Institut für Prozess- und Verfahrenstechnik

117 Items

Recent Submissions
Systematic coalescence investigations in liquid/liquid systems

Kamp, Johannes (2017)

Liquid/liquid dispersions, which are mixtures of (nearly) immiscible liquids, are an integral part of many technical processes and everyday consumer products. For example, in technical processes the interfacial area is increased by dispersion to enhance mass and heat transfer; or consumer products like lotions and creams consist of stabilised oil/water dispersions. The process efficiency and re...

Toward microbioreactor arrays

Glauche, Florian ; John, Gernot T. ; Arain, Sarina ; Knepper, Andreas ; Neubauer, Antje ; Goelling, Detlef ; Lang, Christine ; Violet, Norman ; King, Rudibert ; Neubauer, Peter (2015)

In this study, a slow-responding chemo-optical sensor for dissolved oxygen (DO) integrated into a 96-well plate was developed. The slow response time ensures that the measured oxygen value does not change much during plate transport to the microplate reader. The sensor therefore permits at-line DO measurement of microbial cultures. Moreover, it eliminates the necessity of individual optical mea...

Development of a method for reliable power input measurements in conventional and single-use stirred bioreactors at laboratory scale

Kaiser, Stephan Christian ; Werner, Sören ; Jossen, Valentin ; Kraume, Matthias ; Eibl, Dieter (2017)

Power input is an important engineering and scale-up/down criterion in stirred bioreactors. However, reliably measuring power input in laboratory-scale systems is still challenging. Even though torque measurements have proven to be suitable in pilot scale systems, sensor accuracy, resolution, and errors from relatively high levels of friction inside bearings can become limiting factors at small...

Einsatz von Schlüsselindikatoren zur Berücksichtigung unsicherer Randbedingungen in der Anlagenführung

Werk, Sebastian (2017)

Produktionsprozesse in der chemischen Industrie werden von Operateuren in Leitwarten überwacht und gesteuert. Den Produktionsprozessen liegen komplexe dynamische Modelle zugrunde. Die Zielstellung der Operateure besteht darin, die Prozesse hinsichtlich verschiedener, sich teilweise widersprechender Ziele wie Wirtschaftlichkeits- und Qualitätsanforderungen zu steuern. Hierbei stehen oftmals üb...

Post-mining water treatment

Hoyer, Michael (2017)

Nanofiltration of real uranium-contaminated mine drainage was successfully discussed in experiments and modeling. For the simulation a renowned model was adapted that is capable of describing multi-component solutions. Although the description of synthetic multi-component solutions with a limited number of components was performed before, the results of this work show that the adapted model is ...

Löslichkeitsselektive Mixed Matrix Membranen zur Gaspermeation

Kramer, Verena (2017)

In this work solubility selective mixed matrix membranes consisting of silicon polymers and activated carbon are investigated for transport and separation properties of n-butane and methane. For mathematical description of the permeation process a new model is developed based on one-dimensional discretisation of the separation layer. This is an innovative approach for modelling of mixed matrix ...

Systematic evaluation of ill-posed problems in model-based parameter estimation and experimental design

López Cárdenas, Diana Carolina (2016)

The lack of informative experimental data, the complexity of first-principles models, over-parameterization and parameter correlations make, among others, the recovery of kinetic, transport, and thermodynamic parameters complicated. These issues are sources of non-identifiability and consequently ill-posedness. This research investigates the features, sources, effects and treatments of ill-pose...

Characterization and validation of the high accurate heat meter calibration facility of the Physikalisch-Technische Bundesanstalt PTB

Cordova Murillo, Moritz Leopoldo (2016)

Flow rate calibration facilities have the task to establish a flow rate under predefined conditions and to measure this flow rate within a declared uncertainty. To proof the correctness of the declared uncertainty requires in depth understanding of every hardware component. In cases where those components can not be directly isolated and modeled it is necessary to make assumptions and to make e...

Particle-resolved CFD simulations of catalytic flow reactors

Wehinger, Gregor Dionys (2016)

Dry reforming of methane (DRM) produces syngas from marginal natural gas resources and carbon dioxide. Both are greenhouse gases. Commonly, DRM is carried out in catalytic fixed-bed reactors with a small tube-to-particle-diameter ratio. Backflow, channeling, and strong interactions between local kinetics and local transport phenomena occur. Conventional plug-flow models and pseudo-homogeneo...

Analyse der Tropfendeformation und des Tropfenbruchs in turbulenter Strömung

Nachtigall, Stephanie (2016)

Das Dispergieren zweier nicht mischbarer Flüssigkeiten ist Bestandteil zahlreicher Prozesse der chemischen, pharmazeutischen oder lebensmittelverarbeitenden Industrie. Die Größenverteilung der dispersen in der kontinuierlichen Phase beeinflusst dabei nicht nur die Effizienz einiger Prozesse, sondern auch resultierende Eigenschaften wie die Stabilität und Rheologie emulgierter Produkte. Trotz vo...

Closed-loop adaptive Versuchsplanung zur Parameterschätzung mit modellgestützter Gestaltung einer Mensch-Maschine-Schnittstelle

Yakut, Nataliya (2016)

There are multifarious applications for dynamic process models. In the process industry modeling is essential for design, simulation, optimization of plants and process control. Continuously increasing complexity of chemical engineering processes lead to growing requirements on model accuracy. However, model identification requires time-consuming and expensive theoretical and experimental studi...

Closed-loop active flow control for road vehicles under unsteady cross-wind conditions

Pfeiffer, Jens (2016)

Many road vehicles can be classified as bluff bodies based on their aerodynamic characteristics. Due to their geometry, the flow separates at the back of the vehicle, leading to a large, turbulent wake and a high drag coefficient. Active flow control (AFC) represents a promising technique for mitigating these detrimental effects. Although this has been successfully demonstrated in various wind ...

Fluid dynamics of bubbly flows

Ziegenhein, Thomas (2016)

Bubbly flows can be found in many applications in chemical, biological and power engineering. Reliable simulation tools of such flows that allow the design of new processes and optimization of existing one are therefore highly desirable. CFD-simulations applying the multi-fluid approach are very promising to provide such a design tool for complete facilities. In the multi-fluid approach, however...

Development of continuous lactulose production in parallel membrane reactors

Sitanggang, Azis Boing (2016)

The automated and parallel small-scale reactors are considered as an efficient and a time-saving tool since these reactors can facilitate a straightforward bioprocess development to reach its commercial success. Within this study, a screening and characterization system for continuous biocatalytic processes that had been coined by Lyagin et al. (2010, 2015) was upgraded. The previously establis...

Software-unterstützte Erzeugung von mathematischen Modellen zur biotechnologischen Prozessführung

Violet, Norman (2016)

The aim of this study is to automate the process of finding an adequate model for fermentations of microorganismen and hence to facilitate it. With the aid of the developed methods and the resulting program Modellstrukturgenerator (model structure generator) little effort is needed to generate models to be implemented in an existing process development and control system. The Modellstruktu...

Zusammenhänge zwischen Prozessstörungen und der mikrobiellen Biozönose in Biogasanlagen aus der Abfallwirtschaft

Lienen, Tobias (2016)

In dieser Doktorarbeit wurden die Zusammenhänge zwischen Prozessstörungen und der mikrobiellen Biozönose in großtechnischen Biogasanlagen aus der Abfallwirtschaft und in Laborversuchen mikrobiologisch und chemisch analysiert und verschiedene Gegenmaßnahmen untersucht. Unter Einsatz von Calciumoxid als Additiv wurde die Raumbelastung in einem Laborreaktor stufenweise bis auf 9,5 kg oTS m-3 d-1 ...

Analysis of fluidized-bed and fluidized-bed-membrane reactor concepts for oxidative coupling of methane

Sadjadi, Setarehalsadat (2016)

Oxidative Coupling of Methane (OCM) is a reaction for converting methane, as the main component of natural gas, directly to ethylene. The importance of OCM is based on the economic interest of ethylene which can be used widely in different chemical processes. Currently about 150 billion cubic meters of methane are flared or vented annually which leads to production of about 400 million tonnes...

Conceptual design of a concentrating solar power plant for a combined electricity and water supply of the city El Gouna

Wellmann, Johannes (2015)

The cogeneration of power and water in large concentrating solar power (CSP) plants with thermal storage can have significant energetic and economic benefits to supply regions with high direct irradiation and good seawater access. Due to increasing water scarcity, the Middle-East North-Africa (MENA) region has a high demand of desalinated water and a strongly increasing energy demand which cannot...

MINLP optimization under uncertainty of a mini plant for the oxidative coupling of methane

Esche, Erik (2015-10-26)

Das Formulieren und Lösen von großskaligen Prozesssyntheseproblemen unter Unsicherheit bleibt eine Herausforderung im Chemieingenieurswesen. Im Rahmen dieser Arbeit wird ein Framework für das Lösen von wahrscheinlichkeitsbeschränkten gemischtganzzahlig nichtlinearen Optimierungsproblemen entwickelt. Das Framework ist in Python implementiert und hat Schnittstellen zu Simulatoren für Differential...

Development of operation trajectories under uncertainty for a hydroformylation mini plant

Müller, David (2015-09-25)

In fast allen Disziplinen spielt Unsicherheit im Entscheidungsfindungsprozess eine bedeutende Rolle. Diese kommt besonders zu tragen, wenn neue Prozesskonzepte und Verfahren entwickelt werden. Bei der Bestimmung optimaler Betriebstrajektorien von Miniplants oder Pilotanlagen werden oft modellgestützte Strategien eingesetzt. Um die Diskrepanz zwischen Prozessmodel und Realität zu minimieren und ...