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

A mathematical model is proposed for the partial oxidation on n-butane to maleic anhydride (MAN) in a gas-solid fluidized bed reactor. The reactor consists of two regions, i.e., a lower dense region and an upper dilute region. The dynamic two-phase structure was used for modeling the lower dense bed hydrodynamics. The upper region hydrodynamics was modeled by a cluster based approach. This allows the porosity distribution to be calculated for plug flow reactor model assumed for the gas phase in this region. The basic assumption in the cluster based approach is that the solid particles move only as clusters and the amount of single particles in the upper region is negligible. The mathematical model was obtained from coupling the kinetic sub-model, obtained from the literature, with this hydrodynamics sub-model. Comparing the results of the model with the experimental data available in the literature showed close agreement. Two other methods (i.e., particle based approach and short-cut) were also tested in this work. However, it was found that the cluster based approach modeling is quite suitable for the fluidized bed reactor used in this study. The short-cut method seems reasonably applicable for the prediction of the overall conversion but does not provide any local information (such as concentration profiles, yield, etc.) within the fluidized bed reactor.

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Dynamic modeling and Molecular Weight Distribution of ethylene copolymerization in an industrial gas-phase Fluidized-Bed Reactor

Advanced Powder Technology ◽

10.1016/j.apt.2016.05.014 ◽

2016 ◽

Vol 27 (4) ◽

pp. 1526-1538 ◽

Cited By ~ 14

Author(s):

Mohammad Reza Abbasi ◽

Ahmad Shamiri ◽

M.A. Hussain

Keyword(s):

Molecular Weight ◽

Gas Phase ◽

Fluidized Bed ◽

Molecular Weight Distribution ◽

Dynamic Modeling ◽

Weight Distribution ◽

Fluidized Bed Reactor

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

MATEC Web of Conferences ◽

10.1051/matecconf/201815607002 ◽

2018 ◽

Vol 156 ◽

pp. 07002

Author(s):

Nazratul Fareha Salahuddin ◽

Ahmad Shamiri ◽

Mohd Azlan Hussain ◽

Navid Mostoufi

Keyword(s):

Gas Phase ◽

Fluidized Bed ◽

Fuzzy Logic Controller ◽

Fluidized Bed Reactor ◽

Solid Particles ◽

Phase Model ◽

Regulatory Control ◽

Generic Model ◽

Two Phase ◽

Model Control

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.

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Two Phase Dynamic Model for Gas Phase Propylene Copolymerization in Fluidized Bed Reactor

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.312-315.1079 ◽

2011 ◽

Vol 312-315 ◽

pp. 1079-1084 ◽

Cited By ~ 4

Author(s):

Ahmad Shamiri ◽

Mohd Azlan Hussain ◽

Farouq S. Mjalli

Keyword(s):

Gas Phase ◽

Fluidized Bed ◽

Mixed Model ◽

Model Simulation ◽

Fluidized Bed Reactor ◽

Rate Of Change ◽

Two Phase ◽

Emulsion Phase ◽

Proposed Model ◽

Bubble Phase

A two-phase model is proposed for describing the dynamics of a fluidized bed reactor used for polypropylene production. In the proposed model, the fluidized bed is divided into an emulsion phase and bubble phase where the bubble phase flow pattern is assumed to be plug flow and the emulsion phase is considered to be perfectly mixed. Similar previous models consider the reaction in the emulsion phase only. In this work the contribution of reaction in the bubble phase is considered and its effect on the overall polypropylene production is investigated. The kinetic model combined with hydrodynamic model in order to develop a comprehensive model for gas-phase propylene copolymerization reactor. Simulation profiles of the proposed model were compared with those of well mixed model for the emulsion phase temperature. The simulated temperature profile showed a lower rate of change compared to the previously reported models due to lower polymerization rate. Model simulation showed that about 13% of the produced polymer comes from the bubble phase and this considerable amount of polymerization in the bubbles should not be neglected in any modeling attempt.

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