Amplification of inlet temperature disturbances in a packed-bed reactor for CO oxidation over Pt/Al2O3

Jaree, Attasak; Hudgins, R. R.; Budman, Hector; Silveston, P. L.; Yakhnin, V. Z.; Menzinger, Michael

doi:10.1016/s0009-2509(02)00614-0

Cited by 17 publications

(13 citation statements)

References 7 publications

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“…If this is impractical, the effective conductivity can be increased by placing conductive rods in the catalyst bed. Yakhnin and Menzinger (1999a) and Jaree et al (2003a) discuss this technique in some detail.…”

Section: Discussionmentioning

confidence: 99%

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Dynamic responses of packed bed reactors

Menzinger

Yakhnin

Jaree

et al. 2004

Chemical Engineering Science

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Section: Discussionmentioning

confidence: 99%

“…For more detailed simulations of CO-oxidation on Pt, a Langmuir-Hinshelwood kinetic model (Oh and Cavendish, 1982) was employed. For the function f see Jaree et al (2003a).…”

Section: Notationsmentioning

confidence: 99%

Dynamic responses of packed bed reactors

Menzinger

Yakhnin

Jaree

et al. 2004

Chemical Engineering Science

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“…Systems with similar dispersion relation yield resonance amplification under the same geometric constraints. Resonance amplification is known to arise in a number of different areas from earthquakes [29] to acoustics [30], but in chemical and biological systems temporal forcing is more common [31,32]. In our system a spatial modulation of a parameter interacts with the matching spatial mode determined by the physical …”

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confidence: 97%

Periodic Heterogeneity-Driven Resonance Amplification in Density Fingering

Horváth

Tóth

2006

Phys. Rev. Lett.

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Periodic heterogeneity is introduced in experiments with thin solution layers where downward propagating planar autocatalytic fronts are hydrodynamically unstable and cellular patterns develop. The evolution of fingers is greatly affected by the spatial heterogeneity when the wave number associated with it falls in the vicinity of the most unstable mode of the reference system with uniform thickness. The imposed heterogeneity will drive the instability by amplifying the modes with the matching wave numbers as indicated by the experimentally constructed dispersion curves.

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“…For the reactant-inhibited CO oxidation over Pt/Al 2 O 3 , in contrast, the reaction zone was typically less than the spacing of 6.3 cm (Jaree, 2001;Jaree et al, 2002). …”

Section: A 3b 3cmentioning

confidence: 99%

Amplification of Periodic Temperature Disturbances in a Packed‐Bed Reactor: CO Oxidation over a CuO/Al₂O₃ Catalyst

Na-Ranong¹,

Jaree²,

Hudgins³

et al. 2003

Can J Chem Eng

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T he dynamic operation of packed-bed reactors has been extensively investigated in the last few decades. Research has shown how to improve, through non-steady-state operation, the conversion and selectivity of such reactors and to improve the energy management in exothermic reactions. However, under some circumstances, dynamic operation may induce large temperature excursions inside a catalyst bed. Consequently, some undesirable effects such as deactivation of the catalyst can occur. These temperature excursions have been explained in a number of publications by means of wrong-way behaviour for a step-input (e.g., Crider and Foss, 1966;Chen and Luss, 1989;Mehta et al., 1981) and more generally by the differential flow instability or the disturbance amplification mechanism for periodic and arbitrary time-dependent perturbations (Yakhnin, Rovinsky and Menzinger, 1995;Yakhnin and Menzinger, 1998). However, all the factors that influence temperature excursion are not yet fully understood. Yakhnin et al. (1995) and Yakhnin and Menzinger (1998) predicted a large amplification of the amplitude of an inlet temperature disturbance in a packed-bed reactor for a first-order exothermic reaction using a simplified pseudo-homogeneous reactor model. The amplification is explained by the differential flow instability (DIFI) which involves different propagation speeds between concentration and temperature waves and the tendency for thermal runaway of exothermic reactions. In an attempt to verify these predictions, Jaree (2001) studied the CO oxidation over a Pt/Al 2 O 3 in an insulated tubular packed-bed reactor. This reactant-inhibited reaction was found to have a very narrow reaction zone. The desired amplification of periodic perturbations of input temperature was small and could only be observed after stretching the reaction zone by using a highly diluted low-activity catalyst and a high flow rate. The reason for this behaviour is believed to be the efficient heat dispersion that occurs in narrow reaction zones. Hence, the consequence of a narrow reaction zone appears to be the stabilization of the reactor dynamic response. * Author to whom correspondence may be addressed. E-mail address: hbudman@uwaterloo.caAmplification of periodic variations of input temperature in a product-inhibited reaction -CO oxidation over CuO-γ-Al 2 O 3 -was investigated experimentally in an insulated packed-bed reactor. At steady state the temperature profile was elongated compared with that of a reactant-inhibited CO oxidation over Pt/Al 2 O 3 , studied elsewhere. Under periodic operation, amplitudes of the resulting travelling temperature waves, monitored downstream from the reaction front, were amplified to a greater extent than those in the reactant-inhibited CO oxidation over Pt/Al 2 O 3 . The magnitude of the amplification depended on the perturbation frequency and showed resonance behaviour. The magnitude decreased monotonically with increasing perturbation amplitude.L'amplification des variations périodiques de la température d'entrée dans ...

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Amplification of inlet temperature disturbances in a packed-bed reactor for CO oxidation over Pt/Al2O3

Cited by 17 publications

References 7 publications

Dynamic responses of packed bed reactors

Dynamic responses of packed bed reactors

Periodic Heterogeneity-Driven Resonance Amplification in Density Fingering

Amplification of Periodic Temperature Disturbances in a Packed‐Bed Reactor: CO Oxidation over a CuO/Al₂O₃ Catalyst

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Amplification of inlet temperature disturbances in a packed-bed reactor for CO oxidation over Pt/Al2O3

Cited by 17 publications

References 7 publications

Dynamic responses of packed bed reactors

Dynamic responses of packed bed reactors

Periodic Heterogeneity-Driven Resonance Amplification in Density Fingering

Amplification of Periodic Temperature Disturbances in a Packed‐Bed Reactor: CO Oxidation over a CuO/Al2O3 Catalyst

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Product

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Amplification of Periodic Temperature Disturbances in a Packed‐Bed Reactor: CO Oxidation over a CuO/Al₂O₃ Catalyst