Optimization and Control of Industrial Gas-Phase Ethylene Polymerization Reactors

Esrafili, Ali; Abasaeed, and A. E.; Al-Zahrani, S.M.

doi:10.1021/ie980048+

Cited by 26 publications

(29 citation statements)

References 14 publications

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“…A significant source of this limited use is that these late transition metal catalysts are often thermally unstable, and thus not be suitable for many industrially used polyolefin synthetic processes, such as fluidized bed reactors ( Fig. 4) that may operate at temperatures as high as 70-110 ∘ C. 38 As a result, the quest to develop thermally robust, late transition metal catalysts has been a fruitful area of research over the past two decades and is the primary focus of this review.…”

Section: Introductionmentioning

confidence: 99%

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Recent advances in thermally robust, late transition metal‐catalyzed olefin polymerization

Mitchell

Long

2018

Polymer International

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Olefin polymerization catalysts employing late transition metals, such as Ni, Pd, Fe and Co, have been heavily investigated since their discovery in the mid‐1990s. Despite the advantages and appeal these catalysts have displayed in academic research, their implementation in industry has remained restricted due to a variety of limitations and drawbacks. One specific limitation is the relative thermal instability of most late transition metal olefin polymerization catalysts at the temperatures commonly utilized for industrial polymerizations. This review focuses on the development of Ni‐, Pd‐, Fe‐ and Co‐based olefin polymerization catalysts that display increased thermal stability at super‐ambient reaction temperatures. These advances in thermal stability have been realized using a variety of ligand modifications, and their polymerization activities and thermal stability are summarized herein. Lastly, a brief outlook on the future of thermally stable, late transition metal olefin polymerization catalysts is provided. © 2018 Society of Chemical Industry

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Section: Introductionmentioning

confidence: 99%

“…Schematic diagram of a fluidized bed reactor for gaseous olefin polymerizations 38. Adapted with permission from Ind Eng Chem Res 37:3414 (1998).…”

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confidence: 99%

Recent advances in thermally robust, late transition metal‐catalyzed olefin polymerization

Mitchell

Long

2018

Polymer International

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“…For the production of LLDPE, the polymer can be synthesized by the polymerization of ethylene and short chain 1-olefins, namely 1-hexene, 1-octene and 1-decene, in the catalyst system for better activity. A low pressure slurry process, the gas phase process and the solution-phase process [ 4 ] can be employed for LLDPE. Some 15 million tons of LLDPE are produced worldwide using the metallocene catalyst system, since this catalyst can incorporate many types of comonomer.…”

Section: Introductionmentioning

confidence: 99%

Observation of Different Catalytic Activity of Various 1-Olefins during Ethylene/1-Olefin Copolymerization with Homogeneous Metallocene Catalysts

2011

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This research aimed to investigate the copolymerization of ethylene and various 1-olefins. The comonomer lengths were varied from 1-hexene (1-C6) up to 1-octadecene (1-C18) in order to study the effect of comonomer chain length on the activity and properties of the polymer in the metallocene/MAO catalyst system. The results indicated that two distinct cases can be described for the effect of 1-olefin chain length on the activity. Considering the short chain length comonomers, such as 1-hexene, 1-octene and 1-decene, it is obvious that the polymerization activity decreased when the length of comonomer was higher, which is probably due to increased steric hindrance at the catalytic center hindering the insertion of ethylene monomer to the active sites, hence, the polymerization rate decreased. On the contrary, for the longer chain 1-olefins, namely 1-dodecene, 1-tetradecene and 1-octadecene, an increase in the comonomer chain length resulted in better activity due to the opening of the gap aperture between Cp(centroid)-M-Cp-(centroid), which forced the coordination site to open more. This effect facilitated the polymerization of the ethylene monomer at the catalytic sites, and thus, the activity increased. The copolymers obtained were further characterized using thermal analysis, X-ray diffraction spectroscopy and 13C-NMR techniques. It could be seen that the melting temperature and comonomer distribution were not affected by the 1-olefin chain length. The polymer crystallinity decreased slightly with increasing comonomer chain length. Moreover, all the synthesized polymers were typical LLDPE having random comonomer distribution.

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“…The models used for these predictions have been linear approximations of the process which are obtained experimentally from step response data. Unfortunately, strong nonlinear behavior is often found in real chemical processes such as highly exothermic batch polymerization reactors [2][3][4]. There are also some approaches in which linear control is used, combined with non-linear models for setpoint updating [5].…”

Section: Introductionmentioning

confidence: 99%

Application of experimental non-linear control based on generic algorithm to a polymerization reactor

Özkan

Tekin

Hapoğlu

2009

Korean J. Chem. Eng.

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The dynamics of free radical polymerization of styrene and on-line control of temperature in a cooling jacketed batch polymerization reactor is investigated. The benzoyl peroxide initiator is introduced into the reactor once at the beginning of the reaction to obtain the desired monomer conversion and the desired average chain length in a minimum reaction time. The optimal constant set temperature, which is generally realized in industrial applications, and the set profile are used as two different optimal operating conditions. The temperature control of the polymerization reactor is achieved experimentally and theoretically. The control of nonlinear systems has progressed considerably, and various nonlinear process model based control techniques have appeared in the literature. The problem is how to tune the controller in order to obtain comparable closed loop responses. Generic model control (GMC) is applied and the performance of the control results are compared with the previously published control results.

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Optimization and Control of Industrial Gas-Phase Ethylene Polymerization Reactors

Cited by 26 publications

References 14 publications

Recent advances in thermally robust, late transition metal‐catalyzed olefin polymerization

Recent advances in thermally robust, late transition metal‐catalyzed olefin polymerization

Observation of Different Catalytic Activity of Various 1-Olefins during Ethylene/1-Olefin Copolymerization with Homogeneous Metallocene Catalysts

Application of experimental non-linear control based on generic algorithm to a polymerization reactor

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