title: Installation of a multiplexed Raman system in a chemical process.
abstract: A 785 nm laser dispersive Raman system was installed in a hazardous chemical production plant to monitor two reactors, a still, and a holding tank with measurement directly through sight glasses. Compositional information for several raw materials, intermediates, and products was obtained using partial least squares (PLS) calibrations. Discriminate analysis was used to exclude extremely poor spectra while including usable ones. Derivative/standard normal variate (SNV) treatment was found to be effective for correcting for background fluorescence and for large differences in spectral intensity. Final regression equations incorporated temperature fluctuations, occasional fluorescence, some sunlight effects, large intensity variations, and large compositional changes. Various installation problems were solved via data treatment or mechanical changes. The Raman system provides information for control of the process, resulting in cost savings and improved safety.
authors.affiliation: ATK Elkton LLC, 55 Thiokol Road, Elkton, Maryland 21921, USA.
authors.forename: Lois G
authors.initials: LG
authors.lastname: Weyer
authors.forename: Dupon
authors.initials: D
authors.lastname: Yee
authors.forename: Gary I
authors.initials: GI
authors.lastname: Pearson
authors.forename: John
authors.initials: J
authors.lastname: Wade
mesh_terms: D000465:Algorithms; D002138:Calibration; D002617:Chemical Industry / Q000295:instrumentation* / Q000379:methods*; D020650:Combinatorial Chemistry Techniques / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods*; D018511:Systems Integration