Separation of molybdenum isotope complexes by supercritical fluid extraction (SFE) with carbon dioxide was studied experimentally. The extraction of molybdenum isotope complexes was carried out in the updated extracti...Separation of molybdenum isotope complexes by supercritical fluid extraction (SFE) with carbon dioxide was studied experimentally. The extraction of molybdenum isotope complexes was carried out in the updated extraction chamber (reactor) of the SFE-U installation, which provided an initial pressure of P ≤ 20 MPa at constant temperatures of the upper T1 = 35°C and bottom T2 = 45°C flanges. The device, through which the eluent was discharged, involved a set of four thin tubes of different lengths located inside the reactor. The axes of the tubes and the reactor are parallel and the tubes are equally spaced circumferentially inside the reactor. The extract was removed from each tube through channels isolated from each other and located in the bottom flange with cylindrical expansion, in which several layers of filter paper were placed. After passing through the filters the extract entered a restrictor designed to remove the eluent from the reactor. The initial pressure of carbon dioxide and the holding time of the extract were specified in the experiments. The level of the eluent sampling was set by the lengths of the tubes depending on the reactor height. A method of producing molybdenum complexes was described. It was experimentally shown that at an initial pressure of 20 MPa and a given holding time a difference from the natural content of Mo isotopes for given heights of extract sampling depending on the reactor height was observed in extracts removed through filters. The ranges of deviation of the content of molybdenum isotopes in extracts from natural one were determined.展开更多
[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-puri...[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-purity ginger essential oil from the fresh ginger. [Method] GEO was extracted from ginger roots by supercritical fluid extraction （SFE） method. The effects of flow rate of CO2, mesh size of ginger powder and volume of entrainer were investigated by single-factor experiments and response surface method. The content and extraction rate of 6-gingerol represented the extraction index of GEO. [Result] The conditions were optimized as follows： flow rate of CO2 at 25 L/h, mesh size of ginger power of 80 mesh, and volume of anhydrous ethanol as entrainer of 92.46 ml. The optimal extraction rate of 6-gingerol was 3.21%, which was predicted by RSM. [Conclusion] The optimal process of supercritical carbon dioxide extraction of ginger essential oil was identified by singlefactor experiments and response surface method. The present study provides a satisfactory method for purifying GEO from ginger for industrial purpose.展开更多
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, nonto...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.展开更多
[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oi...[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oil was extracted using supercritical CO2 （SC-CO2）. The effects of extraction time, temperature and pressure were investigated by single-factor experiments and orthogonal array testing （ORT）. The chemical compositions of extracted perilla seed oil were investigated by GC-MS. [Result] The optimal conditions for the extraction of perilla seed oil using SC-CO2 were extraction time of 4 h, extraction temperature at 40 ℃, and extraction pressure at 23 MPa. Under these conditions, the extraction yield of perilla seed oil was maximized to 12.43%. GC-MS analysis revealed that perilla seed oil was a complex mixture containing 76.183% α-linolenic acid. [Conclusion] Supercritical CO2 extraction was proven to be an effective technology to extract oil from perilla seed, and GCMS was also a satisfactory method for analyzing the compositions of perilla seed oil.展开更多
A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-l-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives...A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-l-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr^2＋ and Pb^2＋ extraction in supercritical carbon dioxide.展开更多
Andrographis paniculata Nees has been extensively used for traditional medicine and help against fever dysentery, diarrhoea, inflammation, and sore throat. In this study, andrographolide, the main component of this pl...Andrographis paniculata Nees has been extensively used for traditional medicine and help against fever dysentery, diarrhoea, inflammation, and sore throat. In this study, andrographolide, the main component of this plant was extracted from the leaves of A. paniculata using supercritical carbon dioxide. The operating pressures were varied from 7.50 to 20MPa, the temperatures were varied from 30℃ to 60℃, and the flow rates were varied from 0.5 to 4ml.min^-1. The best extraction condition occurred at 10MPa, 40℃, and a flow rate of 2ml.min^-1 for a 3g sample of A. paniculata ground-dried leaves. The measured extraction rate was found to be about 0.0174g of andrographolide per gram of andrographolide present in the leaves per hour of operation. The future studies must focus on the interaction between the various operating parameters such as temperature, pressure, and flow rate of supercritical carbon dioxide.展开更多
Supercritical carbon dioxide （SC-CO2） extraction was employed to extract oil from Nigella glandulifera Freyn seed in this study. Response surface methodology （RSM） was applied to evaluate the effects of the proces...Supercritical carbon dioxide （SC-CO2） extraction was employed to extract oil from Nigella glandulifera Freyn seed in this study. Response surface methodology （RSM） was applied to evaluate the effects of the process parameters （pressure, temperature, and CO2 flow rate） on oil yield of N. glandulifera seed. A Box-Behnken design was used to optimize the extraction parameters. The analysis of variance indicated that the linear coefficients of pressure and CO2 flow rate, the quadratic term coefficients of pressure and temperature and the interactions between pressure and temperature, as well as temperature and CO2 flow rate, had significant effects on the oil yield （P〈0.05）. The optimal conditions to obtain the maximum oil yield from N. glandulifera seed were pressure 30.84 MPa, temperature 40.57°C, and CO2 flow rate 22.00 L h-1. Under these optimal conditions, the yield of oil was predicted to be 38.19%. The validation experiment results agreed with the predicted values. The fatty acid composition of N. glandulifera seed oil extracted using SC-CO2 was compared with that of oil obtained by Soxhlet method. The results showed that the fatty acid compositions of oil extracted by the two methods were similar. Identification of oil compounds with gas chromatography-mass spectrometry （GC-MS） showed that the contents of unsaturated fatty acids linoleic acid （48.30%）, oleic acid （22.28%） and saturated fatty acids palmitic acid （16.65%）, stearic acid （4.17%） were the most abundant fatty acids in seed oil from N. glandulifera.展开更多
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 generat...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.展开更多
The supercritical carbon dioxide extraction was applied to obtain essential oil from Pogostemon cablin in this work.Effect of extraction parameters including temperature,pressure,extraction time and particle size on e...The supercritical carbon dioxide extraction was applied to obtain essential oil from Pogostemon cablin in this work.Effect of extraction parameters including temperature,pressure,extraction time and particle size on extraction yield was investigated,and the response surface methodology with a Box–Behnken Design was used to achieve the optimized extraction conditions.The maximum yield of essential oil was 2.4356%under the conditions of extraction temperature 47°C,pressure 24.5 MPa and extraction time 119 min.Moreover,based on the Brunauer–Emmett–Teller theory of adsorption,a mathematical modeling was performed to correlate the measured data.The model shows a function relationship between extraction yield and time by a simple equation with three significantly adjustable parameters.These model parameters have been optimized through simulated annealing algorithm.The predicted data from the mathematical model show a good agreement with the experimental data of the different extraction parameters.展开更多
Organic matter was experimentally extracted by supercritical fiuids （CO2 +1% isopropanol） from petroleum source rocks of different thermo-maturities at different buried depths in the same stratigraphic unit in the D...Organic matter was experimentally extracted by supercritical fiuids （CO2 +1% isopropanol） from petroleum source rocks of different thermo-maturities at different buried depths in the same stratigraphic unit in the Dongying Basin. The results show that supercritical fluid extraction （SFE） is more effective than Soxhlet extraction （SE）, with higher amounts and greater varieties of hydrocarbons and soluble organic matter becoming extractive. The supercritical CO2 extraction is therefore considered more valuable in evaluation of petroleum source rocks and oil resources, particularly those of immature types.展开更多
A new expression of mixing rule is suggested according to the Mayson′s mixing rule in this paper, which adopts the Redlich Kwong cubic equation of state and the modified Chueh Prausnitz method to calculate the expe...A new expression of mixing rule is suggested according to the Mayson′s mixing rule in this paper, which adopts the Redlich Kwong cubic equation of state and the modified Chueh Prausnitz method to calculate the experiment critical points of six binary mixtures CO 2+toluene, CO 2+cyclohexane, CO 2+ n butanal, CO 2+ i butanal , CO 2+methanol, CO 2+ethanol. The coefficients of interaction parameter in the expression of mixing rule were optimized from experimental data. The calculated results of critical temperature and critical pressure meet the experiment data well. The maximum relative errors of temperature and pressure between the calculation results and experiment data are 1 493% and 5 2236% respectively, indicating that the proposed expression of mixing rule is reasonable. This may provide a fundamental method for studying and predicting the properties of supercritical fluids.展开更多
The monomer fraction density based analysis of precise thermophysical data for pure fluids is developed to study the molecular structures in supercritical fluids in general and in CO2 in particular. The series expansi...The monomer fraction density based analysis of precise thermophysical data for pure fluids is developed to study the molecular structures in supercritical fluids in general and in CO2 in particular. The series expansion by powers of the monomer fraction density of the potential energy density is used to discover the cluster structure in supercritical fluids and the clusters’ bond energies in CO2. The method of clusters separation between classes of loose and dense clusters in the CO2 supercritical fluid is developed. The method of the energetically averaged number of dense clusters is developed to study the mechanism of the soft structural transition between the gas-like and liquid-like fluids in the supercritical CO2.展开更多
Aspen Adsim was used to simulate the fractionation of citrus oil with extraction and adsorption combined method in supercritical carbon dioxide.The dynamic behavior in a isothemal and adiabatic bed could be described ...Aspen Adsim was used to simulate the fractionation of citrus oil with extraction and adsorption combined method in supercritical carbon dioxide.The dynamic behavior in a isothemal and adiabatic bed could be described succesfully,and the simulation results agreed with the experimental data.The effect of adsorption time,the flow rate of feed on the concentration of components in product and the recovery were studied.The amount of loading composition on the adsorbents changed with adsorption time and axial distance of bed was also investigated.展开更多
In this paper experimental equilibrium data on the system supercritical CO2-orange essential oil and the system supercritical CO2-linalool are reported at 323.15 K and 343.15 K, for pressures in the ranges of 7.6-13.5...In this paper experimental equilibrium data on the system supercritical CO2-orange essential oil and the system supercritical CO2-linalool are reported at 323.15 K and 343.15 K, for pressures in the ranges of 7.6-13.5 MPa. The behavior of the system supercritical CO2-orange essential oil was represented by means of thermodynamic model, based on Peng-Robinson equation of state. To this aim the orange essential oil was represented by a mixture of limonene, linalool and β-caryophyllene, selected to represent the classes of monoterpenes, oxygenated terpenes and sesquiterpenes respectively. The model uses only regression parameters calculated from binary sub-systems, CO2-limonene and CO2-β-caryophyllene (taken from literature) and CO2-linalool (calculated from the fitting of original data reported in the present work) thus being predictive with respect to the multicomponent mixture.展开更多
Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide （quaternary mixture of carbon dioxide ＋ methanol ＋ water ＋ DMC） were mea...Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide （quaternary mixture of carbon dioxide ＋ methanol ＋ water ＋ DMC） were measured using a high-pressure view cell. The results suggested that the critical properties of the reacting mixture depended on the reaction extent as well as its initial composition （initial ratio of carbon dioxide to methanol）. Such information is essential for determining the reaction conditions when one intends to carry out the synthesis of DMC with CO2 and methanol under supercritical conditions.展开更多
Supercritical carbon dioxide(SC-CO_(2))extraction of Conjugated linoleic acid(CLA)ethyl ester was investigated at pressures in the range of 9 to 10.5 MPa and temperature gradients ranging from 0℃ to 21℃.The content ...Supercritical carbon dioxide(SC-CO_(2))extraction of Conjugated linoleic acid(CLA)ethyl ester was investigated at pressures in the range of 9 to 10.5 MPa and temperature gradients ranging from 0℃ to 21℃.The content of CLA-ethyl ester in the fraction was analyzed with gas chromatography(GC).The experimental results indicated that the rate of extraction would rise with the increase of pressure when temperature gradient was given.Moreover,the extraction pressure had insignificant influence on the selectivity of CLA-ethyl ester in SCCO_(2).When pressure was fixed,setting certain temperature gradient can improve the selectivity of CLA-ethyl ester in SC-CO_(2),and CLA-ethyl ester can be concentrated more effectively than without a temperature gradient.The acid value and peroxide value of the fractions were reduced obviously,compared to the raw material.The optimal condition is pressure at 10 MPa and temperature gradient at 11℃.展开更多
Supercritical CO2 extraction was employed to separate simulated and real bio-oils. Effects of extraction pressure, temperature and adsorbents on distribution coefficient (or enrichment coefficient) of five representat...Supercritical CO2 extraction was employed to separate simulated and real bio-oils. Effects of extraction pressure, temperature and adsorbents on distribution coefficient (or enrichment coefficient) of five representative compounds were investigated using a simulated bio-oil, which was composed of acetic acid (AC), propanoic acid (PA), furfural (FR), acetylacetone (AA) and 2-methoxyphenol (MP). The distribution coefficients of AA, FR and MP between super-critical CO2 phase and liquid phase were bigger than 1.5, while those of AC and PA characteristic of relatively strong polarity were less than 1. Temperature and pressure also had impacts on the distribution coefficients of AA, FR and MP, especially remarkable for AA. The extraction of simulated bio-oil spiked on three adsorbents shows that adsorbents influence extraction efficiency and selectivity by changing intermolecular forces. High extraction pressure and relative low temperature are beneficial to reduce the water content in the extract. In addition, the feasibility of supercritical CO2 extraction of real bio-oil was examined. After extraction in the extraction fraction total ketones increased from 14.1% to 21.15~25.40%, phenols from 10.74% to 31.32~41.25%, and aldehydes from 1.92% to 3.95~8.46%, while the acids significantly dropped from 28.15% to 6.92~12.32%, and water from 35.90% to 6.64~4.90%. In view of extraction efficiency, the optimal extraction temperature was determined to be 55℃. Extraction efficiency of the real bio-oil increased with rising pressure. The maximal extraction efficiency of real bio-oil on water-free basis could reach to 88.6%. After scCO2 extraction, the calorific value and stability of the extract fraction evidently increased and the acidity slight decreased with nearly 100% volatility below 140℃, suggesting potentially applicable as substitute for engine fuel.展开更多
The experimental data on supercritical CO2 extraction of microalgae are presented. It is confirmed that microalgae contains omega-3 fatty acid components. Phase equilibria data are presented for the triolein-methanol ...The experimental data on supercritical CO2 extraction of microalgae are presented. It is confirmed that microalgae contains omega-3 fatty acid components. Phase equilibria data are presented for the triolein-methanol (T = 413 K, P = 5.8 - 11.9 MPa) and ethyl eicosapentaenoate-carbon dioxide (T = 313 - 333 K, P = 10 - 21 MPa) binary systems. The scheme of the batch-type experimental setup for supercritical transesterification of oils is presented. Temperature and molar ratio dependences of non-refined palm oil yield to fatty acid methyl esters (FAME) are presented for T = 563 - 693 K, methanol to palm oil molar ratio 39:1. Experiments on ultrasonic emulsification of rapeseed oil-ethanol mixture (molar ratios 150:1 - 7:1) were conducted. Research data on ultrasonic emulsion stability are presented for the time range of 0 - 40 minutes after ultrasonication completion. Correlation is defined between FAME yield of emulsified reaction mixtures and the emulsion grain size. FAME yields are compared for emulsified and non-emulsified reaction mixtures.展开更多
The aim of this study was to determine the extraction technique of supercritical fluid carbon dioxide（SF-CO 2） for the essential oil from Inula britannica flowers and its antifungal activities against plant pathogen...The aim of this study was to determine the extraction technique of supercritical fluid carbon dioxide（SF-CO 2） for the essential oil from Inula britannica flowers and its antifungal activities against plant pathogenic fungi for its potential application as botanical fungicide.The effects of factors,including extraction temperature,extraction pressure,SF-CO 2 flow rate,flower powder size,and time on the essential oil yield were studied using the single factor experiment.An orthogonal experiment was conducted to determine the best operating conditions for the maximum extraction oil yield.Adopting the optimum conditions,the maximum yield reached 10.01% at 40°C temperature,30 MPa pressure,60 mesh flower powder size,20 L h-1SF-CO 2 flow rate,and 90 min extraction time.The antifungal activities of I.britannica essential oil using the SF-CO 2 against the most important plant pathogenic fungi were also examined through in vitro and in vivo tests.Sixteen plant pathogenic fungi were inhibited to varying degrees at 1 mg mL-1concentration of the essential oil.The mycelial growth of Gaeumannomyces graminis var.tritici was completely inhibited.The radial growths of Phytophthora capsici and Fusarium monilifome were also inhibited by 83.76 and 64.69%,respectively.In addition,the essential oil can inhibit the spore germination of Fusarium oxysporum f.sp.vasinfectum,Phytophthora capsici,Colletotrichum orbiculare,and Pyricularia grisea,and the corresponding inhibition rates were 98.26,96.54,87.89,and 87.35% respectively.The present study has demonstrated that the essential oil of I.britannica flowers extracted through the SF-CO 2 technique is one potential and promising antifungal agent that can be used as botanical fungicide to protect crops.展开更多
The oxidation of styrene with molecular oxygen catalyzed by PdCl2+CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and s...The oxidation of styrene with molecular oxygen catalyzed by PdCl2+CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.展开更多
文摘Separation of molybdenum isotope complexes by supercritical fluid extraction (SFE) with carbon dioxide was studied experimentally. The extraction of molybdenum isotope complexes was carried out in the updated extraction chamber (reactor) of the SFE-U installation, which provided an initial pressure of P ≤ 20 MPa at constant temperatures of the upper T1 = 35°C and bottom T2 = 45°C flanges. The device, through which the eluent was discharged, involved a set of four thin tubes of different lengths located inside the reactor. The axes of the tubes and the reactor are parallel and the tubes are equally spaced circumferentially inside the reactor. The extract was removed from each tube through channels isolated from each other and located in the bottom flange with cylindrical expansion, in which several layers of filter paper were placed. After passing through the filters the extract entered a restrictor designed to remove the eluent from the reactor. The initial pressure of carbon dioxide and the holding time of the extract were specified in the experiments. The level of the eluent sampling was set by the lengths of the tubes depending on the reactor height. A method of producing molybdenum complexes was described. It was experimentally shown that at an initial pressure of 20 MPa and a given holding time a difference from the natural content of Mo isotopes for given heights of extract sampling depending on the reactor height was observed in extracts removed through filters. The ranges of deviation of the content of molybdenum isotopes in extracts from natural one were determined.
基金Supported by the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(16KJA550001)~~
文摘[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-purity ginger essential oil from the fresh ginger. [Method] GEO was extracted from ginger roots by supercritical fluid extraction （SFE） method. The effects of flow rate of CO2, mesh size of ginger powder and volume of entrainer were investigated by single-factor experiments and response surface method. The content and extraction rate of 6-gingerol represented the extraction index of GEO. [Result] The conditions were optimized as follows： flow rate of CO2 at 25 L/h, mesh size of ginger power of 80 mesh, and volume of anhydrous ethanol as entrainer of 92.46 ml. The optimal extraction rate of 6-gingerol was 3.21%, which was predicted by RSM. [Conclusion] The optimal process of supercritical carbon dioxide extraction of ginger essential oil was identified by singlefactor experiments and response surface method. The present study provides a satisfactory method for purifying GEO from ginger for industrial purpose.
基金Science Foundation of National Education Commission(99053)
文摘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.
基金Supported by Undergraduate Innovation Training Program of Jiangsu Province(201610327010Z)~~
文摘[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oil was extracted using supercritical CO2 （SC-CO2）. The effects of extraction time, temperature and pressure were investigated by single-factor experiments and orthogonal array testing （ORT）. The chemical compositions of extracted perilla seed oil were investigated by GC-MS. [Result] The optimal conditions for the extraction of perilla seed oil using SC-CO2 were extraction time of 4 h, extraction temperature at 40 ℃, and extraction pressure at 23 MPa. Under these conditions, the extraction yield of perilla seed oil was maximized to 12.43%. GC-MS analysis revealed that perilla seed oil was a complex mixture containing 76.183% α-linolenic acid. [Conclusion] Supercritical CO2 extraction was proven to be an effective technology to extract oil from perilla seed, and GCMS was also a satisfactory method for analyzing the compositions of perilla seed oil.
基金The project was sponsored by the National Natural Science Foundation of China(No.20607031)the Scientific Research Foundation for the Returned 0verseas Chinese Scholars,State Education Ministry(2006-331)+1 种基金We are also grateful to Key Natural Science Fundation of South-Central University for Nationalities(YZZ05001)"Youth Chen-Guang Project"of Wuhan Bureau of Science and Technology(20065004116-34)for financial supports.
文摘A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-l-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr^2＋ and Pb^2＋ extraction in supercritical carbon dioxide.
基金Supported by the Intensification of Research in Priority Areas Project (IRPA)Ministry of Science, Technology and Innovation,Malaysia (No.09-02-03-0101-EA0001).
文摘Andrographis paniculata Nees has been extensively used for traditional medicine and help against fever dysentery, diarrhoea, inflammation, and sore throat. In this study, andrographolide, the main component of this plant was extracted from the leaves of A. paniculata using supercritical carbon dioxide. The operating pressures were varied from 7.50 to 20MPa, the temperatures were varied from 30℃ to 60℃, and the flow rates were varied from 0.5 to 4ml.min^-1. The best extraction condition occurred at 10MPa, 40℃, and a flow rate of 2ml.min^-1 for a 3g sample of A. paniculata ground-dried leaves. The measured extraction rate was found to be about 0.0174g of andrographolide per gram of andrographolide present in the leaves per hour of operation. The future studies must focus on the interaction between the various operating parameters such as temperature, pressure, and flow rate of supercritical carbon dioxide.
基金supported by the Public Welfare Industry (Agriculture) Research Program,China (200903018)
文摘Supercritical carbon dioxide （SC-CO2） extraction was employed to extract oil from Nigella glandulifera Freyn seed in this study. Response surface methodology （RSM） was applied to evaluate the effects of the process parameters （pressure, temperature, and CO2 flow rate） on oil yield of N. glandulifera seed. A Box-Behnken design was used to optimize the extraction parameters. The analysis of variance indicated that the linear coefficients of pressure and CO2 flow rate, the quadratic term coefficients of pressure and temperature and the interactions between pressure and temperature, as well as temperature and CO2 flow rate, had significant effects on the oil yield （P〈0.05）. The optimal conditions to obtain the maximum oil yield from N. glandulifera seed were pressure 30.84 MPa, temperature 40.57°C, and CO2 flow rate 22.00 L h-1. Under these optimal conditions, the yield of oil was predicted to be 38.19%. The validation experiment results agreed with the predicted values. The fatty acid composition of N. glandulifera seed oil extracted using SC-CO2 was compared with that of oil obtained by Soxhlet method. The results showed that the fatty acid compositions of oil extracted by the two methods were similar. Identification of oil compounds with gas chromatography-mass spectrometry （GC-MS） showed that the contents of unsaturated fatty acids linoleic acid （48.30%）, oleic acid （22.28%） and saturated fatty acids palmitic acid （16.65%）, stearic acid （4.17%） were the most abundant fatty acids in seed oil from N. glandulifera.
基金Supported by the National Natural Science Foundation of China （20506014）.
文摘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.
文摘The supercritical carbon dioxide extraction was applied to obtain essential oil from Pogostemon cablin in this work.Effect of extraction parameters including temperature,pressure,extraction time and particle size on extraction yield was investigated,and the response surface methodology with a Box–Behnken Design was used to achieve the optimized extraction conditions.The maximum yield of essential oil was 2.4356%under the conditions of extraction temperature 47°C,pressure 24.5 MPa and extraction time 119 min.Moreover,based on the Brunauer–Emmett–Teller theory of adsorption,a mathematical modeling was performed to correlate the measured data.The model shows a function relationship between extraction yield and time by a simple equation with three significantly adjustable parameters.These model parameters have been optimized through simulated annealing algorithm.The predicted data from the mathematical model show a good agreement with the experimental data of the different extraction parameters.
文摘Organic matter was experimentally extracted by supercritical fiuids （CO2 +1% isopropanol） from petroleum source rocks of different thermo-maturities at different buried depths in the same stratigraphic unit in the Dongying Basin. The results show that supercritical fluid extraction （SFE） is more effective than Soxhlet extraction （SE）, with higher amounts and greater varieties of hydrocarbons and soluble organic matter becoming extractive. The supercritical CO2 extraction is therefore considered more valuable in evaluation of petroleum source rocks and oil resources, particularly those of immature types.
基金Supported by the National Natural Science Foundation of China(No.2 0 0 76 0 0 4 ) and the Research Fund for the Doctor-al Pragram of Higher Education(No.2 0 0 0 0 0 10 0 5 )
文摘A new expression of mixing rule is suggested according to the Mayson′s mixing rule in this paper, which adopts the Redlich Kwong cubic equation of state and the modified Chueh Prausnitz method to calculate the experiment critical points of six binary mixtures CO 2+toluene, CO 2+cyclohexane, CO 2+ n butanal, CO 2+ i butanal , CO 2+methanol, CO 2+ethanol. The coefficients of interaction parameter in the expression of mixing rule were optimized from experimental data. The calculated results of critical temperature and critical pressure meet the experiment data well. The maximum relative errors of temperature and pressure between the calculation results and experiment data are 1 493% and 5 2236% respectively, indicating that the proposed expression of mixing rule is reasonable. This may provide a fundamental method for studying and predicting the properties of supercritical fluids.
文摘The monomer fraction density based analysis of precise thermophysical data for pure fluids is developed to study the molecular structures in supercritical fluids in general and in CO2 in particular. The series expansion by powers of the monomer fraction density of the potential energy density is used to discover the cluster structure in supercritical fluids and the clusters’ bond energies in CO2. The method of clusters separation between classes of loose and dense clusters in the CO2 supercritical fluid is developed. The method of the energetically averaged number of dense clusters is developed to study the mechanism of the soft structural transition between the gas-like and liquid-like fluids in the supercritical CO2.
文摘Aspen Adsim was used to simulate the fractionation of citrus oil with extraction and adsorption combined method in supercritical carbon dioxide.The dynamic behavior in a isothemal and adiabatic bed could be described succesfully,and the simulation results agreed with the experimental data.The effect of adsorption time,the flow rate of feed on the concentration of components in product and the recovery were studied.The amount of loading composition on the adsorbents changed with adsorption time and axial distance of bed was also investigated.
文摘In this paper experimental equilibrium data on the system supercritical CO2-orange essential oil and the system supercritical CO2-linalool are reported at 323.15 K and 343.15 K, for pressures in the ranges of 7.6-13.5 MPa. The behavior of the system supercritical CO2-orange essential oil was represented by means of thermodynamic model, based on Peng-Robinson equation of state. To this aim the orange essential oil was represented by a mixture of limonene, linalool and β-caryophyllene, selected to represent the classes of monoterpenes, oxygenated terpenes and sesquiterpenes respectively. The model uses only regression parameters calculated from binary sub-systems, CO2-limonene and CO2-β-caryophyllene (taken from literature) and CO2-linalool (calculated from the fitting of original data reported in the present work) thus being predictive with respect to the multicomponent mixture.
基金financial support of the State Key Fundamental Research Project(2006CB202504)the National Natural Science Foundation of China(No.20473110)Natural Science Foundation of Shanxi Province.
文摘Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide （quaternary mixture of carbon dioxide ＋ methanol ＋ water ＋ DMC） were measured using a high-pressure view cell. The results suggested that the critical properties of the reacting mixture depended on the reaction extent as well as its initial composition （initial ratio of carbon dioxide to methanol）. Such information is essential for determining the reaction conditions when one intends to carry out the synthesis of DMC with CO2 and methanol under supercritical conditions.
基金supported by Key Laboratory for Green Chemical Process of Ministry of Education,Wuhan Institute of Technology,and the authors would like to acknowledge their financial support.
文摘Supercritical carbon dioxide(SC-CO_(2))extraction of Conjugated linoleic acid(CLA)ethyl ester was investigated at pressures in the range of 9 to 10.5 MPa and temperature gradients ranging from 0℃ to 21℃.The content of CLA-ethyl ester in the fraction was analyzed with gas chromatography(GC).The experimental results indicated that the rate of extraction would rise with the increase of pressure when temperature gradient was given.Moreover,the extraction pressure had insignificant influence on the selectivity of CLA-ethyl ester in SCCO_(2).When pressure was fixed,setting certain temperature gradient can improve the selectivity of CLA-ethyl ester in SC-CO_(2),and CLA-ethyl ester can be concentrated more effectively than without a temperature gradient.The acid value and peroxide value of the fractions were reduced obviously,compared to the raw material.The optimal condition is pressure at 10 MPa and temperature gradient at 11℃.
文摘Supercritical CO2 extraction was employed to separate simulated and real bio-oils. Effects of extraction pressure, temperature and adsorbents on distribution coefficient (or enrichment coefficient) of five representative compounds were investigated using a simulated bio-oil, which was composed of acetic acid (AC), propanoic acid (PA), furfural (FR), acetylacetone (AA) and 2-methoxyphenol (MP). The distribution coefficients of AA, FR and MP between super-critical CO2 phase and liquid phase were bigger than 1.5, while those of AC and PA characteristic of relatively strong polarity were less than 1. Temperature and pressure also had impacts on the distribution coefficients of AA, FR and MP, especially remarkable for AA. The extraction of simulated bio-oil spiked on three adsorbents shows that adsorbents influence extraction efficiency and selectivity by changing intermolecular forces. High extraction pressure and relative low temperature are beneficial to reduce the water content in the extract. In addition, the feasibility of supercritical CO2 extraction of real bio-oil was examined. After extraction in the extraction fraction total ketones increased from 14.1% to 21.15~25.40%, phenols from 10.74% to 31.32~41.25%, and aldehydes from 1.92% to 3.95~8.46%, while the acids significantly dropped from 28.15% to 6.92~12.32%, and water from 35.90% to 6.64~4.90%. In view of extraction efficiency, the optimal extraction temperature was determined to be 55℃. Extraction efficiency of the real bio-oil increased with rising pressure. The maximal extraction efficiency of real bio-oil on water-free basis could reach to 88.6%. After scCO2 extraction, the calorific value and stability of the extract fraction evidently increased and the acidity slight decreased with nearly 100% volatility below 140℃, suggesting potentially applicable as substitute for engine fuel.
文摘The experimental data on supercritical CO2 extraction of microalgae are presented. It is confirmed that microalgae contains omega-3 fatty acid components. Phase equilibria data are presented for the triolein-methanol (T = 413 K, P = 5.8 - 11.9 MPa) and ethyl eicosapentaenoate-carbon dioxide (T = 313 - 333 K, P = 10 - 21 MPa) binary systems. The scheme of the batch-type experimental setup for supercritical transesterification of oils is presented. Temperature and molar ratio dependences of non-refined palm oil yield to fatty acid methyl esters (FAME) are presented for T = 563 - 693 K, methanol to palm oil molar ratio 39:1. Experiments on ultrasonic emulsification of rapeseed oil-ethanol mixture (molar ratios 150:1 - 7:1) were conducted. Research data on ultrasonic emulsion stability are presented for the time range of 0 - 40 minutes after ultrasonication completion. Correlation is defined between FAME yield of emulsified reaction mixtures and the emulsion grain size. FAME yields are compared for emulsified and non-emulsified reaction mixtures.
基金supported by the Scientific and Technological Key Project of Henan Province, China (082102350006 and 102102310242)the College Young Teachers Projects of Henan Province, China (2010GGJS046)
文摘The aim of this study was to determine the extraction technique of supercritical fluid carbon dioxide（SF-CO 2） for the essential oil from Inula britannica flowers and its antifungal activities against plant pathogenic fungi for its potential application as botanical fungicide.The effects of factors,including extraction temperature,extraction pressure,SF-CO 2 flow rate,flower powder size,and time on the essential oil yield were studied using the single factor experiment.An orthogonal experiment was conducted to determine the best operating conditions for the maximum extraction oil yield.Adopting the optimum conditions,the maximum yield reached 10.01% at 40°C temperature,30 MPa pressure,60 mesh flower powder size,20 L h-1SF-CO 2 flow rate,and 90 min extraction time.The antifungal activities of I.britannica essential oil using the SF-CO 2 against the most important plant pathogenic fungi were also examined through in vitro and in vivo tests.Sixteen plant pathogenic fungi were inhibited to varying degrees at 1 mg mL-1concentration of the essential oil.The mycelial growth of Gaeumannomyces graminis var.tritici was completely inhibited.The radial growths of Phytophthora capsici and Fusarium monilifome were also inhibited by 83.76 and 64.69%,respectively.In addition,the essential oil can inhibit the spore germination of Fusarium oxysporum f.sp.vasinfectum,Phytophthora capsici,Colletotrichum orbiculare,and Pyricularia grisea,and the corresponding inhibition rates were 98.26,96.54,87.89,and 87.35% respectively.The present study has demonstrated that the essential oil of I.britannica flowers extracted through the SF-CO 2 technique is one potential and promising antifungal agent that can be used as botanical fungicide to protect crops.
文摘The oxidation of styrene with molecular oxygen catalyzed by PdCl2+CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.
