A Process for the Trimerisation and Tetramerisation of ethylene to 1-hexene and 1-Octene
Publication Date: 2004-Oct-07
The IP.com Prior Art Database
Trimerisation and tetramerisation systems generally share the common requirement of a co-catalyst to be employed. The most favourable results are achieved with an aluminoxane. In particular, the most active systems result when an aluminoxane based on hydrolysed trimethylaluminium is used (methylaluminoxane, MAO). However, the high cost of trimethylaluminium, and as a result MAO, have a significant detrimental impact on the economics of ethylene trimerisation and tetramerisation with these systems. An alternative means of activation which does not rely on aluminoxanes would be advantageous. A process is discussed that utilises the Sasol trimerisation/tetramerisation systems either as preformed complexes or as in-situ systems, for the selective oligomerisation of ethylene to 1-hexene and/or 1-octene. As an activator, a mixture of metal-alkylating agent (for example AlEt3) and an alkyl abstracting reagent (a Lewis acid, for example B(C6F5)3) is used.