Dr.-Ing. Fabian Hagen

Dr.-Ing. Björn Stelzner

Students of chemical engineering/process engineering (or equivalent) interested in experimental work and with a preference for innovative diagnostic tools. Knowledge of optical diagnostics may help you get started but is not required.

Location: CS

Motivation:

Iron particles and their oxides can be utilized in a cycle as a carbon-free chemical energy carrier for storing electricity generated from renewable sources. Renewable electricity is used to reduce iron oxide (storage). Micron-sized iron particles are oxidized to release energy for electricity generation (release) at separate locations and times. This enables renewable energy to be stored and transported on a large scale and released CO2-free - a central challenge of the energy transition that has yet to be solved. At the Engler-Bunte Institute, the high temperature oxidation of iron particle ensembles for energy storage is being intensively investigated. According to current knowledge, it is assumed that the rate-determining step in the oxidation of iron particles is due to the reaction of iron with molecular oxygen to form iron(II) oxide (Fe + 0.5 O₂ -> FeO). The unwanted formation of nanoparticles can possibly also be attributed to a supersaturated gas phase of iron(II) oxide.

Task:

The aim of this master’s thesis is the spatially resolved quantification of the concentration of gas phase iron(II) oxide using planar laser-induced fluorescence (PLIF). Laser-induced fluorescence involves two steps: Absorption of a photon emitted by a laser followed by the emission of a fluorescence photon from the excited electronic state. The first step is to evaluate a suitable and allowed electronic transition to excite a LIF signal from iron(II) oxide. The resulting excitation wavelength must then be tuned using a suitable dye laser. In addition, the detection unit and the light sheet optics must be set up and the excitation pulse synchronized with the detection unit. The functionality of the PLIF system is to be demonstrated by visualizing gas phase iron(II) oxide in a generic validation experiment. This experiment is also to be designed and set up. Here, among other things, the impact of quenching on the LIF signal must be assessed. The master’s thesis concludes with the determination of the two-dimensional concentration field of iron(II) oxide in an iron dust flame as a function of varying boundary conditions.

Responsible:

Prof. Dr.-Ing. Dimosthenis Trimis