ISSN:0009-286X    

DOI:10.1002/cite.330691102

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractLiquid chromatography utilising porous solid phases (adsorption chromatography) is one of the most powerful and versatile methods of modern analytical chemistry. Its widespread application is due in part to the development of a broad range of combinations of solid stationary and liquid mobile phase. Normal phase and reverse phase chromatography with pure and chemically modified silica gel, respectively, affinity chromatography, and ion chromatography can be cited as examples [1]. In addition to its use as an analytical method, chromatography is becoming increasingly important in the preparative‐scale isolation of pure substances in the pharmaceutical industry, in biotechnology, and in the production of fine chemicals. In many cases, the required purity criteria can only be met with chromatographic techniques, as in the resolution of racemates. From a process engineering viewpoint, a better understanding of concentration profile deformations caused by intended overloading of separation columns has recently been acquired [2]. In particular, this cncerns the description of displacement and entrainment effects associated with the competing adsorption. A series of alternative operating modes has been developed and used [3] for enhancing yields and productivities. In spite of a number of attempted comparative studies [4]there is a lack of quantitative information about optimized process. This article aims to compare four different process engineering concepts of preparative chromatography on the basis of a uniform theoretical mode

ISSN:0009-286X    

DOI:10.1002/cite.330691103

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractThese studies consist of experiments, physical modelling, and numerical simulations concerning gas‐induced injection and mixing of reaction inhibitors in vessels containing low viscosity liquids. The mixing times required to achieve a final mixing quality of 95% were determined by means of a decolorization technique and a probe method (conductivity probes). The mixing time decreases with increasing gas flow rate, liquid level, eccentricity of the gas injection point, and with decreasing liquid viscosity. Based on fundamental physical principles, analytical models were developed which can be used to estimate, with an average precision of ± 13 %, the mixing times measured on three different scales. The results of scale‐up were additionally confirmed via numerical simulations. The results of these studies show that gas‐induced mixing of reaction inhibitor solutions can represent a reliable safety system for preventing exothermal runaway reactions. Moreover, direct injection of gas may also be used for admixing additives during normal operation of reactors and storage

ISSN:0009-286X    

DOI:10.1002/cite.330691104

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691105

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691106

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691107

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691108

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691109

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691110

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330691111

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY