The effect of halide and the coordination geometry of chromium center in homogeneous catalyst system for ethylene trimerization

2004 ◽  
Vol 221 (1-2) ◽  
pp. 9-17 ◽  
Author(s):  
He-Kuan Luo ◽  
Da-Gang Li ◽  
Song Li
2012 ◽  
Vol 545 ◽  
pp. 367-372
Author(s):  
Zalita Yaacob ◽  
Nor Asikin Mohamad Nordin ◽  
Mohd Ambar Yarmo

Ionic Liquids (ILs) based on 1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI.NTf2) and ILs based on choline chloride (ChCl) under acidic condition was used as catalysts for esterification reaction between alcohol with fatty acid. Combination various acid namely sulphuric acid, perchloric acid, p-toulene sulphonic and various chloride salts such as ZnCl2, SnCl2 and FeCl3 with ionic liquids BM.NTf2 and choline chloride gave acidic ILs. These acidic ILs were tested as catalysts for esterification reaction. Esterification of alcohol (methanol) with fatty acid (lauric acid) using BMI.NTf2 ILs combination with H2SO4 gave high activity (100 %) and selectivity (100 %) was observed over a period of 2 hours reaction with reaction temperature 70 °C. The ester was easily separated due to ILs form as biphasic with product after reaction where is ester accumulates as the upper phase and ILs with water that produce after reaction at below phase. These ILs were characterized using FTIR and NMR. From FTIR result no significant difference between ILs with combination ILs in acidic condition. The advantages of ILs as catalyst are “clean process” and “green chemistry” due to its behaviour such as non-volatile, no loss of solvent through evaporation and reduced environmentally impact. This ILs-catalyst system can be recycle for futher reaction.


2011 ◽  
Vol 29 (6) ◽  
pp. 1149-1153 ◽  
Author(s):  
Tao Jiang ◽  
Rongxin Ji ◽  
Hongxia Chen ◽  
Chengang Cao ◽  
Guoliang Mao ◽  
...  

2016 ◽  
Vol 18 (8) ◽  
pp. 2341-2352 ◽  
Author(s):  
Lu Chen ◽  
Jiayu Xin ◽  
Lingli Ni ◽  
Huixian Dong ◽  
Dongxia Yan ◽  
...  

A novel pseudo-homogeneous catalyst system consisting of noble metal nanoparticles and ionic liquids is developed for the selective reductive cleavage of C–O and hydrodeoxygenation under mild conditions.


RSC Advances ◽  
2015 ◽  
Vol 5 (52) ◽  
pp. 41372-41376 ◽  
Author(s):  
A. Behr ◽  
Z. Bayrak ◽  
S. Peitz ◽  
G. Stochniol ◽  
D. Maschmeyer

The oligomerization of 1-butene with a nickel-based catalyst system constitutes an elegant synthesis method for obtaining linear octenes from readily available chemicals.


2014 ◽  
Vol 481 ◽  
pp. 39-48 ◽  
Author(s):  
Siyang Tang ◽  
Zhen Liu ◽  
Xiaowei Yan ◽  
Ning Li ◽  
Ruihua Cheng ◽  
...  

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1002 ◽  
Author(s):  
Atiqullah ◽  
Al-Sarkhi ◽  
Al-Thenayan ◽  
Al-Malki ◽  
Alasiri

Crude oil and refinery products are transported worldwide to meet human energy needs. During transportation via pipeline, huge pumping power is required to overcome the frictional pressure drop and the associated drag along the pipeline. The reduction of both is of great interest to industry and academia. Highly expensive ultrahigh molecular weight (UHMW, MW a million Dalton) drag reducing polymers (DRPs) are currently used to address this problem. The present paper, therefore, emphasizes particularly the development of a high-performance catalyst system that synthesizes DRPs (using higher alpha-olefins)—a highly promising cost reduction alternative. This homogeneous catalyst system features a new concept that uses a cost-effective titanium-based Ziegler–Natta precatalyst and a cocatalystLewis base complex having both steric hindrance (around N heteroatom) and electronic effect. This novel work, which involves precatalyst–cocatalyst molecular separation and cocatalystmonophenyl amine association-dissociation phenomena, already generated several US patents. The subject catalyst prepares UHMW DRPs at room temperature, avoiding the use of zero and sub-zero temperatures. The resulting product almost tripled the rate of transportation of a selected grade of refinery product and saved about 50% pumping energy at ppm level pipeline concentration. It is also very easily soluble. Hence, massive modification of existing pipeline will be unnecessary. This will save additional infrastructure cost. This paper also summarizes challenges facing the development of improved heterogeneous catalysts, dispersed polymerization process, molecular simulation-based DRP product formulation, and model/theory of turbulent mixing and dispersion in the transportation pipeline setting.


2016 ◽  
Vol 40 (10) ◽  
pp. 8704-8709 ◽  
Author(s):  
Huei Ruey Ong ◽  
Md. Maksudur Rahman Khan ◽  
Ridzuan Ramli ◽  
Rosli Mohd Yunus ◽  
Md. Wasikur Rahman

A hetero/homogeneous catalyst system was used in glycerolysis of oil and significantly improved the selectivity for monoglyceride at high oil conversion.


1967 ◽  
Vol 9 (6) ◽  
pp. 1372-1378 ◽  
Author(s):  
E.A. Grigoryan ◽  
F.S. D'yachkovskii ◽  
G.M. Khvostik ◽  
A.Ye. Shilov

Sign in / Sign up

Export Citation Format

Share Document