超临界CO_2流体萃取大豆油的研究与数值模拟

本文建立了一套超临界流体萃取的实验装置 ,在压力为 2 0MPa～ 30MPa ,温度为30 8K～ 32 3K的条件下 ,研究了用超临界二氧化碳萃取大豆油。试验证明用超临界流萃取的方法可以较为完全地得到大豆中的油分。基于固定床、积分柱塞流与微分混合流的假设建立了理论计算模型 ,使用这个模型可以根据装料量少耗时短的微分萃取试验结果来较为准确地计算出相同条件下积分萃取的过程。经本试验结果比较证明该方法简便可行 ,在本文条件下误差小于 6 % ,是对超临界流体萃取放大研究的一种探索     

超临界CO_2流体萃取植物油的实验研究

建立了一套超临界流体萃取实验装置,就大豆和花生两种植物油超临界流体萃取进行了较为详细的实验研究.在探讨了压力、温度、颗粒度、空隙率以及时间等对萃取率的影响之后,获得了指导实际生产的最佳工艺参数条件.     

超临界CO_2萃取柞蚕蛹油

为了充分利用柞蚕蛹资源,本文提出了用CO_2作萃取剂,在超临界条件下,用间歇采样称重及降压分离法从柞蚕蛹中萃取蚕蛹油的方法,探索了超临界CO_2萃取柞蚕蛹油的最佳工艺条件。     

超临界CO_2萃取水冬瓜油

研究了用超临界ＣＯ２流体从水冬瓜果实中提取油品的工艺,探索了操作压力、温度、流量及时间对水冬瓜油的萃取率的影响。分析了萃取条件与油品质量的关系,并综合得出了超临界ＣＯ２萃取水冬瓜油的最佳萃取条件。     

超临界CO_2萃取在中药现代化研究中的应用

综述了近年来超临界CO2萃取技术在中药现代化中的最新研究进展,并展望了其应用前景。     

超临界CO_2萃取沙棘油的实验研究及数值模拟

本文利用超临界CO2萃取沙棘油,建立了一套实验流程,分别考察了萃取压力、萃取温度以及颗粒大小对萃取率的影响。同时根据萃取器单元的质量守恒建立了微分方程,并对一定萃取条件下的实验结果进行数值模拟。结果表明, 本文所建立的数值模型能较好地描述实际萃取行为。     

超临界CO_2萃取甜橙皮油的实验研究

在140～160kg/cm~2压力范围内,用超临界CO_2萃取甜橙皮中的绝大部分油,所得皮油具有浓厚的桔香味且富含天然色素。经过GC/MS分析,发现其可与进口优质皮油相媲美,这对于开发利用我国丰富的天然资源有实用价值。     

超临界CO2萃取技术及应用

简述了超临界ＣＯ２萃取技术的原理、特点及其在萃取天然产物内含物方面的一些应用。     

超临界CO_2萃取青皮挥发油的工艺研究

采用正交实验法对超临界CO2萃取中药青皮挥发油的最佳工艺条件进行优选。以挥发油得率为考察指标,探讨了萃取压力、萃取温度、萃取时间三因素在不同水平下对青皮挥发油得率的影响,并与水蒸气蒸馏法进行了比较。研究表明,萃取压力对挥发油得率有显著影响,萃取温度及时间影响不显著,各因素作用主次关系为:压力>温度>时间。优选得到的最佳工艺为:萃取压力25 MPa,萃取温度35℃,萃取时间1.5 h,得率为1.3197%,比水蒸气蒸馏法提高2.4倍,时间减少78.57%。超临界CO2萃取收率高、耗时短、品质好。     

超临界CO_2萃取葡萄籽油的研究

本文对超临界二氧化碳萃取葡萄籽油进行了研究。以物料的粒度、萃取温度、压力、静态萃取时间、动态萃取时间为考察指标,通过正交实验研究了不同的萃取条件对葡萄籽油产率的影响,确立了最佳的工艺条件为:物料粒度40目,在35℃,50 MP,静态萃取0 min,动态萃取60 min。     

超临界CO2萃取的研究与应用

介绍了超临界流体的特性及其萃取的基本原则，讨论了超临界流体萃取技术的优点，评述了超临界CO2的特点，概述了国内外超临界CO2萃取技术在医药，食品，香料，石油化工以及环境保护等领域的开发及应用。     

Supercritical extraction of crude oil by methanol- and ethanol-modified carbon dioxide

The effect of ethanol and methanol cosolvents on the extraction yield and kinetics of crude oil originating from the Halfdan field of the North Sea by supercritical carbon dioxide was investigated across a pressure range of 20–60 MPa under a fixed temperature of 60 °C. Results inform that the pure carbon dioxide recovery varied between 43 and 77% while the recovery of the liquid phase of oil ranged between 22 and 56% across the entire pressure range. Using ethanol- and methanol-modified CO₂, the total recovery yield increased significantly averaging an additional 18.2% and 19.4% respectively when compared to pure carbon dioxide. The ethanol addition improved the recovery of the liquid phase of oil averaging 9.6% while the methanol addition improved it to 7.3% across the entire pressure range.Study of the kinetics of extraction process indicated that heavier fractions were extracted faster with the ethanol- compared to the methanol-modified CO₂. GC–MS TIC chromatographic analysis of the extracted oil fractions showed that the extraction of C₁₉-C₃₀ single carbon number groups with the addition of methanol is more dependent on pressure. Predominantly, ethanol addition was more efficient in extraction of C₁₇-C₃₈ single carbon number groups while methanol contributed more in extraction of C₇-C₉ SCN groups.     

超临界CO2萃取丁香挥发油的实验研究

采用正交实验法对超临界CO2萃取丁香挥发油的条件进行了研究。考察了萃取温度、压力、CO2流量等因素在不同水平下对丁香挥发油提取率的影响。得到了超临界C02萃取丁香挥发油的最佳实验条件：萃取压力30MPa、温度40℃、CO2流量40kg／h和萃取时间80min,得率为20．62％。与水蒸气蒸馏法比较,超临界CO2萃取的收率高,萃取时间短。     

Continuous catalyst-free production of fatty acid ethyl esters from soybean oil in microtube reactor using supercritical carbon dioxide as co-solvent

This work reports the transesterification of soybean oil in supercritical ethanol in a continuous catalyst-free process in microtube reactor using carbon dioxide as co-solvent. For this purpose it was employed two microtube reactors with different internal diameter, 0.775 and 0.571 mm. The experiments were performed in the temperature range of 523-598 K, pressure of 10 MPa and 20 MPa, oil to ethanol molar ratio of 1:20 and 1:40, and co-solvent to substrates mass ratio from 0.05:1 to 0.2:1. Results demonstrated that temperature, pressure and co-solvent to substrate mass ratio had a positive effect on fatty acid ethyl esters (FAEE) production, with appreciable yields achieved at 598 K, 20 MPa, oil to ethanol molar ratio of 1:20, using a CO₂ to substrate mass ratio of 0.2:1. The micro-reactor with the smallest inner diameter led to slightly higher FAEE yields at the specified reactions conditions compared to the micro-reactor with greater internal diameter. A semi-empirical kinetic model was proposed in attempt to represent the experimental data with satisfactory fitting results found.     

二氧化碳超临界萃取乙基香兰素粗制品的研究

采用二氧化碳超临界萃取乙基香兰素粗品,研究萃取压力、萃取温度、萃取时间、流体流量等工艺条件对萃取效率和产品质量的影响.得出最佳工艺条件,采用萃取压力25～30 MPa,萃取温度55～60℃,流体流量5 L/h,萃取5～6 h,萃取效率可以达到95％,可以得到质量分数大于95％的乙基香兰素产品.     

Comparison of processes for the supercritical carbon dioxide extraction of oil from soybean seeds

Three different process alternatives for the production of soybean oil by supercritical carbon dioxide extraction were analyzed. The first two processes were organized according to the classical scheme, based on high-pressure extraction followed by separation induced by pressure reduction. Different techniques were used to recover the solvent in these two schemes, in the liquid and in the gas phases, respectively. The third alternative was based on an isobaric scheme—the oil, extracted at high pressure, was separated by chainging the temperature in the separator. In a further improvement, a technique for the heat transfer network integration was added to all the process schemes. The different schemes were used to establish the process configuration that can produce a lower operating cost for soybean oil extraction. Operating costs were considered on an industrial scale to carry out a screening of the different alternatives. The operating cost of these plants were then compared with the hexane extraction process. A substantial reduction in the specific costs was obtained in the case of heat transfer integration, and the operating costs fell in the same range as conventional extraction plants.     

Purification of hydrocarbons from aromatic sulfur compounds by supercritical carbon dioxide extraction

Supercritical carbon dioxide extraction to purify samples of model hydrocarbons (tetralin, decalin, and tetradecane) containing various aromatic sulfur compounds (benzothiophene, dibenzothiophene, and 4,6-dimethydibenzothiophene) was studied. The influence of extraction temperature and pressure was investigated for the extraction from a tetralin-dibenzothiophene system in the range of 293-353 K and 8-15 MPa, and it was found that the amount of tetralin extracted increased with an increase in carbon dioxide density, while the separation factor decreased with an increase in carbon dioxide density. High recovery and high separation factor values for the tetralin-dibenzothiophene system were obtained under 10 MPa at 313 K. Higher separation factor was obtained for tetralin than decalin and tetradecane, containing 4,6-dimethyldibenzothiophene than that containing dibenzothiophene.     

Removal of contaminants from polluted drilling mud using supercritical carbon dioxide extraction

Liquid drilling fluid is often called drilling mud is heavy, viscous fluid mixtures use to carry rock cuttings to the surface and lubricate and cool the drill bit. During carrying cuttings they contaminated which not only reduce their functionality but also make them a hazardous and dangerous wastes which cannot be discharged anywhere without treatment. Due to this fact, in the present study, supercritical extraction process was used to remove contaminants from the drilling mud. Regarding this, effect of different parameters including extraction temperature (313–338 K) and pressure (100–200 bar), flow rate of CO₂ (0.05–0.36 cm³/s) and static time (20–130 min) on the removal of contaminations from drilling mud was examined using the design of experiment of changing one factor at a time. The obtained results revealed that the optimum operational conditions that lead to the highest removal degree of contaminations are temperature and pressure of 333 K and 180 bar, respectively, flow rate of lower than 0.1 cm³/s and the static time of 110 min. In addition, to examine the effect of the supercritical extraction on the crystalline structure modification and removal contaminations X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed which confirmed the successful removal of contaminations from the drilling mud without significant crystalline modification.     

Supercritical carbon dioxide extraction of evening primrose oil

The oil extracted from the seeds ofOenothera biennis L. (evening primrose) is a major commercial source of gamma-linolenic acid, a fatty acid having potential therapeutic value in the treatment of several diseases. This fatty acid is prone to oxidation and thermal rearrangement; therefore, the conventional recovery of the oil via mechanical expression and hexane extraction must be carried out under very mild and controlled conditions. In this study, supercritical fluid extraction with carbon dioxide has been employed as an alternative method to recover evening primrose oil (EPO). Extractions were performed over the pressure range of 20–70 MPa and at temperatures from 40 to 60°C, with a CO₂ mass flow rate of 18 g/min. The experimental data permitted the determination of EPO solubility in supercritical CO₂ at the tested extraction conditions. Supercritical fluid Chromatographic analysis of fractions collected during the extraction showed a subtle shift in the triglyceride composition. Fatty acid methyl ester analysis on similar fractions indicated that the fatty acid content was invariant with respect to extraction time. The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Experimental and modelling of supercritical oil extraction from rapeseeds and sunflower seeds

The supercritical oil extraction from oleaginous seeds (sunflower and rapeseeds) is presented here through experimental and modelling results. The experimental setup allows an accurate following of the mass of the oil extracted and to derive the experimental influences of pressure, temperature and supercritical CO₂ flowrate on the extraction curves. These parameters are very sensitive and highlight the necessity of precise optimisation of experimental conditions. In order to complete the behaviour of supercritical fluids extraction, an improved modelling is proposed. The modelling basic equations are based on others modelling published previously. In this work, the determination of several parameters comes from correlations and the other constants are fitted with all the experimental results. Thus the modelling is more representative and predictive as other ones. The modelling results present a good agreement with the experimental results, and hence it can be used for the dimensioning of some extraction autoclaves.