Global ETD Search
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Showing 1 to 11 of 11 for “"shrinking core model"”.
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Analysis of hydrodynamic phenomena in a fluidized bed for thermochemical hydrogen production
… using a new non-catalytic gas-solid reaction model, proposed in the literature but here updated for the purposes of the present study. The results are illustrated considering two cases of kinetics for the consumption of particles: Volumetric Model and Shrinking Core Model. Consistent results …
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Models of high-temperature desulfurization using zinc-based sorbents
This study focuses on determining models that are currently available to describe gas-solid reactions to predict the observed (experimental) results from a series of TGA experiments. Variations of the GPM (Grainy Pellet Model) were used and shown to give good agreement with experimental conversion …
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Kinetics of the ferric sulphate leaching of sphalerite and sphalerite/pyrite mixtures : a study of the chemical leaching of base metal minerals under conditions similar to that of bio-leaching by thiobacilli
… The literature showed that two types of model have been used to describe the ferric leaching of the sphalerite. The first type was a shrinking-particle model in which there action was described by first order kinetics or an electrochemical mechanism. The second type included a mass …
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CO2 Separation Using Regenerable Magnesium Solutions Dissolution, Kinectics and VLSE Studies
… absorption process. The dissolution process was modeled using the shrinking core model and surface chemical reaction was found to be the rate controlling mechanism. The formation of MgCO3 will reduce a regenerative capacity of Mg(OH)2 solvent. The impact of pH control and temperature on the …
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Role of Storage Material in NOX Storage and Reduction (NSR) and Three-Way Catalysts (TWC) During Cycling Operation
… from the spinel. A combined experimental and modeling study of dynamic oxygen storage capacity (DOSC) of CZO and MFO spinel using CO and H2 was conducted. During reduction (or oxidation), either oxide exhibits a transition in rate-controlling regime, from a fast, reaction-controlled process to …
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Calcium oxide-based sorbents for CO2 capture at high temperature
… capacity is discussed. This work concludes with modeling the sorbent’s performance via a classical shrinking core model to obtain quantitative values of useful parameters for equipment design (e.g., reaction rate constant and diffusivity decay). [1] Eide, L., I.; Bailey, D., W., Capture …
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Investigation of high-temperature and high-pressure steam gasification kinetics of a coal-derived char surrogate
… among other factors, makes measuring or modeling these conversion rates challenging. In this study, we focus solely on char reactions with steam at high temperature and pressure (i.e., conditions that are applicable to entrained-flow gasification). The feedstock used in this study was a …
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Sustainable Mining - Solving the Problem of Chalcopyrite Treatment/Processing - Leaching, Solvent Extraction & Flotation
… using peroxodisulfate follows a surface reaction shrinking core model. The activation energy of chalcopyrite leaching using peroxodisulfate ion was calculated as 41.1 kJ mol⁻¹. We also report that the leaching of chalcopyrite ore is affected by particle size and that stirring hurts leaching of …
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Salt hydrates for thermochemical energy storage
… investigated. Firstly, a reaction kinetics model was developed for the hydration of SrCl2 to SrCl2·6H2O. Following that, a shrinking-core model for salt in a cement porous host matrix was developed. This model combines both chemical reaction and moisture diffusion to define the overall …
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Rare Earth Extraction from Clayey Waste Materials by Alkali Pretreatment
… sulfate were also investigated based on the shrinking core model. It was found that the leaching process is controlled by a chemical reaction with an activation energy of 61.28 kJ/mol. Besides ammonium sulfate, ammonium formate is a promising lixiviant for NaOH-treated monazite. However, …
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Storage and transport of energy in nanostructures
Nanostructures typically exhibit thermo-physical properties that are different from their bulk counterparts. The size dependence of thermo physical properties is attributed to changing energy and mass transport phenomenon with varying length scales. This size dependence can be profitably leveraged …