TY - JOUR A1 - Meyer, Klas A1 - Ruiken, J.-P. A1 - Illner, M. A1 - Paul, Andrea A1 - Müller, D. A1 - Esche, E. A1 - Wozny, G. A1 - Maiwald, Michael T1 - Process spectroscopy in microemulsions - setup and multi-spectral approach for reaction monitoring of a homogeneous hydroformylation process N2 - Reaction monitoring in disperse systems, such as emulsions, is of significant technical importance in various disciplines like biotechnological engineering, chemical industry, food science, and a growing number other technical fields. These systems pose several challenges when it comes to process analytics, such as heterogeneity of mixtures, changes in optical behavior, and low optical activity. Concerning this, online nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for process monitoring in complex reaction mixtures due to its unique direct comparison abilities, while at the same time being non-invasive and independent of optical properties of the sample. In this study the applicability of online-spectroscopic methods on the homogeneously catalyzed hydroformylation system of 1-dodecene to tridecanal is investigated, which is operated in a mini-plant scale at Technische Universität Berlin. The design of a laboratory setup for process-like calibration experiments is presented, including a 500 MHz online NMR spectrometer, a benchtop NMR device with 43 MHz proton frequency as well as two Raman probes and a flow cell assembly for an ultraviolet and visible light (UV/VIS) spectrometer. Results of high-resolution online NMR spectroscopy are shown and technical as well as process-specific problems observed during the measurements are discussed. KW - Online-spectroscopy KW - Quantitative NMR spectroscopy KW - Process analytical technology KW - Microemulsions PY - 2017 U6 - https://doi.org/10.1088/1361-6501/aa54f3 SN - 0957-0233 SN - 1361-6501 VL - 28 IS - 3 SP - 035501-1 EP - 035501-11 PB - IOP Publishing Ltd. AN - OPUS4-39091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Andrea A1 - Meyer, Klas A1 - Ruiken, Jan-Paul A1 - Illner, M. A1 - Müller, D.-N. A1 - Esche, E. A1 - Wozny, G. A1 - Westad, Frank A1 - Maiwald, Michael T1 - Process spectroscopy in microemulsions — Raman spectroscopy for online monitoring of a homogeneous hydroformylation process N2 - A major industrial reaction based on homogeneous catalysis is hydroformylation for the production of aldehydes from alkenes and syngas. Hydroformylation in microemulsions, which is currently under investigation at Technische Universität Berlin on a mini-plant scale, was identified as a cost efficient approach which also enhances product selectivity. Herein, we present the application of online Raman spectroscopy on the reaction of 1-dodecene to 1-tridecanal within a microemulsion. To achieve a good representation of the operation range in the mini-plant with regard to concentrations of the reactants a design of experiments was used. Based on initial Raman spectra partial least squares regression (PLSR) models were calibrated for the prediction of 1-dodecene and 1-tridecanal. Limits of predictions arise from nonlinear correlations between Raman intensity and mass fractions of compounds in the microemulsion system. Furthermore, the prediction power of PLSR models becomes limited due to unexpected by-product formation. Application of the lab-scale derived calibration spectra and PLSR models on online spectra from a mini-plant operation yielded promising estimations of 1-tridecanal and acceptable predictions of 1-dodecene mass fractions suggesting Raman spectroscopy as a suitable technique for process analytics in microemulsions. KW - Raman KW - Online KW - Chemometrics KW - Hydroformylation KW - Mini-plant KW - Microemulsion PY - 2017 U6 - https://doi.org/10.1088/1361-6501/aa54f0 SN - 1361-6501 SN - 0957-0233 VL - 28 IS - 3 SP - 035502-1 EP - 035502-11 PB - IOP Publishing Ltd CY - UK AN - OPUS4-39032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, Klas A1 - Rademann, K. A1 - Panne, Ulrich A1 - Maiwald, Michael T1 - Quantitative NMR spectroscopy for gas analysis for production of primary reference gas mixtures N2 - Due to its direct correlation to the number of spins within a sample quantitative NMR spectroscopy (qNMR) is a promising method with absolute comparison abilities in complex systems in technical, as well as metrological applications. Most of the samples studied with qNMR are in liquid state in diluted solutions, while gas-phase applications represent a rarely applied case. Commercially available NMR equipment was used for purity assessment of liquid and liquefied hydrocarbons serving as raw materials for production of primary reference gas standards. Additionally, gas-phase studies were performed within an online NMR flow probe, as well as in a high-pressure NMR setup to check feasibility as verification method for the composition of gas mixtures. KW - Quantitative NMR spectroscopy KW - Gas-phase NMR spectroscopy KW - Primary reference gas mixtures PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S1090780716302518 U6 - https://doi.org/10.1016/j.jmr.2016.11.016 SN - 1090-7807 SN - 1096-0856 VL - 275 SP - 1 EP - 10 AN - OPUS4-38803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -