The Mechanism of Zeolite Y Destruction by Steam in the Presence of Vanadium

Trujillo, Carlos; Uribe, Uriel Navarro; Knops-Gerrits, Peter-Paul; A, Luis Alfredo Oviedo; Jacobs, Pierre

doi:10.1006/jcat.1997.1550

Cited by 78 publications

(54 citation statements)

References 27 publications

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“…A large amount of research has focused on understanding the destructive role of vanadium since it is major issue for catalyst performance during the cracking of residuum-containing feeds [204][205][206][207][208][209]. It has been shown that the destruction of zeolite Y in the presence of steam occurs via two pathways [209].…”

Section: Catalyst Deactivationmentioning

confidence: 99%

Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis

2003

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Supported vanadium oxide catalysts are active in a wide range of applications. In this review, an overview is given of the current knowledge available about vanadium oxide-based catalysts. The review starts with the importance of vanadium in heterogeneous catalysis, a discussion of the molecular structure of vanadium in water and in the solid state and an overview of the spectroscopic techniques enabling to study the chemistry of supported vanadium oxides. In the second part, it will be shown that advanced spectroscopic tools can be used to obtain detailed information about the coordination environment and oxidation state of vanadium oxides during each stage of the life-span of a heterogeneous catalyst. Three topics will be discussed: (1) the molecular structure of supported vanadium oxide catalysts under hydrated, dehydrated and reduced conditions, including the parameters, which influence the molecular structures formed at the surface of the support oxide; (2) elucidation of the active surface vanadium oxide during the oxidation of methanol to formaldehyde, the reaction mechanism and the vanadium oxide-support effect; and (3) deactivation of fluid catalytic cracking (FCC) catalysts by migration of vanadium oxides and the development of a method preventing the structural breakdown of zeolites by trapping the mobile vanadium oxides in an aluminum oxide coating.

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Section: Catalyst Deactivationmentioning

confidence: 99%

Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis

2003

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“…The solubilization of V was not influenced by the pulp density or by the type of leaching (chemical or microbial) used. The recovery results are promising since, during the use of catalysts in the HDS process, vanadium complexes are deposited on the catalyst particles and, subsequently, these complexes decompose due to the high temperatures in the reactors (Trujillo et al, 1997). During the regeneration of the catalyst, the water vapor produced from the combustion of coke, deposited on the particles, oxidizes vanadium and the resulting oxide hydrolyzes, forming a volatile species, vanadic acid, which can permeate the inner layers of the catalyst particles, hindering the extraction of vanadium.…”

Section: Indirect Microbial Leachingmentioning

confidence: 99%

BIOLEACHING OF METALS FROM A SPENT DIESEL HYDRODESULFURIZATION CATALYST EMPLOYING Acidithiobacillus thiooxidans FG-01

Ferreira

Sérvulo

Costa

et al. 2017

Braz. J. Chem. Eng.

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-This study evaluates the recovery of heavy metals employing a spent catalyst from the hydrodesulfurization (HDS) of diesel, with no chemical, thermal or physical pretreatment, using the bacterial strain Acidithiobacillus thiooxidans FG-01. Direct and indirect bioleaching tests were carried out in Erlenmeyer flasks (500 mL). The influence of the pulp density and supplementation with elemental sulfur on the bioleaching were also investigated. The spent catalyst contained organochlorines, petroleum hydrocarbons and heavy metals in its composition. The best recovery results (26% Al, 26% V and 39% Mo) were achieved in the two-stage (indirect) bioprocess, with a pulp density of 50 g/L. It was not possible to recover Co, Cu and Ni (< 5%) under any of the conditions tested. The bacterial strain A. thiooxidans FG-01 was found to be a promising candidate for the recovery of Al, V and Mo using the crude spent HDS catalyst.

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“…2. E-CAT1, which was sampled from partial combustion unit wherein V is less oxidized and with a minor mobility due to the lower values of oxygen partial pressure and temperature [10,13], appears to undergo a less drastic deactivation than the full combustion E-CAT2. This indicates that for the catalyst samples considered in this work, the cyclic deactivation method used still overestimates the V poisoning effect encountered in a partial combustion unit that operated with lower temperature and oxygen deficiency compared with a full combustion one.…”

Section: Unit Cell Sizementioning

confidence: 99%

“…also catalyzes dehydrogenation reactions and, more importantly, at oxidative conditions of the regenerator and the presence of high temperature (i.e., *913-1,008 K) steam may produce mobile, aggressive species such as vanadic acid [11]. The latter penetrates into the catalyst pores and hydrolyzes the Al-O-Si bonds of the zeolite crystals leading to the collapsing of its structure [12,13].…”

Section: Introductionmentioning

confidence: 98%

Cyclic Deactivation with Steam of Metallated Cracking Catalysts: Catalytic Testing at the Bench Scale and the Pilot Scale

et al. 2011

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Besides offering an adequate product distributions, a cracking catalyst must exhibit a reasonable resistance to the combined effect of high temperature, steam and metals. Two commercial catalysts, poisoned with Ni ? V (*2,500 ppm), are subjected to a large scale cyclic deactivation with steam, then characterized using mostly basic techniques and finally tested via bench scale and pilot scale cracking experiments. As examples of industrial deactivation, corresponding equilibrium catalysts (E-CATs) are investigated in parallel. Depending on their specific formulation, catalysts deactivate differently due to the exposition to high temperature steam and metals. The intrinsic deviations in the catalytic properties of cyclic deactivated catalysts (CD-CATs) related to E-CATs are further biases by the particular history of the latter and the particular reactor configuration and hydrodynamics, such deviations being magnified in the bench scale testing. Relative differences in activity and product yields (except for coke and hydrogen) of CD-CATs referred to E-CATs are below 10% at the pilot scale, and within 23% at the bench scale. Relative biases in hydrogen and coke yield of may be as high as 75 and 26% in the pilot plant and as much as 150 and 32% at the bench scale.

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The Mechanism of Zeolite Y Destruction by Steam in the Presence of Vanadium

Cited by 78 publications

References 27 publications

Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis

Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis

BIOLEACHING OF METALS FROM A SPENT DIESEL HYDRODESULFURIZATION CATALYST EMPLOYING Acidithiobacillus thiooxidans FG-01

Cyclic Deactivation with Steam of Metallated Cracking Catalysts: Catalytic Testing at the Bench Scale and the Pilot Scale

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