bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraktion mit überkritischen Gasen in direkter Kopplung mit der Dünnschicht‐Chromatographie. Anwendungsmöglichkeiten auf dem Naturstoffgebiet
Authors: Stahl H. C. Egon , Schilz Winfried 
Published: December 2004

AbstractDie direkte Kopplung einer Mikro‐Extraktionsanlage für überkritische Gase mit der Dünnschicht‐Chromatographie ergab, daß sich zahlreiche, auch stärker polare Substanzen auf diesem Wege aus Proben abtrennen lassen. Die bisherigen Ergebnisse wurden in „Faustregeln”︁ zusammengefaßt. Sie erlauben es, die Extrahierbarkeit von Substanzen mit überkritischem Kohlendioxid im Bereich bis 500 bar annähernd vorherzusagen. Auch über die Fraktionierungseffekte in Abhängigkeit vom Druck erhält man Anhaltspunkte. Praktische Beispiele zeigen die Anwendungsbreite des Verfahrens, speziell auf dem Gebiet der pflanzlichen Drogen.
Struktur und Funktion von Membranen für die künstliche Niere
Authors: Strathmann Heiner 
Published: December 2004

AbstractIn der vorliegenden Arbeit werden neue technisch relevante Membran‐Stofftrennverfahren und die dabei benutzten Membranstrukturen diskutiert. Die Herstellung von Polymermembranen und der Einfluß der einzelnen Herstellungsparameter auf ihre Struktur und Funktion wird beschrieben. Verfahrenstechnische Probleme, besonders die Konzentrationspolarisation und ihre Relevanz bei der Entwicklung einer künstlichen Niere, werden diskutiert.
Die Entwicklung der Verfahren zur Herstellung von Acetylen durch partielle Oxidation von Kohlenwasserstoffen
Authors: Bartholomé Ernst 
Published: December 2004

AbstractSchon die ersten industriellen Anlagen zur Erzeugung von Acetylen durch partielle Oxidation von Kohlenwasserstoffen hatten den Beweis erbracht, daß das BASF‐Verfahren technisch sicher und wirtschaftlich befriedigend arbeitet. Als Folge dieser Erkenntnisse setzte für mehr als 15 Jahre eine stürmische Entwicklung im Bau neuer, großer Acetylen‐Anlagen nach diesem Verfahren ein. Ende der sechziger Jahre kam diese Entwicklung zum Stillstand. Das lag nicht am Aufkommen von konkurrierenden Verfahren zur Erzeugung von Acetylen aus Kohlenwasserstoffen, an denen es nicht gefehlt hat. Der Grund ist vielmehr darin zu suchen, daß es in steigendem Maße gelungen war, die wichtigsten Folgeprodukte des Acetylens aus billigeren Rohstoffen, insbesondere Olefinen, herzustellen.
Vor‐ und Nachteile verschiedener Rentabilitätsmaße bei Wirtschaftlichkeitsberechnungen
Authors: Ostertag Gerhard A. 
Published: December 2004

AbstractDie zunehmende Bereitstellung von Planungsdaten durch Informationssysteme und der Trend zum kalkulierten Risiko erfordern, daß sich der Ingenieur in Zukunft erneut mit den Methoden dieses Randgebietes auseinandersetzt. Der Beitrag soll zeigen, daß die Methoden nicht zusammenhanglos nebeneinander bestehen, sondern untereinander konsistent und voneinander ableitbar sind. Er zeigt die uneingeschränkte Anwendbarkeit und somit die Überlegenheit moderner finanzmathematischer Methoden, bei denen Einschränkungen allein aus der Verfügbarkeit von Informationen resultieren. Gleichzeitig wird versucht, terminologischen Schwierigkeiten in ordnender Weise zu entgegnen, was einerseits für eine interdisziplinäre Zusammenarbeit unerläßlich ist und zum anderen einschlägige Literatur, vor allem auch angelsächsische, erschließt.
Die Energieversorgung von Chemieanlagen mit direkt zwangsgekühlten Energiekabeln und Kühlrohren aus HDPE: Stand und Entwicklungstrends
Authors: Konrad Klaus‐Dieter , Cornils Boy , Birnkraut Hans‐Walter 
Published: December 2004

AbstractDie Verlegung zwangsgekühlter Energiekabel in Kühlrohren aus Niederdruck‐Polyäthylen bietet im Chemieanlagen‐Neubau oder ‐Umbau besondere Vorteile: die hochwirksame direkte äußere Zwangskühlung erlaubt eine preiswerte, ökonomische und platzsparende Trassenführung, die Verwendung flexibler Rohre aus Niederdruck‐Polyäthylen eine in jeder Hinsicht sichere und allen Gegebenheiten des Geländes folgende Verlegung. Daneben kann eine rationelle, kombinierte Versorgung von Chemieanlagen mit Wasser/Kühlwasser und elektrischer Energie erreicht werden.
Erfahrungen mit großtechnisch eingesetzten Bioreaktoren
Authors: Sittig Wolfgang , Heine Helmut 
Published: December 2004

AbstractAm Beispiel von Fermentationsreaktoren werden die Erfahrungen beim praktischen Betrieb von Bioreaktoren beschrieben. Ausgehend von den Leistungsanforderungen moderner Anlagen werden insbesondere die Probleme der Steriltechnik und die Meßtechnik besprochen. Aus der Fülle der patentierten Reaktor‐Modifikationen haben nur einige wenige den Sprung in die halbtechnische Untersuchung geschafft, der Einsatz moderner Neuentwicklungen im Produktionsmaßstab ist bisher nur in Randbereichen erfolgt. Einige aussichtsreiche Varianten werden diskutiert und vergleichbare Betriebsdaten mitgeteilt. Nach wie vor werden für großtechnische Reaktionen überwiegend begaste Rührkessel verwendet. Die Gründe für ihre dominierende Stellung werden diskutiert und die Trends für ihre Weiterentwicklung aufgezeigt. Die Entwicklung der letzten Jahre bedeutet fast eine Renaissance des begasten Rührkessels. Er gestattet nicht nur die alternative Umstellung der Anlage auf mehrere Produkte, sondern auch eine Erhöhung des Wirkstofftiters um eine Zehnerpotenz und eine Verschiebung der scheinbaren Zähigkeit der Kulturbrühen um das Dreifache und mehr.
Moderne Flüssig/Flüssig‐Extraktoren–Übersicht und Auswahlkriterien
Authors: Brandt Hans Walter , Reissinger Karl‐Hermann , Schröter Jürgen 
Published: December 2004

AbstractModern liquid/liquid extractors – survey and selection criteria. Various types of industrial extractors are presented with emphasis being laid on a description of the apparatus and the problems met with in their practical application; theoretical considerations are largely avoided. An attempt is made to categorize and assess individual extractors. For this purpose the efficiencies and loadings are given, which enable a rough comparsion to be made since such data are very strongly dependent in the properties of the substances to be processed. A scheme taking into consideration the most important parameters and based on available experimental results and operational experience simplifies the task of preselection of a suitable extractor for a new seperation problem. Final choice and design of extractor to be used under particular conditions are possible only by experiment.
Verwertung der schweren Rückstands‐Fraktionen im Hinblick auf den Umweltschutz
Authors: Mundo Klaus‐Jürgen 
Published: December 2004

AbstractUtilization of residual oil fractions in the light of environmental protection. The conversion of residual fractions produced in refineries into raw materials of chemical industry offers an alternative to fueling in thermal power stations, which is noteworthy from an energetic as well as environmental point of view. Processes may be compared using some criteria as yardstick, which have been derived from the request for pollution abatement. The modern process of high‐pressure gasification keeps in line with those criteria. It is considered as a source of large quantities of hydrogen and carbon monoxide. Furthermore a thermal power plant is considered, in which the flue‐gas desulphurization is replaced by fuel desulphurization operated at high pressure. A comparison of processes shows typical productions and consumptions as well as thermal efficiencies. The remaining environmental pollution is also tabulated. Thermal efficiencies of chemical processes are remarkably higher than that of the power plant process.
Vergleichende Untersuchung der Festigkeitsberechnung von Druckbehältern unterschiedlicher Bauart
Authors: Schwind Hermann , Solmecke Klaus 
Published: December 2004

AbstractComparative study of stress analysis for pressure vessels of various constructions. The present article is intended to demonstrate the need for constant comparison of design, strength, and production aspects in the construction of modern high pressure equipment. The various constructions of pressure vessels should be compared with regard to: the diameter ratios and resulting weight savings at otherwise identical operating pressure, internal diameter, and strength; boundary curves, showing the economically still justifiable diameter ratio for a given operating pressure and strength; limiting values and fields of application in which construction and transport problems also require consideration.
Wärme‐ und Stofftransport in Tankflammen
Authors: Brötz Walter , Schönbucher Axel 
Published: December 2004

AbstractHeat and mass transfer in pool flames. Theoretical and experimental concept of heat and mass transport in liquid pool flames are reviewed. The heat and mass transfer processes in the interface between flame and liquid fuel are outlined, and the concept of the burning rate as a parameter for the quantitative description of a pool fire is discussed. The methods of calculation and experimental results concerning flame length and flame shape as well as buoyancy forces are described. In pool flames, a lower region (flame neck) and an upper region (flame plume) are distinguishable. Both the flame neck and the flame plume show a flow pattern obtained from short or long periods of observation. The flow patterns of the flames have been measured by the techniques of equidensitometry and Laser‐synchronous‐interferometry. The flow pattern observed over a short period of time gives an insight into the eddy field of the pool flame whose turbulence is measured. The flow pattern observed over a long time is obtained from time averaged values of temperature, heat radiation, concentration etc.
Aspekte zur Schadensverhütung und Risikobetrachtung in der chemischen Industrie
Authors: Joschek Hans‐Ingo , Dehler Jürgen , Helmstädter Gerhard 
Published: December 2004

AbstractAspects of loss prevention and consideration of risks in the chemical industry. When dealing with questions of safety and loss prevention, a distinction must be made between the terms danger, safety, source of danger, and risk. Relevant sources of danger are tabulated. The risk in breakdowns is discussed at length in terms of the factors incidence rate and damaging effect with the aid of recent literature. Access to incidence rates is provided by logic diagrams which are of great value on a qualitative basis for loss prevention. The basic requirements for a quantitative treatment are considered and the problems arising with quantitative results are discussed. Loss prevention can be achieved by reducing incidence rates and/or damaging effects.
Vorbeugende und konstruktive Schutzmaßnahmen gegen Gas‐ und Staubexplosionen
Authors: Scholl E. W. , Fischer P. , Donat C. 
Published: December 2004

AbstractPreventive and constructional measures against gas and dust explosions. Even during the planning of plant for processing potentially explosive products, process and constructional aspects should be accompanied by investigations on the products conducted with a view to obtaining as complete a picture as possible of the danger of explosion of the materials. These studies provide the basis for estimates of explosive risks in the plant and for decisions concerning the extent to which safety measures against the occurrence of explosions or the effects of explosions can be implemented. An explosion‐proof plant can be accomplished by preventive measures hindering an explosion, or by constructional measures suppressing the effects of an explosion. This paper is intended to be of assistance in the choice of explosion‐proofing equipment.
Einsatzmöglichkeiten und Wirtschaftlichkeit von On‐line‐Systemen in der Industrie
Authors: Stüdeli Bernhard 
Published: December 2004

AbstractFeasibility and economic aspects of on‐line systems in industry. Starting with a summary description of the principal practical aims, data are given on the magnitude of the resulting material to be dealt with and thus on the extent of the operation. After a comparison with the most important traditional aids, the advantages to be gained from new technology are shown, such as reduction of time losses, more favourable operational running costs, as well as more extensive possible combinations and more precise selection. The main requirements appear to be a knowledge of numerous sources of information and frequent, if possible daily, updating of data as well as thorough professional understanding. Because of the preponderance of literature references and smaller amount of direct data (factual data or hard facts) the main task in decision making and in supporting established decisions lies in relieving the qualified key staff of tedious and laborious literature searches.
Verfahrensverbesserungen in der industriellen Praxis — Ziele, Methoden, Beispiele
Authors: Steiner Rudolf 
Published: December 2004

AbstractProcess improvement in industry – aims, methods, examples. In the last few years the improvement of existing processes has gradually gained more importance than the development of new ones. The main objectives of process improvement are the optimum utilization of raw materials and energy and the fulfillment of increasing environmental and safety requirements. These objectives and the methods used in improving processes are illustrated with the aid of various examples from industrial practice.
Quantitative Risikoanalysen in der chemischen Industrie
Authors: Joschek Hans‐Ingo , Helmstädter Gerhard , Dehler Jürgen , Langensiepen Hans‐Werner 
Published: December 2004

AbstractQuantitative risk analysis in the chemical industry. Consideration of risks on a qualitative basis is a useful, generally applied tool in safety engineering. However, attempts to quantify risk create problems. Quantifying studies have been published concrning nuclear and chemical plant, storage tanks, and port and transport facilities. At present, attempts are also being made in Germany to demonstrate that quantitative risk analysis is also possible for chemical processes. Instead of relying on past empirical values, an ab initio determination of risk from model calculations is being tried. A theoretical basis is already available for such calculations. However, practical execution and simplification of the complicated methods leads to numerous problems which are discussed in this paper. With the aid of selected examples attention is focussed on the following problems: (1) consideration of maintenance; (2) quality of starting data; (3) predictive power of weak‐point analysis.
Wärme‐ und Stoffübertragung in Festbetten
Authors: Gnielinski Volker 
Published: December 2004

AbstractHeat and mass transfer in packed beds. The calculation of heat transfer in packed beds and between packed beds and the surrounding walls requires knowledge of numerous different parameters, since heat is transferred by conduction as well as by radiation and convection. If it is necessary to distinguish between particle‐ and fluid‐temperature the heat transfer is described by a system of coupled differential equations. The differential equations are based on a heterogeneous model. The currently accepted transport coefficients needed to solve the differential equations are reviewed. The simpler case in which distinction between fluid and particle temperature is unnecessary is described by the homogeneous model. Only two transport coefficients are needed here for the calculation of the temperatures and the transferred heat, namely the effective conductivity of a packed bed and the wall heat transfer coefficients. Literature references to these coefficients are reported.
Prozeßsystemtechnik — Gedanken zu Notwendigkeit und Inhalt einer akademischen Lehre
Authors: Blaß Eckhart , Gelbe Horst , Muthmann Erhard , Vogel Ludwig 
Published: December 2004

AbstractProcess System Engineering. Thoughts on the need for and curriculum of an academic course of instruction. The raw material, energy, and environmental situation, international competition, and the decline in product innovation are increasingly casting doubts on conventional processes and their realization. Hence, in the future‐training of chemical engineers a reasonable amount of time should be devoted to the study of system facets, i. e. to thinking and acting in complex systems of interrelationships. Under the general leading „Process System Engineering”︁ those activities are discussed which are relevant to the design and planning of chemical engineering systems (process synthesis) and the mathematical analysis of a given system (process analysis). Process synthesis is the creative facet of project planning involving several methodologies. Process analysis embraces steady‐state and non‐steady state mass‐ and energy‐balancing and the mathematical evaluation of various process alternatives on the basis of operating costs and investment as well as the simulation of operational behaviour and optimization of process configurations using mathematical models. The following article discusses a selection of points which should play an important part in the teaching of process synthesis and process analysis and considers some examples by way of illustration.
Die Abscheidung von Partikeln aus Gasen in Faserfiltern
Authors: Löffler Friedrich 
Published: December 2004

AbstractParticle collection by fibrous filters. Technically employed fibre filters can be classified according to their construction and application in two major groups: deep bed filters and fabric filters. Approaches to the calculation of the collection efficiency for both types of filters start from a clean nondusted filter layer. From this one examines only the initial state, which is especially critical, while the degree of collection as a rule becomes better with increasing dust accumulation. Various models are available for the calculation of the pressure drop. The initial pressure drop for deep bed filters can be calculated with the help of the resistance model. Especially important are those estimates, which for purification filters describe the pressure drop or the gas flow with increasing dust accumulation, because these equations can serve directly for the dimensioning of filter plants. Of courese, characteristic permeability values for filter fabric and dust layer must be determined beforehand. The possibilities and problems of these calculations, as well as open questions, will be discussed.
Kosten der Staubabscheidung
Authors: Reinhardt Heinz , Löffler Friedrich 
Published: December 2004

AbstractCosts of dust removal. The costs incurred in ensuring efficient removal of dust in industrial processes are directly related to current legal regulations. A tightening up of these regulations can necessitate the selection and operation of more highly efficient separators, improvement in the efficiency of dust removal with existing equipment, or the installation of a revolutionary and comprehensive gas cleaning technique. The economic aspects of these alternative approaches are outlined with the aid of three examples taken from different branches of industry. Of paramount importance in all dust collection problems is the “dedusting situation”, defined by the interconnection of production process, dust collector and requisite auxiliaries. There are also further technical and economic parameters. The most important economic parameters are capital investment and operating costs, or total running costs per year. A formula for the computation of annual costs is established and the annual costs for two dust removal techniques are analysed.
Sauerstoff‐Verzehrkathoden für die Chloralkali‐Elektrolyse
Authors: Yeager Ernest , Bindra Perminder 
Published: December 2004

AbstractOxygen‐consuming cathodes for alkali chloride electrolysis. Considerable energy saving can be accomplished in alkali chloride electrolysis if an oxygen‐consuming cathode is used in place of one liberating hydrogen. An overall cell potential saving of ca. 1 V is possible. In particular, diaphragm cells are suitable for air cathodes owing to the high purity of the catholyte. A possible altenative to the use of an in‐situ air cathode is the use of hydrogen/air fuel cells, such as the phosphoric acid system of United Technologies, for electrochemical utilization of the hydrogen. The operating temperature is then 200 °C at most. The waste heat can be utilized for evaporation of, e.g., diaphragm cell caustic soda; this acid system also requires no prior air purification. However, the gain in energy is only two thirds of that accomplished with an in‐situ cathode. At present, great effort is being invested in the development of favourably‐priced air cathodes with long lifetimes in concentrated caustic soda; apart from platinum, numerous transition metal complexes are being tested for this purpose.
Methanisierung kohlenmonoxidreicher Gase beim Energie‐Transport
Authors: Harms Hans , Höhlein Bernd , Skov Allan 
Published: December 2004

AbstractMethanization of carbon monoxide‐rich gases for energy‐transport. The partners of the NFE project (Nukleare Fernenergie, Remote nuclear energy) – Kernforschungsanlage Jülich GmbH (Germany) and Rheinische Braunkohlenwerke AG, Köln (Germany) – in collaboration with Haldor Topsøe A/S, Copenhagen (Denmark), have investigated various problems of the methanization of synthesis gases rich in carbon monoxide. Preliminary results obtained from trial operations with the pilot‐scale methanization plant ADAM I at KFR Jülich and from the catalyst‐development project at Haldor Topsøe A/S are reported. A detailed account is given of the catalyst investigations carried out on the Haldor Topsøe pilot plant for the further development of the TREMP process for SNG manufacture and of the complementary catalyst investigation in the NFE project at the Union Rheinische Braunkohlen Kraftstoff AG and the Kernforschungsanlage Jülich GmbH for the optimization of the methanization process in the remote energy system EVA‐ADAM. In the pilot plant ADAM I, a three‐stage methanization process with product gas recycling and maximum temperature of 600 °C utilizing synthesis gas from methane vapour reforming (EVA) has been demonstrated for the first time. In further experiments to be carried out with ADAM I the influence of operating irregularities on the behaviour of the methanization plant and the dynamics of the remote energy system will be investigated, data for the preparation of mathematical models collected, new components tested, and the process of methanization optimized.
Verfahren zur Kristallisation aus Lösungen
Authors: Schliephake Dietrich 
Published: December 2004

AbstractCrystallization from solution. In general the processes occurring in crystallizers have previously been treated in only summary and phenomenological manner because only little was known about the joint action of the individual steps. An attempt has therefore been made, in the present survey, to examine the relationship between the physico‐chemical properties of the relevant system, the process chosen, and engineering economics.
Naßoxidation — Ein Beitrag zum Stand der Technik
Authors: Perkow Helmut , Steiner Rudolf , Vollmüller Helmut 
Published: December 2004

AbstractWet air oxidation – Present‐day technology. Wet air oxidation is a process of flameless “incineration”, especially of organic compounds, in an aqueous phase with air or other oxidants at relatively high temperatures and pressures. Existing applications such as the sanitizing of sewage sludge, processing of sludges from pulp production, and regeneration of activated charcoal are described. At present, waste water purification by wet air oxidation is being propagated. Difficult degradation of some pollutants enforces the use of temperatures up to 330°C and pressures up to 250 bar. The high investment costs for such plants, which require materials like titanium or hastelloy to handle corrosive wastes, often result in higher operating costs than with other methods, in spite of low energy consumption. Once the effectiveness of existing plants has been proved, especially regarding corrosion problems, rising demands for waste water purification may render wet air oxidation increasingly important.