A Dual Functional Tuneable‐Lewis Acid/Sulfur Scavenging Catalyst System for Alpha Olefin Oligomerization

A novel cost effective tuneable Lewis acid/sulfur scavenging system, comprising of various ratios of group 13 stronger Lewis acid AlCl3 and transition metal weak Lewis acid FeCl3, were developed for oligomerization of alpha olefins to form polyalphaolefins (PAOs). The residence time and temperature dependent oligomer ratio of 1‐decene is studied in the presence of Lewis acid catalysts containing various ratios of AlCl3/FeCl3 [AlCl3, AlCl3/FeCl3 (0.7:0.3), AlCl3/FeCl3 (0.5:0.5), AlCl3/FeCl3 (0.3:0.7), FeCl3]. The transition metal based weak Lewis acid FeCl3 yielded oligomer ratio comparable to commercial PAO 2 cst to PAO 6 cst viscosity grade. With an increase in AlCl3 concentration in the catalyst system, the equilibrium oligomer ratio is shifted towards higher oligomers. With increase in temperature, due to faster termination kinetics in comparison with the propagation, the oligomer ratio is shifted towards lighter dimer and trimer oligomers. The sulfur scavenging abilities of AlCl3/FeCl3 is studied in the presence of model mixture containing thiol in decene. The catalyst system showed superior sulfur scavenging abilities. Cost effective dual functional tuneable Lewis acid/sulfur scavening catalyst system with varying proportions of FeCl3/AlCl3 have been used for 1‐decene oligomerization for the produciton of polyalphaolefin (PAO) synthetic lubricants. The catalyst, reaction time and temperature dependent oligomer ratio is obtained for various viscosity grades of PAOs.The FeCl3/AlCl3 system has been shown to be effective sulfur scavenging, suited for industry.