A new technique for the determination of contact time distribution (CTD) from tracers experiments in heterogeneous systems

Tayakout‐Fayolle, Mélaz; Othman, Sami; Jallut, Christian

doi:10.1016/j.ces.2005.03.014

Cited by 5 publications

(5 citation statements)

References 31 publications

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“…This has been used to explain χ overestimation in heterogeneous reactors when a classical residence time distribution (RTD) was first applied. The present system differs from those considered in Tayakout‐Fayolle et al32 because reactions proceeded only on the electrode surface, and not in a separate catalyst phase (e.g., porous catalyst pellet). The probability of reactant contact with the electrode depends on the overall RTD.…”

Section: Resultsmentioning

confidence: 90%

“…Under this assumption, reactions are considered to proceed uniformly within the reactor volume. The discrepancy between the assumed system and actual spatially nonuniform conditions in heterogeneous reactors has been treated by others using a catalyst‐phase contact time distribution 31, 32. This has been used to explain χ overestimation in heterogeneous reactors when a classical residence time distribution (RTD) was first applied.…”

Section: Resultsmentioning

confidence: 99%

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Effect of gas evolution on mixing and conversion in a flow‐through electrochemical reactor

Petersen

Reardon

2009

AIChE Journal

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Flow-through electrolytic reactors (FTER) emplaced below the subsurface may be used to control the migration of groundwater contamination away from source zones. During prior studies with FTERs, water electrolysis and associated gas generation have occurred concurrently with contaminant degradation. Gas evolution-induced mixing within the electrode assembly has the potential to impact system performance. A mathematical model of the system was developed to capture the impact of mixing on transport processes in the system. Corresponding transient and steady-state tracer experiments using ferricyanide as a model contaminant were conducted to quantify mixing-dependent parameters and verify modeling results. Over a range of relevant groundwater flowrates, Peclet numbers were between 0.1 and 10, indicating that mixing was a important process under low-flow conditions. Comparison of experiments and model calculations demonstrated that incorporating gas evolution into the model was necessary for accurate performance prediction. V

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Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Effect of gas evolution on mixing and conversion in a flow‐through electrochemical reactor

Petersen

Reardon

2009

AIChE Journal

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“…They used observations of the decomposition of ozone in a fl uidised reactor to determine k¢ 4 and its variation with temperature and were then able to determine the distribution function by inverse Laplace transformation. Tayakout-Fayolle et al (2005) summarised earlier work by Nauman and Collinge (1968b) and demonstrated how to obtain G(t) by determining the residence time distributions for a reactor using two separate experimentsone with a non-adsorbable tracer and one with a weakly adsorbed tracer. It would appear that such experiments are undertaken industrially but few have been published (Nauman, 2008): one example on a large, cold model of a fl uidised bed has been described by Pustelnik and Nauman (1991).…”

Section: A Model For the Fl Uidised Bed Reactor With Continuous Feedimentioning

confidence: 97%

“…With the foregoing, it is readily shown (Nauman and Collinge, 1968a;Tayakout-Fayolle et al, 2005) that for a fi rst-order reaction, the overall conversion, X, will be: 3.111] in which G(t) is the distribution of contact times and k¢ 4 = a p r bulk k 4 /e with the fi rst-order rate constant being given by r rxn,1 = -k 4 C, referred, as above, to unit area of catalyst surface. The fi rst measurement of G(t) was made by Orcutt et al (1962) who noted that Eq.…”

Section: A Model For the Fl Uidised Bed Reactor With Continuous Feedimentioning

confidence: 99%

Properties of stationary (bubbling) fluidised beds relevant to combustion and gasification systems

Dennis

2013

Fluidized Bed Technologies for Near-Zero Emission Combustion and Gasification

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“…Some commonly used methods to determine the RTD are the introduction of the tracer (of known concentration) by means of a pulse (E curve), the analysis of their concentration at the exit of this chamber, the effecting of a fluid change or step experiment (F curve), or the introduction of a sinusoidal variation of the concentration of tracer methods. From these, the pulse method is the easiest and most commonly used (Levenspiel 1999;Tayakout-Fayolle et al 2005). The utilized tracer is often a dye and its concentration is measured on the products by spectroscopy or colorimetry (Apruzzese et al 2003).…”

Section: Mixing On Microchannels and Residence Time Distribution (Rtd)mentioning

confidence: 99%

Food Nanoscience and Nanotechnology

Hernández‐Sánchez¹,

Fidel²,

Gutiérrez-Ĺopez³

2015

Food Engineering Series

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Springer's Food Engineering Series is essential to the Food Engineering profession, providing exceptional texts in areas that are necessary for the understanding and development of this constantly evolving discipline. The titles are primarily reference-oriented, targeted to a wide audience including food, mechanical, chemical, and electrical engineers, as well as food scientists and technologists working in the food industry, academia, regulatory industry, or in the design of food manufacturing plants or specialized equipment. This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper PrefaceFood nanoscience and nanotechnology are emergent disciplines that have grown enormously in the last years due to the attractive properties that a number of foodrelated materials have at the nanoscale. Understanding basic principles of such properties constitutes the basis for building a robust knowledge base for developing products with improved and novel characteristics.Understanding fundamentals of food nanotechnology represents a huge challenge for universities, industries and the public sector. The complex mechanisms involved in the research, development, production and legislation of food nanoproducts are studied under multi-and inter-disciplinary scopes. Bearing this in mind, this book was conceived.This book aims to contribute to basic and applied knowledge on these fields by presenting recent advances in selected topics of food nanoscience and nanotechnology, and is divided into a total of 17 chapters. The first chapter presents an overview to the field; the following chapter discusses general techniques for studying foodrelated nanomaterials, followed by six chapters on specific techniques for preparing food nanomaterials while the next contribution on dispersed systems illustrates this important and vast field. The book continues with three chapters on food nanocomposites, including those for packing purposes, and two chapters on advanced aspects of food nan...

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A new technique for the determination of contact time distribution (CTD) from tracers experiments in heterogeneous systems

Cited by 5 publications

References 31 publications

Effect of gas evolution on mixing and conversion in a flow‐through electrochemical reactor

Effect of gas evolution on mixing and conversion in a flow‐through electrochemical reactor

Properties of stationary (bubbling) fluidised beds relevant to combustion and gasification systems

Food Nanoscience and Nanotechnology

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