bluuebunny/crossref_metadata_2025 huggingface dataset:
Wirtschaftliche Einsatzbereiche von Wärmepumpen‐ und Mehrstufenschaltungen in der Rektifiziertechnik
Authors: Lüdeker Heiner , Gelbe Horst
Published: December 2004

Economic applications of heat pumps and of multi‐column heat integrated systems in distillation processes. The influence of relevant parameters (e.g. relative volatility, flow rate, pressure) on the economics of distillation plants involving heat pumps and heat integrated columns is simulated by a computer program. The different structures of possible energy supply (cogeneration heat‐power plant, direct heating) have been taken into account in the models employed. The areas of economic application of the various energy conserving systems are shown in diagrams. These allow a preliminary selection of the most economic variant. The application of heat pumps outside the field of cryogenic engineering is restricted to some special cases like the separation of closeboiling mixtures. In those cases, where a minimum plant size and steam price is exceeded heat integrated columns promise an economic advantage, provided that cheaper configurations of direct heat recovery are impossible.
Prozeßvergleich von Umkehrosmose und Elektrodialyse am Beispiel der Nitrat‐Entfernung aus Grundwässern
Authors: Rautenbach Robert , Kopp Wilfried , van Opbergen Gert , Peters Thomas , Hellekes Rainer
Published: December 2004

Comparison of reverse osmosis and electrodialysis for removal of nitrate from groundwater. Reverse osmosis and electrodialysis are membrane processes suitable for desalination of aqueous solutions. Both processes were tested on a pilot scale in a waterworks for removal of nitrate from groundwater. A combination of the processes was also considered with a view to very high concentration of the residual water. The article shows how information gathered from long‐term reverse osmosis trials and the experiments with the electrodialysis plant with industrial membrane dimensions can provide a basis for safe design of large plants. Treatment costs for large capacities are shown for the example of the above feed water. The advantages and disadvantages of reverse osmosis and electrodialysis are compared. This comparison demonstrates fitting applications of the two processes in other areas (chemical industry, sewage treatment).
Der Durchbruch in Adsorptions‐Festbetten: Methoden der Berechnung und Einfluß der Verfahrensparameter
Authors: Kast Werner , Otten Wilhelm
Published: December 2004

Breakthrough in adsorption beds: Methods of calculation and influence of operation parameters. Calculation of the breakthrough curve of a fixed bed adsorber is performed numerically for industrial applications. Calculation methods are known for solution of the four coupled differential equations and can be performed within a considerable but acceptable time on todays powerful computers. Nevertheless, the present article considers the analytical description and discussion of the individual parameters because the influence of the large number of parameters on the breakthrough curve cannot be appreciated. These relations must be known if individual operating parameters are changed or if a laboratory unit is scaled up to an industrial plant. The influence of the following effects on the breakthrough curve are considered and approximate solutions are given in order to at least estimate the influence: axial dispersion; shape of the isotherms (linear, Langmuir, irreversible), constant pattern conditions; resistance to mass flow (diffusion and transfer); multicomponent adsorption; concentration and temperature fronts; non‐isothermal adiabatic adsorption; adiabatic equilibrium curve (sorption pathway). Mathematical treatment necessitates reference to the literature. The relations of importance for plant and design are presented here.
Gezielte Nutzung biologischer Systeme
Authors: Marquardt Rüdiger , Präve Paul , Winnacker Ernst Ludwig
Published: December 2004

Directed exploitation of biological systems. During the past few decades, our knowledge of molecular process responsible for genetics has increased dramatically. Discovery of the giant molecule deoxyribonucleic acid – abbreviated as DNA – as the carrier of genetic information heralded in a development which nowadays permits us to effect directed changes in the genetic material of an organism. Thus we can provide easily cultured microorganisms with genes which were previously located in a completely different genetic environment. This helps us to obtain high yields of proteins or other substances which were formerly very difficult to obtain. Higher organisms such as animals and plants can also undergo modification of their genetic equipment. This adds a new dimension to the breeding of such species. Above all, genetic engineering provides new insights into the enormously complex interplay of molecules which go to make up a living cell. The resulting understanding of life processes on a molecular level permits recognition of malfunction and therapy of the ensuring disease by new drugs. In addition to these positive aspects, genetic engineering provides scope for conducting experiments whose ethical implications demand very earnest consideration.
Simulation und Optimierung der Mehrstoff‐Rektifikation
Authors: Górak Andrzej , Krastawski Andrzej , Vogelpohl Alfons
Published: December 2004

Simulation and optimization of multicomponent distillation. Different methods for simulating multicomponent distillation columns are presented and compared with respect to the effort required and the accuracy that may be obtained. Inclusion of mass transfer kinetics based on the laws of multicomponent diffusion in the models significantly increases computer time, but the additional accuracy in the prediction of concentration profiles may justify this effort also in design practice. In particular, the unusual behaviour of concentration profiles due to multidiffusion effects can only be explained by such improved models. The new methods of multicriteria optimization offer substantial advantages over a scalar‐optimization and, in addition to economic criteria, also allow inclusion of aspects of operational safety and of environmental requirements.
Von der Datenverarbeitung zur Wissensverarbeitung?
Authors: Henrichs Norbert
Published: December 2004

From data processing to the processing of knowledge. The present article first examines the problems and the claims of artificial intelligence (AI) research. A brief survey of the principal areas of pure and applied AI research then leads to the structure and the basic functions of so‐called expert systems. The account closes with a number of critical, yet unsolved questions.
Simulationstechnik
Authors: Zeitz Michael
Published: December 2004

Computer simulation. Modern simulation tools such as simulation languages, simulation systems, simulation environments, and expert systems support the user in solving complex simulation problems. Partial problems to be solved are the mathematical modelling of the system under consideration, the selection and application of numerical methods, the programming of the simulation problem, and the execution of simulator experiments. In this survey various methods are reviewed for the simulation of continuous dynamic systems as far as this is essential for an evaluation of available or new simulation programms. Moreover, conceptions of knowledge‐based simulation environments and intelligent simulators are discussed.
Auswirkungen moderner Prozeßleittechnik auf Sensorsysteme
Authors: Nicklaus Eberhard
Published: December 2004

Effects of modern process control technology on sensor systems. Sensor and actuator systems constitute the interface between material and energy flow of a process and the corresponding flow of information. Sensor systems can be classified independently of one another from the viewpoint of information utilization and that of information acquisition. This article presents a general structure for sensors, which differ widely depending upon function and design. Processing of the information which becomes available leads to certain demands but also to possibilities which are largely fulfilled or exploited with the aid of inbuilt computers. This concept of sensor systems with computers and its implications for systems components are examined.
Lichtwellenleitertechnik – Trends in der Entwicklung und Anwendung
Authors: Herbrechtsmeier Peter
Published: December 2004

Fibre optics technology – Trends on development and applications. Fibre optics technology has developed rapidly after its successful introduction into commercial use. This progress has led to structural changes in the field of information transmission. New fast‐growing areas of research, development, and production have resulted. After an introduction into fibre optics technology, the most important types of fibres, i.e. silica fibres, non‐oxide fibres, and polymer fibres, are reviewed. Their various uses, production, and development trends are discussed in relation to the properties of these materials.
Ethanol‐Herstellung mit Bakterien
Authors: Sahm Hermann , Bringer‐Meyer Stephanie
Published: December 2004

Ethanol production with bacteria. Strains of Saccharomyces cerevisiae have mostly been used for the production of ethanol from sugar by yeasts. Recently it was shown that the bacterium Zymomonas mobilis has some advantages compared to yeast for the production of industrial alcohol. Compared to traditional yeast fermentation, ethanol yield is about 5% higher than with yeast, since less sugar is incorporated into cell material by this bacterium. Like yeast, Zymomonas mobilis has remarkably high ethanol tolerance which enables the bacterium to produce ethanol concentrations of more than 13 vol.‐% from sugar solutions of appropriate concentration. Investigations of the spectrum of lipids present have shown that this bacterium contains large quantities of hopanoids which are presumably of significance for the stabilization of cell membranes in the presence of ethanol. Since the cost of the sugar greatly influences the profitability fraction formed in the production of glucose syrup from wheat flour was investigated. It was shown that after enzymatic saccharification of this waste starch the glucose was efficiently fermented to ethanol by Zymomonas mobilis. It is planned to broaden the substrate spectrum of Zymomonas mobilis by gene cloning techniques so that in future pentoses, e. g. xylose or arabinose, can also be fermented to ethanol by this organism.
Modellgestützte Prozeßleittechnik in der verfahrenstechnischen Produktion
Authors: Gilles Ernst Dieter
Published: December 2004

Model‐based process control engineering in chemical engineering production. Modern process control engineering nowadays provides almost ideal tools for the implementation of even highly sophisticated control concepts. The very reluctant acceptance of these tools is due to the following bottlenecks:

– insufficient understanding of chemical engineering control processes;

– limitations in the acquisition of sensorial primary information;

– insufficient performance of control engineering concepts.

The present articles considers how these bottlenecks can be overcome.
Kompaktiergranulieren mit Walzenpressen
Authors: Zisselmar Raimund
Published: December 2004

Compacting granulation in roller presses. The application and handling, as well as storage and transport, of a bulk solid depend not only on its material properties but to a considerable degree upon its properties of state, such as the fineness of a solid. In cases where the excessively fine division of a solid has detrimental effects, recourse can be taken to increasing the particle size. Among the methods of granulation developed for this purpose in recent years, that of compacting granulation has prooved to be especially well suited. The heart of a compacting granulation system is the compacting process performed by roller presses. This review therefore critically examines the parameters influencing product quality, throughput, and energy consumption. Typical applications are presented to illustrate compacting granulation systems.
Selektives Trocknen gemischhaltiger Produkte
Authors: Schlünder Ernst‐Ulrich
Published: December 2004

Selective drying of mixture‐containing products. Properties and quality of products containing solvent mixtures can be influenced considerably by the drying process. This concerns, e. g. the aroma content of fruit concentrates, the tear resistance of paper, the intensity of the colour of pigments, the ductility of cable insulation, toxic residues in tablets, residual monomers in polymers, etc. Both, the amount of residual moisture and its composition are of decisive importance. Predictions are possible given a knowledge of both the course of the drying curve and the course of the composition curve. The latter results from five basic physical processes, viz. vapour‐liquid‐solid phase equilibria, diffusion in the gas phase, diffusion in the liquid phase, capillary flow, and heat transfer. This combined action can be described both theoretically and experimentally for simple but indicative cases. There result practical hints for the choice of dryers and drying conditions to fulfill the demands placed on the properties of the dried product.
Entwicklungstrends von Sensoren in der chemischen Technik
Authors: Gundelach Volkmar G.
Published: December 2004

Trends in the development of sensors in chemical engineering. The present article surveys the state of the art and future developments of sensors, mainly in the chemical industry. Existing requirements are compared with solutions becoming possible by means of present or developing new technologies and measuring concepts. The discussion covers a wide range, from sensors for classical state variables to sensors for the determination of concentrations and biotechnological variables. It includes data communication and modern process control. Among new technologies microelectronics and integrated microcomputers are rated highest; in addition possible uses of electrooptics and glass fiber techniques are mentioned as well as solid state and biochemical components. Within the new concepts, measurements based on modelling and multisensor systems have gained a firm position in practical applications.
Rheologische Stoffeigenschaften – Erklärung, Messung, Erfassung und Bedeutung
Authors: Henzler Hans‐Jürgen
Published: December 2004

Rheological properties – Explanation, measurement, determination, and significance. The non‐Newtonian viscous (structurally viscous, dilatant, plastic, thioxotropic, rheopexic) and elastic properties of liquids are explained with the aid of examples and the main methods of measurement are described. In the case of elastic behaviour, particular attention is given to similarity of measurements obtained by different methods (normal stress measurements, relaxation experiments, vibrational measurements). The second part of the paper is concerned with analytical determination of rheological properties via special material functions, their dimensionless formulation, and their consideration in the dimensional analysis of physical processes. The significance of non‐Newtonian properties in the description of physical processes is demonstrated by an example.
Einsatz von fossilen Brennstoffen zur Energie‐ und Wärmeerzeugung
Authors: Bitterlich Eberhard , Adrian Fritz
Published: December 2004

Use of fossil fuels for generation of energy and heat. The 1985 primary energy demand of the Federal Republic of Germany of 385 million tons of coal equivalent was met to the extent of about 90% by fossil fuels; one third of the primary energy consumption ist lost on conversion of primary into secondary energy. Since the market for energy and heat together accounts for about 70% of end user energy, this is where the greatest potential lies for saving non‐renewable resources. High‐temperature processes for energy generation have considerable development potential due to using combined gas‐steam turbine processes and to raising the upper cycle temperature. In the case of coal fired power stations this requires the inclusion of coal gasification plant. For low temperature processes, utilization of waste heat from power plant and industrial processes not only leads to conservation of fossil fuel reserves but also protects the environment from the illeffects of waste heat. The state of the art and future prospects are presented.
Wärmetransformatoren für die Chemische Industrie aus der Sicht des Anwenders
Authors: Plöcker Ulf , PreußNer Uwe , Brandt Bernd
Published: December 2004

Absorption heat transformers for the chemical industry as seen from a user's point of view. Absorption heat transformers can transfer waste heat, that could not hitherto be reused, to a higher temperature level. This is of special interest for the chemical industry, where there is both waste heat available at temperatures below 100°C and a demand for heat at 120 to 150°C. Though absorption heat transformers are able to recycle only a part of the total waste heat, they only need a negligible amount of additional, expensive exergy. The present status of development and advantages and disadvantages of the concept are discussed from a user's point of view. In view of the present low price of energy, special attention is given to economic considerations.
Auslegungskriterien für die Extraktion mit chemischer Reaktion und Flüssigmembran‐Permeation
Authors: Bart Hans‐Jörg , Bauer Andreas , Lorbach Dirk , Marr Rolf
Published: December 2004

Design criteria for extraction with chemical reaction and liquid membrane permeation. Design criteria for extraction and liquid membrane permeation are discussed and related to these classical extraction columns. Well known models, like the diffusion and the forward mixing model, are used to describe the concentration profile in a column. Mass transfer models for a single globule, like the two‐layer and the shrinking core model, are incorporated. The complex chemical interactions on an interface are formulated. A final discussion considers the relevance of the model parameters and their influence on mass transfer.
Die Rolle der Kohle als Energie‐ und Rohstoffträger
Authors: Ziegler Alois
Published: December 2004

Relevance of coal as a source of energy and raw material. Coal ist a versatile energy and prime material whose many benefits were widely used in engineering and the economy until the middle of the present century. Starting three decades ago, however, mineral oil, natural gas, and nuclear energy have caused a substantial restructuring of energy supplies in the Federal Republic of Germany. Based on the present economic and technological situation of coal production and conversion, the paper illustrates the steadily growing contribution coal is expected to make to worldwide energy supplies. The associated technology thus ranks among the so‐called key technologies and as such deserves to be “fostered” and improved.
Sichere Lagerung von Stoffen in der chemischen Industrie
Authors: Pilz Volker
Published: December 2004

Safe storage of chemicals. Stored chemicals can be a health risk, combustible, unstable, or explosive. It is consequently necessary to prevent such substances and their reaction products from damaging the environment or endangering people as a result of their release, decomposition, fire, or explosion. Storage conditions must therefore always be appropriate for the properties of the substances. This paper starts by outlining the basic principles of safe storage, namely minimization of potential hazards, avoidance of potential causes of danger and containing of any possible effects. Examples illustrate how the properties of the substances are taken into account in practice.
Optimaler Energieeinsatz in der Chemischen Industrie
Authors: Körner Helmut
Published: December 2004

Optimal use of energy in the chemical industry. Energy costs represent a considerable proportion of manufacturing costs in the chemical industry. Optimization of energy consumption is therefore an important task, but supply and removal of energy also should be considered in the field. Rising oil prices and a predictable lack of steam from power plants required a new concept of the energy supply at the Ludwigshafen site of BASF. Saving energy turned out to be the best solution, considering the oil price, the costs of investment in power plants and the risks of further developments. Some examples explain the procedure and the results of this concept. Though production has increased by 60% since 1970, the consumption of primary energy has been reduced to less than 50%. Investments in power stations have been avoided, but capital had to be spent in energy saving measures and modifications of supply structures. The processes of productions have been improved, air pollution has decreased, the environment has been relieved. Energy saving remains an important task for the future in spite of present low oil prices.
Produktionslogistik in der chemischen Industrie
Authors: Lenz Jürgen
Published: December 2004

Logistics in the manufacture of chemical products. This survery covers the fields of location analysis, organization of operational material flow, and materials management, all of which are interlocked with each other. Logistics problems with location analysis lie in the area of infrastructure, procurement, and distribution. The organization of the operational material flow has to be based on a closed concept, taking simultanously into consideration interests of production techniques and of logistics. Special attention has to be paid to the reciprocal effect of plant and storage capacity. With complex production structures simulation models should be used, including a statistical model of the market demands, systematic variation of material flows, and grouping of technical equipment. Target is a minimization of total cost. For market oriented operation of complex productions, integrated materials management systems have to be employed. The systems supply a transparent material flow starting from the market demands via the control of production up to the procurement of raw materials.
Modellbildung für Mehrphasenströmungen in Reaktoren
Authors: Zehner Peter
Published: December 2004

Modelling multiphase flow in reactors. This paper is intended to enhance the knowledge of two phase reactors. Their performance depends not only on reaction kinetics but essentially on fluid‐dynamically fixed quantities such as volume fractions, dispersion coefficients in the fluid and in the gas phase, as well as the volumetric mass transfer coefficient. These are basically dependent on the slip velocity of the phases and on the internal circulation speed of the fluid. The circulation either results from the fluid passing through the vessel (as in a bubble column) or it has to be effected separately in order to avoid separation. Suspension of solids or aeration of liquids in loop and stirred reactors can serve as examples. Dimensionless groups that characterize the main material and geometric properties can be derived using the slip velocity of the largest stable bubble and a certain circulation parameter. The power of this method will be shown by the characterization of bubble columns and gas‐liquid mixers. Simple laws comparable with those applying to bubble columns emerge when approaching the flooding point of a disc turbine in a tank. Power numbers, gas volume fractions, and volumetric mass transfer coefficients can be bundled over the whole spectrum of the non‐flooded states, when their characteristic quantities are divided by the quantities relating to the flooding point.
Bioreaktoren — derzeitiger Stand und erkennbare Entwicklungen
Authors: Deckwer Wolf‐Dieter
Published: December 2004

Bioreactors – State of the art and recognizable future developments. Industrial biotechnological processes, which require monoseptic conditions, are currently performed largely batchwise in stirred tank reactors. A broad‐based exploitation of the potential of biotechnology, i.e. both in the production of commodity biologicals/chemicals and in the manufacture of products of the „new”︁ biotechnology, requires, for economic and technological reasons, continuous processes and other reactor configurations, which permit increased biomass concentrations by cell retention or immobilization, and integration of work‐up operations.
Die Entwicklung von Iösungsmittelselektiven Membranen und ihre Anwendung in der Gastrennung und Pervaporation
Authors: Strathmann Heiner , Bell Carl Martin , Gudernatsch Wilhelm , Kimmerle Klaus
Published: December 2004

Development of solvent‐selective membranes and their use in gas separation and pervaporation. Pervaporation and gas separation are two membrane processes whose industrial and economic importance has increased considerably in recent years because they are particularly suitable for selective removal of organic solvents from aqueous and gaseous mixtures. The problem of solvent removal is encountered, inter alia, in the purification of certain industrial gaseous and liquid effluents. However, the removal of solvents is also significant in petrochemistry and biotechnology and both pervaporation and gas separation can again be efficiently used here. On the basis of the equations relating to mass transfer in homogeneous polymers, criteria for the choice of polymers for high‐selectivity membrane production are discussed. The development of suitable membranes and membrane modules is described. Two industrially and economically relevant examples, viz. recovery of organic solvents from gaseous effluent and the continuous removal of ethanol from bioreactors, illustrate the scope and limitations of the procedures.
Bildung und Koaleszenz von Blasen und Tropfen
Authors: Blaß Eckhart
Published: December 2004

Formation and coalescence of bubbles and droplets. Generation and coalescence of bubbles and droplets are essential requirements for technical reactions and exchange processes. The paper deals with the dispersion of gases and liquids with the aid of single orifices and of sieve plates in liquids of various viscosities under gravity and centrifugal conditions and furthermore with the mechanical foam separation and with the coalescence of drops on inclined plates. The paper summarizes results from the literature as well as from the Sonderforschungsbereich (SFB) 153 at the Technical University of Munich.
Makro‐ und Mikromischen im Rührkessel
Authors: Geisler Reinhard , Mersmann Alfons , Voit Harald
Published: December 2004

Macro‐ and micromixing in stirred tanks.Macromixing time, based on turbulence theory, is calculated theoretically as a function of the specific power input, the kinematic viscosity, the Schmidt number, and the degree of segregation. A comparison of the micromixing time with data for macromixing found in literature reveals that the micromixing time governs the reaction for very small vessel diameters. If the vessel diameter is greater than the critical size than the turbulent macromixing time controls the mixing process. The micromixing time θmikrois calculated by means of the experimental results of the turbulent velocity distributions in different stirred vessels for several geometrical arrangements of stirred tanks and different positions of feed input. The calculated data for turbulent mixing times are only valid for geometrically optimized stirred vessels. The necessary mixing time may increase or, if a chemical reaction of 2nd order takes place, the desired yield of the product may decrease considerably if the geometrical conditions are not taken into account.
Verbrennungstechnik für den Umweltschutz
Authors: Hüning Werner , Reher Peter
Published: December 2004

Combustion engineering for environmental protection. Use of combustion as a means of environmentally sound disposal of gaseous, liquid, and solid industrial production residues places new demands on combustion engineering, depending upon the properties of the residues. High temperature process engineering has the task of ensuring reliable disposal while satisfying legal requirements concerning the quality of combustion. Combustion engineering as a means of residue disposal raises many questions of a scientific and practical nature, which will all have to be answered.
Möglichkeiten zur Prozeßintegration bei destillativen Trennverfahren
Authors: Kaibel Gerd , Blaß Eckhart
Published: December 2004

Possibilities of process integration in distillative separation processes. Distillation is the most important method of separation in the petroleum and chemical industries. About one quarter of the energy consumed in these sectors of industry is for distillation. This underscores the importance of improving distillation processes. Optimisation work on distillation processes has been in progress for a long time. Attention has recently been turned to the treatment of overall separation tasks which can be integrated into chemical engineering processes. To this end, the heuristic rules usually employed in the design of distillative separations have been further developed. Use of expert systems which transform these heuristic rules into separation proposals already appears feasible.
Wasserstoff‐Technik
Authors: Fischer Manfred
Published: December 2004

Hydrogen technology. Hydrogen is used today on a large scale as raw material in chemical engineering and in the long term has tremendous potential as one of the most important secondary energy carriers. Hydrogen is produced with fossil and nonfossil primary energy sources from fossil and nonfossil primary raw materials. As an almost pollution‐free secondary energy carrier, which is storable and transportable on a large scale, hydrogen can be used with nearly all energy utilization techniques fueled at present by natural gas, and products of petroleum and coal. Decisive influence on the introduction of hydrogen as energy carrier is exerted by the status and further development potential of hydrogen energy technology, cost of hydrogen production, and safety of a widespread use of hydrogen in the energy economy.
Dosiergenauigkeit bei der Stoffdosierung
Authors: Vetter Gerhard
Published: December 2004

Accuracy of dosage. Confusion sometimes surrounds the concept of dosage accuracy. For this reason, standard definitions and testing and calculation procedures are proposed for dosage accuracy, dosage error, and dosage constancy. Representation of the relationship between dosage error and dosage constancy within the area of tolerance of the dosage accuracy is new. Since the measurement of all error quantities is always bound to relate terms such as short‐term, long‐term, and momentary dosage error to a stated time base. This also facilitates a conceptually smooth transition to operating dosage errors observed in long‐term operation. It would be convenient if some standardization of the concepts, and possibly a set of rules, could be developed on this basis. Evaluation of measured results on comparing guarantees would then be conducted in relation to the accuracy of measurement.
Neue Konvertersysteme für die Methanol‐Synthese
Authors: Westerterp K. Roel , Kuczynski Michal , Bodewes Theo N. , Vrijland Maarten S. A.
Published: December 2004

New converter systems for methanol synthesis. Far‐reaching energy savings in equilibrium reactions requires development not only of better catalysts but also processes with higher conversions in the reactor; wherever possible, so high that recirculation of residual gases is unnecessary. With this aim in mind, two new processes have been developed for methanol production and this paper represents the first report about the second of these processes. The two new reactor concepts are based on the gas/solid/solid‐trickling film reactor GSSTFR and the reactor with intermediate product removal RSIPR. In the case of the GSSTFR, the product formed at the catalyst is removed directly from the reactor with a solid adsorbent which moves down through the catalyst bed. Conversions of 100% are achieved in the simplest way – recirculation becomes unnecessary. Savings in investment costs, energy, and raw materials are discussed and compared with the Lurgi process. With the RISPR, high conversions are achieved by selective absorption of the methanol at the temperature of reaction. Tetraethylene glycoldimethylether, TEGDME, is selected as solvent for this purpose. A possible flow scheme is also shown for this process and savings are estimated. Possible savings are so promising that further development on a semi‐industrial scale is recommended.
Stand und Entwicklungstendenzen in der Prozeßanalysenmeßtechnik
Authors: Melzer Werner
Published: December 2004

State of technology and trends in the process analyzer field. The use of process analyzers is of growing importance in the chemical industry. For demonstration purpose this publication first describes some applications of analyzers in various fields of chemical production, and then surveys commercially available process analyzers and peripheral equipment. Market gaps are indicated. Problems in relating to μ‐processor applications and electromagnetic interference are mentioned and trends in the process analyzer field are discussed.
SATU86 — Simulationsrahmen zur dynamischen Prozeßsimulation für den industriellen Einsatz
Authors: Scheiding Wolfgang , Hartmann H. Harald , Tönnishoff Patrik
Published: December 2004

Simulation framework for dynamic process simulation for industrial purposes. After a brief treatment of the general requirements of simulation software, the article presents the simulation program SATU86 developed at Hoechst AG. SATU86 permits modular model construction, has a clear user surface and allows a wide range of simulations and identifications, with facilities of tabular and graphic output both during and after simulation. An example of a project serves to illustrate the essential characteristics of SATU86. Apart from development of calculational models in SATU86 the main uses are identification, simulation, and presentation of results.
Umweltschutz – eine ständige Herausforderung
Authors: Zlokarnik Marko
Published: December 2004

Environmental protection ‐‐ a permanent challenge. Through the intensive investment activity of municipalities and of the chemical and related industries in the past twenty years it has been possible to greatly reduce the extent of environmental pollution which rose as a result of the rapid urban expansion and industrialisation of the 1950's and 60's. However, a more thorough protection of river and sea waters cannot be achieved merely through the further sophistication of waste‐water technologies. More importantly, every possibility for reducing the quantity and pollutant content of waste‐water must be fully exploited. Such possibilities lie in the recycling of processing water, in the integration of environmental protection into the process itself, as well as in the appropriate redesign and modification of the processes. The various fields of activity, especially those particularly rewarding to the process engineer are examined and numerous possible directions are offered. Six technical examples, which have been applied in practice, serve as illustration.
Der Beitrag von H. Hausen zur Theorie der Rektifikation
Authors: Vogelpohl Alfons
Published: December 2004

Contribution of H. Hausen to the theory of rectification. The theory of distillation, in particular with respect to multicomponent separation has been strongly influenced by Hausen. His major contributions in this field are presented and discussed.
Schwelbrennverfahren zur thermischen Entsorgung von Müll und Klärschlamm
Authors: Vollhardt Frohmut , Lezenik Bernd
Published: December 2004

Combined pyrolysis combustion plant for disposal of refuse and sewage sludge. The present article describes a novel, environmentally compatible process for the disposal of refuse. It features a combination of pyrolysis and high‐temperature combustion and utilizes well‐proven equipment. Thermal decomposition of refuse by pyrolysis precedes high‐temperature combustion leading to full energy utilization and resulting in optimum combustion and refuse disposal. The salient components of the process – the pyrolysing drum and the high‐temperature combustion – are explained in detail. The report draws upon the operational experience obtained with pyrolysis plants and special waste incineration plants already installed.
Membranverfahren zur Fraktionierung von Gemischen mit organischen Komponenten
Authors: Rautenbach Robert , Herion Christof , Janisch Ingo , Dahm Wolfgang
Published: December 2004

Membrane processes for fractionating mixtures with organic components. The maximum demand that can be placed on development of processes for removal of contaminants from waste water and waste gases is that the separated substances can be recovered for use. In this context, membrane processes are attracting steadily increasing interest because the separated substances are changed neither chemically, nor biologically, nor thermally. Two examples, in which solvent mixtures are recovered from waste water and waste gases by means of reverse osmosis, pervaporation, and gas permeation, are cited to demonstrate the potential of the method. The examples, are preceded by a joint consideration of the three above‐mentioned membrane processes, which all use socalled pore‐free solution‐diffusion membranes. The limitations, which result from practical limits of the driving force and the respective resistances to transport are discussed in detail.
Pyrolyse von Biomasse
Authors: Kaminsky Walter
Published: December 2004

Pyrolysis of biomass. Alongside combustion and gasification the pyrolysis of biomass can be looked upon as an attractive alternative for the production of gas and oil. Special procedures using very short pyrolysis times lead to extensive (app. 80%) conversion of wood, for example, into organic liquids. Because of their very high heat‐ and mass‐transfer rates, fluidized bed processes are predestined for this purpose. Longer residence times at higher temperatures raise the overall gas yield and exert a positive effect on defunctionalization of the oil compounds. Apart from the production of charcoal, the pyrolysis of biomass has so far not been run economically, however. The situation will become quite different as soon as this method of disposal itself attracts major attention. In this respect, the pyrolysis of sewage sludge shows considerable promise as a thermal process, because heavy metals can hardly be eluted from the pyrolysis residue and in addition good fuel gases and useful oils are produced.
Gewinnung niedermolekularer organischer Verbindungen aus komplexen wäßrigen Gemischen durch Extraktion
Authors: Schügerl Karl , Degener Wolfgang
Published: December 2004

Recovery of low‐molecular organic compounds from complex aqueous mixtures by extraction.This article considers the recovery of alcohols, aliphatic and aromatic carboxyl acids, amino acids, and penicillins from complex media as well as the separation of chemically similar compounds by extraction from complex mixtures.
Kermische Werkstoffe
Authors: Ratzel Wolf‐Ingo
Published: December 2004

Ceramic materials of construction. New ceramic materials have extremely attractive potential properties and can be optimized within wide limits for specific applications. Predominant properties are pronounced hardness and resistance to wear, chemical resistance, as well as high‐temperature stability in use as structural ceramics and e. g. ionic conductivity for special applications as functional ceramics. Apart from reduction of the brittle fracture behaviour of industrial ceramics by materials modification, attention is focussed on efforts to obtain reproducible component quality and on know‐how transfer for appropriate design and associated joining techniques.
Wärmerohre in der industriellen Praxis
Authors: Paikert Paul
Published: December 2004

Heat pipes in industrial practice. Heat exchangers based on single independent heat pipes have not often been used in chemical engineering processes, in spite of their numerous ad‐1 vantages. This may be because simple design rules are unavailable. After a short introduction into the working principles of heat pipes, some thermal calculation rules and design procedures are given based on dimensionless numbers for the various finned tube components of the heat pipes. A calculation example demonstrates how the design rules should be applied. Finally some practical applications illustrate the successful operation of heat pipes for the purpose of industrial heat recovery.
Die Chromatographie, eine zentrale Methode in der biotechnischen Aufarbeitung
Authors: Müller Peter , Brümmer Wolfgang
Published: December 2004

Chromatography, an essential method for downstream processing in biotechnology.More than ten years ago, largescale chromatography was established for isolation and purification of high molecular weight natural products, such as proteins and nucleic acids, from fermentation broths and extracts of animal and plant tissues. This was a result of the development of rigid, hydrophilic, and biocompatible polymers with large pore sizes. Compared to the precipitation methods previously used on a large scale, chromatography offers in particular the possibility of producing blood proteins and enzymes of higher purity on a technical scale and without pollution. The various chromatographic methods involve many separation possibilities with excellent selectivities. Progress in improving the chromatographic materials together with advanced equipment were the basis for present‐day importance of chromatography in biotechnology downstream processing.
Entwicklung petrochemischer Verfahren vom Laborversuch zur kommerziellen Anlage
Authors: Böckler Rüdiger , Cordes Günter , Smolen Heinrich
Published: December 2004

Development of a petrochemical process from laboratory scale tests to a commercial plant. A plant producing TAME (tertiary amyl methyl ether) and isoamylene serves as an example illustrating the development of a petrochemical process from laboratory scale tests to a commercial size plant. TAME is an anti‐knock compound used in unleaded gasoline, and isoamylene is a multi‐purpose specialty chemical. In an introduction, the laboratory and pilot plants at EC Erdoelchemie GmbH in Cologne, Germany are presented. Subsequently the main process engineering developments made through experience gained with a semicommercial demonstration plant are discussed. These include optimization of the reactors, design of a methanol extraction unit, and the separation of TAME and high purity isoamylene in specially designed distillation towers. The high degree of coordination during the experimental testing phase to match the requirements of the basic and detail engineering allowed the commercial plant to be started up without expensive modifications within 4 years. The resulting savings overcompensate the costs of the semicommercial plant.
Ungewöhnliche Zyklonabscheider
Authors: Schmidt Paul
Published: December 2004

Unusual cyclone separators. Conventional cyclone separators are seldom suitable for dust cleaning of gases according to present standards. The reason is secondary flow within the body disturbing the process of separation based on elementary cyclone theory. This can be avoided by special design of the cyclone e. g. geometry of the separation chamber, the position of openings, flow guides within the cyclone, dimension and geometry of the bin, bleeding and bypass of the gas, switching of cyclones, and means for dust agglomeration.
Was leistet die statistische Thermodynamik für den Verfahrens‐Ingenieur?
Authors: Lucas Klaus
Published: December 2004

What does statistical thermodynamics do for the chemical engineer? Statistical thermodynamics introduces molecular properties of a particular system into model equations for the thermodynamic functions of fluid mixtures. It thus contributes to the prediction, extrapolation or estimation of fluid properties, in particular phase and reaction equilibria, which are fundamental to numerous processes in thermochemical engineering. For systems of small, rigid molecules, as frequently encountered in natural gas and refrigeration applications, this method has reached a high level that is beginning to be introduced into industrial practice. For systems of complicated organic molecules, models from molecular thermodynamics have firmly established themselves in industrial applications.
Mehrstrom‐Wärmeaustauscher als gelötete Aluminium‐Plattenapparate – Stand des Wissens
Authors: Ringer Detlev
Published: December 2004

Multi‐flow heat exchangers as soldered aluminium plate equipment – State of the art. Soldered aluminium plate heat exchangers are the most frequently used pieces of equipment for heat exchange between clean fluids in cryogenic and low temperature processes. Equipment of this type combines high flexibility in the flow arrangement, high heating surface densities (up to 1400 m2/m3), low pressure drops, and low production costs. This article provides a survey of the present state of the art of their manufacture and thermal dimensioning. In conclusion, new developments are treated.
Qualitätssicherung in der chemischen Produktion
Authors: Geibig Karl Friedrich , Furchert Michael
Published: December 2004

Quality assurance in chemical production. Effective quality assurance is of crucial importance to a company. Particularly in view of the transition from classical productoriented to production‐oriented quality assurance and the associated change in customer/supplier relationship the above opening statement is more valid than ever. A prerequisite for successful quality assurance is a systematic and complete documentation of production. Only when this requirement is fulfilled SPC techniques can be successfully applied – special mention is made here of rule cards. Difficulties are expected to accompany the introduction of rule cards in the chemical industry. The article shows ways in which these difficulties can be minimized. In conclusion, the reader's attention is directed to the potential offered by observer and optimizer.
Elektrochemische Energiespeicherung
Authors: Allmendinger Thomas
Published: December 2004

Electrochemical storage of energy. Besides energy density, performance density, and lifetime, the overall efficiency represents a very important criterion for electro‐chemical energy storage systems and influences the costs significantly. The system electrolyser – hydrogen storage – fuel cell exhibits an overall efficiency of about 1/3, half as much as an accumulator. On the other hand, it favours long term storage of energy. Organic liquids, especially methanol which can be synthesised by CO2 hydrogenation, seem to be the most promising mode of storing hydrogen. No optimal system is available yet for the short‐ or mid‐term storage of photovoltaic solar energy in buildings. Connection to the public mains will be the best approach. For special purposes like emergency power sources or load levelling systems the lead accumulator is still interesting. However, electrochemical storage systems exhibit the most promise for energy saving as mobile power sources such as improved accumulators or in the longer term as fuel cells, e. g. for electrically driven vehicles. Some relevant options are outlined.
Verfahrenstechnische Aspekte in der Galvanotechnik
Authors: Kreisel Rudolf
Published: December 2004

Process engineering aspects of electroplating. Process engineering is ubiquitous in electroplating, starting with the manufacture of chemicals required for pretreatment and metal deposition and extending to their use and disposal in electroplating plant. More than anything, enhanced environmental consciousness and new legislation now call for new treatment systems for solutions of chemicals which were formerly used only rarely, if at all. Processes commonly encountered in general chemical process engineering sometimes still have to be adapted to these new applications of regeneration and environmentally friendly treatment. This will ensure that electroplating retains its importance in the future.