ISSN:0009-286X    

DOI:10.1002/cite.330661002

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330661003

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractSimulated Countercurrent Chromatography.This paper reviews simulated countercurrent chromatography, a separation process that has received only little attention. In contrast to standard batchwise operated chromatography, a periodical mode of operation is used. The feed and collection lines are shifted along the column, thus simulating countercurrent operation of the liquid phase and the stationary solid phase. As a result, higher product yield and higher product purity are obtained. At the same time the amount of solid phase and solvent phase required in comparison to discontinuous chromatography is reduced. Industrial applications have been developed since 1964 by Universal Oil Products (UOP). Large scale separation processes in the petrochemical and the sugar industries are already in operation. On the bench scale this process is used to separate biotechnological products and pharmaceuticals. The need to solve difficult separation problems (isomeric or racemic mixtures, biomolecules, polymers) will encourage further developments. Together with improved process‐simulation tools and process control, simulated countercurrent chromatography will be established as a powerful separation technique with widespread industrial applicabilit

ISSN:0009-286X    

DOI:10.1002/cite.330661004

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractRecent Developments in Crystallisation from Solution.Although there have been no great leaps forward in the design of plant for crystallisation from solution in recent years, our understanding of growth rate dispersion, the extension of the two‐step model of crystal growth to a three‐step model when required, and also convenient modelling approaches for crystal morphologies and the development of tailor‐made additives have nevertheless greatly advanced our knowledge of crystallisation processes. Substantial divergencies in the measured values of crystal growth rates in the past decade can often be explained by paying due attention to the measuring methods and the purity of the substances as well as the nature of the solvent. Comparison of results obtained by modelling should always prove more satisfactory when heat effects are considered whenever this is necessary. The possibilities of crystallisation plant design are greatly enhanced by the availability of reliable data as a basis for calculation and when influencing crystal shape can provide downstream processes with a better pr

ISSN:0009-286X    

DOI:10.1002/cite.330661005

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractContinuous Thermodynamics – An Approach to the Treatment of Multicomponent Mixtures.In the chemical industry, complex multicomponent mixtures such as petroleum fractions or polymer systems are of great importance. Characterization experiments on such mixtures mostly result only in continuous distribution functions. In contrast, equations of chemical thermodynamics include the mole fractions of the individual components. An approach suitable for overcoming these difficulties is provided by continous thermodynamics, which is based directly on continuous distribution functions. Here, applications relating preferentially to vapor‐liquid equilibrium involved in the calculation of distillation columns are discussed. Continuous thermodynamics is seen to provide distinct advantages over the traditional approach, i.e. the pseudo‐component m

ISSN:0009-286X    

DOI:10.1002/cite.330661006

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330661007

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330661008

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330661009

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330661010

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330661011

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY