Isomerization of n-Heptane in the Presence of Aromatic Hydrocarbons over Pt/MOR/Al2O3 and Pt/WO3/ZrO2 Catalysts

Abstract

The effect of aromatic hydrocarbons (benzene, toluene) on the isomerization of n-heptane over Pt/MOR/Al₂O₃ and Pt/WO₃/ZrO₂ catalysts is studied. It is shown that the presence of aromatic hydrocarbons results in a need to raise the reaction temperature by 20–30°C to achieve n-heptane conversion at the same level as for individual n-heptane. It is established that the yield of heptane isomers falls in 1.5 times (from 60.1 to 39.9 wt %) during the isomerization of n-heptane mixed with aromatic hydrocarbons over Pt/MOR/Al₂O₃ catalyst and remains at the same level (60.4–68.0 wt %) over Pt/WO₃/ZrO₂ catalyst. The developed catalysts can be used in industry to isomerize the C₇ fraction separated from straight-run and catalytic reforming gasolines. The presence of aromatic hydrocarbons in feedstocks is undesirable when Pt/MOR/Al₂O₃ catalyst is used, as it reduces the yield of isomers.