茂金属催化体系下煤制α-烯烃制备低黏度PAO基础油的工艺研究

以茂金属为主催化剂、三异丁基铝和有机硼化物为助催化剂,煤制α-烯烃为原料,采用釜式聚合法合成了低黏度聚α-烯烃基础油(PAO)。通过考察主催化剂及助催化剂用量、反应温度、反应时间对煤制α-烯烃转化率以及产物分布的影响,确定最佳工艺条件为:主催化剂/煤制α-烯烃质量比为1×10~(-4),Al/Zr摩尔比为9,有机硼化物/茂金属质量比为2,反应温度115℃,反应时间2.5h。在该工艺条件下,所制备的PAO基础油的运动黏度(100℃)为8.15mm~2/s,黏度指数158,倾点-54℃,闪点286℃,诺亚克蒸发损失为3.46%,是一种低黏度、高黏度指数、低倾点、高闪点、低蒸发损失的聚α-烯烃,产品主要由四聚体、五聚体和少量的三聚体、六聚体组成,该工艺具有较好的试验重复性。

LOW VISCOSITY PAO PREPARATION BY OLIGOMERIZATION OF ALPHA-OLEFIN FROM COAL WITH METALLOCENE CATALYST

The low viscosity PAO was synthesized by the oligomerization of olefin from coal with metallocene catalyst systems by kettle type polymerization. The effect of reaction conditions, such as mass fractions of the catalyst and co-catalyst, reaction temperature and reaction time on the conversion of stock and component distribution of PAO were examined. It is found that the optimum conditions are metallocene mass fraction 0.01%, proportion of co-catalyst and catalyst 9, the quality of organic boride and metallocene 2, reaction temperature of 115 ℃, reaction time of 2.5 h for the reaction system, under the optimum conditions, a low viscosity, high flash point, low pour point, low evaporation loss of PAO synthetic basestock with the kinetic viscosity of 8.15 mm2/s at 100 ℃, the viscosity index 158, the pour point -54 ℃, the flash point 286 ℃, the evaporation loss by Noack method 3.74% are obtained. The chromatographic analysis indicates that the produced PAO consists of a large part of tetramer, pentamer and a small part of trimer and hexamer. The same results are well repeated.