Performance of fixed-bed catalytic reactors with poison in the feed

Wheeler, Ahlborn

doi:10.1016/0021-9517(69)90404-7

Cited by 111 publications

(37 citation statements)

References 4 publications

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“…Aspects of catalytic behavior have been explored using classical chemical kinetics [2,3] and diffusion-reaction theory. Studies based on a (Fickian) second-order partial differential equation with a linear dependence on the concentration(s) account for behavior in the near-equilibrium regime.…”

Section: Introductionmentioning

confidence: 99%

Competing reaction processes on a lattice as a paradigm for catalyst deactivation

Abad

Kozak

2015

Phys. Rev. E

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We mobilize both a generating function approach and the theory of finite Markov processes to compute the probability of irreversible absorption of a randomly diffusing species on a lattice with competing reaction centers. We consider an N-site lattice populated by a single deep trap, and N − 1 partially absorbing traps (absorption probability 0 < s < 1). The influence of competing reaction centers on the probability of reaction at a target site (the deep trap) and the mean walk length of the random walker before localization (a measure of the reaction efficiency) are computed for different geometries. Both analytic expressions and numerical results are given for reactive processes on two-dimensional surfaces of Euler characteristic = 0 and = 2. The results obtained allow a characterization of catalyst deactivation processes on planar surfaces and on catalyst pellets where only a single catalytic site remains fully active (deep trap), the other sites being only partially active as a result of surface poisoning. The central result of our study is that the predicted dependence of the reaction efficiency on system size N and on s is in qualitative accord with previously reported experimental results, notably catalysts exhibiting selective poisoning due to surface sites that have different affinities for chemisorption of the poisoning agent (e.g., acid zeolite catalysts). Deviations from the efficiency of a catalyst with identical sites are quantified, and we find that such deviations display a significant dependence on the topological details of the surface (for fixed values of N and s we find markedly different results for, say, a planar surface and for the polyhedral surface of a catalyst pellet). Our results highlight the importance of surface topology for the efficiency of catalytic conversion processes on inhomogeneous substrates, and in particular for those aimed at industrial applications. From our exact analysis we extract results for the two limiting cases s ≈ 1 and s ≈ 0, corresponding respectively to weak and strong catalyst poisoning (decreasing s leads to a monotonic decrease in the efficiency of catalytic conversion). The results for the s ≈ 0 case are relevant for the dual problem of light-energy conversion via trapping of excitations in the chlorophyll antenna network. Here, decreasing the probability of excitation trapping s at sites other than the target molecule does not result in a decrease of the efficiency as in the catalyst case, but rather in enhanced efficiency of light-energy conversion, which we characterize in terms of N and s. The one-dimensional case and its connection with a modified version of the gambler's ruin problem are discussed. Finally, generalizations of our model are described briefly.

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Section: Introductionmentioning

confidence: 99%

Competing reaction processes on a lattice as a paradigm for catalyst deactivation

Abad

Kozak

2015

Phys. Rev. E

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“…The Wheeler-Jonas equation [1,2] (see Eq. (1)) permits the estimation of the breakthrough time of a granular activated carbon (GAC) bed, based solely on measurable and readily available macroscopic parameters:…”

Section: Generalmentioning

confidence: 99%

“…the chemisorption of gases. After all, this equation was originally derived for the catalytic oxidation of carbon monoxide [1]. It stands to reason that both interaction parameters (capacity and adsorption rate) will differ from the ones used in physisorption.…”

Section: Chemisorptionmentioning

confidence: 99%

The Wheeler–Jonas equation: a versatile tool for the prediction of carbon bed breakthrough times

Lodewyckx

Wood

Ryu

2004

Carbon

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“…However, many of the mathematical equations and kinetic processes which describe these phenomena for single vapors should also be applicable to multicomponent mixtures. Of particular interest is the approach taken by Wheeler 18 ,1 9 which has been used successfully for single vapor adsorption kinetics.…”

Section: Kinetics Of Adsorptionmentioning

confidence: 99%

Modeling of Equilibrium Gas Adsorption for Multicomponent Vapor Mixtures. Part 2.

Reucroft¹,

Patel²,

Russell³

et al. 1986

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Performance of fixed-bed catalytic reactors with poison in the feed

Cited by 111 publications

References 4 publications

Competing reaction processes on a lattice as a paradigm for catalyst deactivation

Competing reaction processes on a lattice as a paradigm for catalyst deactivation

The Wheeler–Jonas equation: a versatile tool for the prediction of carbon bed breakthrough times

Modeling of Equilibrium Gas Adsorption for Multicomponent Vapor Mixtures. Part 2.

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