Development and application of optical sensors and measurement devices for the detection of deposits during reaction fouling 13th ECCE and 6th ECAB -post 31762

Abstract

In many chemical/pharmaceutical processes, the technically viable efficiencies and throughputs have not been achieved yet because of the reduction in heat transfer (e.g., in heat transfer units, reactors, etc.) due to the formation of wall deposits. Considerable amounts of energy can be saved by reducing or entirely preventing this problematic area. Therefore, the presented measurement device and its optical and electronic parts were developed for the detection and measurement of deposits in polymerization reactors, simultaneously aiming the in-line monitoring. These methods were elaborated and used in the context of the KoPPonA project (FK: 03EN2004K) in the cooperation of several industrial application partners on direct application examples. The design strategy was carried out systematically via theoretical calculations - such as optical ray tracing and photon flux analysis - via test designs, laboratory investigations, and then in industrial use. The developed sensors are based on fiber-optic technology and thus can be integrated into the smallest and most complex apparatus, even in explosion hazardous areas. Single-photon counters with a count rate of upto 20 mega counts are employed to detect even minimal changes. Combinations of UV, VIS, NIR, MIR, and Raman spectroscopy are used for molecule-selective detection. Critical product and process states in the reactant are detected at an early stage by combining several multi-spectral backscattering technologies. Thus, the formation of deposits can be prevented by changing process parameters.
To evaluate these methods using test setups, we manufactured robust and cost-effective sensors and measurement devices for chemical systems during different reaction fouling processes of the project partners BASF, Covestro, Wacker, and the University of Stuttgart.

Full text

Hochschule Mannheim University of Applied Sciences
Development and application of optical sensors and
measurement devices for the detection of deposits
during reaction fouling
T. Teumer, I. Medina, J. Strischakov, S.Schorz, P. Kumari, M. Rädle, HS Mannheim
A. Hohlen, S. Scholl, TU Braunschweig
S. Welzel, UNI Stuttgart
C. Schwede, K. Hungenberg, BASF
T. Melchin, Wacker Chemie
online lecture – 23.09.2021
13th ECCE and 6th ECAB –post 31762
FZ: 03EN2004K

Deposition on
microreactor wall
•lower throughput
and efficiency
•higher energy
expenditure
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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Research Background
Asua, Jose. Polymer Reaction Engineering. s.l. : Wiley-Blackwell, 2007. ISBN.
formation
of the
deposit
material
transport
material
transport
material
transport
material
transport
cogulation
other
mechanisms
particulate fouling
chemical fouling

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Research Background
Project concept
•early detection of deposit generation
•directly at the point of origin, inline

Installation of probes in the reactors equipped
with optical light fibres

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Theoretical Basics
 ,=0−
(

•Refractive index electromagnetic
wave
•real part 
•imaginary part 
•Poynting-Vector ⃗
with the
combined imaginary proportion ()
⃗
=×=  =0−2
=0−
=

0
=−
•In case of deposit formation
•Scattering properties / intensity
signal
•UV-VIS, NIR, Raman
•Absorption or extinction

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Theoretical Basics
Rod probe in mixing
element
UNIS, BASF
ATR -probe
Wacker, TU Braunschweig
Rod probe
Wacker, TU Braunschweig
deposit
deposit
deposit
Type of deposit?
Earlier detection
Two possible variants
(manifestation):
1. Diffuse scattering
deposits built up from
primary particles
or
2. Homogeneous, non-
scattering, smooth
coverings
scattering Decoupling the light
as a function of the layer
thickness growth
Change in the reflection
of the light
as a function of the layer
thickness growth
reactor wall
mixing element

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Design and selection of the measuring system
•Preliminary examination of the samples in the laboratory using
spectroscopic methods
•VIS, NIR, Raman
•Selection of suitable spectral wavelengths
•Construction of suitable probes
•Rod probe,
•ATR probe
•Electronics structure and development
•Detector selection
•Light source selection

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Design and selection of the measuring system

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Example System BASF

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Example System BASF

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Example System UNI Stuttgart

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Example System Wacker/TUBraunschweig

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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Summary and Further proceeding
•Measurement possible with glasfibre in the micro channel
•Signal changes clearly recognisable
•Detailed measurement series for each system to be able to
interpret the data

Dr.-Ing. Tobias Teumer
HS Mannheim
Institut CeMOS
Tel.: 0621 / 370086 -24
eMail: t.teumer@hs-mannheim.de
www.cemos.hs-mannheim.de
Funded by German Federal Ministry of Economics and Labour as part of
the project KoPPonA (FK: 03EN2004K)
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T. Teumer / optical sensors for fouling detection-KoPPonA / 13th ECCE / online / 23.092021
Thank you for your attention