Decalin and Tetralin as Probe Molecules for Cracking and Hydrotreating the Light Cycle Oil

Corma, Avelino; González-Alfaro, Vicenta; Orchillés, A. Vicent

doi:10.1006/jcat.2001.3181

Cited by 178 publications

(125 citation statements)

References 17 publications

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“…An example of the product distributions obtained with the different catalysts at 723 K is shown in Table 2. These products are consistent with the proposed mechanisms for decalin reaction on acidic catalysts 14,17,19,20 and could be arbitrarily grouped as representative of the main reactions.…”

Section: Resultssupporting

confidence: 76%

“…All these variations can be explained based on a relatively more important occurrence of cracking of side chains, ring opening and alkylation reactions, and support the view that they are favored against hydrogen transfer reactions when temperature is increased. 22 Then, with basis in these results and previous reports, 14,17,[19][20][21] it is possible to postulate a new set of overall reaction paths, which is shown in Figure 7. As shown by the yield curves in Figure 4, direct and subsequent hydrogen transfer would constitute an important set of reactions from the beginning of the reaction system.…”

Section: Resultsmentioning

confidence: 59%

“…23 In coincidence, aromatic selectivities of 35% 19 and initial molar selectivities of 0.791 20 were reported among products in the conversion of decalin over zeolitic catalysts at high reaction temperatures from 723 to 823 K. Other authors found very low yields, possibly due to the low reaction temperatures, below 623 K, or to the co-feeding of hydrogen in the reaction medium that might saturate intermediate olefins. 14,17 Hydrogen transfer was suggested a major reaction at temperatures higher than 623 K, leading to up to 40% of aromatics in the conversion of decalin over acidic catalysts loaded with metals such as Pt or Ir.…”

Section: Resultsmentioning

confidence: 95%

“…For example, at the temperature of 723 K , it was inferred that the first step of the conversion of decalin on Y zeolite is the ring opening to yield a butyl cyclohexyl carbenium ion, which can desorb as butylcyclohexene or β-crack into lighter hydrocarbons. 19,20 When the reaction was performed at lower temperatures (498 to 600 K), higher pressures and with some hydrogen present, it was reported that isomerization products were primary and ring opening products were secondary in the reaction scheme. 14,20 However, it was observed in the present work that various products representative of different possible reactions do show at very low reaction times and conversions, thus giving support to the view that reactions such as cracking, ring opening, ring contraction, isomerization and hydrogen transfer, are present initially in a significant proportion.…”

Section: Resultsmentioning

confidence: 99%

“…These ring opening reactions (indeed cracking reactions) are usually referred to the aperture of one of the rings in decalin or other two-ring naphthenes. 19,20,26,27 Isomerization reactions imply either contraction or expansion of the rings in decalin, leading to hydrocarbons with two alkylated fused rings; further cracking of these compounds may originate lighter olefins, paraffins, and naphthenes, and be also the source for polyalkylated C 5 or C 6 naphthenes.…”

Section: Resultsmentioning

confidence: 99%

See 4 more Smart Citations

Yield of aromatics from naphthenics upon catalytic cracking

Pujro¹,

Falco²,

Pedrosa³

et al. 2012

J. Braz. Chem. Soc.

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Cis-e trans decalina foram submetidas à reação com catalisadores de craqueamento, para estudar a formação de aromáticos numa fração particular de produtos líquidos do processo de craqueamento catalítico fluido (FCC). Um reator batelada em leito fluidizado, CREC, foi usado a 673 e 723 K com tempos de contato entre 3 e 15 s. Cis-decalina foi muito mais reativa. Apesar de diferenças induzidas e medidas na acessibilidade dos catalisadores, seus perfis de atividade foram similares, sugerindo que restrições difusionais não prevalecem. Os produtos foram hidrocarbonetos C 1 -C 12 , enquanto o coque foi muito baixo. Reações de isomerização, craqueamento, transferência de hidrogênio, abertura/contração de anel e alquilação ocorreram, e produtos das várias reações foram observados em tempos de reação muito baixos. Naftênicos bicíclicos C 10 e aromáticos alquilsubstituídos C 7 -C 11 ou nafteno-aromáticos foram os produtos mais importantes. Um mecanismo de reação com três rotas iniciais (isomerização, abertura de anel e reações de transferência de hidrogênio) foi proposto.Cis-and trans-decalin were reacted over cracking catalysts to study the formation of aromatics in a particular fraction of the liquid products obtained in the fluid catalytic cracking process (FCC). A batch, fluidized bed CREC riser simulator reactor was used at 673 and 723 K and contact times varied from 3 to 15 s. Cis-decalin was much more reactive. Despite differences induced and measured in their accessibility indices, the catalysts led to similar activity profiles, suggesting that diffusion restrictions do not prevail. Products were C 1 -C 12 hydrocarbons while coke was very low. Isomerization, cracking, hydrogen transfer, ring opening, ring contraction and alkylation reactions occurred and products from the various reactions were observed at very short reaction times. Bicyclic C 10 naphthenics and alkyl-substituted C 7 -C 11 aromatics or naphtheno-aromatics were the most important products. A reaction mechanism with three initial routes (isomerization, ring opening and direct hydrogen transfer reactions) was proposed.

show abstract

Section: Resultssupporting

confidence: 76%

Section: Resultsmentioning

confidence: 59%

Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

Yield of aromatics from naphthenics upon catalytic cracking

Pujro¹,

Falco²,

Pedrosa³

et al. 2012

J. Braz. Chem. Soc.

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Ring Opening of Aromatics

Weitkamp

2008

Handbook of Heterogeneous Catalysis

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The sections in this article are Introduction Fundamentals of Hydrodecyclization of Cycloalkanes Hydrogenolysis on Metals Hydrocracking on Bifunctional Catalysts Cracking and Activation of Hydrogen on Monofunctional Acidic Catalysts Ring Opening of Aromatics in Diesel and Jet Fuels Bifunctional Catalysts Metal Catalysts Acid Catalysts Ring Opening of Aromatics in Gasoline Without Degradation of the Carbon Number Ring Opening of Aromatics in Pyrolysis Gasoline Followed by Hydrocracking into a Synthetic Steam‐Cracker Feed Hydrodecyclization and Hydrocracking of Cycloalkanes on Acid Zeolites Direct Ring Opening of Aromatics on Bifunctional Zeolites Conclusions Acknowledgments

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Kinetic modeling of catalytic conversion of methylcyclohexane over USY zeolites: Adsorption and reaction phenomena

Al-Sabawi¹,

Lasa²

2009

AIChE Journal

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Catalytic conversion of cycloparaffins is a complex process involving competing reaction steps. To understand this process, FCC experiments using methylcyclohexane (MCH) on USY zeolite catalysts were carried out in the mini-fluidized CREC riser simulator. Runs were developed under relevant FCC process conditions in terms of partial pressures of MCH, temperatures (450-550 C), contact times (3-7 s), catalyst-oil mass ratios (5), and using fluidized catalysts. MCH overall conversions ranged between 4 to 16 wt %, with slightly higher conversions obtained using the larger zeolite crystallites. Moreover, it was found that MCH undergoes ring opening, protolytic cracking, isomerization, hydrogen transfer and transalkylation. A heterogeneous kinetic model for MCH conversion including thermal effects, adsorption and intrinsic catalytic reaction phenomena was established. Adsorption and kinetic parameters were determined, including the heat of adsorption (À40 kJ/mol), as well as thermal and primary catalytic intrinsic activation energies, which were in the range of 43-69 kJ/mol, and 50-74 kJ/mol, respectively. V

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Decalin and Tetralin as Probe Molecules for Cracking and Hydrotreating the Light Cycle Oil

Cited by 178 publications

References 17 publications

Yield of aromatics from naphthenics upon catalytic cracking

Yield of aromatics from naphthenics upon catalytic cracking

Ring Opening of Aromatics

Kinetic modeling of catalytic conversion of methylcyclohexane over USY zeolites: Adsorption and reaction phenomena

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