Olefin oligomerization
Ahad Hanifpour; Mahdi Hashemzadeh Gargari; Mohammad Reza Rostami Darounkola; Zahra Kalantari; Naeimeh Bahri-Laleh
Abstract
Herein a quenched-flow kinetic technique was applied to calculate the rate constants of 1-hexene and 1-octene oligomerization catalyzed by the Cp2ZrCl2 and Cp2HfCl2/MAO catalyst systems, and subsequently a mechanism for the higher α-olefin oligomerization reaction was proposed. The oligomerization ...
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Herein a quenched-flow kinetic technique was applied to calculate the rate constants of 1-hexene and 1-octene oligomerization catalyzed by the Cp2ZrCl2 and Cp2HfCl2/MAO catalyst systems, and subsequently a mechanism for the higher α-olefin oligomerization reaction was proposed. The oligomerization results showed that Zr-based catalyst in the oligomerization of 1-octene had the highest activity of 17 in comparison to Hfbased one with an activity value of 15 g oligomer/(mmolCat.h)). According to the obtained results, increasing monomer length led to a shift in molecular weight and polydispersity index value (Mw/Mn) to lower values. Furthermore, the microstructure-viscosity relationship was followed by the calculation of branching ratio and short-chain branching percentage. The obtained results revealed that, the oligomers synthesized by the Cp2HfCl2 catalyst had lower short chain branching ratio value and short-chain branching percentages. According to the kinetic results, the initiation rate constant (ki) of Zr-based catalyst was higher than that of Hf-based catalyst, and the order of calculated propagation rate constants was Zr>Hf for both the 1-hexene and 1-octene-based oligomerizations.
Polyolefins Industry
Naeimeh Bahri-Laleh; Mehdi Nekoomanesh-Haghighi; Samahe Sadjadi; Ali Pajouhan
Abstract
Due to easy availability of cheaper raw material and increase in new applications, the use of polyolefins in various industries is becoming a major priority. The Middle East region, on account of its vast oil and gas reserves has, in the last decade or so, been developing many new petrochemical complexes ...
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Due to easy availability of cheaper raw material and increase in new applications, the use of polyolefins in various industries is becoming a major priority. The Middle East region, on account of its vast oil and gas reserves has, in the last decade or so, been developing many new petrochemical complexes with their expansion into colossal polyolefin production capacities. The predictions are that by 2020 the Middle East region will dominate the polyolefin industry as a whole. Furthermore, with proven oil reserves of about 21.7 thousand million tons (4th world ranking) and natural gas of 34.0 trillion cubic meters (1st world ranking), Iran’s petrochemical industry is supported by diverse and abundant feedstock reserves. In line with other polyolefin producers’ developments in the Middle East, Iran's National Petrochemical Company (NPC) has undergone massive structural and technological transformations in the last two decades in order to set up ambitious plans for further capacity increase and native technology developments. This article mainly focuses on Iran today’s position and its future plans in the polyolefins industry.
