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

Martı́nez, Agustı́n; Arribas, María Adoración Merino; Pergher, Sibele B. C.

doi:10.1039/c6cy00135a

Cited by 30 publications

(17 citation statements)

References 82 publications

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“…Monofunctional catalysts include catalysts based on acidic zeolites, as well as catalysts containing noble metals on oxide supports. , In bifunctional catalysts, metals are supported on wide-pore zeolites (H-FAU and H-β) with strong Brønsted acidity. Most of the publications are devoted to the study of bifunctional catalysts, − as well as to the comparison of the mechanisms of the SRO process on mono- and bifunctional catalysts. ,, Thus, the activity and selectivity of monofunctional acidic (WO 3 –Al 2 O 3 ) and metallic (Ir/Al 2 O 3 ) catalysts and the bifunctional catalytic system Ir/WO 3 /Al 2 O 3 in the SRO reactions of decalin and methylcyclohexane are compared in the studies of Moraes, , and the reaction mechanisms are proposed.…”

Section: Introductionmentioning

confidence: 99%

Decalin Ring Opening on Heterogeneous Me/Saponite Nanocatalysts (Me = Rh, Ru, and Ir)

Финашина

Avaev

Ткаченко

et al. 2021

Ind. Eng. Chem. Res.

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Heterogeneous nanocatalysts containing metal nanoparticles (Me = Ir, Rh, and Ru) deposited on mesoporous saponite (magnesium aluminosilicate) were prepared from metal chlorides by the incipient wetness impregnation method and tested in the ring-opening reaction at high pressures using decalin as a substrate. The elemental composition of the catalysts and the carrier, the surface area, pore size and pore volume, the charge state, the size of metal nanoparticles, and the acidity were characterized by the following methods: scanning electron microscopy with energy-dispersive X-ray analysis, nitrogen adsorption–desorption analysis, Fourier-transform infrared spectroscopy, diffuse-reflectance Fourier-transform infrared spectroscopy, transmission electron microscopy, CO chemisorption, X-ray photoelectron spectroscopy, and X-ray diffraction analysis. It was shown that the structure of the carrier and the mesopore system were preserved after metal deposition. Metal particles have an extremely small size and high dispersion. The carrier has a small number of Brønsted acid sites (BAS), which decreases when the metal is supported. The highest BAS/LAS (Lewis acid sites) ratio is determined for the Rh/saponite catalyst. It was found that the activity, selectivity, and product composition were mostly affected by the metal nature. The Ir/saponite catalyst provides a selectivity of about 90% for the ring-opening products, both full and partial ring opening, at the total decalin conversion of about 80%. Over the Rh/saponite catalyst, up to 30% of the bicyclic products of the skeletal isomerization of decalin are formed along with the ring-opening products (mainly partial). The formation of a large number of C1–C9 hydrocracking products is observed over the Ru/saponite catalyst, besides the ring-opening products. Changes in the activity and selectivity of the catalysts with the variation of the main reaction parameters (T, P, WHSV, H2/C10 M ratio, and decalin partial pressure) were also determined.

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Section: Introductionmentioning

confidence: 99%

Decalin Ring Opening on Heterogeneous Me/Saponite Nanocatalysts (Me = Rh, Ru, and Ir)

Финашина

Avaev

Ткаченко

et al. 2021

Ind. Eng. Chem. Res.

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“…[ 1,2 ] Moreover, the sulphur content of the LCO fractions is about 0.2 wt% to 2 wt% and the industrial fractions must be hydrotreated in a first stage to decrease the S content between 6 ppm to 16 ppm. [ 3–5 ]…”

Section: Introductionmentioning

confidence: 99%

Influence of the Ir content and the support on the thiotolerance of the Ir/SiO₂‐Al₂O₃ catalysts for selective ring opening of decalin

et al. 2020

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The influence of Ir content on sulphur tolerance for the selective ring opening of decalin was investigated. Ir/SiO2‐Al2O3 catalysts (70 wt% and 80 wt% SiO2) were used. In the absence of sulphur, slight differences were observed on the yields according to the metallic content regardless of the support used. Although the results of cyclopentane hydrogenolysis showed that the metallic function acquires importance as the metal content increases, for these metal percentages the acid function limits the rate of decalin opening reaction. Products distribution are strongly modified using decalin with S content compared to pure decalin. The formation of dehydrogenated products is virtually null due to S adsorbed on the metal sites. The support has low influence on the thiotolerance. The results, related to the amount of S per Ir surface atom, showed that for a moderate S content (S/Irsurf ∼ 0.30), 1.5 Ir/Sy appears to be less poisoned than 1Ir/Sy and 2Ir/Sy.

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“…Current requirements for diesel in the European Union, covered by EN 590, include a minimum CN of 51, a maximum concentration of PAHs of 8 wt%, and a sulfur content of 10 ppm maximum. In the United States a sulfur limit of 15 ppm and a minimum CN of 41 have been efficiently applied since 2010 for ultra-low sulfur diesel (ULSD) for highway use, while a maximum aromatic content of 10 wt% is allowed in certain states like California [1].…”

Section: Introductionmentioning

confidence: 99%

“…Bifunctional catalysts comprised of a noble metal with high hydrogenolysis activity (Pt, Ir) dispersed on large pore zeolites (i.e., faujasites and beta) are among the most prospective so far developed for the SRO reaction [1]. For these catalysts, low density of Brønsted acid sites and very high metal dispersion (>80%) at high metal loading (≥3 wt%) are the main requirements to achieve high yields to SRO products by promoting opening of the naphthenic rings via hydrogenolysis on the metal centers, while minimizing unwanted acid-catalyzed secondary cracking of SRO products into lighter hydrocarbons.…”

Section: Introductionmentioning

confidence: 99%

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

Soares

Pergher

2019

Catalysts

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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.

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

Abstract: 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.

Cited by 30 publications

References 82 publications

Decalin Ring Opening on Heterogeneous Me/Saponite Nanocatalysts (Me = Rh, Ru, and Ir)

Decalin Ring Opening on Heterogeneous Me/Saponite Nanocatalysts (Me = Rh, Ru, and Ir)

Influence of the Ir content and the support on the thiotolerance of the Ir/SiO₂‐Al₂O₃ catalysts for selective ring opening of decalin

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

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

Abstract: 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.

Cited by 30 publications

References 82 publications

Decalin Ring Opening on Heterogeneous Me/Saponite Nanocatalysts (Me = Rh, Ru, and Ir)

Decalin Ring Opening on Heterogeneous Me/Saponite Nanocatalysts (Me = Rh, Ru, and Ir)

Influence of the Ir content and the support on the thiotolerance of the Ir/SiO2‐Al2O3 catalysts for selective ring opening of decalin

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

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Influence of the Ir content and the support on the thiotolerance of the Ir/SiO₂‐Al₂O₃ catalysts for selective ring opening of decalin