Fuzzy-GMC Control of Gas-Phase Propylene Copolymerization in Fluidized Bed Reactor

Abstract

A modified two-phase model for gas phase propylene and ethylene copolymerization was chosen to represent the process in a fluidized bed reactor. This model considered the entrainment of solid particles in the reactor, as a modification to the original two-phase model assumptions. The non-linearity of this process makes it difficult to control just by using conventional controller such as PID. A hybrid control strategy (a simple designed fuzzy logic controller (FLC) integrated with generic model control (GMC)) is designed to control the temperature of the reactor. This advanced control system was compared with the GMC and conventional PID controller. The simulation results showed that the hybrid controller (Fuzzy-GMC) performed better than both GMC and PID in terms of both servo and regulatory control.

Dynamic modeling: The influence of the improved solid elutriation correlation on the two‐phase mathematical model of polyolefin polymerization in a gas‐phase fluidized bed reactor

“…The two‐phase model was built and simulated under the following assumptions: The olefin polymerization reaction occurred in the emulsion and bubble phases. The emulsion phase was well mixed and not set at a minimum fluidization condition. The bubbles formed in the reactor were spherical with a constant diameter, and their upward movement was at a constant velocity. The heat and mass transfer resistance was not taken into account due to the assumption that the solid particle size remains constant. The radial gradient of concentration and temperature was ignored. The solid elutriation at the top of the reactor was taken into account. The heat loss through the fluidized bed wall was ignored. …”

“…Ho et al and Shamiri et al implemented the improved two‐phase model in which the reaction was assumed to occur in both the emulsion and bubble phases and the emulsion phase was not occurring at minimum fluidization. Although Abbasi et al and Salahuddin et al improved the previous two‐phase model by considering the presence of solid elutriation, the accuracy of the proposed solid elutriation correlation could be improved. Thus, the objective of this research is to refine the implemented solid elutriation correlation with the aim of improving the predicted production rate generated from this two‐phase model.…”

Advances in Mathematical Modeling of Gas-Phase Olefin Polymerization

“…Solid elutriation is considered [48] Two-phase Model/Ethylene-1-butene copolymer Well-mixed condition 3.…”

“…[ [48][49][50][51][55][56][57][58][59]62,95,96,102] As mentioned in Table 3, the number of stages in the reaction mechanism for this olefin polymerization process in the gas phase via the coordination mechanism by using the organometallic catalyst, namely Ziegler-Natta catalyst, metallocene-based catalyst, or chromium oxide-based catalyst implemented previously differ from one study to another study. Most of the studies considered that the polymerization reaction commences by activating the active site.…”

“…Then, for a two-phase model where the reactions were assumed to occur in the emulsion and bubble phase, the heat and mass transfer model is written in the following form [48]. For heat and mass balance equations in the emulsion phase, the equations are written as follows:…”