Detection of Agglomeration by Analysis of Vibration Signatures in a Pilot-Scale Fluidized Bed Reactor of Propylene Polymerization

Abstract Polymerization of propylene was performed in a pilot fluidized bed reactor, resembling an industrial unit. In order to detect agglomeration in this reaction process, wall vibration signatures of the bed, which contains useful information about its hydrodynamics, were measured by an accelerometer. This approach is non-intrusive and can be easily applied in industry. Different methods employed to analyze the measured vibration signatures. Average cycle frequency of the signatures showed that agglomerates were formed and settled down in the reactor during the process. Plot of the power spectral density function of vibration signals showed that the peak corresponding to the dominant frequency generated by bubbles is located around 2,000 Hz. Energy of the signal among the three hydrodynamic structures in the bed (i. e., micro, meso and macro-scales) showed a decrease in share of macro-scale and a slight increase in share of micro and meso-scales due to the formation of agglomerates. The principal component analysis was performed to characterize the hydrodynamic changes occurred in bed due to formation of agglomerates during the polymerization reaction. Using the S-statistic test, changes in the hydrodynamics of the bed due to formation of agglomerates were detected about 20 minutes before defluidization.