Influence of the Brønsted Acidity on the Ring Opening of Decalin for Pt-USY Catalysts

A challenging hot topic faced by the oil refinery industry is the upgrading of low-quality distillate fractions, such as light cycle oil (LCO), in order to meet current quality standards for diesel fuels. An auspicious technological alternative entails the complete saturation of the aromatic structures followed by the selective cleavage of endocyclic carbon-carbon bonds in the formed naphthenic rings (selective ring opening—SRO). This work reports the influence of Brønsted acid sites of platinum-ultra stable Y zeolite (Pt-USY) catalysts in the SRO of decalin as a model naphthenic feed. A maximum combined yield to selective ring opening products (ROP: C10-alkylcycloalkanes + OCD: C10-alkanes) as high as 28.6 wt% was achieved for 1.6Pt-NaUSY-im catalyst. The molar carbon distribution curve of the hydrocracked (C9-) products varied from M-shaped for 1.4Pt-USY-im catalyst, indicating mainly C–C bond cleavage of the ring opening products with one remaining naphthenic ring via carbocations and the paring reaction, to not M-shaped for the 1.6Pt-NaUSY-im catalyst, where carbon-carbon bond cleavage occurs preferentially through a hydrogenolysis mechanism on metal sites. High (hydro)thermal stability and secondary mesoporosity of the 1.6Pt-NaUSY-im catalysts make this system highly prospective for upgrading low-quality real distillate feeds.

Influence of rhodium content on the behavior of Rh/SiO2–Al2O3 catalysts for selective ring opening of decalin

Decalin ring-opening is favored on Rh/SiO₂–Al₂O₃ bifunctional catalyst with an optimized acid/metal balance.

Ring opening of decalin over bifunctional Ni–W carbide/Al2O3–USY catalysts and monofunctional acid Ni–W oxide/Al2O3–USY

The ring opening reaction of decalin was studied over two types of catalyst, including bifunctional catalysts (Ni–W carbide/Al₂O₃–USY) and monofunctional acid catalysts (Ni–W oxide/Al₂O₃–USY) with different amounts of metal loading.

Bifunctional noble metal/zeolite catalysts for upgrading low-quality diesel fractions via selective opening of naphthenic rings

Hydrogenation of polyaromatics coupled with selective ring opening (SRO) of naphthenes over bifunctional noble metal/zeolite catalysts can be applied to bring low-quality diesel cuts like LCO into cetane specifications.