Use of Online Spectroscopy to Control Polymerization in Industrial Processes

Abstract

Online analyzers enable manufacturers to operate modern polymerization processes as safely, reliably, and profitably as possible. The most critical application of this technology involves monitoring the reactor itself to determine the molecular weight and comonomer content of the polymer produced. Polymer process streams introduce unique challenges for online analyzers because the process chemistry, sample transport, and stream conditions are harsher, prone to fouling, and pose unique safety hazards. Spectroscopy lends itself very well to online analysis of polymers because the data it provides is information rich and can be deployed using fiber optics for remote sampling of gases, liquids, and solids. Additionally, it is relatively fast and reliable if well designed and installed properly. The combination of spectroscopy, fiber optics, and chemometrics gives manufacturers the ability to use modern spectrometers and statistical models to analyze and monitor diverse types of polymerization processes. Several examples are provided in this article, including application to polyethylene, polycarbonate, polyurethane, and polystyrene processes.

Dynamic Optimization and Non‐linear Model Predictive Control to Achieve Targeted Particle Morphologies

“…To date, there is also a significant body of literature on the application of Raman spectroscopy for monitoring monomer composition in different polymerization systems. A recent review provides several examples of industrial applications of optical spectroscopy methods, including Raman scattering, in the polymerization processes . State of the art of monitoring monomer concentrations in emulsion polymerization was tested: good individual monomer concentration models were developed for up to two monomers, as both monomers were good scatterers and sufficiently accurate chemometric models could be developed.…”

Monitoring of polymer content in an emulsion polymerization using spatially resolved spectroscopy in the near infrared region and Raman spectroscopy

“…Spectroscopy has increasingly been used for online monitoring of polymerization systems, mainly Raman, mid infrared (MIR), and near infrared (NIR) spectroscopies. 11,12 Such techniques use probes that can be inserted in an existing reactor with no need of sampling. Raman spectroscopy has been widely used in emulsion polymerization due to the low interference of water in the measurement.…”

In situ conversion monitoring of styrene emulsion polymerization by deconvolution of a single reference band near 1,000 cm−1

“…Spectroscopic techniques appeared particularly adapted for polymer processes and especially the Raman spectroscopy . Indeed, this fast and noninvasive technique was suitable for monitoring reaction progress, adapted to in situ measurements and provided a lot of information .…”

“…[5] Spectroscopic techniques appeared particularly adapted for polymer processes and especially the Raman spectroscopy. [6][7][8][9][10][11] Indeed, this fast and noninvasive technique was suitable for monitoring reaction progress, adapted to in situ measurements and provided a lot of information. [12,13] Raman spectroscopy was effective for monitoring monomer consumption for any kind of polymerization process.…”