Chromium-Based Catalyst for Ethylene Tetramerization to 1-Octene

2011 ◽  
Vol 347-353 ◽  
pp. 3392-3395
Author(s):  
Bao Jun Zhang ◽  
Bu Wei Yu ◽  
Gang Wang ◽  
Jian Zhong Li ◽  
Si Han Wang ◽  
...  
Keyword(s):  
Catalyst System ◽  
Ethylene Oligomerization ◽  
Steric Effects ◽  
Molar Ratio ◽  
Ethylene Tetramerization ◽  
Electric Effects

Novel diphoshinoamine(PNRNP) ligands have been used in ethylene oligomerization with Cr(III) compounds and cocatalyst. The results indicate that the catalyst system can yield 1-octene in selectivities up to 80%. Another novel diphoshinoamine ligands (((Ar2P)2N)2R)(R=cyclopropylamine) also were synthesized and characterized. Factors which affect the result of ethylene tetramerisation, such as cocatalyst, temperature, pressure and the molar ratio of Al/Cr were examined. Steric effects and electric effects were also considered in this report.

scholarly journals Continuous synthesis of high-performance isobutylaluminoxanes in a compact and integrated approach

2021 ◽  
Author(s):  
Yirong Feng ◽  
Mengbo Zhang ◽  
Haomiao Zhang ◽  
Jingdai Wang ◽  
Yang Yongrong
Keyword(s):  
Catalytic Activity ◽  
High Performance ◽  
Heat Removal ◽  
Integrated Approach ◽  
Catalyst System ◽  
Ethylene Oligomerization ◽  
Molar Ratio ◽  
Measured Temperature ◽  
Line Separation ◽  
3D Printed

We present a 3D-printed continuous flow platform for controllable synthesis of isobutylaluminoxanes (IBAO), an effective olefin polymerization co-catalyst, via highly exothermic hydrolytic reaction of triisobutylaluminum (TIBA). This platform encompasses modules of mixing and reaction, in-line separation, and in situ UV-vis characterization. In addition, two NMR protocols are established to validate the results of in-line UV-vis analysis (31P NMR) and reveal product structures (1H NMR). Measured temperature profiles over the reactor indicate essentially fast heat removal, ensuring inherent safety. Subsequently, co-catalytic activity of IBAO is obtained by ethylene oligomerization experiments using an iron-based catalyst system at atmospheric pressure. Furthermore, we investigate the influence of key operating parameters including initial molar ratio between water and TIBA, initial TIBA concentration, and residence time. High IBAO yield over 98% and superior co-catalytic activity of ~5000 kg·(mol Fe)–1·h–1 are achieved with optimized parameters in this single-pass platform, demonstrating the advantages of process.

scholarly journals Effects of Various Mixed Metal Chlorides- AlCl3 in TiCl4/MgCl2/THF Catalytic System on Ethylene Polymerization

2015 ◽  
Vol 14 (2) ◽  
pp. 12
Author(s):  
Nittaya Sudsong ◽  
Wanna Phiwkliang ◽  
Bunjerd Jongsomjit ◽  
Piyasan Praserthdam
Keyword(s):  
Catalytic System ◽  
Ethylene Polymerization ◽  
Catalyst System ◽  
Polymerization Reaction ◽  
Molar Ratio ◽  
Metal Chlorides ◽  
Mixed Metal ◽  
Icp Analysis ◽  
Co Addition

In this research, the modification of TiCl4/MgCl2/THF catalyst system with various metal chlorides was investigated on ethylene polymerization. Experimentally, metal chlorides (CaCl2, FeCl2 and ZnCl2) were simultaneously introduced different with TiCl4/MgCl2/THF catalyst. ICP analysis was used to determine the total amount of each metal in the catalyst. For polymerization reaction, TEA was used as cocatalyst and hexane was used as a medium solvent. The Al/Ti molar ratio was 140. The activity result of Ca-Al, Zn-Al and Fe-Al was 979, 1009 and 1476 kgPE/molTi.h, respectively. The coaddition of AlCl3 and FeCl2 in TiCl4/MgCl2/THF catalyst system exhibited the highest activity. It suggested that the co-addition of AlCl3 and FeCl2 has higher electronegativity (EN) and the radius of Fe2+ is closer to Mg2+ resulting in an increased efficiency of the THF removal. This result led to improve the catalyst performance.

scholarly journals Isotopic labelling in ethylene oligomerization: addressing the issue of 1-octene vs. 1-hexene selectivity

2019 ◽  
Vol 48 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Nathanael A. Hirscher ◽  
Jay A. Labinger ◽  
Theodor Agapie
Keyword(s):  
Isotopic Labeling ◽  
Ethylene Oligomerization ◽  
Isotopic Labelling ◽  
Ethylene Tetramerization

The selectivity-determining mechanistic steps of ethylene tetramerization and trimerization are evaluated in light of isotopic labeling experiments.

Substituted carbonyl derivatives of the Group VI transition metals. II. Complexes with tritolylphosphines

1971 ◽  
Vol 24 (12) ◽  
pp. 2471 ◽  
Author(s):  
JA Bowden ◽  
R Colton
Keyword(s):  
Steric Effects ◽  
Molar Ratio ◽  
Mass Spectral Data ◽  
Group Vi ◽  
Mass Spectral ◽  
Carbonyl Derivatives ◽  
Nuclear Magnetic Resonance Spectra ◽  
Metal Hexacarbonyls ◽  
Cis And Trans ◽  
Derivatives Of

The reactions of the three tritolylphosphines (ortho, meta, and para) with the metal hexacarbonyls, M(CO)6 (M = Cr, Mo, W), have been investigated under a variety of conditions of temperature, ultraviolet irradiation, and molar ratio. The products were of the general formulae M(CO)5L and cis and trans M(CO)4L2 [L = tri-tolylphosphine] although not all the tetracarbonyl complexes could be prepared. Infrared and nuclear magnetic resonance spectra of these compounds showed interesting trends as the ligand was varied. ��� In addition, a novel series of derivatives with tri(o- tolyl)phosphine (pot) has been isolated, which on the basis of infrared, N.M.R., and mass spectral data are formulated as π- (pot)M(CO)3. ��� The nature of the above reactions and the properties of the products are explained in terms of an argument based on steric effects.

Determination of Composition of Reaction Mixtures from Alkylation of Toluene on Phosphorus-Modified H-ZSM-5 Zeolite

1993 ◽  
Vol 58 (8) ◽  
pp. 1832-1838
Author(s):  
Dušan Mravec ◽  
Jiří Herain ◽  
Štefan Holotík
Keyword(s):  
Gas Chromatography ◽  
Space Velocity ◽  
Ethylene Oligomerization ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Alkylation Reaction ◽  
Cyclization Reactions ◽  
Subsequent Cyclization ◽  
High Resolution Gas Chromatography

Determination of analytical composition of reaction mixtures formed by alkylation of toluene with ethylene on a phosphorus-modified H-ZSM-5 zeolite was made by a capillary high resolution gas chromatography. Identification of individual components of these reaction mixtures was performed by GS-MS method, using the samples obtained at 320 and 400 °C on H-ZSM-5 catalyst (modul 43.6) modified with 3.4 wt.% phosphorus at toluene to ethylene molar ratio 4.5 : 1 and the catalyst loading expressed as weight hour space velocity WHSV (for toluene) = 6.9 h-1. The reaction mixtures contained a total of 86 hydrocarbons. It was confirmed that in the addition to the main alkylation reaction, there proceeds also ethylene oligomerization with subsequent cyclization and aromatization, disproportionation, alkylation and cyclization reactions of alkylaromatic hydrocarbons to give alkylnaphthalenes and alkylindanes.

Binary molybdenum-based catalyst for coordination polymerization of styrene

2016 ◽  
Vol 49 (5) ◽  
pp. 408-421 ◽  
Author(s):  
Jieting Geng ◽  
Youguo Shao ◽  
Feng Song ◽  
Feng Li ◽  
Jing Hua
Keyword(s):  
Molecular Weight ◽  
Catalyst Activity ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Catalyst System ◽  
Bulk Polymerization ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Coordination Polymerization ◽  
Co Catalyst

Coordination polymerization of styrene (St) using molybdenum pentachloride supported by phosphite ligand in the presence of metal organic compound was studied for the first time. The types of phosphite and co-catalysts significantly affected the catalytic activity of the molybdenum (V) (Mo(V)) active center and the number-average molecular weight ( Mn) of the resultant polymer. Among the examined catalysts, tri(nonylphenyl)phosphite (TNPP) ligand and AlOPhCH3( i-Bu)2 as co-catalyst provided the polymer with highest yield (up to 87.1%), metallocene as co-catalyst provided the polymer with highest Mn (up to 5.32 × 105). The effect of [P]/[Mo] molar ratio on catalyst activity of the polymerization was discussed and the structures of Mo·TNPP complexes were preliminarily studied by infrared (IR) and ultraviolet spectroscopies. Besides, the polystyrene (PS) samples synthesized through bulk polymerization and solution polymerization were characterized by gel permeation chromatography, IR, carbon 13 nuclear magnetic resonance, and differential scanning calorimetry, respectively, and the results indicated both of the PS had high molecular weight (approximately 105) and atactic structure. All these results demonstrated that Mo(V) catalyst system was very effective for St polymerization.

Performance of various aluminoxane activators in ethylene tetramerization based on PNP/Cr(III) catalyst system

2007 ◽  
Vol 8 (7) ◽  
pp. 1145-1148 ◽  
Author(s):  
Tao Jiang ◽  
Xiaoyu Liu ◽  
Yingnan Ning ◽  
Hongxia Chen ◽  
Mingjian Luo ◽  
...  
Keyword(s):  
Catalyst System ◽  
Ethylene Tetramerization

Silica supported Schiff-base cobaltIII complex-Lewis base system: a highly selective catalyst for alternating copolymerization of CO2 and propylene oxide

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongsheng Niu ◽  
Hongchun Li
Keyword(s):  
Molecular Weight ◽  
Schiff Base ◽  
Reaction Time ◽  
Propylene Oxide ◽  
Cobalt Complex ◽  
Catalyst System ◽  
Cyclic Carbonate ◽  
Lewis Base ◽  
Molar Ratio ◽  
Base System

AbstractAn binary catalyst system of a silica supported Schiff-base cobalt complex SalenCoIII (OAC)-MCM-41 (Salen = 3-[N,N-bis-2-(3,5-di-tert-butylsalicylidenamino) ethyl] amine) was developed to generate the copolymerization of CO2 and propylene oxide in presence of (4-dimethylamino)-pyridine (DMAP). The influence of the molar ratio of catalyst components, the operating temperature, reaction time, and CO2 pressure on the yield as well as the molecular weight of polycarbonate was systematically investigated. The high selectivity of polycarbonate over cyclic carbonate at 40 °C was maintained after a longer reaction time to attain quantitative formation of the alternating copolymer. High molecular weight of 67 000 were achieved at an appropriate combination of all variables.

scholarly journals Continuous Flow Friedel–Crafts Alkylation Catalyzed by Silica Supported Phosphotungstic Acid: An Environmentally Benign Process

2021 ◽  
Author(s):  
Zsófia Császár ◽  
Tatjána Juzsakova ◽  
Miklós Jakab ◽  
Szabolcs Balogh ◽  
Ágnes Szegedi ◽  
...  
Keyword(s):  
Flow Rate ◽  
Continuous Flow ◽  
Phosphotungstic Acid ◽  
Flow Reactor ◽  
Analytical Techniques ◽  
Catalyst System ◽  
Molar Ratio ◽  
Flow Mode ◽  
Reaction Conditions ◽  
Composite Catalysts

AbstractSix silica-supported phosphotungstic acid catalysts (PTA/SiO2) of different composition (20–70 wt% PTA content) have been synthesized and characterized by elemental analysis, BET, BJH, NH3-TPD methods, FT-IR spectroscopy of adsorbed pyridine and 1H MAS NMR techniques. The new composite catalysts were first applied in the Friedel–Crafts alkylation of toluene with 1-octene as a benchmark process under batch conditions in order to screen their activity and recyclability. The combined analytical techniques together with the catalytic studies enabled the identification of the main factors affecting the activity of the catalysts. Based on these preliminary experiments, the best performing catalyst system (50 wt% PTA/SiO2) was investigated in continuous flow mode using an in-house-made flow reactor. The thorough screening of the reaction conditions (temperature, toluene/1-octene molar ratio and flow rate) provided firm evidence that the 50 wt% PTA/SiO2 composite is highly active, selective and stable catalyst under mild reaction conditions even at elevated flow rate. Additionally, the catalyst used in the flow mode could successfully be regenerated and reused in the alkylation process.

scholarly journals BIODIESEL PRODUCTION FROM PALM OIL USING HOMOGENEOUS CATAYST SYSTEM

2016 ◽  
Vol 11 (10) ◽  
pp. 3807-3815
Author(s):  
Yee Ching Wong ◽  
Nurfarhana Suib ◽  
Nurfarhana Suib
Keyword(s):  
Palm Oil ◽  
Catalyst Concentration ◽  
Environmental Concern ◽  
Maximum Yield ◽  
Catalyst System ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Smoke Emission ◽  
Homogenous Catalyst ◽  
Petroleum Reserves

Due to the depletion of petroleum reserves and environmental concern, biodiesel has emerged as one of the most potential energy to replace petroleum. It is a renewable, biodegradable and non-toxic fuel which can be easily produced through transesterification. Transesterification of palm oil with methanol has been studied in a homogenous catalyst system using different catalysts (CaCO3, SrCO3 and BaCO3). The effects of concentration catalyst (0.25 %w/w-1.5 %w/w) and molar ratio of methanol to oil (3:1-21:1) on biodiesel yield and conversion of FFA to FAME was investigated. From this study, SrCO3 gave better yields of FAME while CaCO3 gave better conversion of FFA to FAME. The lowest yield of FAME was recorded at catalyst concentration of 0.25 %w/w while the highest yield of FAME was at 1.25 %w/w. The lowest conversion of FFA to FAME was at 0.25 %w/w and the highest conversion at catalyst concentration of 0.75 %w/w. For the molar ratio of methanol to oil, the minimum yield of FAME at 21: while the maximum yield of FAME was obtained at 3:1. The minimum conversion of FFA to FAME was recorded at 3:1 molar ratio methanol to oil. However, maximum conversion was recorded at 15:1 molar ratio methanol to oil. This study revealed that biodiesel was successfully reduced 52.3 % opacity level of smoke emission by diesel engine that operated with petroleum diesel.

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