1. |
Extraction with Supercritical Gases—A Foreword |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 701-702
Günther Wilke,
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PDF (198KB)
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ISSN:0570-0833
DOI:10.1002/anie.197807013
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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2. |
Separation with Supercritical Gases: Practical Applications |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 702-709
K. Zosel,
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PDF (934KB)
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摘要:
AbstractExtraction with supercritical gases combines, to a certain extent, the characteristics of both distillation and extraction; the term “destraction” is therefore proposed for this method of separation. The principles of the method are illustrated in this article by a series of color photographs comparing extraction and destraction. Of the practical uses of this new method may be mentioned the separation of cod‐liver oil into 50 fractions, each differing in saponification value and iodine number, by means of supercritical ethane and, in particular, the decaffeination of raw coffee with supercritical carbon di
ISSN:0570-0833
DOI:10.1002/anie.197807021
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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3. |
Fluid Extraction of Hops, Spices, and Tobacco with Supercritical Gases |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 710-715
Peter Hubert,
Otto G. Vitzthum,
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PDF (598KB)
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摘要:
AbstractThis report provides an introduction to the principal methods of extraction with supercritical gases, illustrated by the processing of some natural products with carbon dioxide. The combination of pressure and temperature as process parameters makes it possible to vary the solvent power of the medium within certain ranges as desired without having to change the composition of the solvent, as would be necessary in conventional solvent extraction. The problem‐free handling of carbon dioxide and also of the products obtained open up possibilities whose development has only just starte
ISSN:0570-0833
DOI:10.1002/anie.197807101
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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4. |
Physicochemical Principles of Extraction with Supercritical Gases |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 716-727
Gerhard M. Schneider,
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PDF (1166KB)
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摘要:
AbstractThe present review considers some physicochemical properties of fluid mixtures that are of importance for fluid extraction and supercitical fluid chromatography (SFC). Firstly, the important types of phase diagrams are treated, the occurrence of solid phases also being considered in some simple cases. Specific examples are given of mixtures of a highly volatile component I (e.g.CO2, C2H6) with a relatively involatile component II (e.g.squalane) of very different molecular size, shape, structure, and/or polarity, and it is shown how the rather complicated types of phase diagrams can be calculated and correlated. The importance of fluid mixtures extends far beyond the fields of science and technology reviewed.
ISSN:0570-0833
DOI:10.1002/anie.197807161
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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5. |
Phase Equilibria and Critical Curves of Binary Ammonia–Hydrocarbon Mixtures |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 728-730
Harro Lentz,
Ernst Ulrich Franck,
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摘要:
AbstractLiquid or dense supercritical ammonia has been suggested as an extraction fluid. It is indeed good solvent for very different classes of compounds, as can be seen from phase diagrams. Such diagrams for binary systems of ammonia and hydrocarbons are presented and discussed on the basis of their critical curves. Apparatus and methods for the measurement of phase equilibria and equation of state data of fluid mixtures at high pressure are described.
ISSN:0570-0833
DOI:10.1002/anie.197807281
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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6. |
A Quick Method for the Microanalytical Evaluation of the Dissolving Power of Supercritical Gases |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 731-738
Egon Stahl,
Winfried Schilz,
Erwin Schütz,
Eberhard Willing,
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PDF (713KB)
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摘要:
AbstractA new method of microextraction with supercritical gases involving direct coupling with thin‐layer chromatography enables the solubility behavior of a large number of natural products to be investigated in pressure gradients of up to 400 bar. The results are summarized in general rules that enable the extractability to be predicted on the basis of the chemical structure. The substances that can be satisfactorily extracted in supercritical carbon dioxide and nitrous oxide are preferably lipophilic. The extracting capacity of the two gases was compared using alkaloids. In the case of polar compounds such as sugars and amino acids the solubility is so low even at pressures of 2500 bar (less than 10 μg/Nl) that application is not practicable. Quantitative tests of the solubility behavior of model substances in supercritical gases provide a basis for the technical application of the meth
ISSN:0570-0833
DOI:10.1002/anie.197807311
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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7. |
Chromatography with Supercritical Fluids |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 738-746
E. Klesper,
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PDF (855KB)
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摘要:
AbstractChromatography with supercritical fluids unites the features of both gas chromatography and liquid chromatography, yet retains special characteristics of its own. The diffusion coefficient and particularly the viscosity of fluid phases may approach values for low‐pressure gases, while the solvent power may be similar to that of liquids. However, with supercritical fluids it is possible to control chromatographic separations very effectively by pressure programming, since the solubility increases with increasing density. Temperature programming, on the other hand, can have the opposite effect to that in gas‐ or liquid‐chromatography since the density decreases with increasing temperature at a given pressure. Supercritical fluid chromatography is primarily of interest for the separation of higher molecular weight compounds. The efficiency of this method of separation is demonstrated on several homologous series. Thus, a styrene oligomer with nominalMw=2200 can be resolved by a pressure and temperature program into 40 sp
ISSN:0570-0833
DOI:10.1002/anie.197807381
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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8. |
The Separation of Nonvolatile Substances by Means of Compressed Gases in Countercurrent Processes |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 746-750
Siegfried Peter,
Gerd Brunner,
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摘要:
AbstractMixtures of nonvolatile and heat‐sensitive substances can be separated by means of compressed gases in countercurrent processes. Moreover, such separations can be carried out at lower temperatures than in vacuum distillation. Addition of an entrainer enables alteration of the relative volatilities of the components. That such a method of separation is feasible on a large scale is illustrated using as example the separation of monoglycerides from a mixture of oleic glycerides ate.g.110°C/135 bar. Propane is used as compressed gas, and acetone as entrain
ISSN:0570-0833
DOI:10.1002/anie.197807461
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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9. |
Large‐Scale Industrial Plant for Extraction with Supercritical Gases |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 751-754
R. Eggers,
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PDF (430KB)
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摘要:
AbstractCriteria for the design and construction of plant for obtaining carrier material or extracts are discussed for the example of the extraction of natural products with supercritical carbon dioxide. The parameters to be established and the course of the process in a large‐scale plant are indicated. Plant engineering and optimization must be attuned to specific process‐technological and construction probl
ISSN:0570-0833
DOI:10.1002/anie.197807511
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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10. |
Thermal Degradation of Cellulose and Chitin in Supercritical Acetone |
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Angewandte Chemie International Edition in English,
Volume 17,
Issue 10,
1978,
Page 754-755
Peter Köll,
Jürgen Metzger,
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PDF (260KB)
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ISSN:0570-0833
DOI:10.1002/anie.197807541
出版商:Hüthig&Wepf Verlag
年代:1978
数据来源: WILEY
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