Influence of the metal centers of 2,6‐bis(imino)pyridyl transition metal complexes on ethylene polymerization/ oligomerization catalytic activities

Su, Biyun; Feng, Guoxian

doi:10.1002/pi.2824

Cited by 19 publications

(1 citation statement)

References 25 publications

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“…Linear a-olefins have found wide application in various areas of petrochemical synthesis. They are used for copolymerization with ethylene for the purpose of obtaining low-and high-density linear polyethylene and for the preparation of detergents and synthetic lubricants [12,14,41,48,54,61,62]. They can also be used in the production of surfactants, agents for enhanced oil recovery, corrosion inhibitors, high-performance lubricating oils, linear alkylbenzenes, oxo-synthesis alcohols, a-olefin sulfonates, oil additives, and as drilling fluids [1,3,6,28,35,51,59].…”

Section: Introductionmentioning

confidence: 99%

A kinetic model for ethylene oligomerization using zirconium/aluminum- and nickel/zinc-based catalyst systems in a batch reactor

et al. 2014

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The aim of this work is to develop a kinetic model of the oligomerization of ethylene to linear alpha olefins (LAOs) for zirconium/aluminum and nickel/zinc catalyst systems. The development of such model helps in the study of the behavior of industrial LAOs reactors as well as in the optimization of their operation. The kinetic model was developed based on a four-step mechanism: site activation, initiation and propagation, chain transfer and site deactivation. A novel stochastic optimization algorithm, Intelligent Firefly Algorithm, was used to obtain the kinetic model parameters that best fit the available experimental data that were obtained from published sources. The values of the kinetic parameters were obtained for the developed kinetic models for two catalyst systems. The performance of the model with the estimated parameters was tested against the experimental data. The proposed kinetic model predicts the product distribution for the zirconium/aluminum catalyst system with suitable accuracy. The model can also predict the product distribution for the nickel/zinc catalyst system with good accuracy for all products. As expected, the accuracy of the model to predict the concentration of the higher carbon products decreases with the carbon number. Keywords Ethylene Á Oligomerization Á Modeling Á Zirconium/aluminum catalyst Á Nickel/zinc catalyst Abbreviation Notation A Pre-exponential factor C CAT Catalyst concentration, mol/l C CAT k Active catalyst concentration, mol/l C CAT k ÁM Complex active catalyst/ethylene concentration, mol/l C decy Moles of deactivated catalysts, mol C M Concentration of ethylene monomer, mol/l C M k Concentration of active ethylene monomer, mol/l C M k ÁTEA Concentration of complex active ethylene monomer/co-catalyst, mol/l C P 0 Concentration of active site, mol/l C P i Concentration of living polymers, mol/l C P k i Concentration of active living polymers, mol/l C P k i ÁTEA Concentration of complex active living polymers/co-catalyst, mol/l C TEA Co-catalyst concentration, mol/l C TEA k Active co-catalyst concentration, mol/l C TEA k ÁCAT Complex active co-catalyst/catalyst concentration, mol/l C TEA k 1 ÁCAT Complex active co-catalyst/catalyst concentration-catalyst, mol/l D Moles of dead oligomer, mol E Activation energy, cal/mol k 1 Rate constant of active site k 2 Rate constant of chain initiation k 3 Rate constant of chain propagation k 4 Rate constant of chain transfer k 5 Rate constant of deactivation k ?1 Rate constant of attachment of the catalyst in the site activation k-1 Rate constant of detachment of the catalyst in the site activation

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Section: Introductionmentioning

confidence: 99%

A kinetic model for ethylene oligomerization using zirconium/aluminum- and nickel/zinc-based catalyst systems in a batch reactor

et al. 2014

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Synthesis and Characterization of Polymer Metal Complexes and Their Catalytic Activity in Ethylene Oligomerization

Ahamad

Alshehri

2013

Adv Polym Technol

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ABSTRACT:A new polymeric ligand, 4,7-dihydroxy-1,10-phenanthroline/formaldehyde polymeric ligand [poly-(DHPF)], was synthesized via the polycondensation of 4,7-dihydroxy-1,10-phenanthroline and formaldehyde in an acidic medium. Polymer metal complexes, poly-[DHPF-M(II)Cl 2 ], were subsequently prepared with Co(II) and Ni(II) ions. The synthesized polymers were characterized by elemental and spectral analyses. The polymer metal complexes were evaluated as catalyst precursors for ethylene oligomerization, using methylaluminoxane as an activator. Different Al/M [M = Co(II) and Ni(II)] ratios were investigated at two different ethylene pressures. Poly-[DHPF-Co(II)Cl 2 ] (C 1 ) and poly-([DHPF-Ni(II)Cl 2 ] (C 2 ) were isolated as blue and green solids, respectively. Complex C 2 was found to be a more effective precatalyst than C 1 in the presence of a cocatalyst. Thus, C 2 exhibited the maximum activity of 1.92 × 10 6 g mol −1 (Ni) h −1 bar −1 with an Al/Ni ratio of 3000:1 at room temperature, whereas C 1 exhibited a maximum activity of 1.87 × 10 6 g mol −1 (Co) h −1 bar −1 with a 5-atm pressure of ethylene. Upon increasing the Al/Co ratio at 1 atm pressure of ethylene, the catalytic activity of precatalyst increased and the process became more selective for higher oligomers. The catalytic activity and selectivity with 1-decene using C 1 were 3.16 × 10 5 g mol −1 (Co) h −1 bar −1 and 72%, respectively, with 5 atm ethylene and an Al/Co ratio of 300:1. C

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Effects of aluminoxane cocatalysts on bis(imino)pyridine iron‐catalyzed ethylene oligomerization

Zhang

Jiang

et al. 2018

Can J Chem Eng

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Ethylene oligomerization facilitated with a bis(imino)pyridine iron catalyst in the presence of various aluminoxane cocatalysts is investigated in this work. The effects of different trialkylaluminiums and [H 2 O]/[Al] molar ratios employed in the synthesis of aluminoxanes on the catalytic activity, selectivity to linear a-olefins, and polymer share have been discussed. The results show that MAO-S (methylaluminoxane synthesized herein) renders the highest catalytic activity but with a rather high undesired polymer share, and i-BAO (iso-butylaluminoxane) is the most optimum cocatalyst, rendering the predominant production of a-olefins at high activity with significantly reduced polymer share. On the contrary, EAO (ethylaluminoxane) shows quite poor catalytic activity. The use of mixed aluminoxanes, MBAO (mixed aluminoxanes synthesized from trimethylaluminium and triisobutylaluminium mixtures), and EBAO (mixed aluminoxanes synthesized from triethylaluminium and triisobutylaluminium mixtures) as cocatalysts also renders different catalytic performance, indicating that the composition/structure of mixed aluminoxanes has pronounced effects on the catalytic activity and selectivity to linear a-olefins.

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Influence of the metal centers of 2,6‐bis(imino)pyridyl transition metal complexes on ethylene polymerization/ oligomerization catalytic activities

Cited by 19 publications

References 25 publications

A kinetic model for ethylene oligomerization using zirconium/aluminum- and nickel/zinc-based catalyst systems in a batch reactor

A kinetic model for ethylene oligomerization using zirconium/aluminum- and nickel/zinc-based catalyst systems in a batch reactor

Synthesis and Characterization of Polymer Metal Complexes and Their Catalytic Activity in Ethylene Oligomerization

Effects of aluminoxane cocatalysts on bis(imino)pyridine iron‐catalyzed ethylene oligomerization

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