High-viscosity Lubricating Base Oil Preparation By Mixed Alpha-olefins With Metallocene Catalyst

The crude material of foreign production of PAO is usually from alpha-olefins produced by oligomerization of ethylene,but the technology has not been matured in China,so alpha-olefins required for the production of PAO is still imported.Combined with domestic conditions which is more coal and less petroleum in mineral resources,it has great study value using mixed alpha-olefins from high temperature Fischer-Tropsch synthesis to produce PAO.In this paper,mixed alpha-olefins polymerization catalyzed by three-element catalytic system which was rac-Et(1-Ind)2ZrCl2/Al(iBu)3/[Me2NHPh]+[B(C6F5)4]-,was studied.The effects of reaction conditions on the conversion and the properties of the products were investigated;the conversion of olefins of different carbon numbers under different conditions was analyzed;the effects of the continuous reactor on the polymerization and the polymerization products were discussed;and the properties of the products obtained from different reactors were compared.In the batch reactor,mixed alpha-olefins were catalyzed by the above catalytic system.Under the optimized condition which was Zr/mixed alpha-olefins was 4×10-5,Al/Zr mole ratio was 120,B/Zr mole ratio was 1.2,temperature was 80℃,reaction time was 120min,the conversion of mixed alpha-olefins was 97.3%,100℃ kinematic viscosity(Kv 100)was 377.3cSt,viscosity index(VI)was 262,pour point(pp)was-29℃,flash point was 300℃weight-average molar mass(Mw)was 17227,and molecular weight distribution(MWD)was 1.95.Under the different conditions,olefins with different carbon numbers(C9,C10,C11)had almost the same conversion at each moment though the overall conversion increased as the reaction time increased.In the micro-channel continuous reactor,the optimized conditions of batch reactor was selected except that the residence time was 12min,and the properties of polymers were that Kv100 was 422cSt,VI was 278,pp was-26℃,flash point was more than 300℃ Mw was 19031,MWD was 1.69.Under the same condition,polymers obtained from micro-channel continuous reactor had higher viscosity and viscosity index and lower molecular weight distribution.