bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mikrostrukturen aus Metall/Träger‐Wechselwirkungsprozessen an heterogenen Katalysatoren
Authors: Lamber Ryszard , Jaeger Nils , Schulz‐Ekloff Günter 
Published: December 2004

AbstractMicrostructures resulting from metal‐support interactions on heterogeneous catalysts. The term metalsupport interaction covers a large number of different phenomena due to forces of adhesion, charge transfer including the formation of chemical bonds, covering of the metal surface by reduced species from the support or the formation of new phases at the interfaces. The effect of such interactions on the efficiency and stability of catalysts is studied for numerous metal‐support systems. The formation of silicon‐metal alloys on silica, which has previously been considered as an inert carrier, as well as the formation of graphite on charcoal‐supported metal dispersions are described as examples of special interest. The new phases are characterized by methods of the analytical electron microscopy.
Schmelzkristallisation – theoretische Voraussetzungen und technische Grenzen
Authors: Wellinghoff Georg , Wintermantel Klaus 
Published: December 2004

AbstractMelt crystallization – Theoretical presumptions and technical limitations. The fundamentals of the design of melt crystallization processes on cooled surfaces are presented. Determination of the energy requirement is the essential point. During each freezing step a multiple of the heat of solidification must be removed and must be re‐introduced during the subsequent melting step. Consequently, discontinuous processes of this nature can only compete with other thermal separation techniques – in which a continuous countercurrent operation can be realised – if the plant is well designed and the process is precisely controlled.
Abtrennung und Rückgewinnung von gasförmigen Stoffen durch Adsorption
Authors: Mersmann Alfons , Börger Götz‐Gerald , Scholl Stephan 
Published: December 2004

AbstractSeparation and recovery of gaseous substances by adsorption. After making a number of fundamental remarks on adsorbents, equilibrium, and kinetics of adsorption from the gas phase, the authors of this article first present a variety of regeneration methods. There follows a brief account of the methods used in the design of fixed bed adsorbers. The reader is then led via considerations of safety in the construction and operation of adsorbers to a number of practical examples from the areas of solvent recovery and flue gas purification.
Wäßrige Flüssigmembranen — Stand der Entwicklung
Authors: Ulbrich Michael , Marr Rolf 
Published: December 2004

AbstractAqueous liquid membranes – State of the art. Use of emulsion liquid membranes with an aqueous membrane phase is a promising technique for the separation of hydrocarbons, if distillation is difficult or impossible. Intensive investigations on aqueous membranes during the past five years have increased our knowledge of the mass transfer mechanism which exploits different solubilities and diffusivities for the separation of hydrocarbons. The influence of the most important process parameters on the selectivity of the separation and on an overall mass transfer coefficient, serving as a measure of the mass transfer rate, are discussed. Possible applications and further developments are presented.
Behandlung von Abwasser aus der metallverarbeitenden Industrie
Authors: Marquardt Kurt , Nagel Rolf 
Published: December 2004

AbstractTreatment of waste water from the metal‐working industry. Recent legislation has triggered a round of innovation in purification techniques for the treatment of waste water from the metal‐working industry. The historical development took place essentially in three generations, viz. flow‐through processes, recycling ion‐exchange units, and process oriented work‐up. The process engineering of process oriented work‐up is basically known with regard to the unit operations. Work performed during the last two years has focussed on transforming the known processing principles into plant engineering and accomplishing the step to the industrial scale plant, i.e. to bring it up to the present state of the art.
Rechnergestützte Erstellung verfahrenstechnischer Prozeßmodelle
Authors: Marquardt Wolfgang 
Published: December 2004

AbstractComputer‐aided generation of chemical engineering process models. The availability of adequate process models is still the most striking bottleneck for routine application of model‐based techniques in process design and operation. The development of knowledge‐based software tools to support process modeling is considered an important contribution to a solution of this problem. After a brief summary of the modeling tools offered in current simulator architectures, a future knowledge‐based modeling tool is sketched. In addition to the software engineering, the acquisition and formalization of the modeling knowledge – comprising meaningful submodels and generic modeling strategies – is essential for the feasibility of the approach and for the acceptance of a tool. Therefore, these two themes are discussed in considerable detail. Finally, first prototype developments towards a knowledge‐based modeling tool are presented.
Optische Konzentrations‐ und Temperatur‐Messung in Aerosolen und Sprays
Authors: Schweiger Gustav 
Published: December 2004

AbstractOptical measurement of concentration and temperature in aerosols and sprays. This article surveyes progress in the development and application of optical methods, particullarly in Raman scattering and fluorescence for the analysis of aerosols and sprays. The main emphasis lies on examination of the particle phase. Fundamentals and state of the art in the determination of molecular composition of the particle phase with the aid of linear and simulated Raman scattering are described and the role of structural resonance discussed. Various models are presented for distinguishing between the contribution of the liquid and the gas phase to Raman scattering and fluorescence. Finally, new developments pertaining to the measurement of droplet temperature in aerosols and sprays are described.
Einsatz von Biowäschern in der chemischen Produktion
Authors: Stockhammer Stefan , Schäfer‐Treffenfeldt Wiltrud , Zetzmann Klaus 
Published: December 2004

AbstractUse of bioscrubbers in the chemical industry. Bioscrubbers are an ecologically and economically interesting alternative to conventional processes like combustion, adsorption and absorption. A brief account of the microbiological and engineering fundamentals of bioscrubbers are given followed by a review of new developments illustrating improvements in process design. The field of application for bioscrubbers is continuously expanding. Two examples of the use of bioscrubbers are discussed. They demonstrate the feasibility of deodorization of slightly contaminated waste gas, as well as the purification of waste gas which is highly loaded with organic substances. The authors describe a new concept for reduction of local hold up of biosuspension at the bioscrubber by integrating the waste water plant as a superior reservoir for fresh biosuspension. The most important advantages of the new concept are as follows: No problems with shut‐off time, a better safety in operation, and ready adaptation of the process to changing parameters.
Stand der Emissionsmeßtechnik im Abgas der Rückstandsverbrennung
Authors: Jockel Wolfgang 
Published: December 2004

AbstractState of the art of emission measuring techniques in the flue gas of waste incineration plants. It is necessary to critically consider measuring techniques in the light of new requirements for waste incinerators (17th ordinance dating from Dec. 1990). Selected examples are concerned with the primary components of flue gas: particulate matter and trace metals, organics with total carbon content, and important groups such as organochlorine compounds (e.g. dioxins/furans) and inorganic chlorides (such as hydrogen chlorine). The evaluation concludes by considering manual techniques as well as monitoring systems and measures for quality assurance. Finally, an account of recent developments in the monitoring of ammonia and mercury is presented.
Biologisch abbaubare Kunststoffe: Testverfahren und Beurteilungskriterien
Authors: Augusta Josef , Müller Rolf‐Joachim , Widdecke Hartmut 
Published: December 2004

AbstractBiodegradable Polymers: Test Methods and Assessment Standards. Technological difficulties in plastics recycling as well as critical emission into the environment during waste incineration give rise to considerations of utilizing plastics in composting systems. While market supply of ‘biodegradable plastics’ is increasing there is a need for test methods and assessment standards for these substances. This paper presents the basis and discusses microbial procedures, analytical techniques and requirements for the tests to be developed.
Einsatzmöglichkeiten hydrophober Zeolithe in der Adsorptionstechnik
Authors: Otten Wilhelm , Gail Ernst , Frey Thomas 
Published: December 2004

AbstractDer Einsatz von Zeolithen in der adsorptiven Abluftreinigung und Lösungsmittel‐Rückgewinnung scheiterte bisher daran, daß handelsübliche Zeolithe bevorzugt Wasserdampf adsorbieren. Durch spezielle Synthesen oder Dealuminierungsverfahren können Zeolithe hergestellt werden, die extrem hydrophob, hoch temperaturbeständig und säurestabil sind. Diese Zeolithe sind daher geeignet, selektiv organische Lösungsmittel aus feuchten Abluftströmen zu adsorbieren. Die Unbrennbarkeit der Zeolithe verhindert die Selbstentzündung des Adsorbens. Höhere Desorptionstemperaturen ermöglichen geringere spezifische Energieverbräuche sowie die Ad‐ und Desorption von Schwersiedern und polymerisierenden Produkten. Die geringe Wasseraufnahme reduziert den Energiebedarf bei hohen Abluftfeuchten und erlaubt die Rückgewinnung wasserarmen Lösungsmittels. Mit geeigneten Bindemitteln lassen sich die Zeolithe zu Hohlzylindern mit geringem Druckverlust verformen oder zur Beschichtung von Wabenkörper‐Rotoren einsetzen.
Strukturwandel in der Ingenieurtechnik der chemischen Industrie
Authors: Lipphardt Günter , Pilz Volker , Plöcker Ulf , Wintermantel Klaus 
Published: December 2004

AbstractChanges in the Structure of Engineering in the Chemical Industry. The poor profit situation has stimulated a discussion of the costs of engineering in the chemical industry. The allocation of engineering responsibilities to centralized organizational structures is at issue. This applies to planning just as much as to plant maintenance or to the workshops. These structures are regarded as inflexible, expensive and, in many cases, monopolistic. Decentralized units which are directly responsible to divisions or business units seem to be able to work more efficiently and cheaply. The best alternative, however, is considered to be the outsourcing of work to external firms on a far larger scale than up to now. The article deals with the reasons which have initiated the structural change and with the relating consequences thereto.
Klärschlammpyrolyse mit Rückstandsvergasung
Authors: Schuller Dieter , Brat Boris 
Published: December 2004

AbstractPyrolysis of Sewage Sludge Combined with Gasification of Char. Dried sewage sludge was pyrolyzed over a temperature range of 550 to 650°C and the char produced during this reaction was gasified with steam in a succeeding step at 900°C. Both reactions were carried out in a fluidized‐bed reactor. Besides the composition of products, vaporization of heavy metals and the suitability of the gasification ash for landfilling were investigated. The results indicate that the combined process of pyrolysis and gasification of char can be looked upon as a promising method of disposing of sewage sludge.
Anwendung von Polyelektrolyten bei der mechanischen Fest/Flüssig‐Trennung
Authors: Kulicke Werner‐Michael , Lenk Sylvia , Detzner Heinz‐Dieter , Weiß Thomas 
Published: December 2004

AbstractUse of Polyelectrolytes in Mechanical Solids/Liquid Separation. This article shows how optimisation tasks for the dewatering of sludge can be solved by starting from studies of chemical structure and steric properties of polyelectrolytes and laboratory experiments based thereon with a trans‐portable computer‐aided flocculation and dewatering apparatus. The optimum polyelectrolyte dosage lies in the range of the critical concentration c* (viscosimetric measurements) of the dissolved polyelectrolytes. On optimisation of the flocculant regime for mechanical solids/liquid separation by combined addition of anionic and cationic polyelectrolytes (dual process), it is necessary to consider the overall system of sedimentation and filtration. In an industrial scale plant, the consumption of flocculant could be reduced by up to 10% compared to laboratory studies. At the same time, the dewatering behaviour could be improved by up to 60%, a shearing strength of the sludge in excess of 20 kN/m2 reliably established, and plant operating reliability achieved for changing sedimentation properties.
Qualitätssicherung im Anlagenbau
Authors: Eisenächer Karl , Meurer Peter , Stork Werinhard 
Published: December 2004

AbstractQuality Assurance in Plant Design and Construction. In the field of chemical plant design and construction, quality is understood to mean the strict application of the state‐of‐the‐art rules and the fulfilment of all specific requirements specified by the client, including plant take‐over by the client in accordance with the time schedule. Chemical plants can rarely be handled in the same manner as series products. Therefore, quality assurance requires a large organizational scheme. The definition of quality and the system applied to ensure an adequate quality standard are a rather complicated task. The technical divisions involved in a project are responsible for the quality, i.e. there is no sharing of responsibility. It is also impossible to shift this responsibility to a special QA department.
Expertensysteme in der Verfahrenstechnik — Konfiguration von Rührapparaten
Authors: Knoch Achim , Bottlinger Michael 
Published: December 2004

AbstractExpert Systems in Chemical Engineering – Examples in the Configuration of Agitators. The structuring of relevant knowledge and its formalized representation in a knowledge base is the main prerequisite in employing an expert system. The present paper discusses functionality and conception of expert systems and explains their advantages over conventional programming. Furthermore, the structure of an expert system for the configuration of agitators in food processing is presented.
Auswahl von Sorbenzien für die Gasphasenadsorption
Authors: Eiden Ulrich , Ciprian Jürgen 
Published: December 2004

AbstractSelection of Sorbents for Gas Phase Adsorption. For gas phase adsorption processes it is almost always necessary to select a suitable sorbent by experiment, i.e. a sorbent that is suitable for adsorption as well as for desorption. Therefore sorbents from the group of activated carbons, adsorbent resins and zeolites have been tested and compared with each other under adsorption and desorption conditions. The sorbents have also been checked for reliable function. Operational disturbances are often caused by components such as water vapor or (irreversibly adsorbing) high boiling components. In any case it is useful to select adsorbents which are not susceptible to interference by these components. The co‐adsorption of water vapor, undesirable in practice, normally leads to a reduced adsorbent capacity. It is also shown that a single high boiling component, present in traces in the gas, loads the adsorbent to the same extent as the pure main component, so that there is hardly any capacity left for the main component. The range of investigation was insufficient to draw up general rules for the different groups of sorbents referring to the points considered.
In‐situ‐ und On‐line‐Überwachung und Regelung biotechnologischer Prozesse
Authors: Schügerl Karl , Bellgardt Karl‐Heinz , Kretzmer Gerlinde , Hitzmann Bernd , Scheper Thomas 
Published: December 2004

AbstractIn‐Situ and On‐Line Monitoring and Control of Biotechnological Processes. The advantages of in situ and on‐line monitoring of biological production processes are demonstrated by four examples: production of baker's yeast, manufacturing of alkaline protease by B. licheniformis, formation of intracellular fusion protein by recombinant E. coli, and production of antibiotica by ascomycetes and streptomycetes.
Statistische Prozeßführung (SPC) und Automatisierung (APC)
Authors: Staal Rolf , Rathert Hermann , Schloßer Gerhard 
Published: December 2004

AbstractStatistical Process Control (SPC) and Automatic Process Control (APC). Statistial Process Control as developed by Shewhart and Deming is being used internationally as a method for continuous improvement and cost reduction. SPC is applied to manufacturing and service industries, and is now being used more and more in Germany. In the chemical industry many processes are equipped with automatic control or advanced control strategies. This article outlines how SPC and APC supplement each other. The first part describes APC methods as a means of achieving constant quality. The second part describes SPC in its original form as a method for continuous quality improvement. After the comparison of SPC and APC an example is presented: automatic rectifying column. The combined application of SPC and APC leds to synergistic results which would have been hard to achieve otherwise.
Simulationsmodelle zur Berechnung der Explosionsgrenzen brennfähiger Gasgemische
Authors: Rennhack Rolf , Thiel‐Böhm Andreas 
Published: December 2004

AbstractSimulation Models for Calculating Explosion Limits of Combustible Gas Mixtures. A survey of current knowledge of explosion limit simulation for combustible gas mixtures is given. These models are important for estimating safety risks during process development and plant engineering. Therefore theoretically based and empirical equations are applied. The main subject of this paper deals with the simulation of explosion limits of multicomponent combustible gas/inert gas/oxidant mixtures depending on gas composition and temperature. New developments providing an important basis for software development are presented. Missing determinations and application limits are discussed.
Simulation von Kristallisations‐ und Fällprozessen
Authors: Pawlowski Juri 
Published: December 2004

AbstractSimulation of Crystallisation and Precipitation Processes. The various processes of crystallisation and precipitation lead to a wide variety of particle size distributions, which are also subject to the influence of the specific properties of the material systems. It was examined whether and to what extent these processes can be described in process engineering terms by a consistent simulation with a unified basic model of crystallisation. The basic model corresponds essentially to known concepts: it is based on the law of mass action but purposely omits ad hoc proposals found in the literature in the formulation of nucleation/nucleus decline kinetics. The results of simulation obtained for various material systems and processes demonstrate considerable adaptability of the basic model. It appears to be suitable for uniform description and to serve as an adequate basis of development of crystallisation‐specific properties of material systems.
Rotoradsorber zur Abluftreinigung und Lösungsmittel‐Rückgewinnung
Authors: Konrad Gerhard , Eigenberger Gerhart 
Published: December 2004

AbstractRotary Adsorbers for Waste Air Purification and Solvent Recovery. Thanks to their compact construction and low pressure drops, adsorbers with rotating adsorbent beds are highly suitable both for retrofitting of waste air purification units and generally for the removal of absorbable components from gas streams. When used in conjunction with straightforward hot gas desorption they permit almost complete purification of gas flows with concomitant concentration of the separated components in the desorbate by a factor of 10 to 20. They can also be used in conjunction with recovery of the separated components by partial condensation of the desorbate. Owing to the fixed coupling of adsorption and desorption times, which is determined by the geometry of the unit, the behaviour of the system is distinctly different from that of conventional multiple bed systems in cyclic operation. A detailed model description and computer simulation of operating behaviour are particularly useful for their analysis. It is shown that the behaviour of commercially available rotor concepts can be much better understood in this way and new concepts for exhaust air purification with integrated solvent recovery can be developed which are characterised by significantly reduced energy requirements for desorption and condensation.
Die großtechnische Oxosynthese mit immobilisiertem Katalysator
Authors: Wiebus Ernst , Cornils Boy 
Published: December 2004

AbstractIndustrial Oxo Synthesis with Immobilised Catalyst. The use of water‐soluble catalysts represents a significant advance in homogeneous catalysis; “immobilisation” of the catalyst in a second immiscible liquid phase has the effect of “heterogenisation” and allows the advantages of heterogeneous processing (long lifetimes, straightforward technology) to the combined with those of the homogeneous mode (gentle reaction conditions, high activity and selectivity). In particular, the decisive advantage of homogeneous catalysts, viz. the wide range of variation of their steric and electronic properties which can be adapted to the specific reaction at hand, can be exploited for tailoring highly effective catalysts. Moreover, the mode of action of these homogeneous catalysts remains understandable as a model and under the reaction conditions chosen – in complete contrast to the case of many heterogeneous catalytic systems. The first successful industrial application of water‐soluble catalysts was in the oxo process of Ruhrchemie/Rhǒne Poulenc. The following article reports on ten years' experience with this process and the HRh(CO)[P(msulphophenyl‐Na)3]3 catalyst.
Der Begriff der hochwertigen Dichtung für lösbare Rohrleitungsverbindungen
Authors: Simon Eberhard 
Published: December 2004

AbstractConcept of High‐Quality Seals in Disconnectable Pipeline Connections. The “Technical Instruction Air” of the Federal Republic of Germany stipulates the use of highquality gaskets in flange connections employed in handling of certain hazardous materials, but it gives no detailed informations concerning the high‐quality criterion. This article gives reasons why the highquality criterion should be extended on all elements of disconnectable pipeline connections of various types which are to be evaluated as systems. It further discusses the basic aspect of quality management as well as the terms „secluded emission”︁ and “diffuse emission”, which should be avoided or minimized respectively. The following criteria of high‐quality pipeline connections are discussed: Design reserves, corrosion resistance, position fixing, safety against fracture without deformation, tightnessperiod and process hygiene.
Scale‐up von Destillationskolonnen
Authors: Eiden Ulrich , Kaiser Rudolf , Schuch Gunter , Wolf Dieter 
Published: December 2004

AbstractScale‐up of Distillation Columns. In spite of remarkable advances in the development of computer programs for calculations on distillation columns, it is frequently still impossible to design them without experimental testing. Economic constraints demand use of miniaturised test plant, thus enhancing the importance of laboratory measurements. A system is presented for scale‐up of separation which required information from laboratory experiments, includes data from reference columns, and takes account of models of fluid dynamics and mass transfer. The special feature of this approach lies in the free choise of internals, both in the laboratory and in the designed column.