The investigation of a new catalytic system with high efficiency for production of 1-butene at ethylene dimerization reaction

In order to decrease of heavy and polymeric compounds in 1-butene reactor that it is the most important problem that exists in 1-butene plants and leads to shut down of pertinent reactor, a systematic study was conducted on the Ti catalyzed dimerization of ethylene using a halide compound as a new promoter. It is noteworthy that there is no report on use of promoter in ethylene dimerization for production of 1-butene, up to now. This study revealed that the increase of a vicinal halide as promoter could be improved overall 1-butene selectivity and rate of reaction. It is proposed that the spatial effects of weak coordination of halide on the Ti active species lead to decompose of dimeric TEA into monomeric TEA and modify electronic properties of active sites. The relevant mechanism and reaction between TEA and promoter was disclosed in detail. The effects reaction temperature, reaction pressure, molar ratios of TEA/Ti, modifier/Ti and promoter/Ti on ethylene conversion, overall selectivity to 1-butene, byproducts and weight of polymer were investigated and optimum conditions were determined.