Ring Opening of Methylcyclohexane over Platinum-Loaded Zeolites

The activity of different platinum‐loaded zeolites (Mordenite, ZSM‐12, ZSM‐5, ZSM‐23) was investigated in the hydroconversion of methylcyclohexane (MCH), in the context of upgrading highly aromatic distillates for fuel blending. In all cases, conversion of MCH proceeds according to a pathway where the primary products are a mixture of dimethylcyclopentanes and ethylcyclopentane formed by isomerization and ring contraction of MCH. The primary products undergo consecutive ring‐opening reactions with formation of n‐ and isoheptanes. The latter further react to form lower‐molecular‐weight n‐ and isoalkanes. The selectivity and distribution of products deriving from ring‐contraction and ring‐opening reactions are strongly affected by the pore size and topology of the zeolites. ZSM‐5 exhibits a strong reactant shape‐selectivity effect on ring‐opening products. The evaluated zeolites show the following order of activity in the conversion of methylcyclohexane: Mordenite>ZSM‐12>ZSM‐5>ZSM‐23. Going platinum: Extremely selective catalysts are necessary to improve the cetane number of products obtained from hydroconverting highly aromatic streams for use in fuel blending. In this context, the activity of different Pt‐loaded zeolites (Mordenite, ZSM‐12, ZSM‐5, ZSM‐23) was investigated for the hydroconversion of methylcyclohexane.