Erik von Harbou, Prof. Dr.-Ing.

• Abstract In this work, new methods are presented that facilitate the application of Nuclear Magnetic Resonance (NMR) spectroscopy for monitoring of reactions and processes. NMR spectroscopy has the advantage that it enables both elucidation of species and their following quantification in a reacting mixture in situ without the need of prior calibration. New post-processing methods were developed that enable handling of large sets of NMR spectra and that reduce influence of the user on the outcome of the measurements of the composition. Furthermore, a spectral analysis method was introduced and tested that allows evaluating the acquired NMR signals quantitatively even if the peaks in the NMR spectrum are distorted and the concentration of analytes becomes very small. As the standard NMR equipment is mostly designed for structure elucidation purposes but not for reaction and process monitoring, the apparatuses were tailored in this work. A liquid thermostatted NMR probe head is presented, in which fast reactions can be monitored under isothermal conditions. Methods and experimental procedures were established to investigate chemical equilibria of different industrial relevant systems in situ. Examples are: the formation of intermediates in the reaction system that is found in the synthesis of crotonaldehyde from acetaldehyde and water, and the reaction that take place in aqueous methyl diethanolamine solutions when loaded with carbon dioxide. Furthermore, an inline analysis method for monitoring dynamic processes reliably with a high chemical and temporal resolution is presented. To demonstrate the potential of this method, the complex interactions of reaction and separation in a fixed-bed chromatographic reactor process were studied. Furthermore, a benchtop NMR spectrometer was employed to study liquid-liquid phase equilibria in situ in different systems. This new type of spectrometer are an interesting alternative to the high-field NMR spectrometer because of its smaller size and lower costs. The results show that benchtop NMR spectrometers have the potential to widen the range of application of NMR spectroscopy for reaction and process monitoring significantly. This works demonstrate that NMR spectroscopy is a useful tool in chemical reaction engineering as it enables detailed insights into complex reactions and processes and provides data that is essential for the development of reliable process models.