bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membranverfahren in der Umwelttechnik
Authors: Rautenbach Robert , Janisch Ingo 
Published: December 2004

AbstractMembrane processes in environmental protection. Reverse osmosis and ultrafiltration are well established processes in areas like the production of fresh water from sea‐ or brackish water and the treatment of spent cutting emulsions from the metal working industry. New and interesting applications of these processes can be expected in environmental protection and in the treatment of process effluents. For reverse osmosis, the capacities of presently available membranes will be discussed with respect to chemical resistance and to the rejection of organic components in aqueous solutions. Results of experiments with various real‐life systems will be reported: landfill drainage water; protein‐rich process water of the fish industry; recovery of ε‐caprolactam; solvent‐contaminated waste water. These examples demonstrate the economical and engineering potential of membrane processes in treating process effluents. These examples also demonstrate that, in most cases only a combination of membrane processes and a conventional process, like evaporation, will give optimal results.
Struktur und Aufbau moderner Analyse‐Meßeinrichtungen
Authors: Daffner Klaus , Faulhaber Reimar 
Published: December 2004

AbstractStructure and modular nature of modern analytical measuring equipment. Modern analytical instrumentation exhibits excellent adaptability to a wide range of demands arising from the process concerned and the site of application. Optimization of the specific plant structure according to criteria such as performance data, reliability, and economic factors demands a versatile modular system of components for matching the sensors to the process, the process control system, the discharge locations, and the environment. In addition, functions such as handling, control, and monitoring are steadily increasing in importance.
Werkstoffverhalten in Wasserstoff
Authors: Gráfen Hubert , Kuron Dieter 
Published: December 2004

AbstractProperties of materials in hydrogen. The various kinds of damage to metallic materials of construction induced by hydrogen are described and their effects illustrated. A detailed account is given of the individual processes leading to the adsorption and absorption of diffusable atomic hydrogen and also of the various damage mechanisms, such as embrittlement, hydride formation, blistering and cracking, delayed rupture, and stress corrosion.
Wirtschaftlicher Einsatz von korrosionsbeständigen Werkstoffen im Apparatebau
Authors: Köcher Reiner 
Published: December 2004

AbstractEconomic use of corrosion‐resistant materials in plant construction. Particular attention must be paid to choice of materials, constructional design, and production processes in order to achieve optimum, favourably priced solutions in the planning and construction of equipment for chemical plant. In the choice of materials, special stainless steels and non‐ferrous metals of recent development, should be given special attention, particularly with respect to cost‐saving substitution of expensive quality materials. The use of clad steel sheet fulfills requirements for optimum design of components for many applications; however, the economic use of these composite materials must be compared with that of solid materials from case of case – due attention being given to the strength and working properties of the materials. The lining of equipment with high‐quality corrosion‐resistant materials is also an economic production method but its limited applicability should be borne in mind. Welding is a cost‐relevant production method. Use of welding techniques with high fusion rates, which is feasible for some high quality materials, can lead to considerable cost savings. Economic production of curved plates from Superferrit Remanit 4575 is possible by welding together individual rounds.
Schweißtechnische Gütesicherung im Chemieanlagenbau mit Beispielen aus der Praxis
Authors: Gawlas Georg 
Published: December 2004

AbstractWelding quality assurance in plant construction illustrated by examples from practice. The welding quality assurance concept of a chemical company is shown by way of practical examples. In particular, the importance of quality monitoring by the owner operator is stressed. This must be carried out conscientiously because, in present‐day chemical plant construction, availability plays an important economic role, and also because safety is given the very highest priority.
Verminderung des Cadmium‐Gehaltes von Rohphosphaten und Mineraldüngern
Authors: Von Plessen Helmold , Schimmel Günther 
Published: December 2004

AbstractReducing the cadmium content of crude phosphates and mineral fertilizers. Crude sedimentary phosphates generally contain cadmium together with traces of other heavy metals. These Cd traces generally end up in fertilizers produced from the crude phosphates. Processes have therefore been developed to separate the Cd from the crude phosphate or from the crude phosphoric acids arising therefrom as intermediates. In this way, the Cd content of the crude phosphate can be reduced to less the 10% of its original value, and to 50% thereof by extractive treatment with acidic calcium nitrate solution. Older calcination processes for crude phosphate have been improved to give residual Cd contents of 10 to 50% at temperatures of 800 to 1000°C. Cadmium can be removed almost quantitatively from crude phosphate by means of dialkyl dithiophosphoric acid esters by extraction, binding to adsorbents, or ion flotation. Cadmium can be extracted from crude acids in high yield by long‐chained amines. After partial neutralization of the crude acids, precipitation as cadmium sulphide is also possible.
Herstellung von Aminosäuren mit Hilfe biotechnologischer Methoden
Authors: Leuchtenberger Wolfgang , Plöcker Ulf 
Published: December 2004

AbstractProduction of amino acid by biotechnological methods. Amino‐acids are needed for human and animal nutrition, pharmacy, cosmetics, agriculture, and industry. Particular interest focusses on the production of protein‐forming ß‐amino acids. Among the four methods of industrial production – chemical synthesis, extraction, enzymatic synthesis, and fermentation – the biotechnological process is attracting increasing attention. A joint development programme of KFA Jülich and GBF Braunschweig led to development of the enzyme membrane reactor (EMR) at Degussa. This reactor performs enzyme‐catalysed racemate resolution to produce L‐amino acids on a laboratory and pilot scale. The concept has meanwhile been successfully implemented in production and can be used for other applications too. Fermentation processes are being tested for more complex reaction mechanisms.
Hafttechnik – Grundlagen und Anwendungen
Authors: Zorll Ulrich 
Published: December 2004

AbstractAdhesion science – Fundamentals and applications. Films of paints and adhesives, both polymeric organic substances, must be connected to the pertinent materials strongly enough, so that the bond can withstand ordinary climatic and mechanical stress. At the stage of applying the liquid paint or adhesive, good wetting will be the basis for high adhesive strength after film formation. Moreover, it is necessary to attain a balance in the effectiveness of the forces at the interface, related to the polar und unpolar groups of either adhering material. Adhesion strength can also be improved by selecting an appropriate surface profile, of which roughness as such is not so important as shape. The profile should secure sufficient clamping of the film even under conditions occuring in practice, for example at high shear stress as generated in the case of shock loading. For defined combinations of material, these rules and guidelines are generally sufficient to obtain optimum adhension strength at the interface.
Von der Schadstoffquelle zur Schadstoffsenke – neue Konzepte der Müllverbrennung
Authors: Vogg Hubert 
Published: December 2004

AbstractFrom pollutant source to pollutant sink – Novel concepts of solid incineration. Until a few years ago, solid waste incineration plants were considered to be major sources of pollutant emission. Meanwhile, by enhancing the effectiveness of combustion and by integration of modern flue gas cleaning techniques, solid waste incineration now leads with regard to emission reducing engineering measures. Harmful effects on the environment no longer originate in the stacks of these plants. Recently, pollutants enriched in flue gas cleaning products have caused disposal problems. These problems can be solved by concentrating the harmful inorganic constituents, above all mercury and cadmium, to a still higher level through wet chemical extraction and removal of the resulting concentrate from the process. Organic pollutants can be conveniently destroyed by thermal treatment. Despite all the objections there are good chances of using solid waste incineration as a pollutant sink and hence as a tool helping to protect our environment.
Energieträger aus nachwachsenden Rohstoffen
Authors: Austmeyer Klaus , Röver Helmut 
Published: December 2004

AbstractEnergy from regenerable raw materials. In the long run, some of the agricultural areas in the Federal Republic of Germany will no longer be needed for food production, and could therefore be used for growing raw material plants in order to provide various sources of energy, such as wood, rape seed oil, ethanol, methanol, and biogas. With this indirect use of the solar power accumulated in the plants, the overall expenditure for fossilized fuel energy to produce these energy sources is lower than the amount of primary energy that can be substituted. Based on the assumption that 20% of farmland will be used to grow regenerable raw materials, it would be possible to replace approximately 7 million tons of coal equivalent (SKE) by wood or approximately 4 million tons of coal equivalent (SKE) by ethanol from sugar beet or methanol from wood. In the case of alcohol production from sugar beet, the total energy efficiency including the regenerative part of energy of about 74%, is lower than in the ethanol synthesis. At present, use of biomasses as an energy source is feasible only in a few rare cases, and can only be achieved if the regenerable raw materials are considered as an alternative to surplus food production or to the strategy of gradually using less acreage for growing food.
Gas/Flüssig‐Reaktoren
Authors: Mersmann Alfons 
Published: December 2004

AbstractGas‐liquid reactors. The gas hold‐up in bubble columns increases in proportion to the gas flux density in the homogeneous flow regime and rises less than proportionally in the heterogeneous flow regime. Both the gas and the liquid axial dispersion coefficient increase with gas flow. Gas phase dispersion becomes more intensive with increasing liquid viscosity, while liquid dispersion drops slightly. Experimental results for mass transfer in low viscosity liquids show that the two‐range turbulence model best fits experimental data. When aerating highly viscous Newtonian and non‐Newtonian liquids, mass transfer in the liquid phase is well described by known relations valid for very low bubble‐Reynolds number and very high Schmidt number.
Die Rolle der Sensoren in der Verfahrenstechnik
Authors: Raab Helmut 
Published: December 2004

AbstractThe role of sensors in process engineering. The principal function of sensors in process engineering is to obtain information about an ongoing process in order to ensure optimum management of that process in terms of process engineering. New methods of measuring conventional parameters, and recent advances in instrumentation technology, have improved ways of obtaining information and so influenced the interpretation of process engineering installations. Statistical evidence confirms a sharp increase in the number of sensors, and the increasing tendency to record flow and level measurements and product composition. Changes occurring in process engineering determine the requirements sensors have to meet and the ways in which they can be used. Microelectronics makes it possible to extend the range of functions available and the information content. This is giving rise to an new generation of sensors which are not only helping to meet the higher measurement standards required but are also making modern sensor technology more „user friendly”︁, specially for maintenance.
Anwendung des Temperatur‐Meßsystems QuaT in der Prozeßmeßtechnik
Authors: Schaudel Dieter 
Published: December 2004

AbstractApplication of the QuaT temperature measuring system in process measurement engineering. Resistance thermometers and thermocouples are today's standard in industrial electrical temperature‐measurement techniques. Their weaknesses, which were not so important, have become obvious with the advanced application of digital data loggers and data control units. These weaknesses include: uncertainty wether such a measuring line is predictable; the transmitter has to be defined with regard to the parameter, for each individual application; and transfer of the measured signal from the field to the central unit needs considerable effort. A temperatur measurement system has now been introduced which does not have these disdvantages, because it is using a piezoelectric resonator as a sensor element. Thus signal processing is „digital”︁. Advantages and disadvantages of both kinds of instrumentation are presented. The suitability of the new system, also regarding costs, is confirmed by the results from five industrial test programs.
Moderne Elektrolyseverfahren für die Wasserstoff‐Technologie
Authors: Sandstede Gerd 
Published: December 2004

AbstractModern electrolysis processes for the hydrogen technology. This survey discusses all processes of water electrolysis after having emphasized the central role, which hydrogen plays in chemical technology and which it might play in a hydrogen economy, with the aid of some historical considerations and applications in hydrogen energy systems. In order to understand the development potential of the processes, the physico‐chemical fundamentals as well as the problems of the engineering of water electrolysis are summarized in a structural form. Not only are the purely electrochemical processes reviewed by a classifying systematic, but also all other (indirect) processes, which include an electrochemical step. The following direct processes are discribed: conventional and advanced alkaline water electrolysis, medium temperature cells, acid water electrolysis, membrane water electrolysis, water vapor electrolysis with proton conductive solid electrolyte and high temperature water electrolysis as well as the indirect processes: electrochemical raw material gasification, thermochemical‐electrochemical hybrid processes, photochemical‐electrochemical hybrid processes, and the photoelectrochemical cleavage of water.
Ist hydrodynamische Modellierung tragfähig für die Auslegung von Schwerkraftabscheidern ohne Einbauten?
Authors: Blaß Eckhart , Löbmann Arthur , Meon Walter , Rommel Wolfgang 
Published: December 2004

AbstractIs hydrodynamic modelling a sound approach for the design of gravity settlers without coalescing aids? Liquid/liquid dispersions occur in many chemical operations. Normally they have to be broken down again. This is accomplished by the flowing together of the droplets (coalescence) to a coherent phase. In practice simple gravity settlers without any coalescing aids are used for this purpose. In such settlers the dispersion is separated by the density difference between the phases, while a dense dispersion layer forms at the interface between the dispersion and the clear mother phase. The present paper deals with the modelling of such gravity settlers. First, the models describing the coalescence process of single drops are reviewed and analyzed. A physical notion of the coalescence process is derived thereform. Afterwards the models for the droplet coalescence in dense dispersions taken from the literature are presented and discussed. In conclusion the chances and limitations of the present settler models are indicated by quantitative comparison of selected models. A computer program specially developed for this purpose is presented.
Kombination von Eindicker und kontinuierlichem Druckfilter zur Verbesserung von Fest/Flüssig‐Trennprozessen
Authors: Anlauf Harald 
Published: December 2004

AbstractCombination of thickener and continual pressure filter to improve solid/liquid separation processes. The fundamental concept of the proposed process combination, which basically entails a division of the whole solid/liquid separation stage into sub‐stages, is presented. The influence of the suspension's concentration on the formation and dewatering of filter cakes under ideal conditions is then discussed, after which possible deviations of the product from the ideal behaviour are described along with their influence on the process results. Actual engineering conditions are then considered, and the consequences of a suspension pre‐thickening for the results of a drum filter are demonstrated. The conditions necessary for satisfactory results are discussed. Based on the results of conventional filtration, the further increase in filter efficiency occurring on avoiding the conventionally unavoidable gas throughput by a new process is explained. Finally a conceivable combination of apparatus for performing the described process is sketched.
Produktionsintegrierter Umweltschutz – Verpflichtung der Chemischen Industrie
Authors: Lipphardt Günter 
Published: December 2004

AbstractProduction‐integrated environmental protection – commitment of the chemical industry. Production‐integrated environmental protection represents the optimum goal in attempts to reduce the amount of non‐utilisable substances to a minimum by chemical, physical, biological, and chemical engineering improvements in the overall process. This ranges from avoidance and reduction of residues in individual processes to the utilisation of residual substances in other production processes, also outside the perimeter fence. Combustion of organic by‐products with a high calorific value is also included in this concept as thermal utilisation. Only those waste products should be dumped on disposal sites which have no other use and cannot be disposed of by combustion. It is important to note that chemical production cannot exist without emission; it can only approach this ideal more or less closely.
Produktionsintegrierter Umweltschutz – Verwertung von Reststoffen
Authors: Lenz Heinz , Molzahn Martin , Schmitt Dieter W. 
Published: December 2004

AbstractProduction‐integrated environmental protection – Utilization of residues. Chemical plants as well as coal‐fired powerstations utilize chemical reactions in order to produce materials or energy. Most of these reactions additionally produce gaseous, liquid, or solid residues. It is the main objective of production‐integrated environmental protection to use these residues as suitable feedstocks in order to reduce environmental pollution and lower the consumption of raw materials. Several examples from the BASF Group will show how, by crossing the borders of the respective plant, reasonable solutions for material, or at least energetic, utilization of residues can be achieved. As a result of permanent efforts in production‐integrated environmental protection over many years and despite increasing outputs the emissions of the chemical industry have been continuously reduced.
Mechanische Aktivierung von Festkörpern
Authors: Heegn Hanspeter 
Published: December 2004

AbstractMechanical activation of solids. The main reasons why solids are comminuted are to decrease particle size, to create new free surfaces, and to increase reactivity of solids. In most cases, the comminution process is connected with crystal lattice transformations. A part of the energy supplied increases the energy level of the lattice. Consequently, a new theory of the energy balance of comminution processes is given and verified by experiments. It is shown, by some examples, that the individual mill parameters as well as the different mill types lead to characteristic changes of the crystal lattice of solids. Energy input by comminution is of great importance because it mainly influences the attainable degree of mechanical activation of solids.
Entwicklungslinien der Schüttgutdosiertechnik
Authors: Vetter Gerhard , Wolfschaffner Hubert 
Published: December 2004

AbstractDevelopments in dosage of bulk solids. Dosage of bulk solids is a fast developing field of process‐ and production automation. Developments are determined directly by the current demands of the production process, with the properties of the bulk solids and the process itself playing an important role. A survey of proven dosage techniques from the viewpoint of the operating principles, properties, applications, and limitations demonstrates the great variety of problem solutions. An important difference between the individual dosage techniques is the nature and accuracy of mass limitation. The most accurate techniques are the gravimetric dosage methods, with discontinuous weighing giving the greatest accuracy. Developments have been greatly influenced by the state of weighing cell techniques, weighing electronics and computer engineering. The development of measured data acquisition and processing of control, and of instrumentation are described, compared, and assessed. A trend towards system responsibility and development on the part of manufacturers is noted. A accurate dosage of bulk solids requires constant flow of the solids and finely adjustable control devices. The principal interferences in bulk solids flow and measures for their avoidance are shown by means of examples. Successful solution of dosage tasks ultimately requires agreement between manufacturers and processors with regard to definition, determination, and control of dosage accuracy during calibration and during long term operation.
Scale‐up‐Probleme bei der experimentellen Verfahrensentwicklung
Authors: Hofen Willi , Körfer Martin , Zetzmann Klaus 
Published: December 2004

AbstractScale‐up problems in experimental process development. The experimental process development of a new product can be performed in test facilities of varying dimensions. Small miniplants from a laboratory scale up to larger pilot plants, in which a few tons of product per day can be produced, are used. The scale‐up factors, the risks involved in process and construction design, and a possible necessity of a limited production are important criteria for the size of the first technical realisation of the new process. The following examples highlight some special problems and their solutions in the experimental process development. Whereas a process, involving mainly fluids can be developed relatively well in a miniplant (laboratory scale), it is normally necessary to work on process development for a solid product involving difficult solid handling in a larger pilot plant. At the end of the paper some other scale‐up criteria for process design are explained.