The Use of Nuclear Magnetic Resonance, Microcalorimetry, and Atomic Force Microscopy to Study the Aging and Regeneration of Fluid Cracking Catalysts

Occelli, Mario L.; Kalwei, Martin; Wölker, Axel; Eckert, Hellmut; Auroux, A.; Gould, Steven A.

doi:10.1006/jcat.2000.3016

Cited by 40 publications

(40 citation statements)

References 18 publications

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“…In all of these images, the catalyst surface contains debris that appear as bright spots in the images. As mentioned earlier, other researchers [10] have also made similar observations. However, the exact chemical composition of these debris has not been given in the literature.…”

Section: Figure 1(a) (B)supporting

confidence: 79%

“…AFM has been used successfully to investigate the surface features of pillared rectorite catalysts [6,7,8]. Several studies were also conducted to observe the FCC catalyst surfaces using AFM [9,10]. In these studies, both FCC catalysts artificially contaminated with vanadyl naphthenenate and commercial equilibrium FCC catalysts with metal contaminants have been used.…”

Section: Introductionmentioning

confidence: 99%

“…In the case of equilibrium FCC catalysts, AFM images have shown that the catalyst surface contains debris. It has been speculated that this debris might be nickel and vanadium oxides [10].…”

Section: Introductionmentioning

confidence: 99%

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Visualization of the Equilibrium FCC Catalyst Surface by AFM and SEM–EDS

Bayraktar

Kugler

2003

Catalysis Letters

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The deposition of metal contaminants (e.g., Ni, V, and Fe) from the hydrocarbon feed causes the deactivation of fluid catalytic cracking (FCC) catalyst used in petroleum refining. It is very important to understand the changes in the morphology and chemical composition on the catalyst surface and how these structural and chemical changes affect the catalyst performance. In this research, metal-contaminated FCC catalysts from a commercial unit have been characterized using AFM together with SEM-EDS. The AFM images showed the surface pores as well as the features that surround the pore's entrance on the catalyst surface. Catalyst surface contains debris that appear as bright spots in AFM images. SEM-EDS results have shown the presence of iron in these bright spots. Fe enrichment at the catalyst particle surface was also confirmed by XPS analyses.

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Section: Figure 1(a) (B)supporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

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Visualization of the Equilibrium FCC Catalyst Surface by AFM and SEM–EDS

Bayraktar

Kugler

2003

Catalysis Letters

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“…[21] In agreement with previous TEM studies on deactivated FCC catalyst materials, [14][15][16]21] the most prominent feature we observed was the formation of mesopores in the zeolite crystals (Figure 1 c). The mesopores were visible in the zeolites as either small spherical holes (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) nm, open arrowhead in the inset of Figure 1 c) or as elongated pathways crossing parts or the full length of the crystal (full arrowhead in the inset of Figure 1 c). The more rarely observed neatly severing of zeolites is possibly a result of the coalescence of mesoA C H T U N G T R E N N U N G pores, splitting up the particle in two or more parts (Figure 1 d).…”

Section: Resultsmentioning

confidence: 97%

Probing the Different Life Stages of a Fluid Catalytic Cracking Particle with Integrated Laser and Electron Microscopy

Karreman

Buurmans

Agronskaia

et al. 2013

Chemistry A European J

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While cycling through a fluid catalytic cracking (FCC) unit, the structure and performance of FCC catalyst particles are severely affected. In this study, we set out to characterize the damage to commercial equilibrium catalyst particles, further denoted as ECat samples, and map the different pathways involved in their deactivation in a practical unit. The degradation was studied on a structural and a functional level. Transmission electron microscopy (TEM) of ECat samples revealed several structural features; including zeolite crystals that were partly or fully severed, mesoporous, macroporous, and/or amorphous. These defects were then correlated to structural features observed in FCC particles that were treated with different levels of hydrothermal deactivation. This allowed us not only to identify which features observed in ECat samples were a result of hydrothermal deactivation, but also to determine the severity of treatments resulting in these defects. For functional characterization of the ECat sample, the Brønsted acidity within individual FCC particles was studied by a selective fluorescent probe reaction with 4-fluorostyrene. Integrated laser and electron microscopy (iLEM) allowed correlating this Brønsted acidity to structural features by combining a fluorescence and a transmission electron microscope in a single set-up. Together, these analyses allowed us to postulate a plausible model for the degradation of zeolite crystals in FCC particles in the ECat sample. Furthermore, the distribution of the various deactivation processes within particles of different ages was studied. A rim of completely deactivated zeolites surrounding each particle in the ECat sample was identified by using iLEM. These zeolites, which were never observed in fresh or steam-deactivated samples, contained clots of dense structures. The structures are proposed to be carbonaceous deposits formed during the cracking process, and seem resistant towards burning off during catalyst regeneration.

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“…Considering that CAT1 and CAT2 have a different formulation, it is expected that the response to steaming is not strictly the same for the two samples. The effect of NFAl in the cracking performance of E-CATs appears to be less pronounced since it correlates well with the UCS and the total SSA; in fact, Occelli et al [33] demonstrated that NFAl formed during industrial deactivation have a different coordination compared with those formed after accelerated steaming.…”

Section: Cd-cats Behaviormentioning

confidence: 96%

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 Use of Nuclear Magnetic Resonance, Microcalorimetry, and Atomic Force Microscopy to Study the Aging and Regeneration of Fluid Cracking Catalysts

Cited by 40 publications

References 18 publications

Visualization of the Equilibrium FCC Catalyst Surface by AFM and SEM–EDS

Visualization of the Equilibrium FCC Catalyst Surface by AFM and SEM–EDS

Probing the Different Life Stages of a Fluid Catalytic Cracking Particle with Integrated Laser and Electron Microscopy

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

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