Effect of Support type on the Alpha-olefin oligomerization using AlCl3 catalyst

Poly(alphaolefin)s (PAOs), due to their range and viscosity, are produced by heavy alphaolefins oligomerization. PAOs have advantages such as more fluidity at low temperatures, low volatility, higher viscosity index, higher pour points, high oxidation/heat stability, low toxicity when compared with conventional mineral oils. Different catalysts such as Lewis acid, metallocene, chromium/silica and ionic liquids are reported so far for the catalytic alphaolefin oligomerization. PAO function can be significantly affected by the catalytic system used in oligomerization process. One of the most suitable methods for the production of PAOs is the use of the AlCl3/donor catalytic system. The use of Lewis acid catalysts is very practical for achieving desirable properties. In fact, most of the PAO grades are commercially produced by AlCl3/ or BF3/donor system. However, their highly corrosive and hazardous nature together with the problem of disposal evoked researchers attempt to find new green processes to circumvent such defects. Stabilizing Lewis acid catalysts on different supports is a very promising way to minimize the costs and environmental impacts of these catalysts [1-3]. A valuable research on active species loading, i.e. AlCl3, has been carried out on chlorinated supplements to demonstrate support conditions and fixing conditions [4]. It has been shown that chlorination of support component before catalyst impregnation results catalysts with higher efficiencies. In this study, to diminish AlCl3 disadvantage, it was fixed on various conventional supports including Al2O3 and Silica, Al2O3 + FeCl3 and Silica + FeCl3 in the presence of CCl4 as solvent. After catalysts syntheses, they were characterized by X-Ray, microscopic and spectroscopic methods. Then, oligomerization was conducted in the presence of these catalysts using 1-octene and 1-deccan monomers at 80 oC to produce POct and PDec synthetic oils, respectively. Finally, the properties of the synthesized oils including kinematic viscosity at 40 and 100 oC, viscosity index (VI), molecular weight, and the pour point were fully investigated to unravel the effect of support type on the final PAO characteristic. It was found that support nature has considerable impact on the synthesized PAO molecular weight and its distribution which reflects its effects on the PAO viscosity and grade.