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.

Research on Predicting the Stability of Partially Stabilized Zirconia Based on SVM

2010 ◽  
Vol 146-147 ◽  
pp. 460-465 ◽  
Author(s):  
Sheng Hui Guo ◽  
Dong Bo Li ◽  
Li Jun Liu ◽  
Jin Hui Peng ◽  
Li Bo Zhang ◽  
...  
Keyword(s):  
Relative Error ◽  
Influence Factors ◽  
Commercial Application ◽  
Support Vector ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Typical Data ◽  
Svm Model ◽  
Commercial Process ◽  
The Stability

The stability is one most important product performance index, which can directly determine the quality of the partially stabilized zirconia (PSZ), and the stability of PSZ is always fluctuating in the commercial process, so how to accurately, quickly and easily predict the stability of PSZ in the preparation process is very important. In the present paper, a new mathematical model to predict the stability of PSZ was proposed, based on statistical theory (SLT) and support vector machine (SVM) theory, which relates the stability of PSZ and the influence factors, such as the holding temperature, rising rate of temperature, holding time, decreasing rate of temperature and hardening temperature. Typical data collected from commercial process were collected for the training samples and test samples. Then testing and analyzing was done. The results showed that the max relative error was 1.80%, the least relative error was 0%, and the average relative error was 0.58%. It is accurate and reliable to predict the stability of PSZ by SVM model. Besides, multiple influence factors can be comprehensively considered in the SVM model, thus a new highly effective method for predicting the stability of PSZ is provided for commercial application.

scholarly journals Comparison of Support Effects on Phillips and Metallocene Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 842
Author(s):  
Qing Yang ◽  
Max Paul McDaniel
Keyword(s):  
High Activity ◽  
Chromium Oxide ◽  
Solid Acid ◽  
Metallocene Catalysts ◽  
Solid Oxides ◽  
Support Effects ◽  
Phillips Catalyst ◽  
Chromium Catalysts ◽  
Catalyst Systems

Both metallocene and Phillips chromium catalysts are used in the commercial manufacture of polyethylene. Unlike most other commercial metallocene systems, the Chevron Phillips Chemical (CPC) platform does not use methylaluminoxane or fluoroorganic boranes. Instead, the support itself serves to activate (ionize) the metallocenes, which then polymerize ethylene at high activity. Most of these solid acid supports can also be used to anchor Cr to make a Phillips catalyst. This provides an interesting opportunity to compare the polymerization responses by these two disparate systems, Phillips Cr and CPC metallocene, when supported on the same solid acid carriers. In this study, both chromium oxide and several metallocenes were deposited onto a variety of solid oxides, under a variety of conditions, and the resulting support effects were observed and compared. Although using seemingly different chemistries, the two catalyst systems exhibited a surprising number of similarities, which can be attributed to the acidity and porosity of these diverse supports.

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.

Ethylene Trimerization with Mixed-Donor Ligand (N,P,S) Chromium Complexes:  Effect of Ligand Structure on Activity and Selectivity

2005 ◽  
Vol 24 (4) ◽  
pp. 552-556 ◽  
Author(s):  
David S. McGuinness ◽  
Peter Wasserscheid ◽  
David H. Morgan ◽  
John T. Dixon
Keyword(s):  
Chromium Complexes ◽  
Donor Ligand ◽  
Ligand Structure ◽  
Ethylene Trimerization

Reduction of Interpore Distance of Anodized Aluminum Oxide Nano Pattern by Mixed H3PO4:H2SO4 Electrolyte

2007 ◽  
Vol 7 (11) ◽  
pp. 4206-4209
Author(s):  
Kwang Min Song ◽  
Joonmo Park ◽  
Sang-Wan Ryu
Keyword(s):  
Aluminum Oxide ◽  
Quantum Confinement ◽  
Pore Diameter ◽  
Quantum Effect ◽  
Quantum Confinement Effect ◽  
Commercial Application ◽  
Anodized Aluminum ◽  
Anodized Aluminum Oxide ◽  
Interpore Distance ◽  
Nano Structures

A self-formed and ordered anodized aluminum oxide (AAO) nano pattern has generated considerable interest in both scientific research and commercial application. However, the interpore distance obtainable by AAO is limited by 40–500 nm depending on electrolyte and anodizing voltage. It's believed that below-30 nm AAO pattern is a key technology in the fabrication semiconductor nano structures with enhanced quantum confinement effect, so we worked on the reduction of interpore distance of AAO with a novel electrolyte. AAO nano patterns were fabricated with mixed H2SO4 and H3PO4 as an electrolyte for various voltages and temperatures. The interpore distance and pore diameter of AAO were decreased with reduced anodizing voltage. As a result, an AAO nano pattern with the interpore distance of 27 nm and the pore diameter of 7 nm was obtained. This is the smallest pattern, as long as we know, reported till now with AAO technique. The fabricated AAO pattern could be utilized for uniform and high density quantum dots with increased quantum effect.

Ethylene Trimerization with Cr−PNP and Cr−SNS Complexes:  Effect of Ligand Structure, Metal Oxidation State, and Role of Activator on Catalysis

2006 ◽  
Vol 25 (15) ◽  
pp. 3605-3610 ◽  
Author(s):  
David S. McGuinness ◽  
David B. Brown ◽  
Robert P. Tooze ◽  
Fiona M. Hess ◽  
John T. Dixon ◽  
...  
Keyword(s):  
Oxidation State ◽  
Metal Oxidation ◽  
Ligand Structure ◽  
Ethylene Trimerization

Structure Studies on Chromium—Aluminum Oxide and Related Catalyst Systems

1947 ◽  
Vol 69 (11) ◽  
pp. 2698-2702 ◽  
Author(s):  
Robert P. Eischens ◽  
P. W. Selwood
Keyword(s):  
Aluminum Oxide ◽  
Catalyst Systems

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

Sign in / Sign up

Export Citation Format

Share Document