Removal of cyclopentadiene from 1-octene by transition metal containing zeolites. Part 1: Screening of the adsorption properties

Catalyst activities in olefin (co)polymerisation can be reduced by feed impurities. In the present work, a series of metal exchanged zeolites was tested for the removal of cyclopentadiene from 1-octene. Initial screening was performed at room temperature with a number of (transition) metal exchanged zeolites using 1-octene containing 1000 or 10,000 wt.ppm cyclopentadiene. From these experiments it was concluded that NaX zeolites ion exchanged successively with Ca and Co ions using an intermediate calcination were promising materials. Optimal activation conditions for the CoCaX samples were determined and resulted in the zeolite pretreatment at 500 °C in an oxygen atmosphere. Adsorption isotherms of cyclopentadiene in 1-octene on Ca, Co, and Ag containing NaX zeolites and related materials were recorded, confirming the superior behaviour of a zeolite NaX successively exchanged with Ca and Co ions using an intermediate calcination. Breakthrough experiments using 1-octene feeds containing about 100 wt.ppm cyclopentadiene also demonstrated that this zeolite allowed purification of octene spiked with cyclopentadiene to a concentration below 0.1 wt.ppm.