Development and evaluation of a new screening workflow for the determination of the self-accelerating decomposition temperature of solids
2021-10-26, Zogg, Andreas, Wegmann, Kai
According to the UN (United Nations) recommendations for the transport of dangerous goods self reactive substances need to be identified and classified with a suitable temperature for transportation, the so-called self-accelerating decomposition temperature (SADT). Several test methods (H.1-H.4) are suggested by the UN for the determination of the SADT1. The suggested tests are inappropriate for many practical situations as they require a large amount of test substance, a significant experimental effort and the tests are hazardous with regard to laboratory safety2. Thus, the quantity of performed tests should be reduced to an absolute minimum. This is achievable if these tests could be limited to critical substances that are expected to have an SADT value below the 75 °C threshold for a 50 kg package, as defined by the UN. Hence, the development of a screening workflow, which is able to identify such critical substances is required. Such screening methods already exist, but they are often based on a single calorimetric principle and were not validated consequently. Here we present a new screening workflow to determine the SADT, by combining accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC). The experimental data were evaluated using nth-order kinetic combined with the Semenov model. The results of this screening workflow are validated for twelve solid compounds with data obtained from the H.2-adiabatic storage tests. The H.2-adiabatic storage tests were performed by an iso-certified reference laboratory. All of the twelve evaluated solid compounds were accurately categorized above or below the 75 °C threshold value. Furthermore, the new screening workflow identifies and flags substances with potentially autocatalytic decomposition kinetics. To our knowledge, we offer the first free, validated, standalone ready-to-use screening workflow for the categorization of solid compounds according to the 75 °C SADT threshold value. The workflow is implemented in MATLAB with an open source code. This enables further validation and development of this workflow towards a best practice method for the categorization of substances according to the 75 °C SADT threshold value.
Die Chemie Pilotanlage der FHNW Muttenz
2023-04-25, Zogg, Andreas, Asprion, Jonas
Der Verein Miniplant 4.0 entwickelt im Process Technology Center an der FHNW neuartige Chemie-Pilotanlagen im Miniplant-Massstab. Der zentrale Scale-Down-Reaktor dient der präzisen Prozessentwicklung im Rührkessel. Insbesondere werden darin die lokalen thermischen Verhältnisse des Produktionsreaktors durch den Einsatz eines speziell designten Wärmetauschers exakt nachgebildet. Damit wird den Studenten und lokalen Unternehmen ein neuartiges Entwicklungswerkzeug zur Verfügung gestellt, welches einen schnelleren und präziseren Scale-Up von Produktionsverfahren direkt aus dem Labormassstab in den Produktionsreaktor erlaubt. Herr Prof. Dr. Andreas Zogg von der FHNW in Muttenz zeigt Ihnen den aktuellen Status der Anlage und die vielseitigen Schulungs- und Forschungsmöglichkeiten. Unterstützt wird er durch Herrn Dr. Jonas Asprion von der Firma Tool-Temp AG, welche die Kommerzialisierung der Temperierlösungen für Reaktormantel und Wärmetauscher anstrebt.
Triphenylphosphanoxid Reduktion mit Silanen
2022, Brodmann, Nico, Zogg, Andreas, Zogg, Andreas, DSM
Triphenylphosphan (TPP) ist ein häufig genutztes Reagenz bei der Wittig-Reaktion. Dabei wird es stöchiometrisch zu Triphenylphosphanoxid (TPPO) umgewandelt, welches zum heutigen Zeitpunkt entsorgt werden muss. Eine Rückführung zu TPP ist für die Industrie von grossem Nutzen. Deshalb wurde eine Reduktion mit Silanen für eine Implementierung untersucht. Es war möglich die grössten Hindernisse dieses Vorgehens für einen Prozess zu umgehen oder zu lösen. So wurde in diesem Zusammenhang die Aufarbeitung komplett neu entworfen und alle Abfallströme für eine Rückführung bzw. Weiterverarbeitung optimiert. Zudem konnten alle Reaktionsparameter und deren Einfluss quantifiziert und verbessert werden.
Scale-Up of the agitator speed based on computational fluid dynamics
2021, Zogg, Andreas, Maier, Christian David
Siegfried in Zofingen is currently working on a hydrogenation reaction. To mimic the production condition for the production, the reaction is carried out on a scale-down reactor laboratory scale (approx. 1 liter). One important process parameter that should be similar during the experiments of the scale-down reactor compared to the later production scale reactor is the mixing behaviour of the agitator. The goal of this work is to find a concept for the appropriate scale-down of the agitator speed based on computational fluid dynamics. This concept shall be compared to conventional scale up methods. To validate this concept different experiment with water and glycerol, as well with and without baffles, were carried out in a 5-litre scale reactor. For the simulation without baffles, the size of the vortex has been compared to the real experiment as well as conventional calculation. In general, the simulation predicted only a vortex 63.6 % of the measured size. In further experiments with suspending of catalyst particles, simulation with baffles were validated with catalyst particle behaviour. The particle behaviour in the experiments could not be measured accurately due to the small size of the particles and the insufficient camera quality. The simulation with particles had a critical error where particles got stuck on the wall which made the results unusable for particle movement prediction. Even with the simulation working correctly, it would not be beneficial for this project, due to the large amount of particles and the simplification done for the simulation. A second method was uses, where the mean velocity of cells in the steady state were compared to each other. Out of 3 different agitator speeds, the agitator speed calculated with keeping P/V constant (571 rpm) was most similar to the agitator speed of the reactor MZA1 (120 rpm). Due to the low sample size this only supports the result but does not confirm it. As a consequence, the results of this thesis give an indication for a possible solution to the stirring behaviour but conventional ways of finding the agitator speed are still necessary. It can be used as steppingstone, but it is still required to refine these simulations. Despite the dissatisfying result with the catalyst particles it could be shown that scale down of agitator speed can still be supported by the mean of computational fluid dynamics
Modeling-Based Approach Towards Quality by Design for a Telescoped Process
2022, Zogg, Andreas, Zahnd, This, Zogg, Andreas, Siegfried AG
A synthesis step, consisting of two sub-steps A and B was investigated by applying a model based approach. Deepening the process understanding was achieved through performed experiments, which also led to the generation of valuable knowledge for future improvements. A kinetic model consisting of 12 reactions and 15 components was successfully established. The model predicts the effects of changes in process parameters on quality. On this basis recommendations for process optimizations have been formulated.
New scale-up technologies for hydrogenation reactions in multipurpose pharmaceutical production plants
2021, Furrer, Thierry, Müller, Benedikt, Hasler, Christoph, Berger, Bernhard, Levis, Michael Karl, Zogg, Andreas
The classical scale-up approach for hydrogenation reaction processes usually includes numerous laboratory- and pilot-scale experiments. With a novel scale-up strategy, a significant number of these experiments may be replaced by modern computational simulations in combination with scale-down experiments. With only a few laboratory-scale experiments and information about the production-scale reactor, a chemical process model is developed. This computational model can be used to simulate the production-scale process with a range of different process parameters. Those simulations are then validated by only a few experiments in an advanced scale-down reactor. The scale-down reactor has to be geometrically identical to the corresponding production-scale reactor and should show a similar mass transfer behaviour. Closest similarity in terms of heat transfer behaviour is ensured by a sophisticated 3D-printed heating/cooling finger, offering the same heat exchange area per volume and overall heat-transfer coefficient as in production-scale. The proposed scale-up strategy and the custom-designed scale-down reactor will be tested by proof of concept with model reactions. Those results will be described in a future publication. This project is an excellent example of a collaboration between academia and industry, which was funded by the Aargau Research Fund. The interest of academia is to study and understand all physical and chemical processes involved, whereas industry is interested in generating a robust and simple to use tool to improve scale-up and make reliable predictions.