scholarly journals Industrially relevant ethylene trimerization catalysts and processes

2021 ◽  
Author(s):  
Subhas Madavu Salian ◽  
Mahuya Bagui ◽  
Raksh Vir Jasra
Keyword(s):  
Petrochemical Industry ◽  
High Selectivity ◽  
Product Formation ◽  
Ethylene Oligomerization ◽  
Titanium Catalysts ◽  
Commercial Plant ◽  
Ethylene Trimerization ◽  
Catalyst Systems ◽  
Commercial Applications ◽  
New Generation

Abstract1-Hexene is one of the comonomers used to produce mainly low linear density polyethylene (LLDPE) and high-density polyethylene (HDPE). The production of 1-hexene by ethylene trimerization method gained much interest in petrochemical industry due to its high selectivity towards 1-hexene in comparison to traditional ethylene oligomerization method. In literature, many catalyst systems are reported for ethylene trimerization reaction, but only few of them qualify for the commercial applications. In the present review, activity and selectivity of commercially viable catalyst systems and amount of polyethylene formed as a by-product on using these catalyst systems were discussed. Special attention is given to Chevron Phillips ethylene trimerization technology which is one of the dominant technologies in the production of 1-hexene. The challenges such as fouling issues at commercial plant due to polyethylene by-product formation were discussed and the progress made to overcome the challenges were also discussed. New generation nontoxic titanium catalysts look promising and challenges involved in commercializing these catalysts were presented in the review. Graphic abstract

Oxidative coupling of methane. The effect of alkali chlorides on molybdate based catalyst leading to high selectivity in C3-product formation

1993 ◽  
Vol 18 (1-2) ◽  
pp. 15-26 ◽  
Author(s):  
John Kiwi ◽  
K. Ravidranathan Thampi ◽  
N. Mouaddib ◽  
Michael Gr�tzel ◽  
Peter Albers
Keyword(s):  
Oxidative Coupling ◽  
High Selectivity ◽  
Product Formation ◽  
Oxidative Coupling Of Methane ◽  
Alkali Chlorides

Cascaded Biocatalysis and Bioelectrocatalysis: Overview and Recent Advances

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Yoo Seok Lee ◽  
Koun Lim ◽  
Shelley D. Minteer
Keyword(s):  
Value Added ◽  
Cascade Reactions ◽  
Product Formation ◽  
Deep Oxidation ◽  
Annual Review ◽  
Publication Date ◽  
Oxidation Reduction ◽  
Cascade Biocatalysis ◽  
Analyte Detection ◽  
Catalyst Systems

Enzyme cascades are plentiful in nature, but they also have potential in artificial applications due to the possibility of using the target substrate in biofuel cells, electrosynthesis, and biosensors. Cascade reactions from enzymes or hybrid bioorganic catalyst systems exhibit extended substrate range, reaction depth, and increased overall performance. This review addresses the strategies of cascade biocatalysis and bioelectrocatalysis for ( a) CO2 fixation, ( b) high value-added product formation, ( c) sustainable energy sources via deep oxidation, and ( d) cascaded electrochemical enzymatic biosensors. These recent updates in the field provide fundamental concepts, designs of artificial electrocatalytic oxidation-reduction pathways (using a flexible setup involving organic catalysts and engineered enzymes), and advances in hybrid cascaded sensors for sensitive analyte detection. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Ni-Based Complexes in Selective Ethylene Oligomerization Processes

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 498
Author(s):  
Giyjaz E. Bekmukhamedov ◽  
Aleksandr V. Sukhov ◽  
Aidar M. Kuchkaev ◽  
Dmitry G. Yakhvarov
Keyword(s):  
High Density Polyethylene ◽  
Petrochemical Industry ◽  
Nickel Catalysts ◽  
Catalytic Performance ◽  
Ethylene Oligomerization ◽  
Linear Low Density Polyethylene ◽  
Main Method ◽  
The World ◽  
World Demand ◽  
Alpha Olefins

Linear alpha-olefins are widely used in the petrochemical industry and the world demand for these compounds increases annually. At present, the main method for producing linear alpha-olefins is the homogeneous catalytic ethylene oligomerization. This review presents modern nickel catalysts for this process, mainly systems for obtaining of one of the most demanded oligomer—1-butene—which is used for the production of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE). The dependence of the catalytic performance on the composition and the structure of the used activated complexes, the electronic and coordination states of the nickel center was considered.

scholarly journals Ethylene Oligomerization over Nickel Supported Silica-Alumina Catalysts with High Selectivity for C10+ Products

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 180 ◽  
Author(s):  
Lei Chen ◽  
Guangci Li ◽  
Zhong Wang ◽  
Shuangju Li ◽  
Mingjie Zhang ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Aging Temperature ◽  
Active Sites ◽  
High Selectivity ◽  
Acid Sites ◽  
Ethylene Oligomerization ◽  
Octahedral Coordination ◽  
Activation Temperature ◽  
High Aging Temperature ◽  
Silica Alumina

The nickel (II) loading silica-alumina under various treatments in terms of aging temperature, Si/Al ratio and activation temperature were investigated by XRD, N2 adsorption-desorption, TEM, UV-Vis, NH3-TPD and XRF and then applied to catalyze the ethylene oligomerization. High aging temperature, low Si/Al ratio and high activation temperature were beneficial to high selectivity for C10+ products because of a reasonable match between Ni active sites and acid sites, high Ni loading content and less octahedral coordination Ni2+ species, respectively. Ni loading content was more important than the number of acid sites for high yield of C10+ products, and less octahedral coordination Ni2+ species favored less by-products produced at high reaction temperature. In addition, other experimental conditions, such as reaction temperature, weight hourly space velocity (WHSV) and nickel precursor were discussed in the paper.

scholarly journals NMR and EPR trapping of the active species in the ethylene polymerization and trimerization catalyst systems

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
I.E. Soshnikov ◽  
N.V. Semikolenova ◽  
A.A. Antonov ◽  
K.P. Bryliakov ◽  
V.A. Zakharov ◽  
...  
Keyword(s):  
Epr Spectroscopy ◽  
Ethylene Polymerization ◽  
Catalyst Deactivation ◽  
Active Species ◽  
Ion Pair ◽  
Polymerization Catalysts ◽  
Ethylene Trimerization ◽  
Catalyst Systems

AbstractIn this work, previously undetected intermediates of several practically promising catalyst systems for ethylene polymerization and trimerization are discussed. In particular, the activation of ethylene polymerization catalysts (1) LNiCl2 (L = 2,4,6-trimethyl- (N-5,6,7-trihydroquinolin-8-ylidene)phenylamine) with AlEt2Cl and AlMe2Cl, (2) activation of bis(imino)pyridine vanadium(III) chloride L1VIIICl3 (L1 = 2,6-(ArN=CMe)2C5H3N, Ar = 2,6-iPr2C6H3; 2,6-Me2C6H3; 2,4,6-Me3C6H2; 3,5- F2C6H3) with AlMe3/[Ph3C]+[B(C6F5)]4¯ and MAO, and (3) selective ethylene trimerization catalyst (FI)TiCl3 (FI = phenoxyimine ligand with an additional aryl-OCH3 donor) with MAO have been assessed by NMR and EPR spectroscopy. The nature of ion-pair intermediates – the closest precursors of the propagating species – has been established, and the major catalyst deactivation pathways are discussed.

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

2014 ◽  
Vol 4 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Adil A. Mohammed ◽  
Seif-Eddeen K. Fateen ◽  
Tamer S. Ahmed ◽  
Tarek M. Moustafa
Keyword(s):  
Kinetic Model ◽  
Batch Reactor ◽  
Ethylene Oligomerization ◽  
Nickel Zinc ◽  
Catalyst Systems

Synthesis, Characterization, and Ethylene Oligomerization and Polymerization by 2-Quinoxalinyl-6-iminopyridine Chromium Chlorides

2008 ◽  
Vol 61 (5) ◽  
pp. 397 ◽  
Author(s):  
Saliu A. Amolegbe ◽  
Maliha Asma ◽  
Min Zhang ◽  
Gang Li ◽  
Wen-Hua Sun
Keyword(s):  
High Selectivity ◽  
Ethylene Oligomerization ◽  
Distorted Octahedral Geometry ◽  
Electronic Effects ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Co Catalyst ◽  
X Ray ◽  
Catalytic Activities ◽  
Distorted Octahedral

A series of chromium(iii) complexes ligated by N^N^N tridentate 2-quinoxalinyl-6-iminopyridine were synthesized and characterized by elemental analysis and infrared spectroscopy. Single-crystal X-ray diffraction analysis for the structure of complex C3 reveals a distorted octahedral geometry. When methylaluminoxane was employed as the co-catalyst, the chromium complexes showed high activities for ethylene oligomerization and polymerization. The distribution of oligomers obtained followed Schulz–Flory rules with high selectivity for α-olefins. Both steric and electronic effects of coordinated ligands affected the catalytic activities as well as the properties of the catalytic products. The parameters of the reaction conditions were also investigated to explore the optimum catalytic potentials of these complexes.

scholarly journals Directing the reactivity of metal hydrides for selective CO2 reduction

2018 ◽  
Vol 115 (50) ◽  
pp. 12686-12691 ◽  
Author(s):  
Bianca M. Ceballos ◽  
Jenny Y. Yang
Keyword(s):  
High Selectivity ◽  
Co2 Reduction ◽  
Metal Hydrides ◽  
Product Formation ◽  
Proton Reduction ◽  
Efficient Catalyst ◽  
Faradaic Efficiency ◽  
Catalytic Intermediates ◽  
Proton Activity ◽  
Selection Of

A critical challenge in electrocatalytic CO2 reduction to renewable fuels is product selectivity. Desirable products of CO2 reduction require proton equivalents, but key catalytic intermediates can also be competent for direct proton reduction to H2. Understanding how to manage divergent reaction pathways at these shared intermediates is essential to achieving high selectivity. Both proton reduction to hydrogen and CO2 reduction to formate generally proceed through a metal hydride intermediate. We apply thermodynamic relationships that describe the reactivity of metal hydrides with H+ and CO2 to generate a thermodynamic product diagram, which outlines the free energy of product formation as a function of proton activity and hydricity (∆GH−), or hydride donor strength. The diagram outlines a region of metal hydricity and proton activity in which CO2 reduction is favorable and H+ reduction is suppressed. We apply our diagram to inform our selection of [Pt(dmpe)2](PF6)2 as a potential catalyst, because the corresponding hydride [HPt(dmpe)2]+ has the correct hydricity to access the region where selective CO2 reduction is possible. We validate our choice experimentally; [Pt(dmpe)2](PF6)2 is a highly selective electrocatalyst for CO2 reduction to formate (>90% Faradaic efficiency) at an overpotential of less than 100 mV in acetonitrile with no evidence of catalyst degradation after electrolysis. Our report of a selective catalyst for CO2 reduction illustrates how our thermodynamic diagrams can guide selective and efficient catalyst discovery.

Homogeneous and heterogeneous cyclopentadienyl-arene titanium catalysts for selective ethylene trimerization to 1-hexene

2015 ◽  
Vol 777 ◽  
pp. 57-66 ◽  
Author(s):  
Vojtech Varga ◽  
Tomáš Hodík ◽  
Martin Lamač ◽  
Michal Horáček ◽  
Arnošt Zukal ◽  
...  
Keyword(s):  
Titanium Catalysts ◽  
Ethylene Trimerization

Advances of Chromium(III)-Based Catalysts with Multidentate Heteroatomic Ligands for 1-Hexene Production

2011 ◽  
Vol 317-319 ◽  
pp. 1797-1800 ◽  
Author(s):  
Ya Zhen Wang ◽  
Chuan Feng Yang ◽  
Jie Chen
Keyword(s):  
Aluminum Oxide ◽  
High Activity ◽  
Commercial Application ◽  
Ligand Structure ◽  
Ethylene Trimerization ◽  
Commercial Process ◽  
Catalyst Systems ◽  
Heteroatomic Ligands ◽  
Nitrogen Phosphorus

According to the various multidentate heteroatomic ligands(based oxygen,nitrogen, phosphorus,mixed N and P,mixed N and S donors, composition, activity and overall selectivity to 1-hexene of chromium-based trimerization catalysts were reviewed. Commercial application foreground of these catalyst systems was also expected.It was found that effect of ligand structure on activity and selectivity for ethylene trimerization was the most predominant.The PNP （(Ph2P)2N(cyclopentyl)）ligands were prepared using inexpensive reagents and gave the corresponding complexes in high yields.Due to the inexpensive ligands coupled with low MAO （methyl aluminum oxide）requirements and high activity and selectivity of these systems, this has positive implication for a commercial process to 1-hexene.

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