夹带剂对超临界CO2萃取过程的影响

超临界CO2 萃取技术是近年来兴起的一种高新物质分离精制技术 ,但其本身还存在着一些问题 ,如操作压力大、萃取时间长、对设备的要求较高、能耗相对也较大、提取能力小、萃取率有待进一步提高 ,从而限制了其应用领域的进一步拓展和大范围工业化生产的转化。采用夹带剂对超临界萃取过程进行强化 ,可有效提高萃取得率 ,降低操作压力等 ,因而成为人们研究的一个新方向 ,也将对超临界流体萃取技术产生重要的影响。本文就夹带剂对超临界CO2 萃取过程的影响及应用进行了论述 ,并提出了所存在的问题和研究方向。     

超声强化超临界流体萃取海藻脱氢乙酸的研究

研究了超声强化超临界流体萃取海藻DHA技术,研究了萃取温度、萃取压力、流体流量以及萃取时间的影响.结果表明超声强化超临界流体萃取可以降低萃取温度、萃取压力以及超临界流体的流量,还可缩短萃取时间,提高萃取率.     

超声强化超临界流体萃取薏苡仁油和薏苡仁酯的影响因素及效果

考察了超声强化超临界流体萃取(USFE)薏苡仁中的薏苡仁油和薏苡仁酯的效果。以 CO2作为超临界流体分别研究了萃取过程中萃取温度、萃取压力、原料颗粒大小、超临界流体流量、超声参数、萃取时间等因素对萃取率的影响,并与超临界流体萃取(SFE)进行对比。结果表明,超声强化超临界流体萃取过程,最适宜的萃取温度为 40℃,比超临界流体萃取的最适宜的萃取温度降低了 5℃;最适宜的萃取压力为 20Mpa, 比超临界流体萃取的最适宜的萃取压力降低了 5Mpa;最佳萃取时间为 3.5h,比超临界流体萃取的最佳萃取时间缩短了 0.5h;萃取率提高约 10%左右。若萃取率相同时,流体流量可减少 0.5L·h-1 ,原料粒径的要求可放宽。     

超临界流体萃取技术的发展现状

超临界流体萃取作为一种新型的分离技术,越来越受到各行业的关注和重视,并已广泛应用于医药、食品、化妆品及香料工业等领域.作者对超临界流体萃取技术进行了评述,主要从超临界CO2流体萃取技术的原理、工业应用及其强化过程等几个方面,介绍了国内外关于超临界流体分离技术的最新研究动态,最后针对超临界萃取技术应用现状,探讨了其目前存在的问题及应用前景.     

超临界流体耦合技术的现状及发展

超临界流体萃取技术作为一种新兴的分离技术,目前已经得到广泛研究和应用,但也存在不足.本文在对超临界流体萃取技术介绍的基础上,针对其不足,提出了超临界流体萃取技术与其他分离技术进行耦合是发展趋势.并重点对超临界流体萃取技术与膜分离技术、蒸馏技术、色谱技术及结晶技术的耦合做全面阐述.认为超临界流体耦合技术具有广阔发展前景,应重視其研究.     

超临界CO2流体萃取的应用进展

超临界CO2流体萃取技术已成为一种新兴分离技术,具有操作简单、快速、效率高、无毒、无污染等优点使其广泛应用于各个领域。文章主要介绍了超临界CO2流体萃取技术的原理及优点,综述了近年来超临界流体萃取技术在食品工业、天然香料工业及中草药开发中的应用,并进行了展望,指出了存在的问题和今后发展的趋势。     

超临界二氧化碳流体萃取油茶籽油及其GC／MS分析

采用环境友好的超临界二氧化碳流体萃取技术制备油茶籽油,考察了压力、时间、温度和二氧化碳流量等因素对茶籽油萃取率的影响,得到优化的工艺参数：当萃取压力30MPa、萃取温度35℃、CO2流量30L／h、萃取时间为3h时茶籽油萃取率可高达44．4％。根据中华人民共和国国家标准进行检测的结果表明：超临界二氧化碳流体萃取出的茶籽油,无需进一步精制即可达到国家食用植物油卫生标准GB／T2716—2005,而除含皂量、水分及挥发物外的指标均达到国家一级茶油标准GB11765—2003;GC／MS分析结果表明油茶籽油富含73．6％不饱和脂肪酸。实验结果表明：超临界二氧化碳流体技术萃取茶籽油具有操作简便、萃取率高、无溶剂残留、绿色环保等优点,萃取出的茶籽油具有较高的品质和良好的应用前景。     

超声强化超临界流体萃取机理的研究

从实验和理论上对超声强化超临界流体萃取的机理进行了研究。采用自行设计的内插式超声强化超临界流体萃取装置,运用数码显微成像系统和透射电镜观察了有、无超声作用下超临界流体萃取中空化测试材料和海藻细胞微观结构的前后变化,分析了超声对超临界流体萃取海藻中二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的传质和萃取率的影响,并根据声化学原理对超临界流体中附加超声场时能否产生空化现象进行了探讨。实验结果发现超声对超临界二氧化碳流体中的空化材料和海藻细胞壁不产生破坏作用,不会产生声空化效应,但提高了海藻中EPA和DHA的萃取传质效果。其实验结果与理论推导相一致。结果表明：超声强化超临界流体萃取的机理不是源于超声空化,而是超声在微环境内产生的机械波动效应和热效应。     

超临界CO2流体从紫菜中萃取EPA和DHA的研究

采用超临界CO2 流体萃取技术从紫菜中萃取EPA和DHA ,研究了紫菜粉碎粒度、萃取温度、萃取压力和萃取时间对萃取率的影响。结果表明 :超临界CO2 流体从紫菜中萃取EPA和DHA的工艺可行 ,最佳的萃取条件为 :紫菜粉碎粒度为 2 0～ 80目 ,萃取温度 3 5℃ ,萃取压力 2 5MPa ,萃取时间 1 .5h。     

夹带剂对超临界CO2萃取茄尼醇过程的强化

夹带剂强化技术可显著提高超临界CO2萃取茄尼醇的萃取效率. 本工作在分析讨论萃取机理及夹带剂强化作用的基础上,研究了影响强化效应的夹带剂种类、用量、输入方式3个主要因素及其对茄尼醇萃取率的影响规律,并讨论了夹带剂与茄尼醇从萃取混合物中二级选择性解析的问题. 在设计夹带剂强化萃取茄尼醇正交实验的基础上,进一步分析了夹带剂用量、压力和温度影响茄尼醇萃取率的顺序及显著性. 最优强化萃取操作条件为压力25 MPa,温度40℃, 95%乙醇用量为1.5 mL/g. 并通过建立强化萃取茄尼醇的萃取率模型,对最优条件下超临界CO2萃取茄尼醇的萃取率进行预测,预测值为82.4%,与实验均值81.5%基本一致.     

超临界萃取在天然植物成分提取中的应用进展

本文针对超临界萃取(SFE)技术在医药、食品、化妆品及香料工业等领域的研究现状和应用前景,结合传统萃取技术的不足,从SFE技术的原理、特点出发,重点综述了SFE技术在生物碱、黄酮类、挥发油和油脂类等天然植物有效成分提取中的研究及应用近况,并简述其发展前景。     

Purification of Commercial 2,3-Dimethyl Phenol Using Supercritical Fluid Extraction

The commercial value of phenols is often reduced due to the presence of colored impurities. Several conventional techniques have been used for the purification of phenols. However, conventional purification techniques are tedious and make use of hazardous and expensive organic solvents. In this study, we present a new method for purification of an aged-discolored (orange) commercial 2,3-dimethyl phenol (2,3-DMP) reagent (～97%) using supercritical fluid CO₂ (SCF CO₂), as an extraction solvent. A supercritical fluid extraction (SFE)/purification apparatus was constructed and purification of the reagent under different extraction conditions was investigated. Based on the differential solubility of the 2,3-DMP and the impurities in SCF CO₂, the commercial reagent was successfully purified by SFE; the purified 2,3-DMP was a white solid of high purity (>99.5%). The SFE method was also applied to purify a recently purchased batch of 2,3-DMP reagent. We found that the reagent purified by SFE was of a higher quality than a commercially available analytical standard.     

应用超临界技术进行废水处理

超临界技术是一种新兴的废水处理技术，它主要包括超临界流体萃取和超临界水氧化两种，本文论述了这两种技术的应用研究，应用前景，存在的问题和研究方向。     

新型溶剂萃取技术及应用

萃取是一项在化工、环保等领域广泛应用的分离提纯技术。概述了超临界流体萃取、双水相萃取等各种新型技术的原理和应用研究情况。指出了其优越性和存在的问题以及今后的研究方向。     

Scale-up study of supercritical fluid extraction process for clove and sugarcane residue

Many scale-up criteria for supercritical fluid extraction (SFE) can be found in literature. However, the studies are often divergent and inconclusive; therefore, more studies on this field are needed. The objective of the present work was to study the scale-up of SFE process focusing application to Brazilian raw materials. A laboratory scale equipment (290 mL extraction vessel) and a pilot scale equipment (5.15 L extraction vessel) were used to study scale-up of SFE for clove and sugarcane residue. The scale-up criterion adopted consisted in maintaining solvent mass to feed mass ratio constant. The criterion was successfully used for a 15-fold scale-up of overall extraction curves for both raw materials studied; yields in pilot scale were slightly higher than in laboratory scale. The criterion studied allows a rapid and simple scale-up procedure, which can be very useful for the purpose of developing SFE technology at industrial scale in developing countries where such technology is still not available at industrial level.     

Supercritical fluid extraction of α- and β-acids from hops compared to cyclically pressurized solid–liquid extraction

In this paper, two solid–liquid extraction techniques, supercritical fluid extraction (SFE) with and without modifiers and cyclically pressurized solid–liquid extraction with a Naviglio Extractor, were compared on the basis of extraction of acidic compounds contained in hops flowers. The hops extracts were analyzed by electro-kinetic capillary chromatography (MECK). The results showed that the technique using supercritical carbon dioxide was more effective for the isolation of β acids; the use of ethanol as a co-solvent, as reported in the literature, produced a heterogeneous extract, while cyclically pressurized solid–liquid extraction showed a greater extraction capacity for α acids. Consequently, both techniques are valid for the extraction of α and β acids from hops. By suitably varying the parameters of the two extractive procedures, it will be possible to obtain extracts for use in the production of beer and dietary supplements and drugs. Furthermore, based on the SFE CO₂ extraction process, a mathematical model was applied to the examined process, and a numerical simulation was performed, leading to a model that provides direction for the optimization of further experiments.     

超临界CO2流体萃取肉桂油的研究

优选萃取肉桂油的工艺条件,分别采用水蒸汽蒸馏法和SFE—CO2提取肉桂油,进行SFE—CO2萃取肉桂油的正交试验,优选最佳萃取条件。由实验可知,SFE—CO2萃取肉桂油主要成分桂皮醛的得率大于水蒸汽蒸馏法,其最佳萃取条件为：萃取温度45℃,萃取压力20MPa,萃取时间2．5h。应用SFE—CO2萃取肉桂油,萃取率高,操作纯净,是具有相当发展潜力的提取分离方法。     

超临界流体萃取技术及其在烟草工业中的应用

超临界流体萃取技术是一种新型高效的分离技术。介绍了超临界流体萃取技术的基本原理及其在烟草工业中的应用,并对其今后的主要研究方向进行了展望。     

A Comparative Study on Response Surface Optimization of Supercritical Fluid Extraction Parameters to Obtain Portulaca Oleracea Seed Oil with Higher Bioactive Content and Antioxidant Activity Than Solvent Extraction

Portulaca oleracea (purslane) seed oil is a rich source of omega-6 and omega-3 fatty acids. Extraction of the purslane seed oil while preserving its high nutritive quality has been a challenge since conventional solvent extraction has many adverse effects on bioactive content. This study aims the optimization of purslane seed oil supercritical fluid extraction (SFE) conditions and to compare purslane seed oils obtained with SFE and conventional solvent extraction in terms of oil yield, along with the purslane seed oil quality and bioactive content. For this purpose, the SFE process parameters (pressure, temperature, static time, and dynamic time) are optimized for oil yield, omega-6, omega-3, and antioxidant activity using response surface methodology (RSM). Optimum SFE pressure, temperature, static time, and dynamic time levels are determined as 350 bar, 50 °C, 20 min, and 90 min, respectively. Oil yield and physicochemical quality properties of conventional solvent extract and SFE samples are determined and compared. Consequently, samples obtained via SFE and solvent extraction have similar quality properties. Distinctly, SFE allows an extraction with 5.6% higher total phenolic compound (TPC) and 33% higher antioxidant activity than solvent extraction. Practical Applications: In the study, the extraction of purslane oil using supercritical fluid extraction is optimized with different approaches. At optimum conditions, purslane oil is extracted and all physicochemical properties and the process efficiency (yield) are compared with the solvent-extracted samples. The results of this study make supercritical fluid extraction of purslane seed oil possible since all optimum operating conditions of a pilot-sized extractor are reported in the study. It is believed that the results provide a good starting point for industrial operations. Moreover, researchers also believe that research studies unveiling the new potential oil-bearing seeds are important to overcome the vegetable oil shortage that emerged this year.