Mechanistic Study of the Oligomerization of Olefins

Abstract

A mechanistic study on the oligomerization of olefins of isomeric octenes using a Lewis-acidic ionic liquid as the catalyst is reported herein. This study was aimed at understanding the effects of the position and geometry of the double bond on the probable pathway of the reaction and the properties of the final product. This effort will help in understanding which feed or mixture of feeds can be used as starting materials for oligomerization and also in understanding and estimating the final product properties after oligomerization. We observed an interesting reactivity pattern in the oligomerization of a mixture of olefins, in which there is selectivity for the cis isomer over the trans isomer. In addition, we found that the final oligomer obtained starting from a mixture of olefin isomers displayed better properties, such as a higher viscosity index and a lower side-chain branching percentage, than that obtained starting from exclusively the α-olefin. Kinetic studies were carried out with individual isomers of octenes and their mixtures toward oligomerization. Subsequently, analyses of the structural properties of the final oligomerized and hydrogenated products were undertaken.

Kinetic Study on Microwave-Assisted Oligomerization of 1-Decene over a HY Catalyst

“…The microwave system (45 × 45 × 50 cm in dimension with multi-mode cavity and double-feed magnetrons, 2 × 1000 W and 2.45 GHz) was designed to have the ability to control any desired uniform reaction temperature. To enhance the conversion effectiveness of microwave radiation to thermal energy inside the reactor, activated carbon as a microwave receptor was added into the reactor and mixed well with the 1-decene feed [37,38]. For each experiment, a fixed amount of 50 mL of 1-decene (94%, Sigma-Aldrich, St. Louis, MO, USA) was added into the reactor with 5 g of HY zeolite catalyst (CBV700, Zeolyst, Groningen, The Netherlands) and 5 g of activated carbon (Biocat).…”

Catalytic Isomerization of Olefins and Their Derivatives: A Brief Overview

“…Cation exchange resin (CER) [13][14][15][16][17][18][19][20] is a type of solid catalysts in which its catalytic mechanism is the same as homogeneous catalysts, while it does have active sites like silica gel, Al 2 O 3 , and zeolite as carriers, brings to CER become a pseudo homogeneous system. CER is used to catalyze gaseous short-chain alkene isomerization (C 4 $C 7 ).…”

“…Under the conditions like that of isomerization, higher molecular like 11-C 34 H 68 reacted with lower molecular like butadiene in metathesis reaction to produce a mixture of olefins such as internal C 13 H 26 , and C 25 H 50 , which are for chemical intermediates required by surfactants and detergents. The oligomerization of ethylene by Ni catalysts in the SHOP process was showed in the follows as Figure 8 [18].…”

Double-bond isomerization of hexadecenes with solid acid catalysts

“…However, the above analysis is complicated by the fact that internal alkenes produce oligomers at a slower rate [10,11], so active isomerization catalysts at lower temperatures (where isomerization dominates) would generate fewer oligomers even if they are intrinsically more active for oligomerization of the 1-alkenes. This supposition can be deduced from the greatly decreasing rates of oligomerization in batch oligomerization reactions [31].…”

“…Both skeletal isomerization (branching) and oligomerization compete with positional (double bond) isomerization. Oligomerization is slower with internal alkenes when using weaker, primarily Lewis acid, catalysts [10,11]. Selectivity to internal alkenes decreases with respect to both increasing temperature (usually at >150 • C) and acid strength [12,13].…”