乙烯线性齐聚的研究——Ⅱ.ZrCl_4—Et_2AlCl二组分体系的催化作用

THE LINEAR OLIGOMERIZATION OF ETHYLENE (Ⅱ) THE CATALYSIS OF ZrCl_4-Et_2AlCl BINARY SYSTEM

1.引言 随着石油化工和精细化工的日益发展,工业上对直链α-烯烃的需要愈来愈迫切。乙烯齐聚反应是制备直链α-烯烃的重要方法。以过渡金属锆的化合物与烷基铝化合物组成的二元Ziegler-Natta体系催化乙烯线性齐聚,其文献和专利报导较少,且以合成高碳α-烯烃为目的。我们曾报导过ZrCl_4-Et_3A1_2Cl_3体系催化乙烯齐聚,虽能得到低碳α-烯烃,但效果较差。在使用Et_2AlCl作活化剂时结果较好。

In this paper is presented the catalysis of ZrCl4-Et2 A1C1 binary system in the oligomerization of ethylene to obtain lower linear α-ole-fins (i.e. linear C4 to C10 α-olefins ) . The results show that the catalyst activity was enhanced by increasing the ratio of Al/Zr between 10 and 50. The highest activity was 5800 mol C2/mol Zr.h at Al/Zr= 50 and then was kept constant when more Et2AlCl was added. It was unfavorable to prolong the reaction time for the selectivity of C10=≤ and α-C10≤= in C10≤=.A lower reaction temperature favored the sele- ctivity for both C10≤= and α-C 10≤= in C10≤= but the catalyst activity was low in this case. The most suitable reaction temperature for oligomerization of ethylene was found to be 383 K. Aging conditions influenced the reaction directly. Lower ageing temperature and longer ageing time are necessary for obtaining lower linear а-olefins.