Response Surface Optimization of Nigella glandulifera Freyn Seed Oil Yield by Supercritical Carbon Dioxide Extraction

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.

Experimental optimization and mathematical modeling of supercritical carbon dioxide extraction of essential oil from Pogostemon cablin

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.

A study of the mechanism of enhancing oil recovery using supercritical carbon dioxide microemulsions

Supercritical carbon dioxide （scCO2） microemulsion was formed by supercritical CO2, H20, sodium bis（2-ethylhexyl） sulfosuccinate （AOT, surfactant） and C2HsOH （co-surfactant） under pressures higher than 8 MPa at 45 ℃. The fundamental characteristics of the scCO2 microemulsion and the minimum miscibility pressure （MMP） with Daqing oil were investigated with a high-pressure falling sphere viscometer, a high-pressure interfacial tension meter, a PVT cell and a slim tube test. The mechanism of the scCO2 microemulsion for enhancing oil recovery is discussed. The results showed that the viscosity and density of the scCO2 microemulsion were higher than those of the scCO2 fluid at the same pressure and temperature. The results of interfacial tension and slim tube tests indicated that the MMP of the scCO2 microemulsion and crude oil was lower than that of the scCO2 and crude oil at 45 ℃. It is the combined action of viscosity, density and MMP which made the oil recovery efficiency of the scCO2 microemulsion higher than that of the scCO2 fluid.

Metal Ions Extraction with Glucose Derivatives as Chelating Reagents in Supercritical Carbon Dioxide

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.

A simulation of citrus oil adsorption separation in the supercritical carbon dioxide

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.

Supercritical Carbon Dioxide Extraction of Andrographolide from Andrographis paniculata： Effect of the Solvent Flow Rate, Pressure, and Temperature

Andrographis paniculata Nees 广泛地对发烧，痢疾，腹泻，发炎，和酸的喉咙为传统的药和帮助被使用了。在这研究， andrographolide，这植物的主要部件从 A 的叶子被提取。用超级批评二氧化碳的 paniculata。操作压力从 7.50 被改变到 20MPa，温度从 30 ° C 被改变到 60 ° C，并且流动率从 0.5 被改变到 4ml · m in-1。最好的抽取条件为 A 的一件 3g 样品发生在 10MPa， 40 ° C，和 2ml · m in-1 的流动率。paniculata 弄干地面的叶子。测量抽取率被发现每工作时间每在叶子在场的 andrographolide 的克关于 andrographolide 的 0.0174g。未来研究必须集中于在象超级批评二氧化碳的温度，压力，和流动率那样的各种各样的操作参数之间的相互作用。

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.

Solubility of red palm oil in supercritical carbon dioxide： Measurement and modelling

The solubility of red palm oil(RPO) in supercritical carbon dioxide(scCO_2) was determined using a dynamic method at 8.5–25 MPa and, 313.15–333.15 K and at a fixed scCO_2 flow rate of 2.9 g·min^(-1) using a full factorial design. The solubility was determined under low pressures and temperatures as a preliminary study for RPO particle formation using scCO_2. The solubility of RPO was 0.5–11.3 mg·(g CO_2)^(-1) and was significantly affected by the pressure and temperature. RPO solubility increased with pressure and decreased with temperature. The Adachi–Lu model showed the best-fit for RPO solubility data with an average relative deviation of 14% with a high coefficient of determination, R^2 of 0.9667, whereas the Peng–Robinson equation of state thermodynamic model recorded deviations of 17%–30%.

Supercritical Equilibrium Data of the Systems Carbon Dioxide—Linalool and Carbon Dioxide—Orange Essential Oil

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.

Supercritical Carbon Dioxide Extraction of Organic Matter from Petroleum Source Rocksand Its Implications

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.

Separation of Molybdenum Isotopes at Supercritical Fluid Extraction with Carbon Dioxide in a Vertical Gradient Field of Temperatures

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.

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.

Supercritical carbon dioxide extraction of CLA-ethyl ester

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℃.

Separation of Biomass Pyrolysis Oil by Supercritical CO2 Extraction

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.

Essential Oil from Inula britannica Extraction with SF-CO_2 and Its Antifungal Activity

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.

An extraction-assay system： Evaluation on flavonols in plant resistance to Pb and Cd by supercritical extraction-gas chromatography

In this research, supercritical carbon dioxide extraction （SFE） showed better extraction etlect when compared with Solid- liquid extraction （SLE）, Soxhlet extraction （SEt and Ultrasonic extraction （UE）, not only in the rate but also the time. The comparison among these three extraction modifiers, including acetone, ethanol and methanol demonstrated that ethanol was preferred to SFE due to its high extraction effect and low toxicology. In addition, parameter of SFE, influence of temperature and pressure were investigated, and the best extraction effect was achieved at the optima conditions, temperature of 40℃ and the pressure of 35 MPa. Thus, SFE is a highly effective method for flavonols extraction, requiring minimum energy and producing non-toxic byproduct. SFE-GC system is applied for the evaluation on flavonols that plays a key role in plant resistance to heavy metal, with its content and synthetase gene expression significantly increasing in plant when threatened by heavy metal. Besides, results indicated that flavonols can improve plant resistance to oxidative stress by quenching the redundant ROS in matrix.

机器学习在超临界二氧化碳制膜技术教学中的应用实践

[目的]探索将超临界二氧化碳(CO_(2))辅助制备金属-有机框架(MOF)膜与机器学习技术相结合的创新教学模式,以提高本科生在实验数据处理、分析和预测方面的能力。[方法]在教学过程中,学生首先使用数据提取工具从复杂的实验图表中提取CO_(2)在MOF材料上的吸附等温线数据,构建包含数据点和材料性能参数的数据集。随后,学生应用极致梯度提升(XGB)和随机森林(RF)两种机器学习算法对提取的数据集进行训练和测试,建立材料性能预测模型。[结果]数据提取工具显著提高了数据处理的效率和准确性,XGB模型在材料性能参数预测方面表现出良好的准确性和可解释性。通过这种结合数据提取和机器学习的教学模式,学生在数据处理和预测方面取得了显著进步,增强了他们的数据分析和科研能力。[结论]本工作提出的教学模式为化学工程和材料科学领域的实验数据处理和分析提供了有效的解决方案,具有较高的应用价值。

基于响应曲面法的超临界CO_(2)萃取油基钻屑油相工艺优化

目的对超临界CO_(2)萃取油基钻屑中油相工艺参数进行优化。方法采用响应曲面法对影响超临界CO_(2)萃取工艺的重要参数进行具体实验并根据实验结果进行数值模拟,通过模拟得出萃取时间、压力、温度和超临界CO_(2)流量等参数的优化数据。结果响应曲面分析了各变量之间对萃取效果的影响,基于萃取数据建立了二次多项式模型,能够较好地拟合实验结果,得出最佳萃取条件为萃取压力25 MPa、温度323.15 K、时间90 min和流量25.0 L/h。结论通过具体实验数据结合响应曲面法得出了最佳萃取条件,在该条件下油类最大去除率为95.22%。利用气相色谱仪-质谱联用仪(GC-MS)分析萃取物前后性状未发生明显变化,该方法能够更好地实现固液分离和资源回收。

二氧化碳压裂技术研究进展

水力压裂开发非常规油气存在用水量大、引发储层伤害和污染地下水等问题。二氧化碳压裂技术因拥有造缝范围广、裂缝复杂、增产效果好、对地下水污染小、返排速率快等优势,且响应国家“双碳政策”要求,正逐渐成为非常规油气资源开发的热点。本文调研了国内外二氧化碳压裂技术发展历史及二氧化碳干法压裂、二氧化碳泡沫压裂、超临界二氧化碳压裂三类基本二氧化碳压裂技术,总结了二氧化碳压裂技术的基本工艺流程、增产原理、技术特点并介绍了近年来改进的二氧化碳压裂新方法和增产效果,为今后二氧化碳压裂技术的深入研究和现场应用提供一定的借鉴意义,有利于我国“双碳”目标的实现。

超临界二氧化碳萃取-气相色谱法测定土壤中丙烯酸的研究

建立了超临界二氧化碳萃取、脱水干燥、浓缩、净化、气相色谱分离后,使用带氢火焰离子化检测器(FID)的气相色谱仪检测土壤中丙烯酸的方法。考察了CO_(2)流量和压差对丙烯酸回收率的影响,得到CO_(2)流量为600 mL/min、压差为6000 psi的最优萃取条件。土壤加标回收试验发现,当丙烯酸浓度为50~1000 mg/L时,测定方法线性良好,校准曲线线性相关性可达到0.999;当称取10 g土壤时,方法检出限为3.19 mg/kg,相对标准偏差为1.10%~1.80%,回收率为80.5%~89.0%。该方法具有操作简单、精密度好、准确度高等优点,适用于各类土壤中丙烯酸的测定。