@PhdThesis{duepublico_mods_00082469,
  author = 	{Prenting, Markus Michael},
  title = 	{Optical and laser-based in situ diagnostics in lab-scale and pilot-scale spray flames for nanoparticle synthesis},
  year = 	{2024},
  month = 	{Oct},
  day = 	{16},
  abstract = 	{The flame synthesis of metal-oxide nanoparticles is a rapidly evolving field of research. Nanoparticles feature unique properties and are hence of outstanding interest for numerous applications as, e.g., catalysis, battery technology, or gas sensing. The synthesis in spray flames enables the production of oxides of almost all metal elements based on low-cost precursors. It is possible to synthesize tailored particles with various morphologies and compositions, and thus properties, that are of high interest for industry. However, in its current status the synthesis of metal-oxide nanoparticles is largely on the research stage with production rates on the laboratory scale. Work to upscale processes is progressing, but further research is required to gain a deeper process understanding of the nanoparticle synthesis in spray flames. This work was conducted within the frame of Priority Program SPP1980 ``Nanoparticle Synthesis in Spray Flames'' funded by the German Research Foundation (DFG). The aim of this project consortium is to establish a standardized spray burner (referred to as SpraySyn burner) that enables interdisciplinary collaboration across numerous laboratories on the identical spray flame with consistent operating conditions and characteristics. Efforts are aimed at facilitating the exchange of insight, experimental, and simulation data to advance process understanding of the nanoparticle synthesis in spray flames. In this work, experimental data were generated by optical, mainly laser-based in situ diagnostics for two versions of the laboratory-scale SpraySyn flame and two pilot-scale spray flames. For the first version of the SpraySyn flame, chemiluminescence was measured in a spectrally resolved manner at different heights above the burner under various operating conditions (e.g., the synthesis of iron oxide and silica nanoparticles with the precursors iron nitrate nonahydrate and hexamethyldisiloxane, respectively). Droplet velocity and size distributions were measured for the second version of the SpraySyn burner by laser-Doppler and phase-Doppler anemometry, respectively. The data are provided for different operating conditions (variation of flow rates and liquid fuels) in form of two-dimensional maps spanning vertical and horizontal direction as well as flame-centerline profiles. For two pilot-scale spray flames, time-averaged gas-temperature maps were measured by multi-line laser-induced fluorescence thermometry of seeded NO to investigate the impact of gas temperature on the synthesis and the properties of iron oxide nanoparticles. The main part of this work is on liquid-phase temperature measurements in the evaporating spray of the SpraySyn flame by two-color laser-induced fluorescence thermometry using fluorescing dyes dissolved in the fuel as temperature tracers. An extended study was performed on the suitability of various dyes for the challenging environment. Coumarin 152 turned out to be the most suitable tracer. Its applicability was demonstrated by measuring time-averaged liquid-temperature maps in the first and second version of the SpraySyn burner. Various operating conditions were investigated with ethanol as fuel. The experimental results generated in this work were used by cooperation partners as boundary conditions for simulations and for the validation of various simulation models.},
  doi = 	{10.17185/duepublico/82469},
  url = 	{https://duepublico2.uni-due.de/receive/duepublico_mods_00082469},
  url = 	{https://doi.org/10.17185/duepublico/82469},
  file = 	{:https://duepublico2.uni-due.de/servlets/MCRFileNodeServlet/duepublico_derivate_00082004/Diss_Prenting.pdf:PDF},
  language = 	{en}
}