Verkleinerung verfahrenstechnischer Versuchsanlagen — was ist erreichbar?

Scale-down of chemical engineering pilot plant – what is attainable? The use of fully automated experimental laboratory-scale plantoffer interesting possibilities for assessment of the economic operation and technical feasibility of new or modified processes. An important condition for the success of this kind of experimental approach is the availability of miniaturized equipment, machines, and sensors. The goal of such experimental plant can be both the process engineering development of individual process steps and also integrated running to model complete processes. Moreover, questions of scale-up can be studied and typical quantities can be provided. The state of the art is reported with the aid of selected examples of equipment and mechanical components and measurement and control units.     

Systematic substrate adoption methodology (SAM) for future flexible,generic pharmaceutical production processes

The discovery of an effective and safe pharmaceutical product is based on success in clinical trials. Often, several candidate compounds targeting the same disease area are tested in order to identify the most efficacious products. This involves the manufacture of small quantities of compounds (APIs) for early delivery campaigns. Of these candidates only a few will be successful such that further development is required to scale-up the process. Systematic computer-aided methods and tools are required for faster manufacturing of these API candidates. In this work, a substrate adoption methodology (SAM) for a series of substrates with similar molecular functionality has been developed. The objective is to achieve “flexible, fast and future” pharmaceutical production processes by adapting a generic modular process template. Application of the methodology is illustrated through a case study from the pharmaceutical industry. Use of computer-aided methods and tools as part of the methodology is also highlighted.     

Systematik bei der Entwicklung von Katalysatoren für Oxidationsreaktionen

Systematic approach to development of catalysts for oxidation reactions . The systematic catalyst development presented here for the example of a typical oxidation reaction shows that a systematic procedure is of value for a purposeful approach, and that statistically based planning and evaluation of experimental results represents an efficient tool. Physicochemical methods of study can provide important support for an understanding of catalytic action, with reaction-engineering studies in various kinds of reactors necessarily playing a central role in catalyst development. Technical and economic assessment of a catalyst under development is already feasible in laboratory experiments and ultimately decides for or against its technical applicability. Understandably, the scale-up of a production procedure developed in the laboratory to industrial quantities may also be beset with other problems which cannot be considered here.     

Industrial-scale operation of microbial processes

Interactions between fermentation process development and plant design are explored. An attempt is made to identify the various aspects of microbial reaction and material-transport control of process rates. In scale-up some factors remain constant and some can change and the importance of each is discussed. The case for the use of a stirred fermenter in batch processing is developed and the various non-technical constraints that can determine the scale of operation are described. The production of desirable fluid characteristics at different scales of operation are discussed and it is shown that a deviation from geometrical similarity may be necessary for fermentation process scale-up. A design procedure for aeration-limited processes reveals the complex multitude of factors that must be considered in fermentation-equipment design.     

Entwicklung eines Simulationsprogramms zum Scale-up von Hydrierreaktoren

Development of a simulation program for the scale-up of hydrogenation reactors. The scale-up of trickle-bed reactors to pilot and production scale has been difficult and necessitated considerable over-dimensioning. Therefore a simulation program based on a cell model has been developed in which the dimensions of a cell are directly related to the dimensions of the catalyst particles used. The kinetic equation is formulated with an effective rate coefficient as the only key parameter to be adjusted. With this coefficient the intrinsic rate coefficient, the mass transfer, and the incomplete catalyst particle wetting are considered. The model was applied to the hardening of fatty acids and the hydrogenation of fatty acid methyl esters in laboratory reactors. Comparison with experimental results of pilot and industrial scale is favourable. Thus the model can be used for the scale-up of trickle-bed reactors.     

Recent Developments in Protein Recovery and Purification

This article deals with emerging techniques for the purification of proteins, with an emphasis on those methods which have potential for scale-up. These include membrane processes, some new adsorption and affinity techniques, supercritical gas extraction, 2-phase aqueous liquid/liquid extraction, and electrokinetic methods. Many are at an early stage of development for their use in the food industry. However, it is likely that in the future they will broaden substantially the options available for processing both ‘solid’ and ‘liquid’ streams. Significant and sustained research and development will be needed to convert these techniques to off-the-shelf established technologies.     

Flowsheet Simulation of Soil-Washing Processes

Application of flowsheet simulation systems is not common in solids processing. Commercially available flowsheet simulation systems have usually a strong focus on fluid processes and just a few solids handling features. Special requirements for solids processing are identified and taken into consideration during development and implementation of an appropriate flowsheet simulation system. The features of the prototype simulator SolidSim are presented. Applications to soil-washing – a process for remediation of contaminated soils – demonstrate the usefulness of the simulator in plant design, plant adaptations and related tasks for complex solids processes.     

Scale-up of binder agglomeration processes

This review article describes scale-up of batch and continuous granulation processes where liquid binder is added to fine powder in order to form a granular product. The technical goal of scale-up is to maintain similarity of critical product attributes as the production scale and/or throughput of a manufacturing process is increased. This paper provides a framework for scaling-up that considers critical process transformations in relation to the desired product attributes. A similar approach can be taken in developing process control strategies. In any agglomeration process, transformations can be used to describe how raw materials (typically fine powders and liquid binders) are converted into a granular product. Often the critical product attributes are characterized on the scale of individual granules (e.g., size, shape, porosity, mechanical strength, etc.). On the other hand, industrial scale-up requires predictive relations for the sizing, design and operation of process equipment. Considering scale-up on the basis of transformations is one way to link the macro-scale equipment decisions with micro-scale product attributes. This approach can be applied to the scale-up of batch and/or continuous granulation processes as well as transitioning from small batch prototypes to continuous production circuits.     

Optimization of Improvable Flows by combining BAT Analysis and process simulation

This paper proposes a methodology to improve the sustainability of industrial processes combining two tools: BAT Analysis and process simulation. Both tools are jointly applied to identify the IF of the analyzed process, so that the most appropriate candidate techniques from an inventory can be selected. The selected alternatives are tested in different scenarios that are evaluated using simulation, which would determine the configuration that best improves the sustainability of the process. The combination of both tools in an integrated methodology will help decision makers to select the most sustainable configuration for a given process. The methodology is validated in a case study: a hydrogen production plant. After analysing several scenarios where different candidate techniques are implemented, results show that the IF identified can be highly improved when the appropriate combination of BAT is applied.     

GRAPHICAL TECHNIQUE FOR MODELING INTEGRATING (Non-SELF-REGULATING) PROCESSES WITHOUT STEADY-STATE PROCESS DATA

Model-fitting techniques for controller tuning that require the process to be initially at steady state cannot generally be used with integrating (non-self-regulating) processes. To address this issue, a graphical model-fitting technique is detailed and demonstrated for determination of first order plus dead time integrating model parameters from integrating process response plots. The resulting model parameters can be used directly in a range of tuning correlations designed specifically for integrating processes. The advantage of this technique is that it requires only two periods of constant manipulated and disturbance variables sustained just long enough for the process variable to respond and establish a clear slope. This is an important benefit because integrating processes generally cannot be maintained at an initial steady state as required when using techniques published for self-regulating processes. The result is an industry-friendly method. The method is demonstrated for level control in a pumped tank, a classical challenge in industrial practice. Both a simulation and a bench-scale experimental system are used in the demonstration studies.     

GRAPHICAL TECHNIQUE FOR MODELING INTEGRATING (Non–SELF-REGULATING) PROCESSES WITHOUT STEADY-STATE PROCESS DATA

Model-fitting techniques for controller tuning that require the process to be initially at steady state cannot generally be used with integrating (non–self-regulating) processes. To address this issue, a graphical model-fitting technique is detailed and demonstrated for determination of first order plus dead time integrating model parameters from integrating process response plots. The resulting model parameters can be used directly in a range of tuning correlations designed specifically for integrating processes. The advantage of this technique is that it requires only two periods of constant manipulated and disturbance variables sustained just long enough for the process variable to respond and establish a clear slope. This is an important benefit because integrating processes generally cannot be maintained at an initial steady state as required when using techniques published for self-regulating processes. The result is an industry-friendly method. The method is demonstrated for level control in a pumped tank, a classical challenge in industrial practice. Both a simulation and a bench-scale experimental system are used in the demonstration studies.     

Solvent extraction in platinum group metal processing

This paper indicates the various ways in which the chemistry of the platinum group metals (PGM) can be manipulated to achieve separations using solvent extraction techniques and is not intended to be a comprehensive review of published work. Differences in the chemistry of PGM and base metals are emphasised as the latter are present in refinery liquors. Mechanisms of solvent extraction processes are discussed and related to PGM complex chemistry. Potential economic advantages for solvent extraction over conventional selective precipitation processes are considered.     

Scale-up-Probleme bei der experimentellen Verfahrensentwicklung

Scale-up problems in experimental process development. The experimental process development of a new product can be performed in test facilities of varying dimensions. Small miniplants from a laboratory scale up to larger pilot plants, in which a few tons of product per day can be produced, are used. The scale-up factors, the risks involved in process and construction design, and a possible necessity of a limited production are important criteria for the size of the first technical realisation of the new process. The following examples highlight some special problems and their solutions in the experimental process development. Whereas a process, involving mainly fluids can be developed relatively well in a miniplant (laboratory scale), it is normally necessary to work on process development for a solid product involving difficult solid handling in a larger pilot plant. At the end of the paper some other scale-up criteria for process design are explained.     

Microreactor technology and process miniaturization for catalytic reactions—A perspective on recent developments and emerging technologies

Recent developments in microreactor technology (MRT) are reviewed within the context of discovery, development and commercialization of catalytic systems. Emerging trends and drivers for development of pilot plants and scale-up methods for the next generation of multiphase catalytic processes are presented. Developments in microreactor scale-out, materials of construction, fabrication techniques, and the potential effect of materials of construction on performance are highlighted. Key issues that impact the adoption and implementation of MRT for research, development, and small-scale commercial applications, including safety, potential performance enhancement, environmental impact, distributed production, scale-up, and computer-aided design tools are also analyzed. The role of MRT in portable power systems is given as an example of a potential commercial application.     

搅拌槽内黏性流体流动的DPIV测量与CFD模拟

搅拌槽是化学工业及其相关工业广泛应用的设备之一,由于其内部流动的复杂性,搅拌混合操作目前尚未形成完善的理论体系．对搅拌槽的设计和放大,主要是依赖半经验的方法,对其内部流场有必要进行更深入的研究．目前对不同黏性流体的流动测量及计算流体力学模拟工作见诸报道较少,而     

Some aspects of electrochemical engineering

After a short discussion of the concept of electrochemical engineering, the immediate history of electrochemical process engineering (EPE) is briefly mentioned. Topics then considered are electrolytic reactor design, process modelling and optimisation, and the development and scale-up of electroorganic processes. The article concludes with an assessment of the present state of EPE.     

Simulating the mixing and segregation of solids in the transverse section of a rotating kiln

Rotating kilns are widely used in industry to process granular material. These processes include calcination of mineral ores, drying of foods and grains, combustion of wastes and manufacturing of pharmaceuticals. Since models developed for a particular process are often unique to that process there is a need to develop more generic models to predict the mixing and segregation in the transverse section of a rotary kiln.This paper presents a mathematical simulation - based on experimental observations - to estimate the mixing rate, final extent of mixing and the final distribution of material due to segregation. The models used in the simulation allow for scale-up of processes to produce a simulation that is applicable to a broad range of industrial processes. Independent experiments were used to verify the simulation and it was found that the mixing rate, the final extent of mixedness and the final segregated state could be predicted to within acceptable errors.     

Applying monolith reactors for hydrogenations in the production of specialty chemicals—process and economic considerations

Monolith catalysts, mainstays in gas-phase automotive and environmental process applications, have found new potential in replacing three-phase slurry reactors for the production of specialty chemicals, especially when their advantages are fully utilized in recirculation loop approaches. Many economic and logistical benefits for removing slurry catalysts drive the investment into monolith technology, both for new capacity and for retrofits onto existing stirred tank reactors. Benefits are most pronounced for fast reaction chemistries, where monolith catalysts can achieve volumetric activities several times higher than slurry reactors. This paper demonstrates how engineering design and scale-up can be performed using fundamental equations and literature correlations in combination with pilot plant measurements and presents an economic analysis emphasizing monolith catalyst life as a critical variable. Efforts to develop replacement catalysts must therefore integrate efficient catalyst fabrication and lab testing into the evaluation process.