Increasing the productivity of a porous catalyst granule with respect to the target compound for an arbitrary chemical reaction in a non-stationary regime

A composite combustion duct in compact methane reformers consists of a gas flow channel, porous layer and solid plates. There are various transport processes appeared, such as gas flow in the channel, multi-component species convection/diffusion in the porous layer, and heat transfer. They are further coupled by methane catalytic combustion in the porous layer, which affects the reformer overall performance and reliability. By three dimensional CFD approach, the reacting gas flow and heat transfer processes were numerically studied. The reformer conditions such as mass balances associated with the chemical reaction and gas permeation to/from the porous layer are implemented in the calculation. The results reveal that the catalytic combustion reaction is confined in a thin porous catalyst area close to fuel gas flow duct. Transport processes of the fuel gas species and temperature distribution are significantly affected by the reactions.

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A simplified description of multicomponent diffusion in porous media. II. Conditions for negligible forced flow effects

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19790465 ◽

1979 ◽

Vol 44 (2) ◽

pp. 465-474 ◽

Cited By ~ 1

Author(s):

Marta Černá ◽

Jindřich Zahradník ◽

Petr Schneider

Keyword(s):

Porous Media ◽

Pressure Gradient ◽

Chemical Reaction ◽

Multicomponent Diffusion ◽

Forced Flow ◽

Gas Mixture ◽

Porous Catalyst ◽

Diffusion In Porous Media ◽

Flow Effects

Conditions are examined permitting the pressure gradient in a porous catalyst sustaining multicomponent diffusion of a gas mixture accompanied by chemical reaction to be neglected. Deviations are computed of the sum of mole fractions from unity for selected typical cases as a measure of error commited by neglecting the forced flow.

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Adsorption with chemical reaction in porous catalyst pellets under alternate concentration fields. Uniform temperature case

Chemical and Process Engineering ◽

10.1515/cpe-2016-0039 ◽

2016 ◽

Vol 37 (4) ◽

pp. 473-484

Author(s):

Katarzyna Bizon ◽

Bolesław Tabiś

Keyword(s):

Chemical Reaction ◽

Reaction Diffusion ◽

Freundlich Isotherm ◽

Entire Volume ◽

Porous Catalyst ◽

Linear Isotherm ◽

Catalyst Pellet ◽

Catalyst Pellets ◽

The Impact ◽

Sorption Phenomenon

Abstract The work concerns the dynamic behaviour of a porous, isothermal catalyst pellet in which a simultaneous chemical reaction, diffusion and adsorption take place. The impact of the reactant adsorption onto the pellet dynamics was evaluated. A linear isotherm and a non-linear Freundlich isotherm were considered. Responses of the pellet to sinusoidal variations of the reactant concentration in a bulk gas were examined. It was demonstrated that the dynamics of the pellet is significantly affected both by accounting for the adsorption and by the frequency of the bulk concentration variations. The sorption phenomenon causes damping of the concentration oscillations inside the pellet and damping of its effectiveness factor oscillations. Depending on the frequency of the concentration oscillations in the bulk, the remarkable oscillations can involve an entire volume of the pellet or its portion in the vicinity of the external surface.

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