Lutz Böhm

Lutz Böhm
Technische Universität Berlin | TUB · Chair of Chemical and Process Engineering

Dr.-Ing.

About

47
Publications
3,897
Reads
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325
Citations
Additional affiliations
February 2009 - present
Technische Universität Berlin
Position
  • Research Assistant
Description
  • http://www.verfahrenstechnik.tu-berlin.de/menue/ueber_uns/mitarbeiter/doktoranden/dipl-ing_lutz_boehm/
Education
October 2002 - January 2009

Publications

Publications (47)
Article
The first step in quantifying the performance of organic solvent nanofiltration membranes are usually lab-scale experiments with respect to flux and rejection. The necessary pressurization of the feed is either realized mechanically by a high-pressure pump or by means of a pressurized inert gas. While the latter option is most frequently applied, t...
Article
This work focuses on the measuring and modeling of phase equilibria of interest for the hydroaminomethylation of 1-decene with syngas (CO/H2) and diethylamine to N,N-diethylundecan-1-amine and water in a solvent system of methanol and n-dodecane. H2 solubilities were measured in undecanal and N,N-dimethyldodecan-1-amine at 343 and 363 K between 2 a...
Presentation
Full-text available
Hydrodynamic stress on Aspergillus niger agglomerates in stirred tank bioreactors
Chapter
A joint approach of chemists, mathematicians and engineers in the field of chemical reaction enhanced gas-liquid mass transfer on single bubbles is presented. New chemical systems are developed for homogenous chemical reactions in the liquid. By applying different metal-complex based reaction systems with diverse ligands in different reaction media...
Chapter
Within this project, the mass transfer of single bubbles in an unconfined environment was investigated. Most published works with longer rising paths lack the three-dimensional resolution of the bubble interface while smaller systems lack the long-term effects appearing during the ascent. Here, two cameras were moved in real-time with the bubble al...
Chapter
In the previous chapters it has been shown that the fluid dynamic conditions in bubbly flows might affect a competitive consecutive chemical reaction concerning yield and selectivity. The question arises if this results are transferable to technical apparatuses with industrial conditions. To clarify this question, the competitive consecutive DBED r...
Article
Micellar multiphase systems are versatile examples for smart solvent systems, which can be applied to intensify important process aspects like reaction rate and product separation. Choosing different temperatures and compositions, the phase behaviour of micellar multiphase systems can be changed, and the reaction conditions altered. Due to the chan...
Article
Full-text available
de Fluiddynamik und Stofftransportprozessen kommt bei der Dimensionierung von Flüssig/flüssig-Kontaktapparaten eine entscheidende Bedeutung zu. Die Vorhersage von Betriebsparametern wird durch Schwarm- und Grenzflächeneffekte maßgeblich erschwert. Anhand von Einzeltropfenuntersuchungen kann eine grundlegende Vorhersage für fluiddynamisches Verhalte...
Presentation
Full-text available
Hydrodynamische Beanspruchung von filamentös wachsenden Mikroorganismen in gerührten Bioreaktoren
Article
Full-text available
de Für die Dimensionierung von Flüssig/flüssig‐Kontaktapparaten sind Fluiddynamik und Stofftransport in der Dispersion von entscheidender Bedeutung. Schwarm‐ und Grenzflächeneffekte führen zu komplexen Interaktionen und erschweren die Vorhersage von Betriebsparametern. Anhand von Einzeltropfenuntersuchungen kann eine grundlegende Vorhersage für flu...
Article
Full-text available
The applicability of laser‐induced dye fluorescence (LIF) and rainbow schlieren deflectometry (RSD) for qualitative, non‐invasive real‐time visualization of spatial concentration distributions in two standard reference systems is presented. The combination of LIF and RSD enables measurements inside and outside of droplets and is able to overcome li...
Article
Interdisciplinary approach to designing with phase change materials (PCMs) can widen the range of architectural elements for passive cooling of buildings. Due to the complex nature and the dynamic character of phase-changing processes, the analysis and prediction of the thermal performance of PCM elements can be challenging to implement in architec...
Article
Full-text available
The rheological characteristics of cultivations with filamentous microorganisms define many other crucial process parameters in the system, such as the cell morphology and the productivity. The present study aims to determine the rheological changes of broths during batch cultivations of three filamentous microorganisms: the fungus Aspergillus nige...
Article
Full-text available
Mainly with respect to biotechnological cases, current developments in the field of impeller geometries and findings for multistage configurations with a specific view on aerated stirred tanks are reviewed. Although often the first choice, in the given case the 6‐straight blade disc turbine is usually not the best option. Furthermore, quantities us...
Conference Paper
Full-text available
• Mixing concept determines hydro-mechanical stress on particles in bioreactors. • Liquid-liquid model system substitutes biological system. • New image analysis by neural networks provides faster and more accurate results. • Particle analysis tool provides distinction between different disperse phases.
Article
An experimental setup applying Rainbow Schlieren Deflectometry (RSD) is developed and used successfully for non-invasive measurement of thermal free convection. Tempered, solid test specimens in planar and cylindrical shapes are designed to exhibit a two-dimensional or axisymmetric temperature field. Experiments have been conducted with variation o...
Article
The bubble rise behavior in viscoelastic media is analyzed numerically with CFD. Three different constitutive models, Giesekus, linear and exponential Phan‐Thien‐Tanner, are used to evaluate three different biopolymer solutions. The terminal rise velocity over a range of bubble sizes is validated against experimental data. The local velocity fields...
Article
Hydromechanical stress is a crucial parameter for a broad range of multiphase processes in the field of (bio-)chemical engineering. The effect of impeller type and geometry on hydromechanical stress in stirred tanks is important. The present study aims at characterizing conventional and new impeller types in terms of particle stress. A two-phase li...
Article
The experimental accessibility of disperse systems often is a critical factor when it comes to the development of modeling approaches that intend to converge towards an exact solution. Often, integral or pseudo‐homogeneous values are used to reduce the complexity of the system, but a detailed single particle or interface analysis is crucial to unde...
Article
The design of reactors with a dispersed gas in a liquid phase e.g. bubble columns is often based on rather roughly estimated parameters. To obtain a better understanding of the influence and interaction of the fluid dynamics and the mass transfer in the presence of a chemical reaction of NO and Fe(EDTA) in the liquid phase, the complex system of a...
Article
This fundamental study of single bubbles rising in confined geometries was motivated by the aeration in membrane bioreactors. The parameters channel depth, bubble size, superimposed liquid velocity and rheology of the liquid (Newtonian, non-Newtonian) were varied. The flow field close to the bubble with a negative wake in the non-Newtonian liquid i...
Article
The bubble swarm behavior in a system comparable to a flat sheet membrane module was investigated. The parameters channel depth, superficial gas velocity, superimposed liquid velocity and viscosity of the continuous phase were varied. Besides water as continuous phase, a non-Newtonian liquid was used with respect to the rheology of real waste water...
Thesis
Diese Arbeit diskutiert die Untersuchung eines Gas/Flüssig-Systems motiviert durch Anwendung von Flachmembranmodulen in Membranbioreaktoren (MBR). Solche Systeme werden häufig als Air-Lift-Schlaufenreaktoren betrieben, deren Belüftung zu einem Cross-Flow entlang der Membranoberflächen führen soll. Cross-Flows reduzieren die Ausbildung von Deckschic...
Article
The electrodiffusion method has been used in fluid dynamic research for the past 50 years. It allows the measurement of wall shear stress, a crucial parameter, e.g., for the cleaning of membrane modules used in water filtration. Various authors have published articles dealing with the theory behind this technique. But no paper collects all the know...
Article
With regard to the improvement of the cleaning process of flat sheet membrane modules by aeration, a statistical analysis of the shear stress generated by single bubbles is shown for 21 different parameter combinations of varied channel depths, bubble sizes and liquid velocities. A fully automated rig allowed the generation of a sufficient database...
Conference Paper
Fouling is one of the key challenges in the operation of membrane bioreactors. Aeration is a simple but cost-intensive measure to clean the membranes. The aim of this project is to deepen the understanding of the behavior of the bubbles in such geometries to be able to optimize the cleaning of membrane systems and make them more cost-effective. The...
Article
Full-text available
This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).
Article
The importance of the multiphase fluid dynamics for fouling mitigation in MBR systems has been widely acknowledged with air sparging having been applied commercially for about 20years. However, the effects of air scouring are still not fully understood since the transient orthogonal and parallel flows as well as turbulent eddies created by bubbling...
Article
Full-text available
Since aeration is the largest cost factor in membrane bioreactor (MBR) operation it is clear that the biggest leap towards energy and operational costs savings can be achieved by improving the use of air. Many basics of the complex two-phase fl ow in membrane modules and in the overall MBR tank as well as their interactions, however, are still poor...