One-pot cascade ethylene oligomerization using Ni/Siral-30 and H-ZSM-5 catalysts

Abstract

A study on the ethylene oligomerization was carried out using a one-pot cascade continuous flow fixed-bed reactor, loaded with Ni/Siral-30 and H-ZSM-5 catalysts at the same time. The used Siral-30 and ZSM-5 are commercial silica alumina (Sasol, SiO2/Al2O3 = 30/70) and zeolite (Zeolyst CBV 2314) materials, respectively. Compared to the catalytic results from reactions with the single catalysts under identical conditions, the one-pot cascade Ni/Siral-30 + H-ZSM-5 exhibited close to 100% conversion, resulted in a completely reversed Schulz-Flory type product distribution (C10+ > C8 > C6 > C4), and yielded the highest amount of liquid product for the entire reaction time at 250 °C (0.14 and 0.05 g gcat.−1 h−1 of a total liquid and C10+, respectively). A liquid product containing about 30% aromatic compounds, which is one of the important constituents needed for jet-fuel, was obtained from the one-pot cascade reaction. We also confirmed that the results obtained from Ni/Siral-30 + H-ZSM-5 in the gas-slurry autoclave reactor were significantly different than those obtained from the one-pot cascade reaction. The overall results demonstrate that a sequential one-pot cascade catalysis over Ni-containing and Brønsted acidic catalysts can be a good method for improving the production of jet-fuel range hydrocarbons from ethylene conversion.