Attrition of FCC powder in the jetting region of a fluidized bed

Ghadiri, Mojtaba; Cleaver, J.A.S.; Tuponogov, V. G.; Werther, Joachim

doi:10.1016/0032-5910(94)80014-6

Cited by 38 publications

(21 citation statements)

References 4 publications

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“…ena. This has been demonstrated by Ghadiri et al 1992 , who revealed strong discrepancies in the previously published literature with respect to the influence of the superficial gas velocity on the attrition-induced loss rate of a fluidized-bed Ž . system.…”

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confidence: 79%

Catalyst attrition in fluidized‐bed systems

1999

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confidence: 79%

Catalyst attrition in fluidized‐bed systems

1999

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“…In their review of attrition and attrition test methods, Bemrose and Bridgewater [175] discuss how attrition varies with reactor type, e.g., involves mainly particle-wall impacts in moving pellet bed reactors and particle-particle impacts in fluidized-bed reactors of high fluid velocity. In fact, jet attrition of catalyst particles in a gas fluidized-bed involving principally abrasion due to collision of high-velocity particles has been modeled in some detail [172,176]. Thus, given such important differences in attrition mechanism, realistic attrition test methods should attempt to model reactor operation as closely as possible.…”

Section: Attrition Of Catalyst Agglomerates: Mechanisms Studies Andmentioning

confidence: 99%

Heterogeneous Catalyst Deactivation and Regeneration: A Review

2015

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Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical) and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing). The key features and considerations for each of these deactivation types is reviewed in detail with reference to the latest literature reports in these areas. Two case studies on the deactivation mechanisms of catalysts used for cobalt Fischer-Tropsch and selective catalytic reduction are considered to provide additional depth in the topics of sintering, coking, poisoning, and fouling. Regeneration considerations and options are also briefly discussed for each deactivation mechanism.

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“…In fact, jet attrition of catalyst particles in a gas fluidized bed involving principally abrasion due to collision of high-velocity particles has been modeled in some detail (149,153). Thus, given such important differences in attrition mechanism, realistic attrition test methods should attempt to model reactor operation as closely as possible.…”

Section: Tensile Strengths and Attrition Resistance Of Catalyst Suppomentioning

confidence: 99%

Catalyst Deactivation and Regeneration

Bartholomew

2003

Kirk-Othmer Encyclopedia of Chemical Technology

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This article focuses on the causes, mechanisms, prevention, modeling, and treatment (experimental and theoretical) of deactivation. The causes of deactivation are basically of three kinds: chemical, mechanical, and thermal. The five intrinsic mechanisms of catalyst decay, ( 1 ) poisoning, ( 2 ) fouling, ( 3 ) thermal degradation, ( 4 ) chemical degradation, and ( 5 ) mechanical failure, vary in their reversibility and rates of occurrence. Poisoning and thermal degradation are generally slow, irreversible processes while fouling with coke and carbon is generally rapid and reversible by regeneration with O 2 or H 2 . Catalyst deactivation is more easily prevented than cured. Poisoning by impurities can be prevented through careful purification of reactants. Carbon deposition and coking can be prevented by minimizing the formation of carbon or coke precursors through gasification, by careful design of catalysts and process conditions and by controlling reaction conditions to minimize effects of carbon and coke formation on activity. Sintering is best avoided by minimizing and controlling the temperature of reaction. Regeneration of deactivated catalysts is possible for many catalytic processes and is widely practiced. The purpose of this article is to provide the reader with a comprehensive overview of the scientific and practical aspects of catalyst deactivation, including mechanisms of catalyst decay, prevention of deactivation, regeneration of catalysts, methods for study and treatment of catalyst decay, and deactivation kinetics. The greatest emphasis is on deactivation and regeneration of heterogeneous catalysts, although decay mechanisms of homogeneous catalysts and enzymes as well as methods of stabilizing these catalyst types are briefly addressed.

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Attrition of FCC powder in the jetting region of a fluidized bed

Cited by 38 publications

References 4 publications

Catalyst attrition in fluidized‐bed systems

Catalyst attrition in fluidized‐bed systems

Heterogeneous Catalyst Deactivation and Regeneration: A Review

Catalyst Deactivation and Regeneration

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