Contactperson: M.Sc. Torben Frey
Financing:Federal Ministry of Economics and Energy (BMWI)
Duration: 10/19 - 10/22
Prof. Guido Grundmeier, UP, Technical and Molecular Chemistry (TMC);
Prof. Markus Grünewald, RUB, Fluid Process Engineering (FVT);
Prof. Alexander Mitsos, RWTH, Process Systems Engineering (AVT);
Prof. Ulrich Nieken, US, Institute of Chemical Process Engineering (ICVT);
Prof. Thomas Musch, RUB, Institute of Electronic Circuits (EST);
Prof. Stephan Scholl, TUB, Institute of Chemical and Thermal Process Engineering (ICTV);
Prof. Eberhard Schlücker, FAU, Institute of Process Maschine and Plant Engineering (IPAT);
Prof. Werner Pauer, UHH, Institute of Technical and Macromolecular Chemistry (TMC);
Prof. Matthias Rädle, HSM, Institute of Process Measurement Technology and Innovative Energy Systems (CEMOS);
A number of energy demanding and inefficient processes are allocated within the German chemical industry, especially the production of pharmaceutical, fine and special chemicals. The concerned products are mostly produced utilizing multi-product plants and small batch processes due to small throughput. Increasing energy efficiency of new production processes is the main objective of the ENPRO initiative. The initiative aims to develop new technologies which have not been established yet on the market and furthermore to reduce the project development time for innovative processes. During the first phase of the ENPRO 1.0 initiative (2014-2017) the project partners have developed flexible, scalable and modular plant concepts. These concepts are designed to suit small product lines and specialties while sustaining the benefits of continuous production plants. Micro-structured devices have been proven to suit requirements for the combined product and process development. However, one drawback of micro-structured mixers, reactors and heat exchangers for continuous processes is the formation of gel or solid particles leading to fouling and blocking of the device.
The objective of the second phase (ENPRO 2.0) and especially the KoPPonA 2.0 project is to drive the development of continuous process concepts for polymer production which are sensitive to fouling. A conglomerate of plant operators, equipment and sensor suppliers, material scientists and process engineers work together in KoPPonA 2.0 to research causes and preventive measures of fouling. KoPPonA 2.0 uses innovative approaches in plant design, surface modification, and reaction control are used to allow efficient and safe operation of continuous polymerization processes. By investigating basic fouling mechanisms in continuous polymerization processes a universal comprehension of fouling is to be derived. The goal is to predict and quantify fouling with appropriate models, detect fouling in-line through sensors, and prevent fouling inherently by design precautions. The Institute of Multiphase Flows (V-5) is tasked with generating a comprehensive model of the process components that are prone to fouling. The model incorporates hydrodynamic flow phenomena, mass transfer, kinetics and different fouling mechanisms. The complex interaction of viscosity change and formation of gel particles with the hydrodynamics of the reactive flow lie in the focus of the IMS research.
Mixing is a critical step for describing reactive flows as the kinetics heavily depend on the concentration distribution. In a first step, the IMS investigates the micro mixing of monomer and catalyst in micro structured devices, especially flow phenomena emerging from large volume flow ratios between monomer and catalyst (> 50). The Confocal Laser Scanning Microscope (CLSM) at the IMS is utilized to visualize three-dimensional concentration distribution at micro scale (resolution down to 1 μm) with Laser-Induced Fluorescence (LIF). The measured concentration fields validate the models generated with ANSYS Fluent. The statistical mixing quality can be easily assessed from the simulated (CFD) and measured (LIF) concentration fields. In corporation with the Ruhr University Bochum (RUB) state-of-the-art techniques to assess mixing quality (e.g. Villermaux-Dushman) are compared with the measured mixing quality. The second step builds on the existing models. The kinetics of the catalytic polymerization are modelled within ANSYS Fluent. A simplified reaction network is used to describe the formation of gel particles leading to fouling. The impact on viscosity and precipitation of solid particles is described via User Defined Functions (UDF) to fill the comprehensive model predicting fouling.