Influence of Temperature on the Product Selectivity and Distribution of Aromatics and C8 Aromatic Isomers in the Conversion of Dilute Ethene over H-Galloaluminosilicate (ZSM-5 type) Zeolite

Product selectivity and distribution of the total and C8 aromatics at the different isoconversions (40, 60, and 80%) of dilute ethene (5 mol% C2H4 in N2) over the H-GaAlMFI zeolite catalyst at different temperatures (300–500°C) have been investigated. A strong temperature dependence of the selectivity for aromatics, propene, and C4 hydrocarbons and also of the distribution of aromatics and C8-aromatic isomers has been observed. At lower temperatures (below 400°C) the aromatization involved mainly hydride transfer reactions, but at higher temperatures (≥400°C) it involved mainly dehydrogenation reactions. The distribution of xylene isomers is controlled by steric factors at 300°C but kinetically at 500°C.