Kinetic monitoring methods for ethylene coordination polymerization in a laboratory reactor

Abstract

The kinetic performance of metallocene type catalysts as well as their instantaneous activity is determined on line by two independent methods in the semi-batch polymerization of ethylene via metallocenes. The first-principle basis of both methods is described and guidelines for their implementation at a laboratory scale reactor are offered. Polymerization tests were conducted with two heterogenized metallocene catalysts showing that the direct method (based on ethylene flow measurement) and the calorimetric method (based on energy balances and developed here) report equivalent high quality information. This last method can be readily used by the chemical practitioner as the notions and tools required for its implantation are easily grasped; it also has the advantage of requiring a low cost instrumentation (only thermocouples), whereas the direct method needs a relatively more sophisticated equipment (mass flow meter).

Polymerization Reactor Monitoring by In-line Raman Spectrometry

“…[1][2][3]. These techniques allow the real time monitoring of the reactors, as well as making possible the feedback control of important properties of the process, improving the quality of the product and increasing the productivity as well as the safety of the operation.…”

“…The revision described in the papers mentioned above [2][3][4][5][6][7][8], shows that there is demand in the industrial and academic environment of spectroscopic techniques for inline monitoring and control of polymerization reactors. The present report considers the study of common monomers in order to test the spectroscopic technique and the diverse options of sampling modes (immersion probe, in vials, non-invasive probe) as well as to develop quantitative procedures for the spectra analysis (chemometrics).…”