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。     

萃取-超临界法制备纳米TiO2

以硫酸法钛白生产过程的中间产品钛液(TiOSO4)为原料,经过萃取、酸洗和反萃得到TiO(OH)2白色浆料,用乙醇置换大部分水分后,采用超临界流体干燥制备纳米TiO2。用TEM、XRD等手段对其表征,所得粒子粒径为20～30 nm, 干燥和晶化一步完成。     

中草药提取的新技术--超临界CO2萃取

超临界CO2萃取技术已在中草药研究和生产的许多方面得到了广泛应用，对中药现代化及中草药药用有效成分提取分离有重要意义。文中介绍了中草药提取的特点、超临界CO2萃取中草药有效成分的优缺点、应用现状以及发展前景。     

CO2超临界萃取叶黄素工艺条件的优化控制

采用超临界CO2提取方法探讨了从万寿菊中提取叶黄素的最佳工艺条件.通过单因素和正交实验确定影响叶黄素萃取的因素为:时间>温度>压力>CO2流量;优化工艺条件为:萃取时间3h,萃取压力25MPa,温度55℃,CO2流量10L·h-1,分离罐Ⅰ温度42℃,压力11MPa,分离罐Ⅱ温度38℃,压力同储罐.在该优化工艺条件下,...     

先锋褐煤CO／H2O超临界萃取研究

在不同ＣＯ初压、不同催化剂作用下，以ＣＯ／Ｈ２Ｏ为溶剂对云南先锋褐煤进行超临界萃取，对萃取物的族组成进行了＾１Ｈ，＾１３Ｃ－ＮＭＲ分析。结果表明：萃取产率和转化率随ＣＯ初压增大而增加；ＣＯ和Ｈ２Ｏ可发生变换反应生成中间态活泼氢，从而具有较哟的供氢能力，使萃取产率和转化率提高；碱金属的氢氧化物及碳酸盐对ＣＯ／Ｈ２Ｏ变换反应有较强的催化作用；萃取物的油组分以单环芳香结构为主，具有较高的Ｈ／Ｃ比和较多的     

CO2超临界萃取技术提取中药有效成分

本文较系统地介绍了CO2超临界萃取技术提取中药有效成分的优点,重点讲述了已工业化的几项提取过程,突出了该技术提取中药水溶性有效成分的应用前景。     

超临界CO2萃取木香挥发油的研究

采用超临界ＣＯ２流体萃取木香挥发油。探讨了压力、温度、ＣＯ２密度对挥发油收率的影响，研究了萃取的最适宜条件。对水蒸汽蒸馏法与超临界萃取法进行了比较。     

超临界CO2流体萃取中的在线检测技术

综述了超临界CO2流体萃取中的在线检测技术,介绍了超临界CO2流体萃取与超临界流体色谱、气相色谱、高效液相色谱、核磁共振、近红外光谱等技术的联用在线检测,阐述了在线检测技术的优越性,提出了如何发展超临界CO2流体萃取中的在线检测技术。     

CO2超临界萃取技术提取沙田柚皮的研究

采用沙田柚皮作为实验材料 ,研究在CO2 超临界流体萃取时 ,粉碎度、温度、压力、萃取时间等条件对精油萃取率的影响 ,得到萃取沙田柚皮精油的最佳条件为 13MPa ,4 0℃ ,萃取时间 1h ,为批量生产提供了依据     

超临界流体CO2萃取剂的应用

当一种物质高于临界温度和临界压力时,该状态称为超临界流体状态。这种超临界流体的物理性质介于标准状态的气体和液体之间。改变施加于流体中的压力,就会使超临界流体的密度发生变化。以高压压缩流体,标准气体的密度就变为近于液体的密度。超临界流体在     

超临界流体萃取技术发展新动向

介绍了超临界流体萃取技术发展新动向、新应用领域开发的实例以及基础研究工作     

超临界流体萃取塔的设计

流体相平衡数据是设计超临界流体萃取塔的关键。本文给出了涉及三元混合物相图计量的萃取塔的可行性研究和应用的一些例子。     

煤的超临界流体抽提研究进展

超临界流体抽提技术是一项新型、绿色、环保的技术,超临界流体抽提技术应用于煤的目的分为超临界条件下气化制氢,超临界条件下脱除杂质和超临界条件下煤的液化3个方面,综述了超临界流体抽提技术应用于煤的研究进展,并着重论述了该技术应用于煤液化的研究进展,指出了今后的研究方向。     

Selective extraction of metal ions through liquid surfactant membranes

Selective separation of metal ion from a liquid solution with the help of different permeation rate of solutes through liquid membranes was performed. The salts used were ZnCl₂, CdCl₂, NiCl₂. D2EHPA and LIX64N were used as carrier to study the extraction rate of the solutes. The results show that at low pH value of external phase the order of degree of extraction by D2EHPA or LIX64N is Zn > Cd > Ni, while at high pH value with the presence of ammonia in the feed solution the order of degree of extraction is reversed to Ni > Cd > Zn. The results also indicate that when the mixed carrier is used an enhanced effect on the extraction was observed. Synergistic effect was also noted when comparing the cases with mixed carriers to those with pure carriers.     

An improved micro-extraction cell for supercritical fluid extraction and chromatography of fatty acids

An improved supercritical fluid micro-extraction cell of increased reliability was designed for on-line supercritical fluid extraction and chromatography (SFE/SFC) of food and other lipid-related samples. The key components in the modified cell include a Swagelok stainless steel reducing union with a dual ferrule as the cell, with polyetherether-ketone (PEEK) ferrules and nuts to connect the cell to the control valve. The new cell did not leak under all conditions examined (100–500 atmospheres, 40–80°C), even after numerous extractions (>250). The quantitative performance of the cell was evaluated with fatty acid standard solutions, technical grade fatty acid sources and wheat flour. The percent relative error (%RE) for the fatty acid standards and technical-grade fatty acid samples was ≤6.0% for oleic, linoleic and linolenic acid. The %RE for oleic and linoleic acid in the whole-wheat samples was ≤10%. The results demonstrate that the new extraction cell can be used for quantitative extractions and that the sensitivity of the SFE/SFC technique is excellent. Similar SFE/SFC methods could prove useful in studying the interaction of free fatty acids with various food components such as enzymes, amylose and proteins.     

超临界流体萃取技术的应用及研究进展

超临界流体萃取技术近年来被广泛应用于中草药、食品、香料、化工及环境保护等领域。介绍了超临界流体萃取技术与传统的萃取方法相比所具备的优势及其发展前景。     

超临界流体萃取脱除人参中痕量有机氯农药

利用在线固相吸附柱收集,淋洗剂洗脱超临界流体萃取出的真实人参样品中的有机氯农残实验,确定最佳的吸附柱和淋洗剂。通过实验确定利用C18作吸附剂,用正己烷洗脱可取得最优效果。此外,还对直接冷凝收集法、索氏提取法与固相吸附柱收集法进行了对比。     

Supercritical fluid extraction of walnut kernel oil

The objective of this study was to investigate the effects of the main process parameters on supercritical fluid extraction of walnut (Juglans regia L.) kernel oil. The recovery of walnut kernel oil was performed in a green and high-tech separation process. CO₂ and CO₂ + ethanol mixtures were used as the supercritical solvent. The extraction was carried out at operating pressures of 30, 40 and 50 MPa, operating temperatures of 313, 323 and 333 K, mean particle sizes of 1.78×10⁻⁴, 3.03×10⁻⁴, 4.78×10⁻⁴, 7.00×10⁻⁴ and 9.00×10⁻⁴ m, supercritical CO₂ (SC CO₂) flow rates of 1.67×10⁻⁸, 3.33×10⁻⁸, 6.67×10⁻⁸ and 13.33×10⁻⁸ m³/s and entrainer (ethanol) concentrations of 2, 4, 8 and 12 vol-%. Maximum extraction yield and oil solubility in SC CO₂ obtained at 50 MPa, 333 K, 9.00×10⁻⁴ m, 3.33×10⁻⁴ m³/h were 0.65 kg oil/kg of dry sample and 37.16 g oil/kg CO₂, respectively. The results obtained in this study showed that the crossover pressure effect of walnut kernel oil was at 30 MPa. At 30 MPa and 313 K, the obtained extraction yields above 4 vol-% ethanol reached the organic solvent extraction yield of 68.5 kg oil/kg dry sample. Extraction time was decreased significantly because of the higher solubility of walnut kernel oil in SC CO₂ + ethanol mixtures.     

煤焦油超临界流体提取的研究进展

超临界流体抽提技术是一项新型、绿色、环保的技术,超临界流体抽提技术应用于煤焦油研究的主要目的分为超临界条件下提取其中成分,使煤焦油轻质化,本文介绍了超临界流体抽提技术应用于煤焦油的研究进展,指出了今后的研究方向.