bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wärme‐Integration und Prozeßoptimierung
Authors: Linnhoff Bodo , Lenz Walter 
Published: December 2004

AbstractThermal integration and process optimization. The Pinch method for optimization of thermal integration of chemical plant has been widely accepted in recent years. Serving initially only as an aid in the design of energetically optimized heat exchanger networks, the method was developed in the course of time with regard to the following questions: optimization of heating and cooling systems; simultaneous optimization of energy and investment costs; operability, start‐up and shut‐down behaviour; inclusion of heat engines; optimization of old plant; and process optimization. The fundamentals of the Pinch method are summarized and further developments concerning development of the method for simultaneous optimization of energy and capital costs are presented. Optimization of the BASF butadiene process and the mutual interaction of process and energy system are then presented as practical applications.
Neuere technische Verfahren in der Kohlechemie
Authors: Collin Gerd 
Published: December 2004

AbstractNew technical processes in coal chemistry. The most important commercial basic processes of primary coal conversion are carbonisation, gasification, and hydrogenation. Some 450 mio t/a of coal are converted by coking in horizontal slot type ovens to 350 mio t/a of metallurgical coke for the reduction of iron ore in blast furnaces, coke oven gas, and some 20 mio t/a of coke oven benzole and coal tar as raw material for aromatics. The coke ovens are being developed to high‐capacity coking reactors. New second generation processes for the gasification of coal and lignite have advanced to an industrial scale. A vapor‐phase hydrocracking refining step has been integrated within the further developed process for the catalytic liquid‐phase hydrogenation of coal. Plasma pyrolysis of high‐volatile bituminous coal investigated on a semi‐industrial scale yields acetylene. Pressure hydropyrolysis of coal currently being tested on a pilot plant scale generates high‐aromatic liquid products. New processes for the upgrading of such liquids have been developed above all for aromatics from coal tar, e. g. for the production of naphthalene derivatives, and the conversion of polycyclic aromatic hydrocarbons into the technical carbon products carbon black, electrographite, carbon electrodes, and carbon fibres.
Zur Auswahl wirtschaftlicher Wärmeträger
Authors: Kilger Hans‐Joachim 
Published: December 2004

AbstractHeat transfer media: the economical choice. The products currently marketed as technical heat transfer media can be classified according to their physical and chemical properties or to the temperature range of their applications. Below 300°C, mineral oils dominate the scene; beyond that range, increasing attention is paid to synthetic media, as novel products with even better performance at high temperatures are being developed. This paper deals with selecting heat transfer media with respect to their characteristics, working life, and the technical conditions under which they are put to use. Additionally, they are evaluated from an economical point of view. Computer‐aided simulation of any kind of heat transfer system in liquid phase is shown to permit calculation of operating expenses for any kind of heat transfer medium. The variety of physical characteristics of these media may result in remarkable differences concerning transfer costs. However, the initial costs and working life turn out to have the greatest influence. Therefore detailed analysis remains indispensable to establish which medium will be best suited to the purpose.
Kinetik und Reaktionstechnik der anaeroben Abwasserreinigung
Authors: Wiesmann Udo 
Published: December 2004

AbstractKinetics and reaction engineering of anaerobic sewage treatment. In numerous papers the reaction rate of acetic acid metabolism by methanogenic bacteria, which is frequently suspected as the slowest step in anaerobic digestion, is described by Monod kinetics using total acetic acid concentration as the substrate for catabolism. However, in some papers the authors try to include the influence of pH by using only the un‐ionized acetic acid as the substrate in a Haldane‐kinetic term taking substrate inhibition into account. From this viewpoint, some conclusions regarding reaction engineering aspects of anaerobic waste water treatment are drawn and simple models for the conventional and for the contact process are discussed. The advantage of using support materials for anaerobic bacteria is shown. The space loading can be increased in a two step cascade of fixed bed reactors with external loops for water recycling, with the system being filled with synthetic foam particles as support.
Grenzflächen in der Medizin
Authors: Zembrod Alfred 
Published: December 2004

AbstractInterfaces in medicine. Some 6 × 1013 individual cells and a variety of differential structures make human organism a highly complex interfacial system. Interfaces play a predominant role in almost all areas of medicine. A number of topical developments which have led to important advances in medical research and practice are selected from the wealth of known phenomena.
Multifunktionale Reaktoren für die heterogene Katalyse
Authors: Agar David W. , Ruppel Wilhelm 
Published: December 2004

AbstractMultifunctional reactors for heterogeneous catalysis. Consequential exploitation of heat and mass transfer processes in heterogeneous catalysis provides numerous possibilities for reaction engineering. This paper presents a classification covering conventional and new reactor configurations and thus supporting development of optimum reaction engineering for any given case. The classification of catalytic reactors with regard to heat and mass transfer is demonstrated for eight examples taken from the heavy chemicals area. The extended reactor model proves to be a useful framework for reactor design and shows an unequivocal analogy between configurations with corresponding heat and mass transfer processes. The systematic approach indicates possible new solutions for reaction engineering problems.
Instrumentierungsmöglichkeiten an Rundlauftablettenpressen
Authors: Schmidt Peter C. 
Published: December 2004

AbstractInstrumentation of rotary tableting machines. Instrumentation of rotary tableting machines has two main purposes: to control the tableting process during production and to investigate the compression behaviour of substances. While the former is routinely implemented today, the compression process itself is still under investigation. Measurements are carried out to record compression‐, ejection‐, residual‐, die‐wall‐, and adhesion forces. In addition, displacement of punches is registered. Strain gauges are commonly used for force measurements. For more precise investigations, piezoelectric load washers are installed. Displacement measurements, which are seldom performed on rotary tableting machines, are carried out with inductive displacement transducers. This paper describes the present state of the art. The problems of routine compression force control in tablet production have now been solved. In contrast, a general description of the powdercompression process is not possible in detail. New methods for data collection from rotary tableting machines are described, enabling the pharmacist to reach a better understanding of the compression process.
Einfluß von Additiven und Verunreinigungen auf Kristallisationsprozesse
Authors: Van Der Leeden Mieke , Rosmalen Gerda Van , Vreugd Kees De , Witkamp Geertjan 
Published: December 2004

AbstractInfluence of additives and contaminants on crystallisation processes. The presence of additives and contaminants in a crystallising solution can have a considerable influence on the crystallisation properties of the products, such as nucleation and growth kinetics, agglomeration or dispersion of the crystals, and the incorporation of foreign ions into the crystal lattice. These influences are caused by various mechanisms, depending upon the type of additive or contaminant. Tailor‐made and multifunctional additives are distinguished. Trace amounts of metal ions can also modify the kinetics of crystallisation. The metal ions can be incorporated to a greater or lesser extent in the crystal, depending upon thermodynamic and kinetic factors.
Einsatz von Cross‐flow‐Techniken in der Bioverfahrenstechnik
Authors: Faust Tillmann , Kopf Michael H. 
Published: December 2004

AbstractUse of cross‐flow techniques in biotechnology.This progress report summarises experience and results gained during the development and optimisation of various micro‐ and ultrafiltration process. The major emphasis lies on the calculation of data which precede actual separation experiments and which define the separation or work‐up problem and the product system involved. To this end the author presents a checklist covering the following areas: definition of the problem at hand, characterisation of the product system and demands placed on membrane plant and membranes. The second area of emphasis is the concept of a flexible membrane test plant. With the aid of this plant, all the data necessary for design and optimisation of a membrane process can be worked out during the laboratory experimentation phase. The principal process engineering tools available for optimisation of the specific filtration performance and maximisation of the product yield are considered. The report considers both the effects and the theoretical fundamentals of techniques for maintaining steady flow of filtrate and for avoiding nonspecific adsorption.
Neue Aspekte zum Einfluß des Blasenwakes auf die Hydrodynamik und den Stoffaustausch in einer Blasensäule
Authors: Wasowski Tomasz , Blaß Eckhart 
Published: December 2004

AbstractNew aspects of the influence of the wake of bubbles on fluid dynamics and mass transfer in bubble columns.Wake‐phenomena behind solid and fluid particles moving in a continuous liquid are an important fluid‐dynamic effect which has a pronounced influence on heat‐ and mass transfer in two‐phase dispersions. In this paper results reported in the literature are used to analyse the influence of wakes behind bubbles on the hydrodynamics of bubble columns. A new class of model is introduced to describe the flow and mixing of the liquid phase, taking into account major hydrodynamic effects.
Werkstoffauswahl für luftgekühlte Wärmeaustauscher
Authors: Paikert Paul 
Published: December 2004

AbstractChoice of materials for air‐cooled heat exchangers. Air has many advantages as a coolant for industrial processes. It is available in any desired quantity and does not incur costs for supply and disposal. Although air is far less corrosive than water, there are limitations for certain materials and air contaminations. The possibility of using different materials for the process side and the cooling air side, with the latter preferably having an enlarged surface area, can be exploited to advantage to take account of material‐specific properties of the two sides. Process‐dictated limits of optimum surface area increase and temperature‐dictated limits of application and proven fin patterns, are demonstrated. Attention is drawn to actual cases of damage taken from practice and their lessons and also to some unexplained cases.
Prinzipien der Herstellung und Stabilität von Emulsionen
Authors: Schubert Helmar , Armbruster Harald 
Published: December 2004

AbstractPrinciples of formation and stability of emulsions.The present state of knowledge concerning the principles of emulsion formation and stability are summarised and new theoretical and experimental results are presented. Also described are the characteristic features of the most common types of machines used for emulsification and the mechanics of droplet disruption in laminar and turbulent flow as well as cavitation. In laminar flow, the minimum droplet size is theoretically determined by the shear stress and regulated by a critical Weber number, provided that the particular emulsifier can rapidly occupy sites on the newly formed interface. If this occupation is inhibited, than only larger droplets can be formed. The upper size limit can be calculated from kinetic considerations. The second part of the paper addresses the fundamentals of emulsion stability and the emulsifier's influence on interactions between dispersed droplets. A way of describing the state of the droplets in an emulsion at rest using a population balance theory is also discussed.
Biosensoren –‐ Sensoren für die Biotechnik?
Authors: Kasche Volker , Renken Eckhard 
Published: December 2004

AbstractBiosensors – Sensors for biotechnology? Increasing analytical requirements are to be expected in biotechnology, diagnostics, and environmental protection as a result of increasing product purity demands and the need to satisfy legal requirements. Biosensors are suitable for some of these purposes. The present review discusses the principal types and properties of such sensors in order to compare them with other sensors for the same purpose. It is seen that biosensors in combination with equipment having automated sample preparation and calibration can serve to overcome shortfalls in managing the increased analytical requirements for a number of substances.
Photovoltaik‐Anlagen
Authors: Stahl Dietrich 
Published: December 2004

AbstractPhotovoltaic plant. Presently available technologies for production of photovoltaic cells and modules and the principal developments aiming to improve the price/performance structure of the components are described in this article. Considerable attention is devoted to differences between the crystalline silicon cell (thick‐layer technology) and the thin‐layer cell. A description follows of the structure of simple to sophisticated photovoltaic systems of 100 Wp to 20 kWp, as well as the developmental status of the principal system components such as alternating and direct current converters. In the second part, the costs of photovoltaic plant are discussed from a present‐day viewpoint and the costs made comparable with those of conventional generation plant. The special significance of operating cost comparisons instead of those of pure investment costs in the examination of economic applications of photovoltaic systems is emphasized.
Trockenentschwefelung für Kombikraftwerke mit Kohlevergasung
Authors: Hederer Hartmut 
Published: December 2004

AbstractDry desulphuration of combination power stations with coal gasification. Dry gas purification processes for combination power stations can raise the thermal efficiency by 1 to 4%. This increase in efficiency is due, on the one hand, to the higher heat content of the gases, and on the other hand to avoidance of loss of combustible components during wet scrubbing, the constant water vapour content, and the possibility of using low‐pressure steam, e.g. for drying the coal prior to gasification. The various possibilities of dry desulphuration are listed and wet and dry desulphuration compared in tabular form. A former comparison of investment and operating costs for a 600 MW combination power station proves positive for dry desulphuration.
Möglichkeiten der Feuchtemessung bei verfahrenstechnischen Trocknungsprozessen
Authors: Freudenberger Adalbert 
Published: December 2004

AbstractMoisture Measurement in Technical Drying Processes. Drying processes still have a large potential for optimization with respect to economy and uniform quality of the products. A necessary condition to improve these processes is the continuous availability of information about the water content of the product. Only in few cases a satisfactory solution of this problem has been found. In addition, the more simple moisture measurements of the exit air of dryers also involve numerous problems. This publication presents a survey of the different methods of moisture measurement together with the inherent problems. Finally it describes an arrangement for a humidity measurement of a flash‐dryer's exit gas by the infrared technique.
Integrierte Informationsverarbeitung im Anlagenbau
Authors: Schmidt‐Traub Henner 
Published: December 2004

AbstractIntegrated information processing in plant design. Characteristic for plant design is the cooperation of quite different engineering disciplines. The quality of the engineering therefore is influenced mainly by technical coordination and flow of information between these disciplines. Software applications for plant design are very often individually written systems. It is the aim of data integration to increase the quality of engineering besides the rationalization of work. Depending on existing software, individual solutions for data integration are predominant. These solutions have to correspond to iterative procedures during plant engineering. Object‐oriented CAD systems instead of only graphics‐oriented CAD software are an important condition for further data integration. However, in order to utilize these advantages for exchanging electronically stored documentation between different companies, all interfaces and data structures have to be publicly available.
Meßtechniken für Gas/Feststoff‐Wirbelschichtreaktoren
Authors: Werther Joachim , Hartge Ernst‐Ulrich , Rensner Detlef 
Published: December 2004

AbstractMeasuring techniques for gas/solid fluidized bed reactors. Significant progress has been made in the field of fluidization in recent years due to its application to the combustion of coal as well as sewage sludges and other residues. The new applications have also created a demand for new measuring techniques. In the present paper the available measuring techniques for fluid mechanical properties are reviewed, ranging from simple measurements for the determination of bed expansion to more sophisticated techniques for the determination of local solids concentrations, velocities, and mass flows. Furthermore, the problem of gas sampling from fluidized bed reactors is discussed. Among others, a measuring technique based on mass spectrometry is presented for local and instantaneous measurements of gas concentrations.
Methoden und Anwendungen der statistischen Prozeß‐ und Qualitätskontrolle im chemischen Betrieb
Authors: Kreitner Hermann , Kersting Franz‐Josef , Schuler Hans 
Published: December 2004

AbstractMethodology and applications of statistical process and quality control in chemical plant. Statistical process and quality control, known respectively as SPC and SQC, presently command considerably attention. Originating with buyers of chemical products, the vocabulary and methodology of this area of expertise are increasingly entering the chemical plant. Appropriate use of these techniques is considered in the present article. A brief presentation of the philosophy of quality assurance in production using the methods of SPC and SQC is followed by a terse explanation of the goals and techniques of SPC/SQC. The applicability of the methods to process engineering is a special problem. Questions of the necessary adaptation and introduction into the conventional procedures of process control are discussed. Instrumentalization of plant with digital process controllers provides a framework for implementation of integrated solutions of such quality assurance systems in production. This is explained with the aid of examples.
Instantisieren pulverförmiger Lebensmittel
Authors: Schubert Helmar 
Published: December 2004

AbstractInstantisation of powdered foods. Instantisation of powdered substances is a form of special technical treatment designed to make the particles dissolve or disperse faster in liquid than the untreated product. This article presents the principal processes for instantising foods, compares their advantages and disadvantages, and discusses them with the aid of examples. In this instantisation of foods it is important to note that additives for improving wettability are used only in limited quantities or not at all, and that aroma components are frequently present which should be preserved unchanged in the product as far as possible. Developments accounting for these demands are shown. Instantising is intended to improve properties which are grouped together as instant properties. Methods used for measuring instant properties are shown and fast method is presented. Depending upon the question raised, it may be necessary to employ different measuring methods. An overall property is appropriate for assessing an instant product; such a criterion can be made up of individual properties such as wettability, dispersibility, and solubility. If an instantisation process is to be assessed or improved, then the individual properties are of interest. Results obtained so far and a simple theory provide information about the most favourable agglomeration size and porosity. The paper concludes with a discussion of the special difficulties encountered in the instantisation of strongly swelling foods and in the determination of their instant properties.
Anwendung der Ähnlichkeitsgesetze bei vollständiger und partieller Ähnlichkeit
Authors: Stichlmair Johann 
Published: December 2004

AbstractApplication of similarity laws in cases of complete and partial similarity. Application of similarity laws frequently permits solutions of difficult problems with the aid of simple model experiments. The first part of this contribution presents the fundamentals of similarity and the limitations which have to be considered in the conception of simple model conditions. The second part demonstrates the application of similarity laws in the case of complete similarity. Since the limitations applying to the conception of model experiments often preclude maintenance of complete similarity, the third part of the article develops strategies for model transfer for partial similarity. The potential of these strategies is demonstrated for several examples from process engineering.
Noch mehr Vorschriften – der Umwelt zuliebe?
Authors: Weizsäcker Ernst Ulrich Von 
Published: December 2004

AbstractEven more regulations – for the sake of the environment. The flood of environmental regulations will continue to swell. Man's rape of nature will not be stopped by a hunt for pollutant nanograms. A gentle ecological tax reform holds more promise. It could trigger the structural change leading to a welfare model which could benefit the whole of mankind without destroying the earth. Nature‐conserving industries and technologies would attract investors. They would move over to the „sunrise side”︁ of the economy. The change of structure would be characterized by an „efficiency”︁ revolution in dealing with natural resources. Environmental protection will be transformed from a cost factor to a benefit factor. A broad social concensus comes into view.
Grenzflächeneffekte bei der Fest/Flüssig‐Trennung
Authors: Roth John‐Edwin 
Published: December 2004

AbstractInterfacial effects in solid‐liquid separations. In this survey the nature and origin of interfacial effects in finely dispersed suspensions are explained. Their influence upon conventional process steps in solid‐liquid separation is discussed. Examples of technical applications of electrokinetic effects in separation processes are reviewed. The state‐of‐the‐art in solid‐liquid separation is characterized by qualitative knowledge about the effects of interfacial phenomena and empirically based electrokinetic separation processes. Knowledge is still insufficient for quantitative calculation of real processes or proper design of technical equipment. The field between interfacial physics, physical chemistry of surfaces and chemical or process engineering is interesting and far‐reaching. If the preceding step of particle generation by precipitation or crystallization is included in a comprehensive research program, a better understanding and a systematic use or prediction of electrokinetic interfacial phenomena in solid‐liquid systems can be expected.