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。     

超临界流体萃取塔的流体力学和传质性能

New models for describing hydrodynamics and mass transfer performance in supercritical fluid extraction columns were proposed.Those models were proved by experimental data,which were obtained in supercritical fluid extraction packed column,spray column and sieve tray column respectively.The inner diameter of those columns areΦ25mm，These experimental systems include supercritical carbon dioxideisopropanol-water and supercritical carbon dioxide-ethanol-water,in which supercritical carbon dioxide was dispersed phase,and another was continuous phase.The extraction processes were operated with continuous countercurrent flow.The predicted values are agreed well with experimental data.     

超临界流体喷淋萃取塔流体力学特性和传质性能

在内径为25mm的连续逆流喷淋塔内进行了流体力学特性和质量传递性能的研究,实验压力为(8～14)MPa,实验温度为35℃,实验体系为CO_2/异丙醇/水和CO_2/乙醇/水.建立了描述连续逆流超临界流体喷淋萃取塔的流体力学关联式,根据双膜理论,建立了用于计算液相总体积传质系数的质量传递模型.流体力学关联式和质量传递模型的计算值与实验结果符合较好.     

超临界流体萃取技术的应用

介绍了超临界CO2萃取技术的优点及使用的改性剂,对超临界流体萃取技术在医药工业、食品工业、环境保护中的应用进行了详细阐述,指出应加快超临界流体萃取技术应用的产业化步伐。     

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。     

超临界流体萃取技术的发展及应用

超临界流体萃取技术(Supercritical fluid extraction technology,简称:SFE)是利用流体在超临界状态下具有选择性溶解能力的特性对不同的物料进行分离。超临界流体萃取技术在天然有机物质的提取方面有着巨大的优势。随着现代化工业工程技术的发展,超临界流体萃取技术在食品、石油、化工、医药等各个领域显示出广阔的发展前景。     

超临界流体填料萃取塔流体力学和传质性能(Ⅱ) 传质性能

根据双膜理论,建立了超临界流体填料萃取塔液相总体积传质系数关联式;依据柱塞流模型,应用超临界二氧化碳-异丙醇-水和超临界二氧化碳-乙醇-水2种实验体系在内径为25mm的塔内对金属板波和金属丝网θ环2种填料的传质性能进行了模拟计算。结果表明,本文提出的传质数学模型能较好地描述超临界流体填料萃取塔的传质性能。     

超临界流体填料萃取塔流体力学和传质性能(Ⅰ) 流体力学数学模型

推导和建立了描述超临界流体填料萃取塔两相流体力学特性的数学模型。在25mm内径的连续逆流填料萃取塔中,应用超临界二氧化碳-异丙醇-水、超临界二氧化碳-乙醇-水2种实验体系和金属板波、金属丝网θ环2种填料对流体力学模型进行了实验验证,计算结果与实验数据符合较好。     

超临界流体萃取技术及其应用

本文讨论了超临界流体萃取技术的特点和工业设计基本要点。介绍了该技术在食品工业、医药工业、化妆品工业、化工、及废物处理方面的应用。     

均匀设计法优化超临界萃取姜油树脂工艺条件的研究

采用均匀设计法,考察了CO2超临界萃取过程中萃取压力、萃取温度、萃取时间及萃取剂CO2流量4个因素对姜油树脂萃取率的影响。结果表明,超临界萃取姜油树脂的最佳工艺条件为:萃取压力30 MPa,萃取温度50℃,萃取时间4.5 h,CO2流量为26 kg/h,在此条件下,姜油树脂萃取率为5.27%。     

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。     

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.     

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。     

超临界流体技术在环境保护中的应用研究

综述了超临界流体技术在环境保护各领域的应用。介绍了国内外超临界流体技术 (超临界水反应、超临界萃取以及超临界色谱 )处理环境污染物的实例     

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     

Preparative-scale supercritical fluid extraction/supercritical fluid chromatography of corn bran

A preparative-scale supercritical fluid extraction/supercritical fluid chromatography (SFE/SFC) procedure has been developed for the removal of oil from corn bran to obtain fractions enriched with free sterols and ferulate-phytosterol esters (FPE). Operational parameters from an analytical-scale supercritical fluid fractionation technique were translated to and optimized on a home-built, preparatory-scale SFE/SFC apparatus. SFE was performed at 34.5 MPa and 40°C using supercritical carbon dioxide. These conditions did not result in exhaustive extraction of the corn bran, but yielded about 96% of the available oil. SFC was conducted in three steps, followed by reconditioning of the sorbent bed. Preparative-scale SFE/SFC of corn bran produced a fraction enriched greater than fourfold in free sterols and 10-fold in FPE, suggesting that such a scheme could be used industrially to produce a functional food ingredient.     

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.