摘要:

AbstractMode of action and characterization of multifunctional automotive exhaust catalysts. Because of the pending reduction in permissible concentration of toxic components in automotive exhausts the catalysts presently available will have to be replaced by more efficient systems. For these “second generation” catalysts multifunctional platinum/rhodium based catalysts are in the course of development, with provision being made for control of the fuel/air mixture. The new catalysts destroy both NOxas well as carbon monoxide and hydrocarbons and are effective in the neighbourhood of the stoichiometric composition of the fuel/air mixture. The mode of action of the new “three‐way” catalysts is described in detail and the present trends in development are

ISSN:0009-286X    

DOI:10.1002/cite.330501202

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractProcessing of information and data in construction of equipment and plant. Computers are playing an everincreasing role in plant construction. Partly integrated programming solutions have meanwhile become available for many sectors of the engineering and commercial sides of plant design. The design and construction of larger plants, which because of the necessity to save on energy and raw material consumption and to conform with ecologically unobjectionable standards are becoming more and more complex, is virtually impossible without the aid of computers. And this development trend is still continuing. At present efforts are mainly directed at the use of computers in the preparation of engineering drawings and to the assembly of partly integrated processing steps of larger integrated complexes. Projects of this nature are often beyond the capabilities of individual firms and demand cooperative development. Apart from a few exceptions, electronic data processing has not been exploited in plant construction beyond the commercial side. Even NC machines are frequently not employed in plant construction, mainly because of the custom‐built nature of the components. Essential rationalization even in this area poses the question of the extent to which a wider use of electronic data processing might be helpfu

ISSN:0009-286X    

DOI:10.1002/cite.330501203

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractGasification of coal – a status report. On the basis of industrially available conventional coal gasification processes (Winkler, Koppers‐Totzek, and Lurgi pressure gasification) the paper describes developmental trends in such processes. Elevated operating pressure is a common feature of all new processes, thus opening up new applications. An economic incentive to the development of new gasification processes also comes from combinations with new technologies, e. g. with direct reduction. Moreover, an advanced version of the high‐temperature Winkler process is described and evaluated in comparison with conventional commercial processes. Apart from processes conducted above ground, recent developments also include thoughts about underground gasific

ISSN:0009-286X    

DOI:10.1002/cite.330501204

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractStability and Dynamics of Reactors with Heterogeneously Catalyzed Reactions. Our knowledge of causes and consequences of problems arising from instability and dynamic effects in reactors with heterogeneously catalyzed reactions has increased remarkably in recent years. Especially thermal effects, caused by the self‐acceleration of an exothermic reaction in combination with heat and mass transport, are now well unterstood. In addition kinetic effects, i. e. phenomena which have to be explained by the kinetic peculiarities of surface reactions, have attracted increasing interest. For both cases the state of the art will be reviewed, highlighting the physical and chemical causes of the observed phenomen

ISSN:0009-286X    

DOI:10.1002/cite.330501205

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330501207

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCriteria for the choice and design of gas/liquid reactors. The mass transfer area in a given reactor volume can be varied over several orders of magnitude by the choice of operating parameters. The way in which the volume‐specific conversion can be altered by variation of the volume‐specific mass transfer area depends upon the rate of the chemical reaction. The greater the volume‐specific mass transfer area chosen, the more power is required per unit reactor volume. Analysis shows that not only the attainable conversion but also the yield can be greatly influenced by the volume‐specific mass transfer area. This applies both to parallel and to consecutive reactions. In the case of consecutive reactions, the liquid retention time must also be included as a parameter in yield determination. If a reactor system requires economic optimization, then, in addition to the yield, the power required for mixing and the investments in reactor volume are also of importance. All three parameters can be modified by means of quantities accessible to the engineer, such as gas throughput, specific power dissipation, and residence time. The quantitative relations depend upon reactor type. The relation between these parameters can be plotted quantitatively in a working diagram for each reactor type. Its plotting and use in reactor optimization on the bases of laboratory experiments are con

ISSN:0009-286X    

DOI:10.1002/cite.330501208

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330501209

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330501210

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330501212

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330501213

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY