摘要:

AbstractStirred tank reactors for polymerization. A general survey on stirred tank reactors and cascades of stirred tanks in industrial polymerization (bulk, solution, precipitation, grain and emulsion polymerization) is presented. Special consideration is given to the various designs of both agitator and cooling devices. Scale‐up problems arising from the multitude of process functions (homogenisation, suspension, dispersion, promotion of heat transfer) carried out in a stirred vessel are explained and the divers methods of indirect cooling (jacketed tank, internal coil, external heat exchanger) as compared to evaporative cooling are assessed. Finally, safety measures in operating polymerization vessels are discusse

ISSN:0009-286X    

DOI:10.1002/cite.330540602

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractAutomatic analysis for monitoring and control of pilot plant. The utility of automation of gas chromatography GC and high performance liquid chromatography HPLC for routine tasks in research is demonstrated with the aid of examples. Particular attention is paid to problem‐oriented and economically contained analytical instruments and to the constant availability of analytical dat

ISSN:0009-286X    

DOI:10.1002/cite.330540603

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractAlkali chloride electrolysis using the membrane process. Some 300,000 tonnes per year of chlorine are currently produced by the membrane process; the installed capacity will have tripled by 1984; a further increase is certain owing to the advantages of this new process as compared to the mercury and diaphragm processes. After a description of the different ion‐exchange membranes and cell types these advantages of the membrane cell process are elucidated in a comparison with the other two electrolysis processes. Subsequently recent development trends in respect of the membrane cell process are described which concern a further lowering of the energy consumption such as reduction of the hydrogen overvoltage at the cathode, the use of air‐consuming cathodes in the place of the hydrogen‐evolving cathodes, membrane electrolysis under pressure and the SPE process or zero‐gap elect

ISSN:0009-286X    

DOI:10.1002/cite.330540604

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540605

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractNon‐steady‐state operation of continuous reactors. The behaviour of continuous chemical reactors can be altered significantly by forced oscillation of the reactor parameters such as feed concentration of the reactants, flow rate, and temperature. In contrast to autonomous oscillations in unstable systems, the forced periodic disturbances are controlled and can be used as a further parameter for process optimization. The dynamic behaviour of individual steps of the overall reaction and of the reactor can be exploited to obtain performances and selectivities which cannot be accomplished in the traditional way on steady‐state operation under comparable conditions. This is shown in discussing some simple kinetic schemes published in theoretical studies and comparing them with experimental results for homogeneous and heterogeneous reactions. The physical and chemical causes for the predicted and observed advantages of periodic operation are disc

ISSN:0009-286X    

DOI:10.1002/cite.330540606

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractMeasuring methods for fermentations under sterile conditions. In process development as well as in industrial production it is necessary to obtain information about the state of the process by the measurement of characteristic variables. This is true for bioengineering in the same way as for chemical processes in general. Characteristic variables to be taken into consideration include temperature, pressure, masses and mass‐flow rates, operating parameters such as liquid level and impeller speed, and especially the concentrations of reactants, intermediates, and products. In contrast to other processes, a particular problem exists in fermentation because introduction of microorganisms, into the system by the measurement has to be prevented. Since taking samples from the reactor is hardly suitable for controlling the process for various reasons (amount of work, loss of time), this review considers only those methods which can be used for measurements directly in the fermentor. Essentially these are physical and physico‐chemical methods, e. g. for concentrations (O2and CO2in gas and liquid phase, pH, biomass). Of special interest for future development are spectroscopic and enzymatic methods for fast determination of substrates and of important intermediates and products. Here the sterility required entails special problems in the case of enzyme electrodes. Important information on the state of the process can, of course, also be obtained from physical variables, such as gas hold‐up, bubble size, viscosity, and turbulence properties of the medium. These variables are less critical with regard to ster

ISSN:0009-286X    

DOI:10.1002/cite.330540607

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540608

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540609

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540610

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540611

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY