Broadening the polyethylene molecular weight distribution by controlling the hydrogen concentration and catalyst feed rates

Emad, Ali; Ali, Mushir

doi:10.1016/j.isatra.2009.11.001

Cited by 8 publications

(4 citation statements)

References 30 publications

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“…Using both C 2 and H 2 simultaneously helps to obtain the required MWD as shown in Figure 1. The simulation in Figure 1 is reproduced from Ali and Al‐haj Ali 17. However this approach leads to undesirable plant operations.…”

Section: Resultsmentioning

confidence: 99%

“…Thus it is thoughtful to control X via manipulating F H2 exclusively at fixed F C2 . However, earlier investigation17 indicated that, using F H2 alone, the desired MWD can be either unachievable or hard to be achieved for two reasons. The possible attainable range for X is restricted because the permissible range for H 2 feed flow rate is physically limited.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, at low monomer feed rate a reduced production rate is obtained. Ali and Al‐haj Ali17 tried to overcome the undesirable operation by altering X via manipulating the hydrogen flow rate solely. Relying on the hydrogen flow rate was a difficult task because it has a slow dynamics and a limited effect on the attainable range for X .…”

Section: Introductionmentioning

confidence: 99%

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Broadening the Polyethylene Molecular Weight Distribution by Periodic Variation of the Hydrogen Feed Rate

Ali

Esrafili

2010

Macro Reaction Engineering

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The ability to control the molecular weight distribution of the created polyethylene in gas‐phase fluidized‐bed reactors is discussed. This objective is achieved via nonlinear model predictive controller utilizing the hydrogen feed rate as the only manipulated variable. The idea for limited usage of manipulated variables is to avoid economically unfavorable operations such as excessive purge and/or reduced production rate. The simulation results indicated successful implementation of the control algorithm to attain the desired molecular weight distribution. The success depends on the improved hydrogen activities inside the reactor by employing a modified catalyst that is responsive to hydrogen variation and allowing a wider range for hydrogen feed rates.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Broadening the Polyethylene Molecular Weight Distribution by Periodic Variation of the Hydrogen Feed Rate

Ali

Esrafili

2010

Macro Reaction Engineering

Self Cite

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“…By using modified three-phase model, the neural-network based MPC displayed greater performance in handling servo and regulatory control than PID. To control molecular weight distribution (MWD), E. M. Ali and Ali (2010) [10] designed nonlinear MPC to manipulate hydrogen flow and catalysts feed rate. The non-linear predictive control managed to give a good performance even when there is modeling errors.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2018

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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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Hybrid observer for parameters estimation in ethylene polymerization reactor: A simulation study

Ali

Hoang

Hussain

et al. 2016

Applied Soft Computing

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Broadening the polyethylene molecular weight distribution by controlling the hydrogen concentration and catalyst feed rates

Cited by 8 publications

References 30 publications

Broadening the Polyethylene Molecular Weight Distribution by Periodic Variation of the Hydrogen Feed Rate

Broadening the Polyethylene Molecular Weight Distribution by Periodic Variation of the Hydrogen Feed Rate

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

Hybrid observer for parameters estimation in ethylene polymerization reactor: A simulation study

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