bluuebunny/crossref_metadata_2025 huggingface dataset:
Anlagen zur Sondermüllverbrennung
Authors: Vollhardt Frohmut
Published: December 2004

Plant for incineration of hazardous waste. Owing to the growth in world population and increasing industrialization, a constant rise in the production of industrial waste is to be anticipated. Thermal conversion of the pollutants leads to products which meet the requirements of “T́ Luft” (German technical regulation for air). The conditions required therefore, such as combustion temperature, excess air ratio, retention time, layout of the plant, are explained on the basis of examples. The individual components such as rotary kiln, burners, lances, container feed system, etc. are dealt with, as well as the gas cleaning, slag treatment, and heat recovery systems.
Die Bedeutung der Chemietechnik für fortgeschrittene Technologien zur Stromerzeugung
Authors: Deggim Dietmar , Poller Jürgen , Weinzierl Klaus
Published: December 2004

Significance of chemical engineering for advanced power generation technologies. The demands placed on power plant engineers have altered with the introduction of advanced technologies of power generation, with the classical physical areas of work being increasingly augmented by tasks requiring considerable knowledge of chemical engineering. This change began with the introduction of the desulphurization of flue gases in fossil‐fuel fired power plant and continued steadily with the further development of environmental protection requirements. In addition, demands for reduction of emission in connection with high fuel prices led to the development of new power plant technologies permitting better utilization of input energy. With the aid of examples taken from the whole field of advanced powerplant technology and which range from development and design of non‐polluting and more efficient power plant processes to questions of disposal of power plant by‐products it is shown to what extent conventional powerplant engineering is pervaded by chemical engineering questions.
Die kontinuierliche Druckfiltration – Stand der Technik
Authors: Bott Reinhard , Anlauf Harald , Stahl Werner H.
Published: December 2004

Continuous pressure filtration – new developments. Continuous pressure filtration permitting high throughputs with a low residual moisture content, is a suitable (solely mechanical) means of separating solids systems with high fines contents. It is thus not only technically advantageous but also with regard to energy consumption. The physical fundamentals of pressure filtration are briefly reviewed. A survey of the apparatus follows and the various commercially available models are presented and discussed. Process calculation for the crucial sub‐processes of continuous pressure filtration is then explained. The process optimization shows how the advantages of greater cake formation and reduced residual moisture content characterizing the new development and the disadvantage of increased air throughput determine the economy of this successful separation process in comparison to the common vacuum filtration methods.
Das System sicherheitstechnischer Regelungen für die chemische Industrie im europäischen Vergleich
Authors: Pilz Volker
Published: December 2004

Comparison of safety regulations for chemical plant in Europe. The purpose of this review is to demonstrate the status of the safety of chemical plant in selected Western countries. It is shown what demands on the safety of chemical plant have to be fulfilled, how these demands are transformed into practice, and how their fulfillment is monitored. The starting point is a short overview of the technical requirements in the Federal Republic of Germany and the associated system of approval and monitoring of chemical plant. The corresponding systems in various other European countries are then briefly described. Thus a survey is presented of the measures required for chemical plant safety in Europe, and in particular of the stipulations for operating approval and surveillance.
Sicherheitsmaßnahmen bei der Lagerung chemischer Produkte. Neue Empfehlungen des Verbandes der Chemischen Industrie
Authors: Schäfer Helmut K.
Published: December 2004

Safety measures in the storage of chemical products. New recommendations from the Federation of the Chemical Industry. Accidents in the storage of chemical products are comparatively rare, but can have enormous consequences for the vicinity if large quantities of materials are involved. Hazards are presented by the possibility of combustion, explosion, and thermal decomposition of the products, by the spread of toxic substances, and by the generation of dangerous decomposition products or contaminated fire‐extinguishing water in case of fire. This paper considers the safe storage of explosive substances and protective measures to prevent thermal decomposition, especially of fertilizers. It also reports on the determination of dangerous combustion products and on measures for preventive fire‐fighting measures and retention of fire extinguishing water in the case of plant protection agents. New legislation and a number of proposals by the Federation of the Chemical Industry are described.
Kernenergie – Rohstoff im Energieverbund
Authors: Bürkle Wulf , Taud Robert
Published: December 2004

Nuclear energy – A primary resource in the interconnected energy system. Against the background of renewed discussion of the use and future role of nuclear energy, the terms of reference for nuclear energy will be redefined. By contrast with fossil fuels, nuclear fuels are energy resources which can be used practically only for the provision of energy, and thus directly affect the conservation of more valuable resources. On the basis of the boundary conditions with respect to worldwide energy supply, the contribution of nuclear energy to electrical energy supplies will be illustrated in terms of national and world figures. Prospects will be considered as to the future possibility of further development of proven systems for nuclear energy utilization, while appraising the development and significance of advanced systems which will also open up new markets in the interconnected energy system for the primary resource nuclear energy.
Organische Spurenschadstoffe in Brennräumen von Anlagen zur thermischen Entsorgung
Authors: Hasberg Willy , Römer Rainer
Published: December 2004

Organic trace pollutants in combustion chambers of thermal waste disposal plant. Alongside carbon monoxide, nitrogen oxides, and residual hydrocarbons are “conventional” pollutants from combustion processes, thermal disposal of chlorinated hydrocarbons by combustion may also give rise to organic trace pollutants, such as polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF). Recent advances in our understanding of the kinetics of thermal degradation (pyrolytic, oxidative) in conjunction with information about the degree of backmixing and the residence time characteristics of combustion chambers permit estimation of the influence of temperature, residence time, and oxygen concentration on the formation and degradation of trace pollutants in reals combustion chambers. With conservative assumptions, the maximum parameters required (temperature, residence time) for certain destruction can be obtained. Comparison of the required profile with actual behaviour in combustion chambers demonstrates that the combustion systems used almost exclusively for industrial residue disposal, consisting of a rotary furnace and afterburner chamber, are suitable for disposal of chlorinated wastes providing “normal” operating conditions are maintained.
Perspektiven der Prozeßleittechnik
Authors: Brombacher Manfred , Polke Martin
Published: December 2004

Prospects of process control engineering. The future opportunities for process control engineering in chemistry depend upon the joint efforts of users and manufacturers. It is the user's responsibility to ensure that modern system engineering is demanded – he must pay greater attention to higher functionality of process und production control levels. The manufacturer must take account of these wishes in his development work on future control systems – he must expand his modular libraries and spectrum of components and increasingly supply high performance instruments for rationalisation of project realisation and maintenance. Control systems of the foreseeable future will be measured against these requirements.
Entwicklungen bei der Druck‐ und Vakuumfiltration
Authors: Anlauf Harald
Published: December 2004

Recent developments in pressure and vacuum filtration. The fundamental particle‐technological processes of cakeforming filtration are described together with the present theories of machine design. This involves a discussion of the limitation of the use of theoretical models with regard to technical problems and illustrates the possibilities of their practical engineering application. A systematic analysis of the different types of filter equipment available is followed by a description of the development tendencies in this engineering sector, from which not only a profusion of machine improvements and enhanced process automation follows, but completely new filter apparatus and separation techniques evolve. A widespread transitition from vacuum to pressure filtration has become apparent in the past few years. This particular tendency is also expounded with the aid of selected examples.
Lastprognoseverfahren zur Verbrauchersteuerung und Energiebezugsoptimierung im Rahmen eines Energiemanagements
Authors: Brand Martin , Hüner Peter , Backes Hans‐Michael
Published: December 2004

Load demand optimization using adaptive short‐term load forecasting. Computer aided energy management systems provide information for utility management. In particular, they support the monitoring of powerplant performance, report generation, and load allocation. Load demand control and load allocation are most effective when applied to electrical power usage, since electrical power is difficult to store and peak load demands are usually expensive. Forecasting of the electrical load can be employed to control electrical power supply units and to schedule selected customers. A short‐term load forecasting method which has been programmed and implemented into a computer is described here. The method is based on the characteristics of daily load curves, which are divided into load patterns. Comparison of actual load data with the results of the forecast algorithm shows that the required accuracy of the forecast is attained. Large unexpected load changes cannot be predicted by the load model, since they are not represented in the daily load curves.
Suspendieren im Rührbehälter – Vergleich unterschiedlicher Berechnungsgleichungen
Authors: Kraume Matthias , Zehner Peter
Published: December 2004

Suspension of solids in stirred tanks – Comparison of different calculations. The suspension of solids in stirred tanks has been the subject of various investigations over the last three decades. Though many equations for the calculation of the critical impeller suspension speed were derived and published during this period of time no conclusive descriptions have been achieved. As a consequence, serious problems arose concerning the scaling‐up of the mixer, since the various equations led to completely different designs. Over the last few years new physical models have been developed to improve on this point. These models aimed to reach a better description by considering the fluid‐dynamic process more accurately. This survey presents the actual state of investigation by systematically comparing the results of the latest models. Careful consideration of the experimental conditions gave fairly consistent results. The decisive problem of the scale‐up procedure, however, remains unsolved.
Meßdatenerfassung, Steuerung und Automatisierung bei Apparaten der Mechanischen Flüssigkeitsabtrennung
Authors: Steiner Karl‐Heinz
Published: December 2004

Data acquisition, control, and automation in equipment for mechanical separation of liquids. Mass‐ and energy flow in a production process are accompanied by a flow of information. While data processing has reached a high standard, there is a lack of suitable sensors for acquisition of measured data in solid/liquid separation processes. Methods used for acquisition of data relevant to separation engineering are presented for selected separation equipment, possibilities of control with changing product properties are discussed, and unsolved problems of sensor technology are considered.
Gestaltung destillativer Trennungen unter Einbeziehung thermodynamischer Gesichtspunkte
Authors: Kaibel Gerd , Blaß Eckhart , Köhler Jürgen
Published: December 2004

Design of distillative separation with due consideration of thermodynamic aspects. This article presents a method for development of advantageous distillative separation equipment by starting from the ideal case of a thermodynamically loss free separation and applying simplifications. Process engineering boundary conditions can serve for clear divisions into individual areas. Possibilities of process integration by a direct thermal and mass linkage are indicated, and promising thermal networking measures are mentioned. The procedure is illustrated by examples.
Der Entwicklungsstand der Hochtemperatur‐Verbrennung und Rauchgasreinigungstechnik — dargestellt an zwei laufenden Bauvorhaben
Authors: Kubisa Ryszard , Pollack Helmut
Published: December 2004

State of development of high‐temperature combustion and flue gas purification — illustrated for two current construction projects. The state of the art in rotary furnace combustion plant is described with the aid of two current construction projects for a chemical plant and for a publicly accessible plant. The concepts of the plant are adapted to the waste material to be disposed of, the energy utilisation system, and disposal of the residual materials. Data for the chemical plant indicate higher concentrations and fluctuations in the flue gas constituents. Flue gas scrubbing is accomplished here by quenching, passage, through two rotary scrubbers, and wet electrofiltration. Scrubber liquid is passed to a company purification plant. In the other case, no waste water may occur. A two‐field electrofilter and a two‐stage milk of lime washer are employed. Washing liquid is passed to a waste water treatment unit with vacuum evaporation. Special process engineering measures are necessary to maintain pure gas values even in cases of pronounced concentration fluctuations. Household and special waste incineration are discussed increasingly from the viewpoint of NOx reduction. Possible developments of SCR processes up to use of activated charcoal final purification stages are considered.
Immobilisierte Enzyme – Kinetik, Wirkungsgrad und Anwendung
Authors: Buchholz Klaus
Published: December 2004

Immobilized enzymes – kinetics, efficiency, and applications. Immobilized enzymes represent an important class of catalysts. They are used in many industrial processes, some of which are economically significant. The introduction of other new processes is to be expected, and some examples are briefly described. Certain conditions have to be satisfied for their practical application. They can be summarized in a set of characteristic parameters or properties. The principal properties of a biocatalyst include its kinetics and its efficiency. Both of these are discussed at length. Possible catalyst designs permitting improvement of efficiency with mass transfer limitation are described.
Möglichkeiten computergestützter Konstruktion im Chemieanlagenbau
Authors: Futterer Eberhard , Koopmann Christoph
Published: December 2004

Computer aided design of chemical plant. The effort necessary for computing and design of a chemical plant as well as the preparation of documentation has increased. This is a result of the growing complexity of process design in order to satisfy economic criteria and more stringent safety and environmental requirements. The available time is limited. CAD is one of the tools that assists the plant designer by solving all these requirements. Even at the very beginning of the development of digital computers, their possibilities in graphics electronic data processing were recognized. Since the 1970s, CAD has been utilized in plant design. The use of two‐dimensional or three‐dimensional CAD software is possible. In most cases this is done by using self‐contained dedicated solutions. The integration of the applications promises an increase of productivity. To reach this aim a database management system (DBMS) may be useful. DBMS is also useful as an interface to other computing tools like FEM‐ or process flowsheeting programs. The development of the soft‐ and hardware domain has reached a level of sophistication which makes the economic utilization of CAD possible. Nevertheless, much work still remains to be done.
Produktionsintegrierter Umweltschutz — Verminderung von Reststoffen, gezeigt anhand ausgeführter Beispiele
Authors: Bakay Tibor , Domnick Klaus
Published: December 2004

Practical examples of production‐related environmental protection and volume reduction in residual substances. Minimizing the volume of residual substances produced in chemical production processes is a matter of growing significance. One example is the production of toluylene diisocyanate where HCl gases generated as by‐products are reclaimed by a special HCl electrolysis process and subsequently used in the production of precursors for toluylene diisocyanate. Another example is a combined disposal system for sewage sludge and for a particular chlorine‐laden residue (a chlorinated hydrocarbon). Once this plant had gone on stream it was possible both to reduce considerably the volume of waste to be dumped in the landfill and to discontinue the incineration of the chlorinated hydrocarbon at sea.
Verwertung von Natriumsulfat
Authors: Plessen Helmold V. , Kau Heinz , Münster Gerhard , Scheibitz Wolfgang
Published: December 2004

Utilization of sodium sulphate. Commercial sodium sulphate is usually obtained by crystallization and calcination. Processes for utilizing sodium sulphate that have previously been studied or used are mainly the following methods: electrochemical processes, conversion processes, and reduction processes. At present the first two groups of these three appear more advantageous than the reduction processes, which are technically complex and suffer from the formation of waste gases. The lower energy requirements of the conversion processes offer advantages over electrolytic methods. Only comparative cost estimates for the different processes could help one arrive at a sound evaluation.
Funktionen der Produktionslogistik in der Verfahrenstechnik
Authors: Riemer Joachim S.
Published: December 2004

Functions of production logistics in process engineering. This article demonstrates the evolution of individually developed production‐management systems to a computerized standard information system for the production‐management level. The goal is to introduce this system company wide with in a large enterprise of chemical industry. Preconditions are uniform infrastructure of company data and the economic development and maintainance of the software. It is explained why from the viewpoint of production logistics all parts of the modular system have to be open within themselves and in connections with the corporate‐management level (sales oriented logistics) and the process‐management level.
Sortieren von Mineralsalzen nach spezifischen Eigenschaften
Authors: Singewald Arno
Published: December 2004

Separation of mineral salts on the basis of specific material properties. This survey explains how different specific properties which are „inherent”︁ to the material, such as density, magnetizability, and conductivity, can be utilized to separate mixtures of solids into individual components. As for salt minerals, the differences in their physical characteristics are very small and mostly not significant enough to allow a technical separation. Therefore the selective leaching based on the difference in hydration of the crystal components (ions) has been the predominant process. However, the selective dissolution of a specific type of salt and its subsequent recrystallization requires a high energy input and leads occasionally to environmental problems. It is for this reason that the mechanical procedures of „flotation”︁ and „electrostatic separation”︁ (ESTA‐process) have meanwhile become interesting alternatives. In these processes specific surface properties, i. e. „external”︁ properties, are used for the separation. Non‐utilizable residual liquids, which often occur in the dissolution process and result in waste water problems, can thus be avoided. The principle of these two separation procedures as well as their application to the refinement of crude salts containing potassium and magnesium are described.
Pulvermetallurgische Bauelemente in der Verfahrenstechnik
Authors: Fischer Axel , Arnhold Volker
Published: December 2004

Powder‐metallurgical components in process engineering. Applications of structural parts made by powder metallurgy can be found in nearly all kinds of industries, especially the automotive industry, and the electrical and electronics industry. This paper describes applications of porous P/M materials for chemical technologies. Quite well known are sintered metal filter elements of different sizes in the form of tubes, plates, and cartridges. Porous P/M materials can also be used as flame resistors and silencers, for the dispersion of gases in liquids, for drying processes, and for homogenisation of various products. Almost all technically interesting alloys are available for these elements. New applications for porous metal structures are under development for the use of catalytically active reactor beds in solid bed reactors. It was found that some reactor bed materials are themselves active as catalysts. In such a reactor, the temperature gradient is very small, so that chemical reactions can be controlled much more efficiently.
Meß‐ und Dosiertechnik beim Betrieb von Miniplants
Authors: Schulz‐Walz Axel
Published: December 2004

Measuring and metering technology in the operation of mini‐plants. The technology of measuring and metering in mini‐plants differs considerably from that in production plants. The number of measuring points is greater, the process control system has to be more flexible, and the actuators, sensors, and metering devices require small construction methods. Examples taken from the author's experience serve to illustrate this situation.
Das Zerstäuben als Grundverfahren
Authors: Bauckhage Klaus
Published: December 2004

Atomization as a unit process. Liquid atomization can be classified by three successive steps: disintegration; multiphase flow in the spray; and impact of droplets on the substrate. The most important process parameter is the size distribution of the droplets. By means of this parameter the liquid disintegration process can be related to the different transport phenomena in the spray or to the impacting process. The size distribution of the droplets is not a static parameter but an evolving result of local changes depending on sifting effects, on strand formation, on coalescence, on evaporation, on drying or chemical reaction processes. It is thus essential, for further analysis, to start from local instead of integral size distributions. This will be possible because of the efficiency of new particle sizing instruments with high spatial or temporal resolution. This opens the possibility for differential instead of integral balance. From this one can derive, for the future, higher precision of apparatus design and improved optimization procedures for process design. Finally, appropriate measuring techniques are discussed with regard to their special applicability to liquid atomization analysis.
Instationäre Reaktionsführung zur Modellierung heterogen katalytischer Reaktionen
Authors: Renken Albert
Published: December 2004

Transient processes in modelling heterogeneous catalytic kinetics. It is often difficult to obtain mathematical models to describe the dynamics of heterogeneous catalytic reactors. Kinetics determined under steady‐state conditions are normally not valid for the transient behaviour of catalytic reactions. In order to find valid kinetic models, information is needed about the adsorption‐desorption processes and the formation of intermediates on the surface. To get single step models, experiments have to be carried out under transient or oscillatory conditions. This is discussed for different examples taken from the literature.
Sicherheitsanalytische Vorgehensweise für Alt‐ und Neuanlagen
Authors: Ruppert Kurt Alfred
Published: December 2004

Safety analysis approach to existing and new plant. Technical advances and steadily increasing knowledge, as well as the extension of breakdown ordinances, call for more rational systematic approaches in order to master the current volume of necessary documentation. During development to operational maturity, including modification of plant and processes, various internal and external interdisciplinary teams are involved in setting up and evaluating the safety measures. A comprehensive procedure was therefore developed for new and existing plant which should optimally satisfy demands for clarity, systematic structure, openness for individual process steps, and facilities for updating data.
Wäßrige Stoffsysteme zur Absorption von SO2
Authors: Meckl Stefan , Wunder Rainer
Published: December 2004

Aqueous absorbents for absorption of SO2. The removal of SO2 from flue gases is dominated by processes of absorption with aqueous absorbents. Aqueous systems are favourable in contrast to organic absorbents because the water vapour contained in the flue gas does not interfere with the separation. The transport of gaseous SO2 into the liquid phase and the subsequent transformation into sulfite/bisulfite or sulfate after oxidation is typical for the aqueous processes of absorption. Starting from water as absorbent the addition of various basic agents makes an increase in the absorption capacity of the washing solution possible by several orders. Different solubilities of the agents or the resulting compounds, the dependence of the vapour pressure on the concentration and desired and undesired reactions determine the thermodynamics of the processes. The regenerative sodium salt processes as the Wellman‐Lord (sodium sulfite) process, the Flakt‐Boliden (sodium citrate) process and the sodium phosphate process, the regenerative ammonium sulfite process, the processes producing gypsum and the absorption with oxidation to sulfuric acid are noted. The advantages and limitations of the particular processes are pointed out by means of the vapour liquid equilibria, the solubilities of the salts and the oxidation reactions.
Abscheidung und Messung sehr feiner flüssiger und fester Partikeln in der chemischen Industrie
Authors: Bürkholz Armin
Published: December 2004

Separation and measurement of very fine liquid and solid particles in the chemical industry. In comparison to power stations, the total amounts of waste gases emitted by the chemical industry are fairly low. On the other hand, the complexity of the waste gases and their components is far higher. In the chemical industry we can therefore not be content with one overal concept for gas purification, but must use a multitude of individual solutions. These should be applied at source, i.e. to each separate production plant. To solve an aerosol separation problem successfully and economically, a knowledge of the composition, the fineness and the amount of aerosols is essential. Cascade impactors have proved to be the most suitable instruments for a fractionated measurement of solid and liquid particulates in the super and sub‐micron size range. The results of these measurements make is possible to choose the right equipment and to calculate its performance. Very complex aerosols, e.g. aerosols which are composed both of liquid and solid particles, or of sticky particles, are likely to present the most difficult problems. This article deals with a small selection of cases by demonstrating the problems of separation and the different ways of solving them. It considers among others acid mists and oil mists as well as organic mists, together with very fine particulates from waste incineration plants.
Biologische Denitrifikation nitrathaltiger Abwässer und Grundwässer
Authors: Lompe Dieter , Wiesmann Udo
Published: December 2004

Biological denitrification of nitrate‐containing waste water and ground water. The differing objectives serve to distinguish processes for the treatment of waste water and those for the production of drinking water. In waste water purification, frequent use is made of submerged reactors with deposition and recycling of bacteria. The carbon compounds required by the bacteria are either present in the water or have to be added. If the nitrogen is present as ammonium in the waste water, then there are several different ways of combining nitrification and denitrification reactors. In production of drinking water, both heterotrophic and autotrophic bacteria are used. Since the bacteria are not allowed to enter the supply network, fixed reactors or other reactors with immobilised biomass are used. Sand bed filters are still necessary to retain compounds from the water after denitrification.
Meß‐ und Rekonstruktionsmethoden für tomografische Messungen
Authors: Mewes Dieter , Renz Rudolf
Published: December 2004

Methods of measurement and reconstruction for tomographic records. Tomographic measuring methods are being used more and more frequently in process engineering studies. This technique permits contactless and reactionless measurement of concentration, temperature, and velocity fields. The measuring methods used in tomography are explained in this article. In addition, the paper also considers mathematical methods for the reconstruction of measured field quantities and examines their quality of reconstruction. Numerous applications of tomography are cited.
Die zirkulierende Wirbelschicht als Reaktionssystem für katalysierte Gas/Feststoff‐Reaktionen
Authors: Herrmann Erhard , Weisweiler Werner
Published: December 2004

The circulating fluidized bed reactor for catalyzed gas/solid reactions. For many years circulating fluidized beds (CFB) have been successfully employed for a variety of technical applications, e.g. for dry sorption processes to clean waste gases from alumina electrolysis, waste incinerators, and from coal dust combustion. A new application of the CFB principle, the dry and simultaneous removal of nitrogen oxides and sulfur oxides both from power plant and industrial waste gases has been developed and tested in laboratory‐scale, bench‐scale, and pilot plant facilities and has since reached technical maturity. In this dry DeNOx/DeSOx process, desulfurisation is accomplished by dry sorption with Ca(OH)2 whereas NOx is eliminated by selective catalytic reduction (SCR) with NH3 as reducing agent. To perform the process in a CFB reactor, powder‐like DeNOx catalysts are required. Referring to the simultaneous DeNOx/DeSOx CFB‐process, the main features of highly expanded gas/solid reaction systems as well as the requirements for fine catalyst particles used therein are evaluated. First basic results of the simultaneous NOx und SOx removal from firing gases in the CFB will be reported.
Optische Sensoren für die Bioprozeß‐Kontrolle
Authors: Dremel Bernd A. A. , Schmid Rolf D.
Published: December 2004

Optical sensors for bioprocess control. Bioprocess techniques are an important field in biotechnology. To run processes with high yields of products, to ensure product quality and for process optimization it is essential to acquire relevant process and control parameters quickly with high reliability. Therefore, various types of sensors are used; recently, beside chemosensors, new emphasis has been placed on biosensors for bioprocess control. At the same time optical transducers are gaining in significance. One reason for the increasing interest in optical sensors is the ready availability of fiber optic technologies. The combination of sensor technologies with fiber optics offers many possibilities due to miniaturisation and remote control and therefore meets the special requirements of bioprocess techniques. This review introduces various classes of optical chemo‐ and biosensors for bioprocess control.
Simulatoren zur Unterstützung der Prozeß‐ und Betriebsführung
Authors: Holl Peter , Schuler Hans
Published: December 2004

Simulators for support of process and plant management. Process simulators are increasingly used for plant and process operation purposes. These simulators differ from those used in process design in the user interface, which is identical to the usual operator interface of distributed control systems. The progress of the numerical solution parallels the dynamic behaviour of the real process, and not that of the numerical procedure. The simulation‐supported tasks of plant and process operation are: education of operators, training and instruction of operators, support of plant operation by interpretion of plant states and transitions and by helping to formulate operating instructions. These tasks, the available simulation concepts and examples are discussed in detail.
Bewertung von Füllkörpern und die Grenzen ihrer Weiterentwicklung
Authors: Billet Reinhard
Published: December 2004

Evaluations of Packings and the Limitations of their further Development. The performance of a newly developed packing can generally only be determined experimentally. Tests can be carried out to find the dependence on geometry, load and physical properties of the system, a knowledge of which is required to develop a physical model. Such a model then enables description of the fluid dynamic behaviour and the effectiveness of mass transfer within packed columns and their dimensioning. The model also clearly indicates the possibilities and limitations of further development of packings. Practical examples will confirm the theoretical considerations.
Vorgehen bei der Trocknerauswahl
Authors: Schultz Peter , Hilligardt Klaus
Published: December 2004

Selection Procedure for Dryers. Many different dryers have been developed in the past because of strongly varying drying behavior and widely changing consistency of the drying products. Therefore, a strategy to select the most appropriate dryer for a given problem is needed in order to minimize the cost of process development. A selection procedure consisting of seven steps is presented in this paper. Applying this procedure, a uniform and reproducible selection is obtained.
Abschätzung des Gefährdungspotentials druckverflüssigter Gase
Authors: Strohmeier Klaus
Published: December 2004

Estimation of Potential Danger Arisig from Pressure‐Condensed Gases. Analytical solutions are shown for a specific industrial application in order to estimate the potential danger of pressure condensation of gases. First of all it should be determined in which positions high stresses have to be expected. Afte excluding the case “Bruch vor Leck” (breakage before leak), possible cross sections of leakages can be stated. The laws of thermodynamics laws can be used to determine quantities pertaining to the states of aggregation concerned (liquid/gaseous) may be determined in case of failure. Finally it is possible to determine the size of the ground cradle as well as possible undergrate firing by an investigation of the processes at the liquied pools. Finally we indicated a water sprinkling plant sufficient for handling cases of fire. It was taken into account that the total heat of combustion of the leakage stream will be transferred to the cooling water film.
Berechnungsansätze zur Crossflow‐Filtration
Authors: Ripperger Siegfried
Published: December 2004

Calculation of Crossflow Filtration. Crossflow filtration is the most widely used dynamic filtration process. The suspension to be filtered constantly flows over the filter medium. This counteracts formation of a filter cake and the height of the cake is limited. Reliable design of equipment still relies on the results of laboratory and pilot studies. Increasing use in practice has led to the development of approaches to the calculation of crossflow filtration which are reported in this article.
Kreislaufreaktor mit Konzentrationsregelung
Authors: Löwe Arno , Schnitzlein Klaus
Published: December 2004

The Concentration‐Controlled Recycle Reactor. The scope offered by the concentration‐controlled recycle reactor for elucidatin the kinetics of heterogeneous gas reactions is presented in three contexts: identification of reaction networks; experimental design; and separate determination of changes of activity. Control strategies appropriate for the problem at hand are an essential prerequisite for the application of experimental strategies. In particular, long analysis cycles require appropriate modification of modern methods of control theory. Various model‐based control concepts have been developed and tested by experiment and simulation.
Zirkulationsströmungen und die Vermischung der kontinuierlichen Phase in Blasensäulen
Authors: Millies Marco , Mewes Dieter
Published: December 2004

Circulatory Flow and Mixing of the Continuous Phase in Bubble columns. Bubbles columns are widely used as reactors and mass transfer equipment between gas and liquid or solid phases in many areas of the materials‐transforming industry. The results known from theoretical and experimental research on flow and mixing of the continuous liquid phase and the relative gas content in bubble columns having diameters up to 0.30 m are presented. Evidence is presented for stable circulatory flow. The field of flow of the two phases is then described with the aid of mass and momentum balance equations. These are solved simultaneously by an analytical and a numerical procedure. Non‐linear flow instabilities in the form of several circulation cells are demonstrated as a result of the calculation. In the field of flow of circulation cells the local gas content increases towards the centre of the cell. This is a second‐order fluid‐dynamic effect which has so far eluded description in two‐phase flow using the numerical calculation techniques applied hitherto. The results provide the first possibility of calculating several circulation cells. Theoretical prediction of mixing the continuous phase and the transition from the homogeneous to the heterogeneous flow state in a semi‐industrial scale bubble column has thus become possible.
Teilen und Trennen im Recycling‐Prozeß
Authors: Melchiorre Michele , Güldenpfennig Martin , Löhr Karsten , Zürn Jörg
Published: December 2004

Division and Separation in the Recycling Process. The recycling process comprises a preparation and a reutilization step. This article describes preparation processes which are of importance for the recycling of used products and production wastes. The goal is to provide a clear presentation of the individual processes of division and separation and their mode of functioning with the aid of the systematic classification discussed in the paper. This is important for the overall process of recycling since combinations of various processes are usually employed. A systematic classification thus also provides a basis for new processes and combinations of processes.
Integrierte biotechnologische Produktionsprozesse
Authors: Schügerl Karl , Kretzmer Gerlinde , Freitag Ruth , Scheper Thomas
Published: December 2004

Integrated Biotechnological Production Processes. Manufacturing processes for ethanol and butanol are investigated with respect to reduction of product inhibition by integration with reversed osmosis, pervaporation, extraction, adsorption, flash evaporation, vacuum evaporation, and gas stripping. The integration of lactic acid formation with precipitation, extraction, electrodialysis, ion excange, and crystallization are considered. Adsorption, extraction and crystallization are examined as possible integrated recovery processes for antibiotics production. The possible future integrated use of adsorption, chromatography, membrane chromatography, extraction and flotation for protein production processes is discussed.
Einsatz von Enzymen und Antikörpern in organischen Lösungsmitteln
Authors: Stöcklein Walter F. M. , Scheller Frieder W.
Published: December 2004

Application of Enzymes and Antibodies in Organic Solvents. This review outlines the influence of organic solvents on antibodies, enzymes and their reactions, the different kinds of enzyme‐solvent systems, the various advantages of organic solvents compared with water and how they can be used for synthetic and analytical purposes. Main applications are the enzymatic synthesis of optically pure organic chemicals used as drugs, research chemicals, dyes or fragrants, as well as the analysis of hydrophobic compounds. Examples can be given of bioconversions in organic media by microbial cells and of syntheses with catalytic antibodies. Moreover, the full biotechnological potential of chemically or genetically engineered enzymes can only be exploited if the diversity of possible media is taken into account.
Zum Automatisierungsgrad von verfahrenstechnischen Prozessen
Authors: Schuler Hans
Published: December 2004

Remarks on the Degree of Automation of Chemical Processes. In the discussion of lean production, the degree of automation is very often called into question. Overengineering of automation functions is often presupposed. In order to rationalize this discussion, this contribution outlines the broad spectrum of automation functions, automation principles and automation structures. On this basis, terms like the degree of automation, the connectivity of automation function, etc. are defined. These terms build the basis of the adequate choice of the degree of automation. Factors determining this choice and its consequences are described.
Kombination von mechanischer und thermischer Trocknung
Authors: Thurner Franz
Published: December 2004

Combination of Mechanical and Thermal Drying. The first part of this paper presents the various hardware approaches to combining mechanical and thermal drying. The various solutions are illustrated by applications. The second part addresses cost optimisation in the combination of mechanical and thermal drying. The approach to cost optimisation is illustrated for the example of corn starch.
Sicherheitstechnische Beurteilung von Trocknungsverfahren in der chemischen Industrie
Authors: Maurer Bodo , Riede Thomas
Published: December 2004

Safety Engineering Assessment of Drying Processes in the Chemical Industry. Dried products encountered in the chemical industry are frequently flammable and susceptible to dust explosions. Moreover, some of the products to be dried contain flammable solvents. Since the two product states moist and dry co‐exist in a drying process, the dry potenially explosive solid, flammable solvent vapours, and fuel gases could all be present in a drying plant. A comprehensive safety engineering assessment of the entire drying process is therefore absolutely essential in the planning of new plant and in the examination of existing plant. The starting point and basis of safety engineering assessment is a knowledge of just a few characteristic safety data. If these are known then a decision can be made whether safety measures are necessary and if so what measures can asure safe operation of a plant. This contribution describes the approaches adopted in deciding upon such measures. Recent developments in the area of safety assessment of flammable dusts are included. An example is then presented to illustrate how the joint efforts of experts in the fields of safety engineering and drying technology can assure optimum plant safety, product quality, and cost‐effectiveness.
Wasserstofftechnologie für Antriebssysteme mit Zukunft
Authors: Tachtler Joachim
Published: December 2004

Alongside constant optimisation of conventional motors, BMW has long been conducting basic research on the use of new energy sources and drive systems having significant advantages with respect to emission levels and availability of resources. Electricity stored in batteries or in the form of hydrogen hold considerable promise in the long term. During the present decade, electrically powered cars come into question for short runs; these are characterised by higher efficiency if certain conditions relating to the overall energy balance are met. Significantly greater action radii are possibly only with liquid hydrogen. Although the engineering questions and factors such as storage, safety, and handling can be regarded as basically solved, use of hydrogen‐powered vehicles will initially be in niche areas because of the lack of infrastructure. Hybrid systems to compensate for battery risks and charged with natural gas stored in gaseous (CNG) or liquid form (LNG) will serve important pioneering functions. BMW will market natural gas‐driven vehicles from the end of 1995.
Low Cost and Efficient Photovoltaic Conversion by Nanocrystalline Solar Cells
Authors: Grätzel Michael
Published: December 2004

Solar cells are expected to provide environmentally friendly solutions to the worlds energy supply problem. Learning from the concepts used by green plants we have developed a molecular photovoltaic device whose overall efficiency for AM 1.5 solar light to electricity has already attained 10 %. The system is based on the sensitization of nanocrystalline oxide films by transition metal charge transfer sensitizers. In analogy to photosynthesis, the chemical solar cell achieves the separation of the light absorption and charge carrier transport processes. Extraordinary yields for the conversion of incident photons into electric current are obtained, exceeding 90% for transition metal complexes within the wave‐length range of their absorption band. The use of molten salt electrolytes together with coordination complexes of ruthenium as sensitizers has endowed these cells with a remarkable stability making practical applications feasible. Quite aside from their intrinsic merits as photovoltaic device, the mesoscopic oxide semiconductor films developed in our laboratory offer attractive possibilities for a number Of Other applications. Thus, the first example of a briefly discussed.
Stand der Berechnung bei den Flexibilitäts‐ und Spannungserhöhungsfaktoren von Rohrbögen und deren Auswirkungen auf das Gesamtsystem
Authors: Kauer Robert , Strohmeier Klaus
Published: December 2004

In calculating piping systems components are taken into account by flexibility and stress intensification (SIF) factors. These factors, tabulated in codes, include many simplifications. Considering the component itself this leads to conservative results. Factors can yield wrong data referring to the elasticity of the whole system if the flexibility is computed in this way. Elbows play an enormous role in providing necessary elasticity to accommodate strains caused by temperature or accidental effects. For the elbow the pressureless bend is critical and the stiffness caused by the inside pressure can be ignored. However, this leads to mistakes in the calculation of the piping system elasticity and its reactions with the equipment. For this purpose results from papers are compared with own calculations and a lower limit for the stiffness of pipe elbows is given.
Phasengrenzflächen in Blasenströmungen – Teil 1: Blasensäulen
Authors: Millies Marco , Mewes Dieter
Published: December 2004

Mehrphasig betriebene Reaktoren, in denen eine Blasenströmung vorliegt, finden eine weite Anwendung in der chemischen und energietechnischen Industrie. Zur Auslegung dieser Reaktoren muß die vorhandene Phasengrenzfläche berechnet werden. Sie läßt sich auf die Größenverteilung der Blasen zurückführen. Die Größenverteilung der Blasen ist lediglich mit sehr hohem Aufwand aus den Bilanzgleichungen von Koaleszenz und Zerfallsvorgängen für jede einzelne Blasenfraktion berechenbar. In der vorliegenden Arbeit werden diese Bilanzgleichungen aufgestellt und mit Hilfe einer analytischen Näherungslösung vereinfacht. Als Ergebnis wird eine einzige Bilanzgleichung für wahlweise das mittlere Blasenvolumen, die Anzahldichte der Blasen oder die spezifische Phasengrenzfläche erhalten. In dem vorliegenden ersten Teil werden lediglich die spezifische Phasengrenzfläche und die Größenverteilung der Blasen in Blasensäulen berechnet, und zwar für niedrige Gasgehalte und reine, niedrigviskose Flüssigkeiten, so daß Großblasen und Gaspfropfen noch nicht berücksichtigt werden müssen.