Diffusion and reaction in catalyst pellets with bidisperse pore size distribution

Date

1998-06-01

Author

Doğu, Timur

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

23
views

0
downloads

Catalysts with bidisperse pore structures are extensively used in chemical industries. In such catalysts, diffusion and reaction in the microporous particles are preceded by diffusion in the macropores. The relative significance of macro-and micropore diffusion resistances on the observed reaction rates with Linear and nonlinear rate forms, heat effects, catalyst deactivation and selectivity problems in bidisperse catalysts are investigated in number of published works. In this article, a review of the models proposed in the literature is presented together with a critical analysis of assumptions involved. Criteria are presented to test the relative significance of transport limitations. Also, a review of experimental techniques and experimental values of micro-and macropore effective diffusivities of gases in solids with bidisperse pore structures, such as zeolite pellets and supported porous catalysts, is given.

Subject Keywords

Shape normalization, Restrictive diffusion, Network model, Sorption kinetics, Gas-chromatography, Micropore Diffusion;, Mass-transfer, Porous catalysts, Ion-exchange resin, Frequency-response method

URI

https://hdl.handle.net/11511/62328

Journal

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Thermal degradation of Polylactide/Poly(ethylene glycol) fibers and composite fibers involving organoclay Ozdemir, Esra; Hacaloğlu, Jale (2018-01-01) In this study, electrospun fibers of melt blended poly(lactic acid) and poly(ethylene glycol), (PLA)-PEG blends involving 10, 15 and 20 wt% PEG and their corresponding composites with organically modified montmorillonite, Cloisite 30B were prepared and characterized by x-ray diffraction, differential scanning calorimetry, thermogravimetry and direct pyrolysis mass spectrometry techniques. The narrower fiber diameters observed for the PLA-PEG fibers involving organoclay compared to the corresponding neat fib...
Synthesis of calcium carbonate particles for biomedical applications Oral, Çağatay Mert; Ercan, Batur; Department of Metallurgical and Materials Engineering (2020) Calcium carbonate (CaCO3) particles have been widely used in biomedical applications owing to their biocompatibility and biodegradability. In order to effectively utilize CaCO3 particles in biomedical applications, their physical and chemical properties should be systematically controlled. However, this is a challenging task due to the presence of three different anhydrous CaCO3 polymorphs having complex crystallization behavior. In this thesis, CaCO3 particles were synthesized at distinct environments to c...
Hydrothermal synthesis of TiO₂ nanostructures for photocatalitic and photovoltaic applications Erdoğan, Nursev; Öztürk, Abdullah; Park, Jongee; Department of Metallurgical and Materials Engineering (2017) Titanium dioxide (TiO2) nanostructures with different crystal structures and various morphologies were synthesized by hydrothermal process to utilize them in photocatalytic and photovoltaic applications. The investigations were conducted in three different sets of systematic experimental studies. The first set of experiments was based on the synthesis of TiO2 nanostructures in the presence of strong sodium hydroxide (NaOH) catalyzer. Temperature and molarity of NaOH were kept constant while hydrothermal rea...
Molecular dynamics study of random and ordered metals and metal alloys Kart, Hasan Hüseyin; Tomak, Mehmet; Department of Physics (2004) The solid, liquid, and solidification properties of Pd, Ag pure metals and especially PdxAg1-x alloys are studied by using the molecular dynamics simulation. The effects of temperature and concentration on the physical properties of PdxÞAg1-x are analyzed. Sutton-Chen (SC) and Quantum Sutton-Chen (Q-SC) many-body potentials are used as interatomic interactions which enable one to investigate the thermodynamic, static, and dynamical properties of transition metals. The simulation results such as cohesive ene...
Pesticide and model drug release from carboxymethylceullose microspheres Darvari, R; Hasırcı, Vasıf Nejat (1996-01-01) Water soluble derivatives of cellulose are widely used in various biomedical and biotechnological applications. Sodium carboxymethyl cellulose was insolubilized in the form of microspheres using aluminium chloride as the crosslinking agent. It was observed that, depending on the preparation medium pH, the spherical product could either be a microsphere with an ionotropic interior or a microcapsule. Various microspheres with different crosslinker, biopolymer, and drug (2',7'-dichlorofluorescein and aldicarb)...

Citation Formats

T. Doğu, “Diffusion and reaction in catalyst pellets with bidisperse pore size distribution,” INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, pp. 2158–2171, 1998, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/62328.