bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rauchgasreinigung mit trockenen Sorbentien – Möglichkeiten und Grenzen
Authors: Michele Helmut 
Published: December 2004

AbstractPurification of flue gases by dry sorbents – possibilities and limits. The desired level of purification of the gases, even with smaller amounts of exhaust gases, requires technically straightforward methods. Purification of flue gases using socalled „dry”︁ methods offers the advantage that no problems associated with waste water arise. The gaseous impurities are deposited onto dry sorbents, which can subsequently be disposed of in the dry state. In the article the advantages and disadvantages of „dry”︁ methods are contrasted using examples from plant both at the planning stage and that already commissioned.
Alternative Transportsysteme für den Langstreckentransport in der Chemischen Industrie
Authors: Bahke Erich 
Published: December 2004

AbstractAlternative transport systems for long‐distance transport in the chemical industry. The survival of a company in the chemical industry is nowadays determined by the location of raw materials and the transportation routes and transfer centres to the chemical production sites, and particularly also on the availability of economical and environmentally unobjectionable transport systems and procedures. Increasing difficulties and legislation in the chemical industry, especially due to environmental and disposal problems, as well as the increasing density of mass flow thanks to increasing productivity, demand new technologies and alternative transport systems which can be integrated into a network of modern and environmentally appropriate conveying and storage systems. In a framework of increasing automation of all transport, pipeline transport will become increasingly attractive to the chemical industry with increasing environmental consciousness. Even though not all products can be transported through pipes, such materials can still be transported in „pipeline‐like”︁ manner, i.e. continuously in closed systems.
Siebklassieren
Authors: Schmidt Paul 
Published: December 2004

AbstractSizing by sifting with screens. Viewed physically, screening comprises superposition of segregation, diffusion, and passage through the screen. Frictional and cohesive forces have to be overcome and the coarse feed material transported over the screen, primarlily by circular, elliptical, or linear vibration. The specific screening performance and the sharpness of separation prove to be a measure for the quality of screening. There are three uses for screening: protective screening with mean particle size Dm ≪ mesh w with a simultaneous wish for high screen performance; classification with Dm ≈ w with a desire for greater sharpness of separation; and dust removal with Dm ≫ w and the problem of deagglomeration, i. e. separation of fines from the screened material. The maximum screen performance can be calculated for the coarse range; it is attainable with most screening machines. A problem encountered in the medium to fine size range is prevention of blinding of the screening machine and deagglomeration of sieved material, with attrition phenomena deserving attention. A range of machines is available: casting, planar, tumble, agitator screening machines are available, as are those with deforming screens, those utilizing centrifugal forces, and, as the latest addition, flow screening. New developments concentrate on fine screening, e. g. screening machines with direct activation of the screen fabric, tumble screening machines, combinations of mechanical and pneumatic screening extending through to pure flow screening. Plastic screens made of polyurethane are of advantage for wet screening; they exhibit greatly reduced wear. Safety requirements are met by silenced and explosion‐proof‐screening machines.
Industrielle Anwendung zeolithischer Katalysatoren bei petrochemischen Prozessen
Authors: Hölderich Wolfgang , Gallei Ewald 
Published: December 2004

AbstractIndustrial use of zeolites in petrochemical processes. The cost rise of feedstock triggered by the energy crises as well as increased environmental awareness have accelerated the development of new, environmentally more acceptable processes and the introduction of improved catalysts in the petrochemical industry. In this regard, zeolites have an important contribution to make as catalysts. The utilisation of zeolites in large‐scale technical operations in crude oil processing and petrochemistry is reviewed and the advantages of these catalysts and their influence upon process design are presented. Hydrocracking, dewaxing, methanol‐to‐gasoline (MTG), the Mobil‐Badger process and xylene isomerisation are discussed. A description of the conversion of methanol to olefins indicates that zeolite catalysts will continue to be of great interest in chemistry.
Die Schmelzkristallisation von organischen Stoffen und ihre großtechnische Anwendung
Authors: Rittner Siegbert , Steiner Rudolf 
Published: December 2004

AbstractMelt crystallization of organic substances and its large scale application. In the separation and purification of organic substances, water‐ and solvent free melt crystallization is gaining importance as an independent thermal unit operation. This contribution reviews the physico‐chemical fundamentals, the various process fundamentals, large scale application examples and advantageous possibilities of combination of melt crystallization with other separation processes. A consideration of advantages and disadvantages of this particular separation process should indicate possibilities for new fields of application.
Wiederaufarbeitung von Kernbrennstoffen
Authors: Mischke Joachim 
Published: December 2004

AbstractReprocessing of spent nuclear fuels. The present waste disposal concept for nuclear power plant requires the rapid construction of a reprocessing plant in the Federal Republic of Germany, with the location still being uncertain (Bavaria or Lower Saxony). The task of such a plant will consist in recovering usable nuclear fuels and processing them to new fuel elements. Waste materials are prepared for final disposal. The components of the plant are presented with their design data, associated development plans are discussed, and changes with respect to former plans, in particular the maintenance concept, are outlined. The article also reports the present status of the licensing procedure and current planning.
Pervaporation und Gaspermeation — Grundlagen der Prozeßentwicklung
Authors: Rautenbach Robert , Albrecht Rainer 
Published: December 2004

AbstractPervaporation and gas permeation – fundamentals of process development. Non‐porous membranes represent the basis of reverse osmosis, of pervaporation, and also of gas permeation. In each case, economic viability was achieved only when it proved possible to use this kind of membrane in its asymmetric form in each of the processes concerned. Starting from the mass transfer in the membrane, the influence of each of the following points on plant design for pervaporation and gas permeation is discussed: 1. asymmetry of the membranes; 2. concentration polarization; 3. flow in the module; 4. the pressure drop; and 5. the heat transfer problem (exists only for pervaporation). In connection with the flow in the modules, the economics of series of membranes and membrane columns are compared. In conclusion, a number of applications are discussed which demonstrate where economically sound uses of the two processes are to be found.
Leitsysteme für Produktion und Labor „Stärken und Schwächen der heutigen Hardware und Software, Entwicklungstrends und Zukunftsaussichten
Authors: Best Roland 
Published: December 2004

AbstractControl systems for production and laboratory. Strengths and weaknesses of contemporary hardware and software, developmental trends and future prospects. The state of the art of control systems in production and laboratory is considered with the aid of some representative examples. The strengths and weaknesses of available control systems are discussed. It is shown that further rationalization in production can only be achieved when the interchange of information between the control layers of production is improved. Also open to considerable improvement is the flow of information in the laboratory and the cross‐flow between laboratory and production. The present development of microelectronics (microprocessors, personal computers, data busses, local area networks (LAN)) will greatly change process control technology.
Dosieren von festen und fluiden Stoffen
Authors: Vetter Gerhard 
Published: December 2004

AbstractDosage of solids and liquids. Dosage of reaction components is an important step in chemical engineering processes. In an age of increasing automation, the development of dosage procedures is highly topical; electronics and data processing have long made inroads into dosage procedures. However, today's more stringent demands with regard to pressure, temperature, viscosity, and abrasion necessitate intensified research and development efforts. The present article considers mainly volumetric and geometric dosage methods. The many types of metering pumps cover a large area of dosage of liquids. Minimal flow rates, pressures up to several 1000 bar, and also dangerous and difficult fluids can all be safely handled. Leakproof designs with membranes, tubes, or bellows as displacement devices are particularly important nowadays. Volumetric dosage of solids requires establishment of a reproducible packing density. The survey considers the principle methods of dosage (also against pressure) with special emphasis on screw dosage. Gravimetric dosage methods are extremely reliable and accurate but generally require volumetric systems for energy supply. Especially when used in combination with metering pumps or screw dosage, differential balances have numerous possible applications.
Verfahren zur Minderung von NOx‐Emissionen in Rauchgasen
Authors: Schrod Manfred , Semel Joachim , Steiner Rudolf 
Published: December 2004

AbstractProcesses for lowering NOx emissions in flue gases. The authors survey processes currently under development for reducing NOx emission levels of combustion units. Primary measures, i.e. acting upon the combustion process itself, do not suffice to meet the recently stiffened limiting emission values; particular attention is therefore paid to secondary measures involving the flue gases. The article describes both wet processes and dry catalytic and non‐catalytic processes, some of which can also be employed for simultaneous removal of NOx and SO2. In view of the fast large‐scale implementation demanded, only a few, already extensively developed processes will presumable be accepted, and will play a considerable role on an industrial scale.
Mikrofiltration von Fermenterbrühen
Authors: Rähse Wilfried , Carduck Franz‐Josef 
Published: December 2004

AbstractMicrofiltration of fermentation broths. Crossflow microfiltration is a modern process for the work‐up of fermentation broths. In the case of intracellular components, the cells can be enriched by this technique prior to disintegration of the cells. Extracellular products can be separated from the cells by the microfiltration membrane, and also from solids originating from the nutrient. The approach adopted in isolation of dissolved products by crossflow microfiltration is illustrated for alkaline protease, particular attention being directed to the dependence of the flow of permeate and the retention of the membrane material, the mean pore size of the membrane, the operating conditions, the physical data of the fermentation broth, and the addition of solids, which are discussed and quantified.
Aufstellung von Sicherheitsanalysen durch die Betreiber chemischer Anlagen
Authors: Hezel Carl 
Published: December 2004

AbstractSafety analyses conducted by companies operating chemical plant. The problems with safety analyses have shifted from existing plants to analyses for plants which are subject to an approval procedure. The latter require more effort and cause additional problems although legislation requirements are identical for both types. At BASF safety analyses are carried out by a group of experts responsible for design and operation of the respective plant. The authorities of the State of Rheinland‐Pfalz have formed a team to examine these analyses statewide. Difficulties still exist in presenting every possible hazard source and sequence of failure steps and in quantifying the effects of a hypothetical breakdown. However, one can generally state that the companies have learnt to satisfactorily carry out the extensive documentation task required by law.
Aktuelle Entwicklungen auf dem Gebiet der Reinigung und Desinfektion in der Lebensmittel‐Industrie
Authors: Loncin Marcel 
Published: December 2004

AbstractRecent developments in cleaning and disinfection in the food industry. Dirt consists of residues of food which adhere to the equipment, of deposits which have a composition different from the product itself, or of microorganisms grown on solid surfaces. Fouling depends primarily on the nature of the food processed, but is also strongly influenced by the design of equipment, by the magnitude of shear forces, and possibly by the use of solid particles to prevent adhesion in suspension or fluidized beds. Cleaning implies efficient mechanical action (pumping or spraying) and the use of a detergent. Caustic and mineral acids plus surface active agents are always preferred. In this case the disinfection itself is no problem and can be completed by rinsing with chlorinated water. A method is presented which allows determination of the sometimes unexpected influence of bacterial residues on the shelf life of foods. Some recommendations for cleaning and disinfection in biotechnology are also formulated.
Grenzflächenprobleme bei der Fest/Flüssig‐Trennung
Authors: Gösele Walter 
Published: December 2004

AbstractInterfacial problems in solid/liquid separation. Mechanical solid/liquid separation is one of the unit operations of chemical engineering, which is far from having been mastered theoretically. This is because interfacial forces play such a pronounced role in this process step, and these forces have so far largely withstood scientific investigation. The present article enumerates the problems involved, and necessarily presents more open questions than ready answers.
Sicherung chemischer Produktionsanlagen mit Mitteln der Elektro‐/Meß‐, Steuerungs‐ und Regelungstechnik
Authors: Haas Klaus De , Magin Rudolf , Storck Heinz 
Published: December 2004

AbstractSafeguarding of chemical production plant by means of control engineering. Control equipment is becoming increasingly important for safeguarding of plant. According to VDI/VDE 2180, sheet 3, control equipment is classified as operational equipment, as monitoring equipment, or as protective equipment. Operational and monitoring control equipment serves the proper operation of plant in its correct state or in a faulty but still acceptable state. Protective control equipment is intended to prevent occurrence of an unacceptable faulty state of the plant. It is helpful if the control equipment is classified at an early stage of planning. Preferably the protective control equipment should be considered separately from the other control equipment. It is then possible to design it in such a way that its behaviour in the event of faults can be clearly defined. A distinction is made between active faults (or functiontriggering faults) and passive faults (or function‐inhibiting or blocking faults). An active fault reduces the availability of chemical plant for production by inadvertent shut‐down. Passive faults of protective equipment prevent triggering of the protective function, even though the conditions for triggering are fulfilled. They adversely affect the safety of the plant. Passive faults of control equipment must therefore by prevented or kept under control. A selection of appropriate measures for achieving this is presented.
Reaktionstechnik bei industriellen Hochdruckverfahren
Authors: Maier Siegfried , Müller Franz‐Josef 
Published: December 2004

AbstractReaction engineering in industrial high‐pressure processes. The essential task of industrial chemistry is to transform cheap raw materials into high‐quality materials and substances economically. From the very beginning, the chemical industry has used the energy sources coal, oil, and gas as the starting point for synthesis. These substances are introduced into the product line through high‐pressure reactions. Joint developments in catalytic chemistry reaction kinetics, and plant design have permitted construction and operation of high‐capacity, high‐pressure plants at remote sites, where coal, oil, and gas are won. Industrial high‐pressure chemistry is thus capable of transforming in situ raw materials that could be used otherwise into high‐value products worth transporting to energy‐poor regions and whose distribution is secured. The second part of this paper considers the technical limits of pumps, compressors, and high‐pressure reactors. Approximate estimates of investment costs as a function of the pressure as process parameter are given for a high‐pressure process step. Aspects to be taken into consideration during design, construction, and installation of factory‐built high‐pressure reactors are considered in condensed form in the last part.
Produktansatzbildung beim Erhitzen und Eindampfen flüssiger Lebensmittel
Authors: Kessler Heinz‐Gerhard , Fiedler Josef , Hege Wolfgang 
Published: December 2004

AbstractFormation of deposits from liquid foods on heated surfaces during heating and evaporation. In the past, deposit formation on heated surfaces in food processing has been investigated by considering the whole of the deposited material. This precluded reaction kinetic studies and it was therefore impossible to introduce preventive measures. However, ultrafiltration of milk and whey has now furnished model systems in which deposit formation by proteins and salts can be studied separately. The tendency for deposit formation of proteins is similar to the denaturation reaction of whey proteins. The heat sensitive native proteins in the liquid are deposited preferentially on surfaces already covered with reactive proteins. The deposition of milk salts is determined by the degree of supersaturation of the solution. For milk salts deposition, an activation energy was found which is typical for diffusion processes.
Selektive Reduktion von Stickoxiden in Rauchgasen – Stand der Technik und neue Wege
Authors: Kotter Michael , Lintz Hans‐Günther , Weyland Friedrich 
Published: December 2004

AbstractSelective reduction of nitrogen oxides in flue gas–state of the art and trends. The selective reduction of nitrogen oxides by ammonia may be catalyzed by different substances. The suitable choice of the catalyst is determined largely by where the reduction step is placed in the overall process. The technical problems and the required catalyst properties are demonstrated and discussed. A new process, based on a periodically operated reactor, avoids some of the difficulties otherwise encountered.
Neuere Ergebnisse des Betriebes der Pilotanlage zum Hochtemperatur‐Winkler‐Verfahren
Authors: Lambertz Johannes , Schrader Lothar , Teggers Hans 
Published: December 2004

AbstractRecent results obtained on operation of a pilot plant for the high‐temperature Winkler process. Rheinische Braunkohlenwerke AG is developing the high‐temperature Winkler (HTW) process for gasification of coal and biomass in a fluidized bed. Preliminary studies in a lab‐scale plant at the Technical University of Aachen served as a basis for construction of a pilot plant with a throughput of 25 tonnes of dry lignite per day which went into operation in mid 1978. The gasification pressure was raised to 10 bar and the temperature to over 1000 °C, and the exiting dust was recycled to the fluidized bed, with the aim of significantly improving the specific performance relative to operation at atmospheric pressure. In view of experience gained in operation with both low‐ash and high‐ash lignite, the availability of the pilot plant could be increased to almost 75% and the performance greatly improved. Thus significantly higher values were achieved than by the atmospheric‐pressure Winkler process: 96% C‐gasification and almost 1 600 m3 of synthesis gas per tonne of dry lignite; at over 7700 m3 of synthesis gas per tonne of dry lignite per m2 reactor cross‐section and per hour, the performance exceeds three times the former figure.
Large‐scale Continuous Production of Single Cell Protein
Authors: Westlake Richard 
Published: December 2004

AbstractThe PRUTEEN plant represents a major innovation in the green field of biotechnology. The 50 000‐t/a‐plant was sanctioned in 1976 as a £40‐million‐project and built by contractors John Brown. The 600 t fermenter vessel in particular was an impressive piece of engineering: fabricated in Dunkirk, it was transported to the Billingham site in one piece. This paper illustrates why, given the risks of innovation on such a scale, ICI chose a novel fermentation process. Particular reference is made to the pressure cycle fermenter and how it works, and to the product recovery stage. The approach to sterile engineering, which is crucial to the effective operation of the fermentation process, is also discussed. Faced with unique technical challenges, ICI pioneered practical solutions, and, through operational experience, has arrived at the point today of being able to license the process.
Verfahrenstechnische und wirtschaftliche Vorteile der Kochextrusion im Vergleich zu herkömmlichen Verfahren der Lebensmittel‐Industrie
Authors: Wiedmann Werner , Strobel Edgar 
Published: December 2004

AbstractEconomic and process engineering advantages of extrusion cooking in comparison with conventional processes in the food industry. Extrusion cooking is introduced as a modern high‐temperature short‐time process. Possible process steps in extruder machine systems, such as continuous conveying, mixing, homogenizing and reactions, mechanical and thermal energy dissipation for plasticizing and modifying biopolymers, are explained. This process creates new products with completely new textures, for example in the snack and breakfast cereal sector, while on the other hand the extrusion process competes with long‐standing conventional processes. The latter work slowly with low pressures, low temperatures and energy dissipation with high water contents in large batch‐operated machines. The quality of extruder‐cooked products depends on the extrusion system. The self‐cleaning corotating twin‐screw extruder with its narrow residence time spectrum is the optimum system. However, the counter‐rotating intermeshing machine has certain advantages for products of low viscosity. The cooking time at high temperature is a matter of seconds, which serves to maintain the properties of the ingredients and active substances, while ensuring fast destruction of microorganisms. The end‐products have a long shelf‐life on account of their low process moisture content. Continuous extrusion cooking has economic advantages mainly because it replaces many batch processes and because extrusion is carried out entirely or almost entirely with the final moisture content, thus avoiding the necessity to evaporate huge quantities of water.