OLEFIN OLIGOMERIZATION CATALYSTS

Abstract

The article presents an analysis of literature and patent data concerning olefin oligomerization catalysts used for the production of long-chain linear α-olefins, which are of significant importance in the manufacture of consumer goods such as base lubricating oils, detergents, and various other products. Olefin oligomerization catalysts are typically coordination compounds of transition metals in combination with organoaluminum compounds. A key factor influencing catalytic performance is the nature of the central metal in the coordination complex: the greater the variety of oxidation states the metal can adopt, the more diverse the resulting complexes. In this context, chromium stands out, as evidenced by the large volume of patent literature dedicated to it. Olefin oligomerization catalytic systems generally comprise transition metal complexes and organoaluminum co-catalysts, and the reactions are typically carried out in solution under elevated temperatures and pressures. For each metal, the catalytic properties are determined by the nature of the ligands: their composition, structure, geometry, and acid-base characteristics. However, no clear patterns have been established for ligand selection, and the optimization remains largely empirical. Zeolites and ionic liquids may also serve as olefin oligomerization catalysts. Zeolite-based oligomerization is applied to butene-1 or butane-butylene fractions derived from petroleum refining to produce gasoline, with reactions conducted at temperatures above 300°C, where the zeolite acidic sites are activated. Of particular interest is using of ionic liquids as catalysts, on which oligomerization can be carried out at atmospheric pressure and below 100 °C, although there is little information on this.