bluuebunny/crossref_metadata_2025_split huggingface dataset:
Entwicklung von technischen Katalysatoren
Authors: Gallei Ewald F. , Neumann Hans‐Peter 
Published: December 2004

AbstractDevelopment of Industrial Catalysts. This paper considers the industrial development of catalysts as an important component of chemical processes. Starting from the desired properties, a detailed description is presented of the heterogeneous catalysts which account for some 80% of all the catalyst systems in industrial use. In addition to an treatment of catalyst structure, particular emphasis is placed on interdisciplinary aspects of catalyst development. The factors influencing catalyst performance and the range of methods used for their characterisation are also discussed. The approach adopted in catalyst development is then presented and four topical examples are given to illustrate the influence of structural parameters on catalyst performance. The article concludes with a description of the industrial production of catalysts and a look at the future of catalyst development.
Entwicklungsstand der Alkalichlorid‐Elektrolyse. Teil 2: Elektrochemische Größen, wirtschaftliche Fragen
Authors: Bergner Dieter 
Published: December 2004

AbstractState of Development of Alkali Chloride Electrolysis (II). Electrochemical Quantities, Economics. The first part of this rewiew article described cells, membranes, electrolytes and products of the membrane cell process. The second part, presented below, deals with cell voltages, current efficiences and energy consumption, as well as with plant construction and plant conversion with membrane cells. A brief look at the connection between the discussion on chlorine chemistry and the introduction of the membrane cell process concludes this review.
Ausgewählte Problempunkte bei Simulation und Gestaltung rektifikativer Trennprozesse
Authors: Scholl Stephan , Polt Axel , Krüger Siegfried 
Published: December 2004

AbstractSelected Problem Points in the Simulation and Design of Distillative Separation Processes. Thermodynamic simulation represents an important tool in the process engineering treatment of distillative separation processes. The degree of detail in the representation of the real process is orientated upon the question of the stage of process development at which thermodynamic simulation is utilized. For three examples of practical relevance it is shown that an improper representation of process reality in the simulation may lead to ambiguous and even false interpretations. In most cases problems arise when process‐relevant functions of single units are not incorporated adequately. It is shown that a Langrange‐type consideration of the process avoids most of the problems discussed.
Strategie für eine Konversion der Chlorchemie
Authors: Plinke Eckhard , Schüssler Reinhard , Kämpf Klaus , Darimont Thomas 
Published: December 2004

AbstractStrategy for Conversion of Chlorine Chemistry. After years of discussion about „cessation of chlorine chemistry”︁, the study entitled „Conversion of Chlorine Chemistry”︁ [1] commissioned by the Environmental Ministry of the State of Hesse in Germany and undertaken by Prognos AG provides the very first detailed comparative ecological and economical assessment of production process and products of „chlorine chemistry”︁ and industrially feasible alternatives and presents a strategy for partial transformation. This accomplished on the basis of a systematic assessment of risks and benefits, as demanded by the Geman parliametary commission „Protection of Humankind and the Environment”︁.
Stationäre Chemische Energieumwandlung als Herausforderungen für den Verfahrensingenieur
Authors: Fischer Manfred , Köhne Rainer , Schnurnberger Werner , Tamme Rainer 
Published: December 2004

AbstractMeeting future energy demands with more efficient, lower emission, and safe energy technologies has top priority in the medium term. Consumer‐friendly energy concepts, integrated into regional and supraregional energy supply structures, represent further elements. These will make important contributions to resource‐conserving and environmentally compatible power supplies utilizing local energy sources including renewable resources. Supplying energy to large areas involves additional tasks, from compensation of large amounts of fluctuating energy to the transport of fluctuating energy to the transport of renewable energy over long distances. Solar dish, parabolic section, and tower power generating plant have considerable economic and CO2‐reduction potential in sunny countries, such as in the Mediterranean region, However, the costs of solar‐thermal electricity generation have to be reduced by a factor of 1.5 to 2. Fuel cell systems can attain particular significance as efficient low‐emission energy conversion systems in power plant and automative engineering once their technical and economic potential can be realized.
Fahrzeugantrieb mit PEM‐Brennstoffzelle
Authors: Klaiber Thomas 
Published: December 2004

AbstractIn the areas of traffic and vehicle power units, high energy consumption an resource depletion have led during the past twenty years to improvements to vehicles with Diesel and Otto enigines, improved traffic control, and the development and introduction of alternative power units. One alternative is the fuel cell motor. The advantages of a fuel cell vehicle lie in reduced or zero emission. The electrical efficiency of the fuel cell is very high and not subject to the constraints of the Carnot process. Owing to their technical properties, such as their working temperature range, CO2 compatibility, solid electrolyte in the form of a film, PEM fuel cells appear most suitable for use in vehicles. They can be operated fairly straightforwardly so that the periphery remains well controllable on construction of a complete system. If an alternative power unit such as the fuel cell is to acquire customer acceptance beyond initial niche applications then not only better primary energy consumption and significantly better emmision behavior than conventional drives are required. Further technical an economic demand will have to be meet in order satisfy sutomer expectations.
EU‐Öko‐Audit‐Verordnung und produktions‐integrierter Umweltschutz am Beispiel der Lebensmittelindustrie
Authors: Chmiel Horst 
Published: December 2004

AbstractThe eco audit directive of the Europen Union (EEC 1836/93) requires that a company applying for certification should lay open its environmental policy, install enviromental management, and conduct an internal environmental analysis. It can be demonstrated that the investments required to eliminate weak points is often recovered within a few years owing to savings relating to energy and fresh an waste water. The same can be expected for other sectors of industry. A prerequisite is a holistic approach and integration of the measures adopted into the production line. Selective separation processes play a special role in practical application of the information acquired.
Der Dialog zwischen Hochschule und Industrie im GVC‐Fachausschuß „Partikelabscheidung‐Abgasreinigung”︁
Authors: Bueb Michael 
Published: December 2004

AbstractIn spite of industrial growth in the western states of the Federal Republic of Germany, considerable advances have been made in clean air maintenance since the 1950s. Contributions came from improved waste air purification processes, appropriate legislation, and a broad‐based industrial implementation of primary and additive measures for waste gas avoidance or purification. Particularly in the area of environmental protection, the need for constructive collaboration between the state, university research, and industry is very clear. Knowledge gained from fundamental research at universities is an important resource for industry, particularly when such university research stays mindful of the problem solutions and innovations required in practice. At the Institute for Mechanical Process Engineering and Mechanics at the University of Karlsruhe a number of very important and fundamental research projects in the area of particle separation and waste gas purification were undertaken in recent years by F. LÖFFLER and coworkers. These clearly show how appropriate fundamental research work can provide valuable contributions to the understanding and further development of processes. As Chairman of the GVC Specialist Committee „Particle Separation – Exhaust Gas Purification”︁ for many years, F. LÖFFLER made exemplary contributions to a successfull dialogue between university research and industry.
Verbesserung der Entscheidungs‐findung bei der Produktionssteuerung eines erdölverarbeitenden Anlagenkomplexes
Authors: Peuker Thomas , Hartmann Klaus 
Published: December 2004

AbstractDie erdölverarbeitende Industrie ist durch große verfahrenstechnische Anlagenkomplexe gekennzeichnet. Der Betrieb dieser erfordert im Rahmen der Produktionssteuerung Entscheidungen, um das Produktionsziel optimal zu erreichen. Dem Entscheidungsträger soll ein Hilfsmittel zur Verfügung gestellt werden, das der Komplexität des Problems gerecht wird und ihn bei der Entscheidungsfindung unterstützt.
Strömungsverhalten wäßriger Schizophyllanlösungen in Kugelpackungen
Authors: Müller Markus , Brunn Peter Otto 
Published: December 2004

AbstractSchizophyllan ist ein Ausscheidungsprodukt des Pilzes Schizophyllum commune, was nur Glucose als Monomer hat. In Abb. 1 ist die molekulare Primärstruktur des Monomers dargestellt [1]. Die Monomehrzahl n in diesem extrazellulären Polymer beträgt zwischen 9000 und 38 000. In wäßrigen Lösungen liegt es nach YANAKI et al. [2] als stäbchenförmige Tripelhelix vor. Erste Anwendungen mit diesem Biopolymer fanden in der Medizin zur Tumorbekämpfung Einzug [2]. RAU und HAARSTRICK [1, 3] untersuchten den Einsatz als Widerstandsverminderer bei turbulenten Strömungen und die Anwendung als Flutungshilfsmittel unter der Berücksichtigung hoher Temperaturen und Salzgehalten. Bei dieser letztgenanten Arbeit wurde aber lediglich das Filtrationsverhalten und die Scherviskosität untersucht. Aussagen über die Strömungen innerhalb von Schüttungen wurden keine getroffen.
Quality Engineering mit statistischer Versuchsmethodik
Authors: Soravia Sergio 
Published: December 2004

AbstractThe strategic orientation towards a modern and widely demanded quality management is said to be substantial for reaching and maintaining competitiveness. Methods and tools to realize related objectives such as quality improvement, cost reduction, and shortening of development periods are often only known by name. However, there are frequently no or only vague ideas about their concrete contents and how they can be used in practice. One of the most efficient techniques of Quality Engineering is the methodology of statistical experimental design (DoE, Design of Experiments). The determination of optimal and robust product characteristics and process conditions, especially before starting large‐scale production, increases process capability/safety and therefore improves product quality. All considered experimental parameters are varied in a systematic and balanced way so that a maximum of information and knowledge is gained from the analysis of the experimental results. The intention of this paper is to give an insight into essential principles and possible industrial applications of experimental design by means of examples and completed projects without entering into mathematical and statistical details.
Leckageraten von Dichtungen für Flanschverbindungen: Einflußgrößen, Anforderungen, meßtechnische Erfassung und leckageratenbezogene Dichtungskennwerte
Authors: Kockelmann Hans 
Published: December 2004

AbstractFlow theories can help in determining the fundamental interrelationships between the leak rate of gaskets for flange connections and the relevant influencing parameters. The basic rule for the transfer of results obtained for special boundary conditions to other conditions can be derived. In this way the effort involved in gasket testing can be reduced. This paper gives the interrelations between the leak rate of gaskets on the one hand and the internal pressure, the temperature, the medium, and the gasket thickness on the other and discusses them with aid of measured results. The effect of the gasket stress and thickness can be determined only of experimental investigations. Furthermore, the requirements placed on gaskets, the leak rate related gasket characteristics defined in various standards and the measuring techniques for their determination are discussed.
Wärmetechnische Optimierung eines Chemiestandortes
Authors: Wolff Andreas , Groebel Markus , Janowsky Ralf 
Published: December 2004

AbstractAusgangspunkt für die wärmetechnische Optimierung eines Chemie‐standortes sind die Pinch‐Analysen der wichtigsten Anlagen. Häfiges An‐ und Abfahren sowie ständige Lastwechsel erschweren die Durchführung einer Total‐site‐Analyse. Aus diesem Grunde und wegen der stofflichen Kopplung von Energieversorgungssystemen und Anlagen ist die Entwicklung eines Standortmodells erforderlich. Aufgrund der Flexibilität des Modells läßt sich ein Programm erstellen, das als Analyse‐ und Planungsinstrument einsetzbar ist. Dieser Beitrag beschreibt das zugrundeliegende Modell und zeigt, wie durch den Einsatz des Programms technisch realisierbare Einsparpotentiale aufgezeigt werden können.
Phasengrenzflächen in Blasenströmungen — Teil 2: Großblasen und Pfropfen
Authors: Millies Marco , Mewes Dieter 
Published: December 2004

AbstractIn the first part of this article an equation was derived for calculation of the specific interfacial are and the size distribution of bubbles in bubble flow. However, its application is limited to gas contents lower than 12%. At higher gas contents, large bubbles and gas plugs occur in the field of flow. These have a very low interfacial area per unit volume compared to small bubbles. Since large bubbles and gas plugs contain a large proportion of the gas in the flow, the overall interfacial area is reduced. In the present contribution, the gas content above which large bubbles and gas plugs occur is calculated. The results are subjected to experimental testing for vertical pipe flow. In addition, the volume fraction of the larger bubbles is calculated and the results verified experimentally by measurements in bubble columns. Subsequently, the specific enterfacial area with and without large bubbles is calculated for high gas contents. The results are in agreement with values measured for bubble columns and column plates.
Vergleich der Effektivität von bewehrten und unbewehrten Rührsystemen in der chemischen Verfahrenstechnik
Authors: Markopoulos Joannis 
Published: December 2004

AbstractIn spite of the fact that vortex formation, in unbaffled agitated vessels, is in most cases an undesirable phenomenon, many cases exist in chemical engineering where unbaffled systems can be used with greater effectivness than systems with baffles, at the same or even smaller energy consumption levels. Satisfactory results can also be obtained in unbaffled agitatated vessels without an air‐liquid interface. These facts, viewed in the light of energy problems in the chemical industry, show the current importance of comparative studies of baffled and unbaffled systems. In the present review article some characteristic cases from the fields of fluid dynamics, homogeneous distribution processes, suspensions, as well as mass‐transfer and heat‐transfer operations in baffled and unbaffled agitated vessels are presented and comparatively discussed in relation to their effectivness.
Entwicklungstendenzen in der Feststoff‐verfahrenstechnik
Authors: Peukert Wolfgang 
Published: December 2004

AbstractThis paper describes trends in the field of particle technology. The properties of dispersed matter which has to be handled in the chemical engineering processes or which has to be produced are of decisive importance. Future trends can be characterized by improvement of existing technologies, by a better understanding of fundamentals, combination of principles, extension of process parameters, process control and simulation, and new processes. An important trend is the production and handling of finer particles. Traditional methods of comminution and classification reach their limit around 1 μm. New processes for synthesis of particles by physical and chemical methods appear to becoming more popular. Nano‐sized particles may become of future relevance in various fields of technology such as material science, micro electronics or medicine.
Entwicklung membranunterstützter Reaktionsprozesse
Authors: Schirg Peter , Waldburger Raoul M. , Widmer Fritz 
Published: December 2004

AbstractThe use of membrane technology is developping from the solely work‐up of product and waste streams all the way to integration into processes. The membrane reactor offers, by analogy with biological cells, great possibilities for product‐integrated environmental protection. Two principal areas of application of membranes in reactors are becoming apparent. Use for removal of products or by‐products from bioreactors and the coupling with chemical reactions considered in this article. The first such membrane reactors served for the removal of water from esterification reaction mixtures. Significant advances for membrane reactor technology came with the recent development of membranes of enhanced selectivity and flow density as well as improved thermal and chemical stability. In addition to the availability of high‐performance membranes, fundamental knowledge and methods are required to assure efficient reaction‐engineering utilization of membrane reactors. This paper discusses fundamental concepts relating to the use of various membrane reactors in parallel, consecutive, and equilibrium reactions. In general, in the case of membrane‐supported parallel reactions, controlled addition of reactant can raise the reaction selectivity. Selective removal of primary and side products from consecutive or equilibrium reactions can increase yields. Comparison of membrane‐supported reactor types (batch, loop, and plug‐flow membrane reactors) indicate that the membrane‐supported loop reactor will prove most effective in the majority of cases thanks to its pronounced flexibility.
Fortschritte in der Adsorptionstechnologie
Authors: Rafflenbeul Rolf 
Published: December 2004

AbstractThe high purchasing price of organic solvents has stimulated interest in their recovery from emissions. While conventional adsorption units for recovery of monosolvents have been in industrial use for some 70 years, it has hitherto proved impossible to costeffectively desorb solvent fractions sufficiently pure for direct use in the case of emissions of mixtures. The solvent mixtures obtained by desorption had to be separated in expensive rectification steps, with the high costs thus precluding widespread use of adsorption for recovery projects in the chemical and printing industries. After conclusion of development work performed in the USA and Germany over a period of 10 years, it is now possible to control the adsorption steps in such a way that the purities necessary for reutilisation of the individual solvent fractions can be attained without the aid of rectification steps.
Rauchgasreinigung mit Reststoffbehandlung und Wertstoffgewinnung in der Abfallverbrennung — Stand und Tendenzen
Authors: Schaub Georg 
Published: December 2004

AbstractThe design of flue gas treatment equipment in municipal waste incineration plants worldwide varies according to the requirements with respect to pollutant emissions and resource recovery. Various combinations of individual separation processes may be encountered, such as dry particle separation, gas absorption (wet or dry), adsorption, catalytic or thermal conversion. The present comparison of different basic process alternatives indicates that firstly any degree of pollutant removal can be achieved by the available process technologies with corresponding expenditure of money and energy demand, secondly, German plants generally are more complex than plants in other countries due to more stringent separation and resource recovery efficiency requirements, and thirdly, a trend can presently be seen towards more simple and cheaper processes with simultaneous separation of several pollutants in one process step.
Modelluntersuchungen zur Partikelbeanspruchung in Reaktoren
Authors: Henzler Hans‐Jürgen , Biedermann Anja 
Published: December 2004

AbstractThis paper reports systematic studies on hydrodynamic stress in agitated vessels with baffles, reactors with predominantly laminar flow, SERALE viscosimeters, bubble columns, and gas‐driven loop reactors. The stress on particles is determined by way of the destruction of model particle systems, with the kinetics of destruction, the equilibrium particle diameters, and the enzyme activity after a given time serving, respectively, for assessment of the stress. Thereof one obtaines an indication of the methodology necessary for determining the stress and it permits selection of appropriate reactor systems according to the criterion of particle stress. In the case of reactors with turbulent motion without dominant laminar flow or gas/liquid interfaces give analogous results, permitting the assumption that they are also applicable to other particle systems. Specifically for stirred reactors a geometric function is derived from the experimental results which permits prediction of stress caused by various types of impellers. Impellers with large blade areas relative to the dimensions of the tank produce less shearing forces owing to their uniform power input, in contrast to small and especially axial flow impellers. In laminar flow or reactors with gas/liquid interfaces the level of particle stress depends upon the proclivity of the particles to enter the boundary layers. It can therefore be deduced that particles with different surface properties, which lead to differing interactions with boundary layers and interfaces, will also experience different kinds of particle stress on laminar flow or in aeration processes. Thus the scope for application of the results obtained with model particle systems to other particle systems is limited in such reactors.
Computerunterstützungen für Planung und Steuerung in der Fertigungstechnik und in der Prozeßindustrie
Authors: Jänicke Winfried 
Published: December 2004

AbstractThis contribution is concerned with computer support in the planning and execution of production with regard to the chemical industry. It examines the question whether strategies and software from production engineering can also be used in the processing industry and the extent to which chemically specific supplementation is necessary.
Korrelation physikalischer mit anwendungs‐technischen Größen bei Dispersionen
Authors: Lent Boudewijn Van , Klinksiek Bernd 
Published: December 2004

AbstractThis review shows the relationship which exists between certain applications related and physical properties of dispersions. It also presents the possibilities at our disposal for determining such properties and influencing them in a desired manner. However, the available knowledge and methods are not sufficient for complete prediction of applications‐related properties. Gaps in our knowledge and in the experimental possibilities are indicated. What is feasible is demonstrated with the aid of some typical examples. The example are selected so that certain properties of the dispersions, such as particle size, rheological behaviour, or charge behaviour exert a pronounced influence on the applications‐related properties. The examples cover various material systems, such as emulsions, polymer dispersions, dispersions of active principles, and inoganic pigments. In conclusion, the article considers what knowledge and methods will be required in the future for more purooseful product develooment.