Journal ArticleDOI
A single‐pore model for gas‐solid noncatalytic reactions
P. A. Ramachandran,J. M. Smith +1 more
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In this article, single-pore behavior in a porous pellet of reactant is used to develop a new model for predicting the conversion-time relationship for gas-solid non-catalytic reactions.Abstract:
Analysis of single-pore behavior in a porous pellet of reactant is used to develop a new model for predicting the conversion-time relationship for gas-solid noncatalytic reactions. The model accounts for the influence of pore diffusion, diffusion through the product layer which builds upon the pore walls, and surface reaction. By focusing attention on one pore, it is possible to include the effects of the changes in pore geometry that occur during reaction. Thus, both pore-mouth clocure and uniform deposition of product throughout the pellet can be predicted by using appropriate values for the diffusional and physical properties of the reaction system. The key parameters of the model are the effective pore length and effective diffusivity in the product layer. Numerical values of these quantities can be approximated from measurements of the pore volume and surface are of the unreacted and reacted forms of the pellet, or they may be evaluated from a limited amount of conversion vs. time data. The use of the model for predicting conversion-time curves is illustrated with available data for the reduction of nickel oxide pellets with carbon monoxide and for the reaction of sulfur dioxide with calcium carbonate.read more
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A random pore model for fluid‐solid reactions: I. Isothermal, kinetic control
TL;DR: In this paper, a random pore model is developed for fluid-solid reactions, which allows for arbitrary pore size distributions in the reacting solid. But the model is not suitable for the case of gasification, and it cannot represent the behavior of a system that shows a maximum in reaction rate as well as one that does not.
Journal ArticleDOI
The combustion rates of coal chars: A review
TL;DR: In this article, a brief description of coal develatilization and combustion of residual char is given, and a theoretical consideration is given to the changes in the size, density, and pore structure of coal chars as they burn.
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Oxidation Mechanisms and Kinetics of 1D-SiC/C/SiC Composite Materials: II, Modeling
Ludovic Filipuzzi,Roger Naslain +1 more
TL;DR: In this paper, a simple axisymmetrical fiber/interphase/matrix assembly is derived to depict the oxidation behavior of 1D-SiC/C/SiC composites within the temperature range 900-1300°C and for 10
Journal ArticleDOI
Coupling exothermic and endothermic reactions in adiabatic reactors
TL;DR: In this paper, the steady state and dynamic behavior of coupling exothermic and endothermic reactions in directly coupled adiabatic packed bed reactors (DCAR) are analyzed using one-dimensional pseudo-homogeneous plug flow model.
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The Importance of Pore Structure and Diffusion in the Kinetics of Gas-Solid Non-catalytic Reactions: Reaction of Calcined Limestone with SO2
TL;DR: The pore size distribution of the calcined CaO samples is found to be affected considerably by the calcination temperature and the sample calcined at 950 °C has the lowest diffusion resistance and the highest activity for SO2 removal as mentioned in this paper.