Patent Document ID: 7645841
Application ID: 10928047
Patent Flag: 1

Claim One:
1. A method comprising: acquiring a first set of reactor operations data of a liquid-phase polymerization reactor for a first period of reactor operation utilizing a first catalyst; acquiring a second set of reactor operations data of the liquid-phase polymerization reactor for a second period of reactor operation utilizing a second catalyst; performing a periodogram analysis of each of the first and the second sets of reactor operations data; evaluating plots of the respective periodogram analyses to detect first and second periodic components within each of the respective periodogram analyses and to determine which of the respective periodogram analyses has a more reduced or absent second periodic component; selecting one of the first catalyst and the second catalyst based on the evaluation, such that the selected catalyst corresponds to the periodogram analysis with the more reduced or absent second periodic component; and operating the liquid-phase polymerization reactor with the selected catalyst.