J. Viell
RWTH Aachen University
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Publication
Featured researches published by J. Viell.
Applied Spectroscopy | 2016
Julian Meyer-Kirschner; Michael Kather; Andrij Pich; Dirk Engel; Wolfgang Marquardt; J. Viell; Alexander Mitsos
This contribution presents in-line monitoring of microgel synthesis by precipitation polymerization based on Raman spectroscopy. The spectra are evaluated via multivariate Indirect Hard Modeling (IHM) regression. Therefore, mechanistic models of the pure component spectra for solvent, monomer, and microgel are created by a sum of adaptable parameterized peak functions (Gaussian–Lorentzian). Instead of individual calibrations for each analyte, one comprehensive model is calibrated to predict both the monomer and microgel fraction while ensuring a consistent mass balance. As a novelty, this leads to an in-line microgel quantification based on an interactive spectral model. The results show cross-validation errors (RMSECV) of monomer and microgel fractions as low as 0.028 wt % and 0.084 wt %, respectively. The ability of IHM to account for non-linear spectral changes was found to reduce the microgel RMSECV by a factor of two compared to linear CLS regression. The calibration model allows simultaneous observation of the decrease in monomer content and the formation of microgels. Long as well as short focus immersion optics reveal characteristic vibrations of the turbid microgel suspension, although long focus optics are influenced by scattering particles to a greater extent. Precise examination of the model proves that the prediction is robust against changes in microgel particle size or temperature, which opens up the application of Raman spectroscopy as a comprehensive process analytical technology in microgel synthesis.
Computer-aided chemical engineering | 2012
Wolfgang Marquardt; Andreas Harwardt; Sebastian Recker; J. Viell; Anna Voll
Abstract This paper argues for a paradigm shift to properly address the requirements of modelbased design of future bio-based value chains. Rather than focusing on the process with emphasis on separations and heat integration, the decisions on the molecular level require much more attention. A rough sketch of a systematic sequential and iterative model-based design strategy is presented and illustrated by a few examples related to the manufacturing of future bio-based fuels.
Aiche Journal | 2010
Wolfgang Marquardt; Andreas Harwardt; Manuel Hechinger; Korbinian Kraemer; J. Viell; Anna Voll
Journal of Raman Spectroscopy | 2018
Julian Meyer-Kirschner; Alexander Mitsos; J. Viell
Chemie Ingenieur Technik | 2016
Kirsten Ulonska; Mirko Skiborowski; Alexander Mitsos; J. Viell
Chemie Ingenieur Technik | 2014
Julian Meyer-Kirschner; J. Viell; Alexander Mitsos
Chemie Ingenieur Technik | 2014
Wolfgang Marquardt; Kirsten Ulonska; J. Viell; Alexander Mitsos
Chemie Ingenieur Technik | 2012
J. Viell; Wolfgang Marquardt
Chemie Ingenieur Technik | 2012
J. Viell; Andreas Harwardt; Wolfgang Marquardt
Chemie Ingenieur Technik | 2010
Helene Wulfhorst; Philip Engel; A. Ogolong; J. Viell; Jochen Büchs; Antje C. Spiess