board ? The following article has been retracted due to special reason of the authors. This paper published in Vol.2 No. 3, 2012, has been removed from this site. ? Title: Supercritical Fluid Extraction of Uncrushed Jordanian Olives Authors: Awni Al-Otoom, Sameer Al-Asheh, Mamdouh Allawzi, Khalid Mahshi, Nahawand Alzenati, Bader Banat, Bdour Alnimr ? ACES Editorial Board? May 19,

Production of Submicroparticles of β-Sitosterol Using an Aerosol Solvent Extraction System

The submicroparticles of β-sitosterol were produced by using an aerosol solvent extraction system （ASES） and characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, and Fourier transform infrared （FT-IR） analysis. The effects of operational parameters including pressure, temperature, solution concentration, and ratio of flow rate （CO2/solution, r） on particle size （PS）, yield, and morphology were investigated. The results showed that microparticles of β-sitosterol （less than 1000 nm size and larger than 70% yield） could be obtained at 10-15 MPa, 35 50℃, 15 mg·ml^-1, 10/1（r）; β-sitosterol particles were found to occur as three mophologies： flakes, rods, and spheres by varying ratio of flow rate or solution concentration. In contrast, the crystallinity of β-sitosterol decreased, whereas its molecular structure remained almost unchanged after being ASES-treated. Therefore, ASES was an effective method to produce submicroparticles of β-sitosterol.

Study on the Composition and Super Critical Carbon Dioxide Extraction of Chinese Hickory (<i>Carya cathayensis</i>Sarg.) Kernel Oil

Chinese hickory (Carya cathayensis Sarg.) is one of the most productive woody oil-bearing plant in China. Four different extraction methods were explored and supercritical CO2 was selected as green and non-toxic solvent to extract Chinese kernel oil. Four experiment factors, particles size, extraction time, extraction temperature and extraction pressure, were selected to carry out the single factor experiments. According to the results of orthogonal experiments design, the condition of B3C2A2D2 was the optimum reaction parameters. When the experiments were carried out at the optimum parameters, the yield of Chinese hickory kernel oil was 74.5%. The oil fatty acids profiles were analyzed, the results showed that total unsaturated fatty acids were 93.05%. Among them, oleic acid was 66.5 ± 0.44 as the main component. Saturated fatty acids were 6.92 ± 0.21.