Forming of high surface area TiO2 to catalyst supports

Bankmann, M.; Brand, R.; Engler, Bernd; Ohmer, J.

doi:10.1016/0920-5861(92)80025-i

Cited by 49 publications

(28 citation statements)

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“…Agglomerate strength would depend greatly on the preparation of the compact. Representative data for catalyst agglomerates (see Table 15) suggest they are generally substantially weaker than polycrystalline ceramic materials prepared by high temperature sintering, such as the alumina cited in Figure 27 [163,165,[167][168][169][170][171]. For example, Pham and co-workers [163] found that the breaking strength of a VISTA B alumina agglomerate during uniaxial compaction is in the range of 5-10 MPa-substantially lower than the reported values for heat-treated polycrystalline alumina of 280-550 MPa [165].…”

Section: Compressive Strengths Of Ceramic Materialsmentioning

confidence: 84%

“…For example, spheres of γ-Al2O3 prepared by sol-gel granulation are substantially (17 times) stronger than commercial γ-Al2O3 spheres [166]. Moreover, 30-and 90-μm diameter particles of TiO2 prepared by thermal hydrolysis or basic precipitation are 30 and 15 times stronger than commercially available 4-mm extrudates [169].…”

Section: Effects Of Preparation and Pretreatment On Catalyst Agglomermentioning

confidence: 97%

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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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Section: Compressive Strengths Of Ceramic Materialsmentioning

confidence: 84%

Section: Effects Of Preparation and Pretreatment On Catalyst Agglomermentioning

confidence: 97%

Heterogeneous Catalyst Deactivation and Regeneration: A Review

2015

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“…A detailed description of the extrusion process of pyrogenic titania is provided in Refs. [45,46]. The procedure comprises four crucial steps, namely kneading of the raw materials, extrusion, drying of the green bodies, and calcination.…”

Section: Preparation Of Formed Supportsmentioning

confidence: 99%

Flame Hydrolysis

Kerner¹,

Rochnia²

2008

Handbook of Heterogeneous Catalysis

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“…Titanium dioxide (TiO 2 ) nanoparticles are traditionally used as pigments but have found use in diverse areas such as photocatalysis 1 and in reducing nitrogen oxide emissions. 2 The production of TiO 2 is an important industrial process and usually occurs via a chloride process in which the titanium tetrachloride (TiCl 4 ) precursor is oxidized in a flame reactor to produce TiO 2 nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Multiscale Modeling of TiO₂ Nanoparticle Production in Flame Reactors: Effect of Chemical Mechanism

Mehta

Sung

Raman

et al. 2010

Ind. Eng. Chem. Res.

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For titanium dioxide (TiO 2 ) nanoparticles manufactured in flame reactors, the precursor is injected into a pre-existing flame, exposing it to a high-temperature gas phase, leading to nucleation and particle growth. Predictive modeling of this chemical process requires simultaneous development of detailed chemical mechanisms describing gas-phase combustion and particle evolution, as well as advanced computational tools for describing the turbulent flow field and its interactions with the chemical processes. Here, a multiscale computational tool for flame-based TiO 2 nanoparticle synthesis is developed and a flamelet model representing detailed chemistry for particle nucleation is proposed. The effect of different chemical mechanisms (i.e., one-step, detailed, flamelet) on the prediction of nanoparticle nucleation is investigated using a plug-flow reactor and a partially stirred tank reactor to model the flow field. These simulations demonstrate that particle nucleation occurs much later in the flame with detailed titanium oxidation chemistry, compared to one-step chemistry. Finally, a large-eddy simulation tool is developed to study the effect of precursor injection configuration on nanoparticle formation in turbulent flames. For titanium dioxide (TiO 2 ) nanoparticles manufactured in flame reactors, the precursor is injected into a pre-existing flame, exposing it to a high-temperature gas phase, leading to nucleation and particle growth. Predictive modeling of this chemical process requires simultaneous development of detailed chemical mechanisms describing gas-phase combustion and particle evolution, as well as advanced computational tools for describing the turbulent flow field and its interactions with the chemical processes. Here, a multiscale computational tool for flame-based TiO 2 nanoparticle synthesis is developed and a flamelet model representing detailed chemistry for particle nucleation is proposed. The effect of different chemical mechanisms (i.e., one-step, detailed, flamelet) on the prediction of nanoparticle nucleation is investigated using a plug-flow reactor and a partially stirred tank reactor to model the flow field. These simulations demonstrate that particle nucleation occurs much later in the flame with detailed titanium oxidation chemistry, compared to one-step chemistry. Finally, a large-eddy simulation tool is developed to study the effect of precursor injection configuration on nanoparticle formation in turbulent flames.

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Forming of high surface area TiO2 to catalyst supports

Cited by 49 publications

References 1 publication

Heterogeneous Catalyst Deactivation and Regeneration: A Review

Heterogeneous Catalyst Deactivation and Regeneration: A Review

Flame Hydrolysis

Multiscale Modeling of TiO₂ Nanoparticle Production in Flame Reactors: Effect of Chemical Mechanism

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Forming of high surface area TiO2 to catalyst supports

Cited by 49 publications

References 1 publication

Heterogeneous Catalyst Deactivation and Regeneration: A Review

Heterogeneous Catalyst Deactivation and Regeneration: A Review

Flame Hydrolysis

Multiscale Modeling of TiO2 Nanoparticle Production in Flame Reactors: Effect of Chemical Mechanism

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Product

Resources

About

Multiscale Modeling of TiO₂ Nanoparticle Production in Flame Reactors: Effect of Chemical Mechanism