Inst. Prozess- und Verfahrenstechnik

234 Items

Recent Submissions
Process model adaption for the autotrophic cultivation of Ralstonia eutropha mutant strains

Neddermeyer, Flavia (2020)

Bioprocesses, in which gases serve as substrates, have become popular in the past years, as they are used, for example, to upgrade industrial exhaust gases. In this thesis, first a regulatory concept for the autotrophic cultivation of the bacterium Ralstonia eutropha is presented. The focus lies on a model-based gas phase controller that works independently of the strain. It adjusts the gas com...

Optimal Control of Droplets on a Solid Surface Using Distributed Contact Angles

Bonart, Henning ; Kahle, Christian ; Repke, Jens-Uwe (2020-07-06)

Controlling the shape and position of moving and pinned droplets on a solid surface is an important feature often found in microfluidic applications. However, automating them, e.g., for high-throughput applications, rarely involves model-based optimal control strategies. In this work, we demonstrate the optimal control of both the shape and position of a droplet sliding on an inclined surface. ...

A pressure-driven, dynamic model for distillation columns with smooth reformulations for flexible operation

Hoffmann, Christian ; Weigert, Joris ; Esche, Erik ; Repke, Jens-Uwe (2020-08-17)

Dynamic models for plants including the startup or shutdown phase are still scarce as the (dis-)appearence of phases or streams is challenging to implement. We present an approach to model a distillation column, in which these operation modes are also considered without exchanging equations. For this purpose, the well-known modeling equations for distillation columns are reformulated robustly t...

Combination of an anaerobic membrane bioreactor (AnMBR) with microalgae production for decentralized wastewater treatment

Foix-Cablé, Mathilde (2020)

Most of the world’s inhabitants still do not have access to sanitation facilities, particularly in remote or poor regions. Consequently, efficient solutions for decentralized wastewater treatment are urgently needed. This study investigates the technical feasibility of the coupling of an anaerobic membrane bioreactor (AnMBR) process with microalgae cultivation for decentralized domestic wastewa...

Rigorous analysis of reactive microemulsion systems for process design and operation

Illner, Markus (2020)

In recent years, significant effort towards more sustainable chemical processes and products is noticeable in both academia and industry. Hence, process development and operation aim for the implementation of new synthesis paths for emerging renewable feedstocks and waste prevention. However, industrial realization of developed process concepts is often enough challenging due to their novelty, ...

Density and Thermodynamic Speed of Sound of Liquid Vinyl Chloride

Javed, Muhammad Ali ; Rüther, Moritz ; Baumhögger, Elmar ; Vrabec, Jadran (2020-04-23)

Vinyl chloride is one of the world’s most important industrially synthesized substances, but due to its physicochemical nature, comparably little is known about its thermodynamic behavior. Accurate density and thermodynamic speed of sound data of vinyl chloride in the liquid state are measured along nine isotherms, covering the temperature range from 283 to 362 K up to a pressure of 91 MPa. Dat...

Fick Diffusion Coefficient Matrix of a Quaternary Liquid Mixture by Molecular Dynamics

Guevara-Carrion, Gabriela ; Fingerhut, Robin ; Vrabec, Jadran (2020-03-23)

For the first time, the Fick diffusion coefficient matrix of a quaternary liquid mixture is sampled consistently by means of molecular dynamics simulation. The required phenomenological diffusion coefficient and thermodynamic factor matrices of the mixture water + methanol + ethanol + 2-propanol are determined following the Green–Kubo formalism and Kirkwood–Buff theory. Further, a system size c...

Investigation on the simultaneous removal of COS, CS2 and O2 from coke oven gas by hydrogenation on a Pd/Al2O3 catalyst

Kamp, Eva ; Thielert, Holger ; Morstein, Olaf von ; Kureti, Sven ; Schreiter, Norman ; Repke, Jens-Uwe (2020-04-07)

The present study deals with the processing of coke oven gas mainly composed of H2, CH4, N2 and CO to provide a feedstock for the synthesis of base chemicals. In this respect, the particular focus of this work is the simultaneous reduction of critical trace components like COS, CS2 and O2 by catalytic reaction with H2. The investigations were performed in synthetic coke oven exhaust using a Pd/...

Multi-Scale Analysis of Integrated C1 (CH4 and CO2) Utilization Catalytic Processes: Impacts of Catalysts Characteristics up to Industrial-Scale Process Flowsheeting, Part II: Techno-Economic Analysis of Integrated C1 Utilization Process Scenarios

Godini, Hamid Reza ; Azadi, Mohammadreza ; Khadivi, Mohammadali ; Schomäcker, Reinhard ; Gallucci, Fausto ; Wozny, Günter ; Repke, Jens-Uwe (2020-04-30)

In the second part of this paper (Part II), the potentials and characteristics of an industrial-scale Oxidative Coupling of Methane (OCM) process integrated with CO2-hydrogenation, ethane dehydrogenation, and methane reforming processes are highlighted. This novel process concept comprises a direct conversion of methane to ethane and ethylene and further conversion of the resulted carbon dioxid...

Multi-Scale Analysis of Integrated C1 (CH4 and CO2) Utilization Catalytic Processes: Impacts of Catalysts Characteristics up to Industrial-Scale Process Flowsheeting, Part I: Experimental Analysis of Catalytic Low-Pressure CO2 to Methanol Conversion

Godini, Hamid Reza ; Khadivi, Mohammadali ; Azadi, Mohammadreza ; Görke, Oliver ; Jazayeri, Seyed Mahdi ; Thum, Lukas ; Schomäcker, Reinhard ; Wozny, Günter ; Repke, Jens-Uwe (2020-05-04)

A multi-aspect analysis of low-pressure catalytic hydrogenation of CO2 for methanol production is reported in the first part (part I) of this paper. This includes an extensive review of distinguished low-pressure catalytic CO2-hydrogenation systems. Specifically, the results of the conducted systematic experimental investigation on the impacts of synthesis and micro-scale characteristics of the...

Bioengineering aspects of microcarrier-based hMSC expansions in different single-use bioreactors

Jossen, Valentin (2020)

Human mesenchymal stem cells (hMSCs) are a valuable cell source for the treatment of degenerative diseases. For the mass expansion of hMSCs, Single-use (SU) bioreactors in combination with microcarriers (MCs) represent a suitable solution. In the present thesis, different aspects of the MC-based expansion of hMSCs in different SU bioreactors were investigated. Special emphasis will be placed on...

Photo-Optical In-Situ Measurement of Drop Size Distributions: Applications in Research and Industry

Panckow, Robert P. ; Reinecke, Laura ; Cuellar, Maria C. ; Maaß, Sebastian (2017-05-17)

The exact knowledge of Drop Size Distributions (DSD) plays a major role in various fields of applications to control and optimise processes as well as reduce waste. In the microbial production of advanced biofuels, oil droplets are produced under turbulent conditions in an aqueous medium containing many surface active components, which might hinder the recovery of the product. Knowledge of DSD ...

Characterization of fast-growing foams in bottling processes by endoscopic imaging and convolutional neural networks

Panckow, Robert P. ; McHardy, Christopher ; Rudolph, Alexander ; Muthig, Michael ; Kostova, Jordanka ; Wegener, Mirco ; Rauh, Cornelia (2020-05-27)

Regardless of whether the occurrence of foams in industrial processes is desirable or not, the knowledge about the characteristics of their formation and morphology is crucial. This study addresses the measuring of characteristics in foam and the trailing bubbly liquid that result from air bubble entrainment by a plunging jet in the environment of industry-like bottling process es of non-carbon...

Influence of Ozone Treatment on Ultrafiltration Performance and Nutrient Flow in a Membrane Based Nutrient Recovery Process from Anaerobic Digestate

Gienau, Tobias ; Ehrmanntraut, Artjom ; Kraume, Matthias ; Rosenberger, Sandra (2020-04-04)

Membrane filtration of biological suspensions is frequently limited by fouling. This mechanism is well understood for ultrafiltration of activated sludge in membrane bioreactors. A rather young application of ultrafiltration is the recovery of nutrients from anaerobic digestates, e.g., from agricultural biogas plants. A process chain of solid/liquid separation, ultrafiltration, and reverse osmo...

Untersuchungen zur Stabilität gestampfter und gepresster Kohlekuchen für den Kokereieinsatz

Sander, Sven (2020)

Die vorliegende Arbeit beschäftigt sich mit der Stabilitätsuntersuchung von gepressten und gestampften Kohlekuchen. Um einen hohen Anteil an günstigen, schwachbackenden Kohlen bei der Kokserzeugung einzusetzen, kommen verschiedene verfahrenstechnische Vorbehandlungen der Kohlen bzw. der Einsatzmischung zur Anwendung. Bei schwachbackenden Kohlen hat eine steigende Dichte der Ofencharge in der Re...

Uncertainty Analysis for Data-Driven Chance-Constrained Optimization

Häußling Löwgren, Bartolomeus ; Weigert, Joris ; Esche, Erik ; Repke, Jens-Uwe (2020-03-20)

In this contribution our developed framework for data-driven chance-constrained optimization is extended with an uncertainty analysis module. The module quantifies uncertainty in output variables of rigorous simulations. It chooses the most accurate parametric continuous probability distribution model, minimizing deviation between model and data. A constraint is added to favour less complex mod...

A Numerical Implementation of the Soret Effect in Drying Processes

Häussling Löwgren, Bartolomeus ; Bergmann, Julius ; Alves-Filho, Odilio (2020-02-17)

Drying of porous media is strictly governed by heat and mass transfer. However, contrary to the definition that drying is simultaneous transport mechanisms of heat and mass, most past and current models either account for temperature or concentration gradient effects on drying. Even though the complexity of computations of these processes varies with area of application, in most cases, the Dufo...

Molecular Modeling and Simulation: Force Field Development, Evaporation Processes and Thermophysical Properties of Mixtures

Janzen, Tatjana ; Fingerhut, Robin ; Heinen, Matthias ; Köster, Andreas ; Muñoz-Muñoz, Y. Mauricio ; Vrabec, Jadran (2019-06-08)

To gain physical insight into the behavior of fluids on a microscopic level as well as to broaden the data base for thermophysical properties especially for mixtures, molecular modeling and simulation is utilized in this work. Various methods and applications are discussed, including a procedure for the development of new force field models. The evaporation of liquid nitrogen into a supercritic...

PetaFLOP Molecular Dynamics for Engineering Applications

Neumann, Philipp ; Tchipev, Nikola ; Seckler, Steffen ; Heinen, Matthias ; Vrabec, Jadran ; Bungartz, Hans-Joachim (2019-06-08)

Molecular dynamics (MD) simulations enable the investigation of multicomponent and multiphase processes relevant to engineering applications, such as droplet coalescence or bubble formation. These scenarios require the simulation of ensembles containing a large number of molecules. We present recent advances within the MD framework ls1 mardyn which is being developed with particular regard to t...

A Benchmark Open-Source Implementation of COSMO-SAC

Bell, Ian H. ; Mickoleit, Erik ; Hsieh, Chieh-Ming ; Lin, Shiang-Tai ; Vrabec, Jadran ; Breitkopf, Cornelia ; Jäger, Andreas (2020-02-14)

The COSMO-SAC modeling approach has found wide application in science as well as in a range of industries due to its good predictive capabilities. While other models for liquid phases, as for example UNIFAC, are in general more accurate than COSMO-SAC, these models typically contain many adjustable parameters and can be limited in their applicability. In contrast, the COSMO-SAC model only conta...