bluuebunny/crossref_metadata_2025_split huggingface dataset:
Umrüstung auf Membranzellen in der Alkalichlorid‐Elektrolyse vor dem Hintergrund der FCKW/CKW‐Diskussion
Authors: Staab Rudolf , Bergner Dieter , Scheibitz Wolfgang 
Published: December 2004

AbstractConversion of Alkali Chloride Electrolysis Plant to Membrane Cells in the Face of the On‐going CFC/CHC Discussion. The environmental discussion on chlorine‐containing chemical products such as chlorinated hydrocarbons, chlorofluorocarbons and PVC is resulting in lower demand or even abandonment of production in certain areas. This in turn is leading to reduced production or even to the shutdown of alkali chloride electrolysis plants. In view of this general situation and the high capital expenditure required for switching from mercury cells to membrane cells, the change is not economically feasible despite the considerable savings in energy consumption it would bring.
Grundsätze der Qualitätsarbeit im Unternehmen
Authors: Sommer Ernst 
Published: December 2004

AbstractFundamentals of Quality Work in Companies. The new quality consciousness originating in Japan, and meanwhile adopted by the industrialised countries of the west, goes far beyond mere adherence to agreed technical criteria. All departments of a company are to be included in the quality assurance system in order to prevent errors from arising in the first place. The introduction of quality assurance systems must be instigated by top management and go down from there to all employees. Above all in the case of companies with highly complex structures, an internal customer‐supplier relationship should be developed which corresponds to that between the company and its customers. It makes good sense to incorporate existing activities into the quality assurance system. Since customer demands change with time, quality improvement must be approached as a dynamic process.
Die Entwicklung der Destillationstechnik im 19. Jahrhundert
Authors: Deibele Ludwig 
Published: December 2004

AbstractDevelopment of Distillation during the 19th Century. Up until the end of the 18th century distillation plant consisted only of an evaporation and a condensation unit. The rectification column is an invention of the early 19th century. This article surveys these developments and the advances in alcohol distillation made up to the end of the 19th century. Developements in France, England and Germany are considered separately since different starting materials were used for alcohol production in these three countries. In France the starting material was wine, in England grain, and in Germany potatoes. Wine could be fed directly to the rectification column. Grain first had to be transformed into grain mash before being transferred together with husks to the distillation apparatus. The highly viscous potato mash containing potato pieces and skins produced by a similar process proved particularly hard to handle. The widely varying properties of these raw materials led to development of different equipment in the different countries.
Tendenzen in der EG‐Umweltschutzgesetzgebung und Auswirkungen auf die chemische Industrie in Deutschland
Authors: Hezel Carl 
Published: December 2004

AbstractTrends in the Environmental Legislation of the European Community and their Consequences for the German Chemical Industry. Environmental legislation from the EC has changed considerably in recent years. The directives of the early eighties contained mainly general guidelines and generous limit values. Due to the need for unanimous voting for the decisions stricter thresholds were not achievable. They had relatively small impact on Germany because that country's internal legislation was more stringent. There is now a new trend which gives cause for concern. Many elements of the latest directives do not match the German legal system and lead to stringent conditions. This is due to the fact that they have to be implemented in addition to existing legislation: Much written information and evidence of performance are required, relating to e.g. the installations and the management of the company. As a consequence there will be further complications in the approval procedure for chemical plant.
Persönlichkeitsbildung durch das Studium
Authors: Stephan Karl 
Published: December 2004

AbstractPersonality Development through University Studies. At present universities are often accused of contributing insufficiently to the personality education of their students. There is a demand for a more comprehensive personality education during university studies. This runs counter to contradiction to demands for a shorter duration of studies, because personality education takes time. This paper examines what personality education means and to what extent the study of engineering sciences can contribute to it. It demonstrates that the study of engineering disciplines imparts many values contributing to the personality education. Some other features of the development of a person are embedded in the structure of that person and can only be communicated in part through education. Engineers are usually not well trained to assess the social consequences of their technical actions. It is therefore suggested that some universities concentrate on the education of generalists who acquire a broad knowledge in the engineering sciences and a high social competence.
Prototyp eines wissensbasierten Programmsystems für die Systemsimulation
Authors: Eickhoff Jens , Futterer Eberhard 
Published: December 2004

AbstractPrototype of a Knowledge‐Based Program System for System Simulation. The present article describes a new approach for merging numeric simulation techniques and knowledge‐based methods for process simulation. In a first step the potential of such a combined technology is outlined, concerning both knowledge‐based user support in handling and application of simulation codes as well as the support of the engineering task for chemical process development. An analysis of implementation techniques outlines, how an adequate integration of numeric and knowledge‐based software modules can be achieved by adoption of the object oriented programming paradigm. The resulting requirements for the modelling of knowledge and the corresponding inference mechanisms are explained and a software prototype is presented by which this knowledge‐based simulation technology is currently being evaluated and refined using a case study from aerospace domain.
Entwicklungen bei der Lösungskristallisation in den letzten Jahren
Authors: Ulrich Joachim 
Published: December 2004

AbstractRecent Developments in Crystallisation from Solution.Although there have been no great leaps forward in the design of plant for crystallisation from solution in recent years, our understanding of growth rate dispersion, the extension of the two‐step model of crystal growth to a three‐step model when required, and also convenient modelling approaches for crystal morphologies and the development of tailor‐made additives have nevertheless greatly advanced our knowledge of crystallisation processes. Substantial divergencies in the measured values of crystal growth rates in the past decade can often be explained by paying due attention to the measuring methods and the purity of the substances as well as the nature of the solvent. Comparison of results obtained by modelling should always prove more satisfactory when heat effects are considered whenever this is necessary. The possibilities of crystallisation plant design are greatly enhanced by the availability of reliable data as a basis for calculation and when influencing crystal shape can provide downstream processes with a better product.
Wandel in der Verfahrenstechnik — Anforderungen an die Ausbildung
Authors: Frey Walter 
Published: December 2004

AbstractChemical Engineering in a State of Change – Educational Requirements. The structural change taking place in the chemical industry will influence future requirements for chemical engineers and hence also the training of these engineers. Owing to the advancement of the knowledge base of chemical enginnering, greater emphasis will in future be placed on substance‐orientation and a holistic approach. This will allow chemical engineering to enter new areas. There will also be greater demands for such additional abilities as teamwork sensitivity, and creativity. The training of chemical engineers should take account of these developments.
Kritische Anmerkungen zu den Werkzeugen der Verfahrensüberarbeitung
Authors: BeßLing Bernd , Ciprian Jürgen , Polt Axel , Welker Rüdiger 
Published: December 2004

AbstractCritical Remarks on Tools for Process Revision. The revision of production processes is based on data, results and experience gained from a wide range of tools and instruments. It is therefore important to critically examine the limits and meaningfulness of these tools and instruments as they apply to process revision. Following a description of a normal revision procedure, the limits and meaningfulness of the information obtainable by modelling, experiment and full‐scale operation are discussed as a basis for process revision. Particular emphasis is placed on fundamental operational information obtained from production plant. In addition, tools specially developed for process revision are presented and evaluated. The common theme of these tools is the ability to provide improved material balances of operating processes. Some of the better known process evaluation tools are also considered. The main feature of these tools is the abstraction of the task of individual unit operations as a starting point for possible process improvements.
Schaum und Schaumzerstörung – ein Überblick
Authors: Pahl Manfred H. , Franke Dirk 
Published: December 2004

AbstractFoam and Foam Breaking – A Review. Many technical processes produce foams which complicate the performance of a given process or even make it possible. Foam breaking, therefore, becomes necessary. This paper outlines well known and new methods of foam breaking as well as the breaking principles. For the example of sprinkling, the influence of selected parameters on the destruction efficiency and the formation of secondary foam can be demonstrated. After a discussion the properties of foam, stabilizing and destabilizing effects, possibilities of foam characterization and foam avoidance are presented.
Hydrogele: Verwendungsmöglichkeiten und thermodynamische Eigenschaften
Authors: Thiel Joachim , Maurer Gerd , Prausnitz John M. 
Published: December 2004

AbstractHydrogels are crosslinked macromolecules in which at least part of the network consists of hydrophilic groups. Hydrogels are widespread in nature; for example, plant and animal tissues consist mainly of hydrogels. They are becoming increasingly important in chemical engineering, e. g. as ion excahngers, in gel chromatography, and for dewatering. Hydrogels swell or shrink in aqueous solutions. Such swelling equilibria are the basis for most of their applications. This article surveys the applications and also the swelling behaviour of hydrogels. It covers both the termodynamic principles and methods for correlation of experimentally determined swelling equilibria for nonionic and ionic hydrogels. The swelling of a hydrogel results from the interplay of intermolecular interactions in aqueous, partly ionic polymer solutions on the one hand and elastic properties of polymeric networks on the other. It ist therefore hardly surprising that it is presently impossible to quantitatively predict phase equilibria and the swelling behaviour of such hydrogels from a few basic data. However, it is possible to describe the swelling of hydrogels with straightforward approaches reported in the literature if a number of the parameters of these approaches are adapted to experimentally determined swelling data.
Reaktorintegrierter Umweltschutz in der chemischen Produktion
Authors: Zlokarnik Marko 
Published: December 2004

AbstractIn the series of environmental protection measures avoidance‐utilisation‐disposal the greatest priority in the chemical industry is given to the first, particularly since it is the chemical reaction which predetermines the nature and extent of subsequent work‐up steps and the environmental burden. This reactor‐integrated environmental protection leads to a process reappraisal which is divided into searches for alternative synthetic routes, reactants, reaction media, and catalysts. However, one of the principal tasks concerns reexamination of the thermodynamics and kinetics, not only to ensure optimised concentration and temperature control but also to examine the possibility of integrating separation operations during the course of reaction with the aim of shifting equilibria.
Wärmeaustauscher aus nichtmetallischen Werkstoffen, insbesondere für korrosive Medien und Rauchgase
Authors: Suhr Ludwig 
Published: December 2004

AbstractCorrosion‐resistant heat exchangers made of plastics can open up a new field of heat recovery from power station exhaust gases, even below the dew point of sulphuric acid. This article reports about plant constructed and experience gained. In addition: special heat exchanger geometries for increasing power generation efficiency and avoiding acid aerosols are also presented.
Berechnung und Modellierung komplexer Phasen‐ und Reaktionsgleichgewichte in wäßrigen Elektrolytlösungen
Authors: Luckas Michael 
Published: December 2004

AbstractIn many natural and industrial processes the thermodynamic properties of aqueous electrolyte solutions play an important role. Systems of interest are frequently characterized by a large number of components and possible reactions. Due to low solubility, some reaction products precipitate as solids. The thermodynamic modelling therefore implies the computation of simultaneous phase and chemical equilibria. The minimization of the Gibbs free energy and the K‐value method are powerful algorithms for numerical computation and permit the simulation of complex electrolyte systems. The behaviour of the liquid solution has to be described by suitable activity coefficient models.
Wiederaufladbare Zink/Luftsauerstoff‐Batterien
Authors: Haas Otto , Müller Stefan , Wiesener Klaus 
Published: December 2004

AbstractThanks to their high specific energy content, their cost‐favourable materials, and their good environmental compatibility, zinc/atmospheric oxygen batteries are of interest as energy source for electrotraction. Rechargeable zinc/atmospheric oxygen batteries are particularly suitable for this application. Use of atmospheric oxygen as reactant requires a semi‐open construction with stringent demands on the materials of the interface. The state of the art of variants of this battery type and the principal components (air‐diffusion electrode, zinc electrode, electrolyte) are presented in detail and discussed in this review article.
Optimierung verfahrenstechnischer Prozesse
Authors: Keil Frerich J. , Keil F. J. 
Published: December 2004

AbstractMethoden der Optimierung werden in der Verfahrenstechnik häfig angewandt. Parameteridentifikation oder die Optimierung von Anlagenverschaltungen sind nur zwei Beispiele. Es werden Methoden der linearen und nichtlinearen Programmierung mit und ohne Nebenbedingung dargestellt, wobei eine Beschränkung auf in der Praxis besonders bewährte und verbreitete Verfahren erfolgt. Probleme der globalen Optimierung werden besprochen. Von den heuristischen Algorithmen wird die Linnhoff‐Pinch‐Methode erwähnt. Abschließend werden einige Anwendungen der Optimierung in der Verfahrenstechnik dargestellt.
Simulierte Gegenstromchromatographie – eine effiziente Technik zur Herstellung optisch aktiver Verbindungen im industriellen Maßstab
Authors: Schulte Michael , Kinkel Joachim N. , Nicoud Roger‐Marc , Charton Frédéric 
Published: December 2004

AbstractSeit der Einführung stabiler chiraler stationärer Phasen (CSP) für die Hochleistungsflüssigchromatographie (HPLC) wird die präparative Chromatographie mehr und mehr als ein effizientes Verfahren zur Herstellung enantiomerenreiner Verbindungen im industriellen Maßstab angesehen. Die aus der Natur der klassischen Chromatographie resultierende Diskontinuität des Verfahrens, verlangt die Umwandlung des Prozesses in einen kontinuierlichen Betrieb. Fine intelligente Lösung dieses Problems ist mit der simulierten Gegenstrom‐chromatographie (SMB) gelungen. Diese ermöglicht die kontinuierliche Trennung eines Gemisches in zwei Komponenten mit hoher Reinheit und hoher Ausbeute. Zudem werden im Vergleich zur klassischen Chromatographie große Einsparungen an mobiler und stationärer Phase erzielt. Durch die Komplexität des Verfahrens bedingt, ist eine Simulation der chromatographischen Bedingungen erforderlich. Es werden das Prinzip des Verfahrens, die technischen Ausgestaltungen der Anlagen und das Verfahren zur Ermittlung der Betriebsparameter vorgestellt. An einem Beispiel wird ein Vergleich zwischen verschiedenen chromatographischen Verfahren durchgeführt.
Optimierungsstrategien für Batchreaktoren
Authors: Uhlemann Jens , Garcia Valérie , Cabassud Michel , Casamatta Gilbert 
Published: December 2004

AbstractThe successful development of a new fine chemical always comprises the selection of a synthesis process including the appropriate reactants, solvents, catalysts and so on. The operating strategy ‐ i.e. the operating conditions ‐ of the synthesis has to be established in order to obtain optimum quality. The present paper reviews the optimization strategies for batch reactors in fine chemical industries.
Tomographisches Messen der relativen Phasenanteile in zweiphasigen Strömungen fluider Phasen
Authors: Reinecke Nicolas , Boddem Martin , Petritsch Georg , Mewes Dieter 
Published: December 2004

AbstractA new tomographic process measures the spatial phase fractions in slug flow and possesses high positional and temporal resolution. The measuring method is based on the electrical conductivity of the flowing fluids, which is measured between numerous parallel wires. The individual measurements are directly proportional to the relative liquid content. With the aid of an iterative reconstruction procedure they permit calculation of the phase fractions. The quality of reconstruction is improved by consideration of a priori knowledge. The temporal resolution is 0.009 s and the spatial resolution less than 0.1% of the flow cross‐section.
Extraktion – ein historischer Rückblick
Authors: Blass Eckhart , Liebl Thomas , Häberl Michael 
Published: December 2004

AbstractThe extraction of plants with the aid of water is one of the oldest techniques known to humankind for obtaining aromatic principles and medicaments from these sources. Extraction vessels excavated in Mesopotamia can be dated back to around 3500 BC, and Sumerian clay tablets describing the preparation of medicaments which were found in the same region date from around 2100 BC. The Greek and Roman civilisations of antiquity inherited extraction together with other skills from their predecessors, and this knowledge was passed on to Christendom by Arabian scholars. Europe of the Middle Ages saw the development of pharmacy, medicine, and mining, as well as the sugar industry, all of which made active use of extraction with a wide range of solvents. Whereas technological applications of extraction were thus steadily increasing prior to the industrial revolution, the equipment used underwent hardly any changes up the end of the 18th century. It was only in the 19th century that active development of equipment, materials, and modes of operation started, while successful combination of theory and practice and treatment of extraction by the methods of engineering science had to wait until the 20th century. This article reports about equipment, solvents, and extraction processes up to the beginning of the present century, and places then in a political and sociological context.
Multifunktionale Reaktoren
Authors: Hoffmann Ulrich , Sundmacher Kai 
Published: December 2004

AbstractIn multifunctional reactors chemical and physical unit operations are carried out simultaneously. Traditionally chemical reaction engineering considers mass and heat transfer processes in combination with chemical reactions. However, the term multifunctional reactor points to an extended and more detailed view of process integration. By application of these reactors it is possible to save investment and/or operating costs, to meet environmentally relevant limits or to improve process safety. Mechanical and thermal unit operations are especially good candidates for integration with a chemical reaction step. In this contribution selected multifunctional reactors are presented, which were either adopted from the literature or are the subject of the authors' own research activities.
Rechnergestützte Problemlösungsstrategien in der mechanischen Flüssigkeits‐abtrennung
Authors: Uhlemann Jens 
Published: December 2004

AbstractThe decision‐making process in an expert group involved in solid‐liquid separations cannot be covered by a monolithic methodology or software. The analysis of typical problem‐solving processes shows the experts' knowledge requirements and turnover. According to the proposal in the present paper, these requirements are covered by a three‐tier computer‐based knowledge supply comprising databases, simulation programs and hypertexts. Software details of a typical simulation program for continuous vacuum filtration on belt filters are presented. In addition, a hypertext‐based electronic handbook on equipment scale‐up and design is described. This handbook represents an easy‐to‐use reference manual for empirical knowledge in the expert group. The above‐mentioned tools enhance work quality and efficiency in the expert group; knowledge is pre‐served and easily accessible. The tools allow rapid training of newcomers. In a crossfunctional team effort, the solid‐liquid separation expert can provide rapidly well‐founded informations.
Technische Konzepte zum Recycling von Homogenkatalysatoren
Authors: Behr Arno 
Published: December 2004

AbstractTechical Concepts for the Recycling of Homogeneous Catalysts. Homogeneous transition metal catalysis will only be used by industry if almost complete recycling of the expensive catalyst is guaranteed. This can be realized by using the liquid‐liquid two phase technique in which the catalyst stays in one liquid phase and the products in another. This contribution gives a general survey of this technique and different ideas for its technical realization.
Einsatz von Membrantrennverfahren in der chemischen Industrie
Authors: Knauf Rüdiger , Meyer‐Blumenroth Ulrich , Semel Joachim 
Published: December 2004

AbstractMembran Processes in the Chemical IndustryIn the chemical industry (less so in the pharmaceutical industry), membrane technology is still at an early stage of acceptance. However, in this field too, it is gaining increasing importance as an innovative, reliable and, first and foremost, cost‐effective alternative to conventional processes. This trend is evidenced by a variety of new plants which have been installed in recent years, and also by the rapidly growing interest in this technology shown by production and design departments. This article gives an overview of the industrial importance of membrane processes in chemical and pharmaceutical production and also presents some typical examples of applications in this field by describing plants which have already been installed and are now in production.