bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tendenzen der Energieversorgung im Hinblick auf die CO2‐Diskussion
Authors: Burkel Wolfgang 
Published: December 2004

AbstractEnergy supply trends with regard to carbon dioxide (CO2). Carbon dioxide (CO2) is regarded as the main cause of the „greenhouse effect”︁ in the atmosphere. Although this problem is well known, the chances for a reduction of CO2 emissions are limited. On the one hand there is no immediate need for action because for the time being the catastrophes are taking place on the computer only. On the other hand population figures and thirst for energy are steadily increasing. Moreover, the possible measures for a reduction of CO2 are limited. Considering the FRG's share of the carbon dioxide concentration, the targeted 25% reduction of CO2 emissions by the year 2005 could be achieved. A large potential of energy saving and CO2 reduction are realized by industrial cogeneration. No further technical development in order to open up this potential is needed because the technically and economically optimal solution is already available with the combined gas turbine process. In order to make use of this potential, the hurdle in the licensing procedure for industrial power plants with an output of more than 10 MW must be removed. In addition, cooperation between the energy supply corporations and industry has to be improved.
Dynamische Prozeßsimulation in der industriellen Praxis
Authors: Wozny Günter , Jeromin Lutz 
Published: December 2004

AbstractDynamic process simulation in industrial practice. Dynamic process simulation is gaining in importance in process development and plant design. In addition to simulation tools for steady state calculations and optimization, recent years have seen increased development of software tools suitable for dynamic simulation. In particular, dynamic process models have been developed for various unit operations at universities and in industry. Application of the models includes synthesis and analysis of the control structure, start‐up and shut down, safety assessments, optimization, and training. In addition, dynamic flowsheet programs analogous to the steady state programs were developed. Wider use of these program systems requires increased flexibility, solving procedures, user interfaces, model library, interfaces to external programs, etc. The present article is intended not only to describe the state of the art and describe some typical applications, but in particular to examine the demands placed on dynamic process simulation and the simulators and to delineate the current limitations of dynamic process simulation from an industrial viewpoint.
Prozeßentwicklung: Von der Exergieanalyse bis zur EDV‐gestützten Optimierung
Authors: Streich Martin , Kistenmacher Hans , Mohr Volker 
Published: December 2004

AbstractProcess development: From exergy analysis to computer‐aided optimisation. In processes in which chemical compositions or states are altered, limiting case analyses based on the first and second laws of thermodynamics are often of use during preliminary process analyses. Since the introduction of computers for process calculations exergy analyses can be carried out in a simple way and weak points in initial designs in the sense of the second law conveniently located. It is also possible to use exergy analyses to make product predictions if transferable practical exergy losses are available from past experience. In low temperature and energy technology the use of suitably defined efficiencies have been of use for many years in eliminating less attractive processing routes and thus reducing the number of possible designs to be investigated. For many decades so‐called „Sum Q/T Diagrams”︁ have been used in low temperature processing to visualize and improve temperature profiles in heat exchanger networks. Recently technology has been further developed into „Pinch Technology”︁. At the end of process development comes the final detailed optimization. The expensive and time consuming sequential way of working used in the past is being gradually replaced today with equation‐oriented simulation and optimization tools such as the OPTISIM program. Expert systems, in principal, offer the chance of supporting the chemical engineer during the initial design of complete and complex processes. However, the experience with such systems to date has shown that a practical solution lies a long way into the future.
Abwasserreinigung bis zur Rezyklierungsfähigkeit des Wassers
Authors: Brauer Heinz 
Published: December 2004

AbstractWaste water treatment for recycling quality. Treatment of industrial waste water is the most effective measure to be taken for the protection of surface waters. This ecological aim must be combined with the economic constraints of industry by designing the industrial process in such a way that production of harmful substances is reduced to an absolute minimum, that transfer of these substances into the carrier fluid, i.e. water, is limited, and that the volumetric flow rate of water required for the overall process is also reduced to the minimum. However, even when all these possibilities which modern process technology offers are successfully applied, a certain amount of harmful substances will still remain in the effluent, causing damage to the environment. This can in the long run only be prevented by developing closed loops for the process water, which include a waste water treatment process, in which mechanical, biological, and physico‐chemical stages are integrated.
Simulation chemischer Reaktionen in turbulenten Strömungen
Authors: Bockhorn Henning 
Published: December 2004

AbstractSimulation of chemical reactions in turbulent flow. This article considers various methods for the simulation of turbulent reactive flow. The description of such flows by the statistical moments of the fluid‐dynamic and thermochemical variables is discussed at length. The modelling problems in the transport equations for the statistical moments are presented and various approaches are examined, especially for mid‐range turbulent reaction rates, and illustrated with the aid of examples by comparison of simulation with experimental results.
CAPE in der Verfahrenstechnik aus industrieller Sicht – Status, Bedarf, Prognose oder Vision?
Authors: Wozny Günter , Gutermuth Wolfgang , Kothe Wolfgang 
Published: December 2004

AbstractCAPE in chemical engineering from an industrial viewpoint – Status, demands, outlook. The use of computers for solving chemical process problems is steadily gaining in importance. Simulation, design, optimization, and synthesis of processes are the main applications. The working group “Process simulation and process design” in the Dechema specialist committee “Use of computers in chemical engineering” has discussed the state of the art of simulation tools. Demands of industry on future tools have been outlined and a new simulator concept presented. If this concept is pursued, then interested companies will have to support development. The article presents background information and is intended to stimulate further interest.
Expertensysteme zur Automation von Bioprozessen
Authors: Hitzmann Bernd 
Published: December 2004

AbstractExpert systems for the automation of bioprocesses. A requirement for the automation of bioprocesses is extensive knowledge – especially practical knowledge. At present this knowledge is supplied by experienced operators during process operation. To process knowledge explicitly with a computer, expert systems are used. So far, there have been only few applications of expert systems for bioprocess supervision and control. This contribution considers the technique of knowledge processing and its application for bioprocess automation. The benefits of expert systems for bioprocess automation are discussed.
Schätzung der Investitionskosten bei der Prozeßentwicklung
Authors: Schembra Mario , Schulze Joachim 
Published: December 2004

AbstractEstimation of Investment Costs in Process Development. This article gives an overview of plant cost estimating; the corresponding data and authors who have described the individual methods can be obtained from the primary literature. The definitions, the present authors, own data and experience gained in Germany, the pros and cons in practice of each cost estimating method are presented. The turnover ratios, capacity ratio exponents, step‐counting methods, and factor methods are emphasized for cost estimating in a situation of comparative uncertainty in the early stages of a project, because unit cost methods and detailed cost estimating are often used for budgeting.
Auslegung von Kontakttrocknern für rieselfähiges, mit Lösungsmittel‐Gemischen beladenes Trocknungsgut
Authors: Schlünder Ernst‐Ulrich 
Published: December 2004

AbstractDesign of Contact Dryers for Free Flowing Solids Loaded with Solvent Mixtures. Vacuum contact drying of free flowing granular material loaded with a binary volatile mixture (iso‐propanol/water) has been studied experimentally in a bench scale disc dryer of 250 mm diameter. Particle diameters ranged from 1 to 5 mm, the pressure was 1250 Pa and the wall temperature was between 50°C and 180°C. Both the drying rate as well as the selectivity of the drying process could be predicted well by the previously developed so‐called heat transfer penetration model together with vapor phase mass transfer correlations.
Dreiphasenextraktion zur Anreicherung bei der Flüssig/Flüssig‐Extraktion von Carbonsäuren
Authors: Hartl Josef , Marr Rolf 
Published: December 2004

AbstractThree‐Phase Extraction – Enhancing Enrichment in Liquid‐Liquid Extraction of Carboxylic Acids. The three‐phase extraction process, a new variant of reactive extraction, has been investigated for its applicability in the separation of organic acids. It has been compared with reactive extraction, liquid membrane permeation and supercritical fluid extraction. These processes are based on the use of amine extractants, which have to be dissolved in non‐polar solvents, for the extraction of carboxylic acids, hydroxycarboxylic acids and aminocarboxylic acids. This paper compares the above processes and considers their possible use for acid extraction.
Neue Methoden der Prozeßanalysentechnik für die verfahrenstechnische Produktion
Authors: Hotop Reiner 
Published: December 2004

AbstractNew Methods for Process Analysis in Chemical Production Processes. Process analysis provides methods and techniques for the continuous and automatic measurement of the composition of the substances handled in chemical production processes. Due to the growing automation of the processes and the necessity of on‐line product quality control as well as the increasing demands on safe and environmentally compatible processing the importance of process analyzers has been steadily growing during the last years. Therefore, existing techniques of on‐line analysis had to be improved, new applications have been realized and new on‐line methods have been established. This paper gives some insight into these fields and illustrates trends by means of some examples.
Ökobilanzen als Instrument der Produktbewertung
Authors: Klöpffer Walter 
Published: December 2004

AbstractEcological Balances as an Instrument for Product Evaluation. The predecessor of today's increasingly important ecological balances was the Limits of Growth Report published by the Club of Rome in 1972. Ecological balances cover mass and energy flows and emissions from the raw materials via intermediates all the way to the end products, as well as waste disposal. This also includes the balance of ecological activity at all stages. The components of ecological balances are goal definition, material balance, action balance, balance evaluation, and optimisation analysis. The advantages of ecological balances are their fundamental acceptance by industry and environmental protection groups, clarity and essentially objective assessment, and the possibility of application to systems, comparison of equivalent products, systems, and services and comparison of null variants. Problems encountered with ecological balances arise, for example, because of frequently inaccessible data basis and because of the system definition.
Radiale Wärmeleitung in durchströmten Schüttungsrohren
Authors: Martin Holger , Nilles Michael 
Published: December 2004

AbstractHeat Transport to the Wall of Packed Tubes. Radial conduction of heat in packed tubes has a crucial influence on yield and selectivity of many heterogeneously catalyzed reactions. In spite of many years of intensive research in the field, there are still tremendous discrepancies between correlations of different origin. Even the standard model using two constant heat transport parameters, which was introduced in the fifties and has since become most widely accepted, has been controversially discussed and called into question. The unsatisfactory state of the art has been an incentive for several groups of researchers to take up this old topic once again. Three parallel experimental investigations on heat transport with air flowing in packed tubes of similar dimensions, electrically heated, steam‐heated, or water‐cooled, were completed in 1991. Comparative evaluation of the results of these three investigations, together with other data from the relevant literature, now provides the first clear answers to some of the questions so controversially discussed in the past.
Rühreinrichtungen in Schneckendosiergeräten — Wirkung und Auslegungsstrategie
Authors: Vetter Gerhard , Wolfschaffner Hubert 
Published: December 2004

AbstractStirring Devices in Screw Metering Equipment – Action and Design Strategy. The accurarcy of metering by screw dosage equipment with or without gravimetric control depends primarily on the flow of material to the discharging screw. In the case of cohesive solids, stirring devices are generally required to prevent bridging. Experimental observations show that flow conditions correlate directly with the intensity of stirring. Mass flow in the metering container and hence optimum constancy of metering are attainable only from certain stirring efficiencies upwards. Cases of interference to metering due to poor flow of solids can be explained and overcome by modified dimensioning. The effects of the principal parameters – geometry and speed of rotation of the stirrer – are studied with the aid of two stirrer configurations – viz. overhead and concentric. Straightforward model calculations provide a mathematical method of estimation for optimum and reliable stirrer dimensioning also applicable to strongly cohesive solids.
Dynamische Belastungen von Zyklonabscheidern bei Anwendung in Blowdown‐Systemen
Authors: Muschelknautz Sebastian , Ruppert Kurt Alfred , Klug Franz 
Published: December 2004

AbstractTransient Loading of Cyclone Separators on Use in Blowdown Systems. On use of cyclone separators for phase separation in blowdown systems, pressure‐discharge systems, and flaring units, considerable momentary liquid forces are often encountered. Only few details are known about the transient loading and dimensioning of such systems. Thus the behaviour of the entering surge of liquid and its effect on cyclone separators has now been studied experimentally and theoretically. Water/glycerol mixtures of various viscosities were used in these model experiments. After entering the separator the liquid immediately forms a compact wall film. It rapidly expands sideways under the action of the centrifugal force and simultaneously decelerates. A two‐dimensional planar mathematical model serves for stepwise calculation of the experimental results with regard to film extension, deceleration, and the resulting transient forces. The results are summarised in the form of design criteria.
Qualitätssicherung bei der Betreuung und Instandhaltung von Anlagen
Authors: Brunberg Raimund 
Published: December 2004

AbstractQuality Assurance for the Service and Maintenance of Chemical Plants. The production facilities must be incorporated into the quality‐assurance system in order to comply with the requirements of a reproducible high product quality. All activities relating to this subject are combined in the “Anlagenwirtschaft”; this discipline stays with the production facility throughout its entire life‐cycle. Attention is focussed on maintaining and improving the production facility during its useful life in several ways, i.e. in terms of quality of the goods produced as well as the production facilities and their components. A system of hierarchically, clearly structured and identified plant components is the prerequisite for this work and for a complete technical documentation of all activities. Supplementary means and tools to effectively master this task are available. They may be of a technical or of an administrative nature.
Heuristisch‐numerisches Beratungssystem für die Reaktorauswahl bei der Verfahrensplanung
Authors: Dröge Thomas , Schembecker Gerhard , Westhaus Ulrich , Simmrock Karl Hans 
Published: December 2004

AbstractA Heuristic‐Numerical Advisory System for the Choice of Reactors in Process Design. Since it has become apparent that neither expert systems nor numerical calculations alone satisfy requirements placed on them in the search for the most suitable industrial reactor, a new type of system, viz. the heuristic‐numerical advisory system, was developed. It utilises both knowledge‐based techniques (production rules and/or frames) and the wide range of calculation tools available in chemical reaction engineering, which are addressed via interfaces. In this way it has become possible to obtain very early reliable information about the later design of an appropriate industrial reactor.
Simulierte Gegenstromchromatographie
Authors: Deckert Petra , Arlt Wolfgang 
Published: December 2004

AbstractSimulated Countercurrent Chromatography. This paper reviews simulated countercurrent chromatography, a separation process that has received only little attention. In contrast to standard batchwise operated chromatography, a periodical mode of operation is used. The feed and collection lines are shifted along the column, thus simulating countercurrent operation of the liquid phase and the stationary solid phase. As a result, higher product yield and higher product purity are obtained. At the same time the amount of solid phase and solvent phase required in comparison to discontinuous chromatography is reduced. Industrial applications have been developed since 1964 by Universal Oil Products (UOP). Large scale separation processes in the petrochemical and the sugar industries are already in operation. On the bench scale this process is used to separate biotechnological products and pharmaceuticals. The need to solve difficult separation problems (isomeric or racemic mixtures, biomolecules, polymers) will encourage further developments. Together with improved process‐simulation tools and process control, simulated countercurrent chromatography will be established as a powerful separation technique with widespread industrial applicability.
Konzept zur Maßstabsübertragung beim Suspendieren im Rührbehälter
Authors: Kraume Matthias , Zehner Peter 
Published: December 2004

AbstractConcept for Scale‐up on Suspension in a Stirred Tank. The relationships derived for the suspension of solids in a propeller loop can be applied to corresponding processes in a stirred tank by means of analogy considerations. Accordingly, the ratio of stirrer power to slip power of laminar flow state is inversely proportional to the vessel diameter. In contrast, the power ratio remains constant in turbulent flow. There is a pronounced transition range between these two limiting states. The author's own experimental studies performed over a wide range of Re numbers for the recycling flow confirm this relationship. The observations presented explain why numerous authors have determined scale‐up rules lying between these two extremes. The experiments shows that the power input for suspension is always significantly greater than the slip power. Under otherwise identical conditions, the necessary stirrer power is smaller by a factor of three for a propeller stirrer than for a disk impeller. The suspension of small solids concentrations can also be approximated by the flow model presented. The somewhat different physical relations valid in this case are substantiated by the author's experiments. The model also provided information relevant to scale‐up when the particle properties are unknown. This is demontrated for an example in a 21 m3 vessel.
Rückvermischung in Blasensäulen mit Einbauten
Authors: Berg Stefan , Schlüter Stefan 
Published: December 2004

AbstractBack‐mixing in Bubble Columns Fitted with Internals. Interals installed in bubble column reactors serve mainly for heat transfer and for influencing (suppressing) liquid circulation. Reinforcement of mixing is observed for experimentally for internals subjected to longitudinal flow, which is attributable in limitation of transverse exchange and the resulting increase of axial eddy dimensions. The experimental findings can be readily described by the axial dispersion model for uniform cross sections and equations are given for estimating the dispersion coefficients of the gaseous and liquid phases as a function of the central liquid circulation velocity. Internals subjected to transverse flow hinder the establishment of a large scale circulatory motion and therefore suppress mixing on the bubble column. Two calculation procedures of differing model depth are presented which permit determination of concentration and temperature profiles in bubble column reactor cascades. Moreover, equations are given for estimating reflux conditions on sieve plates and bundled tube heat exchangers in cross flow which are based on experimental investigations.
Mathematische Modelle der morphologischen Entwicklung von myzelförmig wachsenden Mikroorganismen
Authors: King Rudibert 
Published: December 2004

AbstractMathematical Models of the Morphological Development of Mycelium‐Forming Microorganisms. A significant proportion of the products produced by biotechnology come from mycelium‐forming microorganisms. The highly complex growth and product formation behaviour of these organisms places special demands on process control and on reactor design. This article demonstrates the possible contribution of mathematical models. Particular attention is directed to morphological aspects of an important class of organisms, viz. streptomyces.
Inertgaseinsatz in Füllkörperkolonnen für die Flüssig/Flüssig‐Extraktion
Authors: Braun Christopher , Billet Reinhard 
Published: December 2004

AbstractGas is fed into static countercurrent extractors with the goal of introducing more energy into the binary liquid/liquid system. Increasing the turbulence raises the particle dispersion and thus increases the mass transfer area. This in turn should lead to improved mass transfer. Decision aids for more or less promising use of inert gas in liquid/liquid extraction are presented on the bases of recent publications and the authors' own studies and correlations.
Mini‐Technikumsanlage für Hochdruck‐Polymerisationen bei kontinuierlicher Reaktionsführung
Authors: Buback Michael , Busch Markus , Lovis Kai , Mähling Frank‐Olaf 
Published: December 2004

AbstractMiniaturisierte Apparaturen als Nachbildung kompletter Produktionsanlagen sind für die Entwicklung neuer oder die Modifikationen bestehender Verfahren von besonderem Interesse. In dieser Arbeit soll eine Anlage vorgestellt werden, die es erlaubt, Hochdruck‐Polymerisationen bei kontinuierlicher Betriebsweise durchzuführen. Sie ist vor allem für Reaktionen mit Ethen konzipiert und bietet die Möglichkeit, Homo‐ und Copolymerisationen bei photochemischer Initiierung, etwa mit Excimerlaser‐Licht, sowie auch bei chemischer und bei spontaner (thermischer) Initiierung bei Drucken bis 3000 bar und Temperaturen bis 300 °C auszuführen und detailliert zu studieren [1].