DOCSLIB.ORG

Bipolar Membrane Electrodialysis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bipolar Membrane Electrodialysis Bipolar Membrane Electrodialysis Friedrich Georg Wilhelm 2001 Ph.D. thesis University of Twente Twente University Press Also available in print: www.tup.utwente.nl/uk/catalogue/technical/electrodialysis Bipolar Membrane Electrodialysis Twente University Press Publisher: Twente University Press, P.O. Box 217, 7500 AE Enschede, the Netherlands, www.tup.utwente.nl Cover design: Jo Molenaar, [deel 4] ontwerpers, Enschede Print: Grafisch Centrum Twente, Enschede © F.G. Wilhelm, Enschede, 2001 No part of this work may be reproduced by print, photocopy or any other means without the permission in writing from the publisher. ISBN 9036515270 BIPOLAR MEMBRANE ELECTRODIALYSIS MEMBRANE DEVELOPMENT AND TRANSPORT CHARACTERISTICS PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de rector magnificus, prof.dr. F.A. van Vught, volgens besluit van het College voor Promoties in het openbaar te verdedigen op vrijdag 19 januari 2001 te 13.15 uur door Friedrich Georg Wilhelm geboren op 20 mei 1969 te Maulbronn (D.) Dit proefschrift is goedgekeurd door de promotoren Prof. Dr.-Ing. H. Strathmann Prof. Dr.-Ing. M. Wessling en de assistent-promotor dr.ir. N.F.A. van der Vegt To my parents For their sense of justice and their challenging views on technology, for passing on the ability and courage to ask differently. Contents I Electrodialysis with Bipolar Membranes - Possibilities and Limita- tons 9 1. Introduction 10 2. Background 11 2.1 Membrane technology 11 2.2 Bipolar membrane electrodialysis 12 2.3 Bipolar membrane function 16 2.4 Limitations 17 2.5 Economics considerations 17 3. Approaching some Challenges 18 3.1 Long term operation 18 3.2 Product purity 19 3.3 Energy usage 19 4. Conclusions and Outlook 20 5. References 20 II Bipolar Membrane Preparation 23 1. Introduction 24 2. Bipolar Membrane Components 26 2.1 Ion permeable layers 27 2.2 Contact region 31 2.3 Other multi-layered ion permeable membranes 37 2.4 Components of commercial bipolar membranes 41 3. Bipolar Membrane Preparation Procedures 42 3.1 Processing steps 42 3.2 Integration of processing steps 44 3.3 Applied preparation techniques 46 4. Summary and Outlook 47 5. References 49 III Cation Permeable Membranes from Blends of Sulphonated Poly(ether ether ketone), S-PEEK and Poly(ether sulphone), PES 53 1. Introduction 54 2. Methods 55 2.1 Polymer modification 55 2.2 Film formation 56 2.3 Membrane characterisation 56 3. Results and Discussion 59 3.1 Blend ratio 59 3.2 Time dependence of transport properties 64 3.3 Degree of sulphonation 66 4. Conclusions and Recommendations 68 5. Nomenclature 69 6. References 69 III APPENDIX Fibres from S-PEEK 71 1. Introduction 72 2. Experimental 72 3. Results and Discussion 73 4. Conclusions and Recommendations 75 5. References 76 IV Stability of Ion Permeable Membranes in Concentrated Sodium Hydroxide Solutions 77 1. Introduction 78 2. Experimental 79 3. Results and Discussion 80 3.1 Anion permeable membranes 80 3.2 Cation permeable membranes 83 4. Conclusions and Recommendations 86 5. Nomenclature 87 6. References 87 V Optimisation Strategies for the Preparation of Bipolar Membranes with Reduced Salt Ion Leakage in Acid-Base Electrodialysis 89 1. Introduction 90 2. Theory 93 2.1 Acid compartment mass balance 96 2.2 Limiting current density calculation 99 2.3 Calculation of the required layer parameters 102 3. Experimental 103 3.1 Bipolar membrane characterisation method 103 3.2 Membrane preparation 106 4. Results and Discussion 107 5. Conclusions 111 6. Nomenclature 112 7. References 113 VI Simulation of Salt Ion Transport across Asymmetric Bipolar Mem- branes 115 1. Introduction 116 2. Theory 116 2.1 Background 116 2.2 Salt ion transport model up to the limiting current density 118 2.3 Ion transport at the limiting current density 121 2.4 Current-voltage curve below the limiting current density 122 3. Simulations 123 3.1 Current-voltage curves 123 3.2 Increasing the cation permeable layer thickness 127 3.3 Parameter studies 127 4. Conclusions and Outlook 130 5. Nomenclature 131 6. References 132 VII Asymmetric Bipolar Membranes in Acid-Base Electrodialysis 135 1. Introduction 136 2. Theory 138 2.1 Salt ion fluxes in bipolar membrane electrodialysis 139 2.2 Current-voltage curves of electrodialysis repeat units 140 3. Experimental 142 3.1 Electrodialysis unit and membranes 142 3.2 Recording current-voltage curves 143 3.3 Procedures for electrodialysis experiments 144 4. Results and Discussion 145 4.1 Current-voltage curves 145 4.2 Acid / base electrodialysis 149 5. Conclusions and Recommendations 151 6. Nomenclature 152 7. References 152 VIII Chronopotentiometry for the Advanced Current-Voltage Charateri- sation of Bipolar Membranes 155 1. Introduction 156 2. Theory 157 2.1 Chronopotentiometry Principle 157 2.2 Time development of concentration profiles 159 2.3 Electric circuit elements model 162 3. Experimental 164 3.1 Apparatus 166 3.2 Experiments 168 4. Results and Discussion 169 4.1 Low current chronopotentiometry 169 4.2 High current chronopotentiometry 170 4.3 Steady state 172 4.4 Characteristic electric potentials 174 4.5 Ohmic resistances 175 4.6 Reversible and irreversible potential 176 5. Conclusions and Recommendations 177 6. Nomenclature 178 7. References 179 IX Current-Voltage Behaviour of Bipolar Membranes in Concentrated Salt Solutions Investigated with Chronopotentiometry 181 1. Introduction 182 2. Theory 183 2.1 BPM chronopotentiometry: principle and characteristic values 183 2.2 Transition times 184 2.3 Membrane selectivity 186 3. Experimental 186 4. Results and Discussion 188 4.1 Steady state current-voltage curves 188 4.2 Chronopotentiometric response curves 189 4.3 Transition time 191 4.4 Discharging time 194 4.5 Ohmic resistances 195 4.6 Reversible and irreversible potential 196 5. Conclusions and recommendations 198 6. Nomenclature 199 7. References 200 X Comparison of Bipolar Membranes by Means of Chronopotentiometry 203 1. Introduction 204 2. Theory 204 3. Experimental 206 3. 1 Commercial membranes 206 3.2 Apparatus and Procedures 207 4. Results and Discussion 208 4.1 Current voltage curves 208 4.2 Chronopotentiometric response curves 209 4.3 Characteristic times with different membranes 212 4.4 Contribution to steady state potential 213 4.5 Characteristic resistances 216 5. Conclusions 218 6. References 219 XI Extended Summary and Outlook 221 English summary 227 Dutch summary 228 German summary 229 Glossary 231 Curriculum vitae 235 List of publications 235 Preface When I arrived in Twente about four years ago, I did not intend to write the thickest thesis in the history of the Membrane Technology Group, but rather to work out how membranes could be applied for advanced separations in chemical processes. Ap- parently I have achieved the earlier, but I hope the reader can agree that this book also contributes to the latter. Thanks to Professor Heiner Strathmann, head of the Membrane Technology Group, and Matthias Wessling, now succeeding him as professor and head of this group. Because of them I was able to work on an interesting and challenging project on the development of bipolar membrane technology in an integrating research environ- ment. These few words implicitly include all I want to say about the last four years and three months of work resulting in this book. However, I want to be a little more explicit. The project was granted funding by the Dutch Science Foundation NWO through the STW/CW program. The support and interest of the research departments of Akzo Nobel, DSM, and Solvay Pharmaceuticals ensured and enforced the industrial relevance of the project. Nevertheless, with three different companies involved, the project could keep a broad and fundamental scope and did not have to focus on a single application issue or problem. During the project and discussion with many people (whom to name would go too far here), it became clear that indeed the devel- opment of a basic understanding was required for the improvement of this technol- ogy. In that respect it must be understood that I did not include the work of the stu- dents I was able to supervise during their independent projects. Nonetheless, these projects on the use of bipolar membranes and/or electrodialysis for operation at low electrolyte conductivity (Karin Nordland), with electrolytes of high fouling tendency (Elsbeth Roelofs) or in methanolic environments (Armand van Daalen) and the lit- erature survey on bipolar membrane applications (Christiaan Zeilstra and Marius Biewenga) increased the chances for discussion on more fundamental issues. Simi- larly, the chance to work together with fellow researchers Antonio Alcaraz, Ninel Berezina, Elena Komkova, Robert Gärtner, and Sebastien Chirié from other back- grounds helped to foster better understanding of electro-membrane processes as well. One of the issues was the translation of known research results between the English, German and Dutch literature but more importantly between the different scientific and engineering disciplines. The many discussions, especially with Nico van der Vegt, helped to work out the important points and to bring the text into a comprehensible form. In that sense, this book may give interface scientists insights into why transport properties are important and process engineers may be able to see the importance of material science in membrane applications. In that respect, it may be worthwhile mentioning that the chapters are rather independent of one another and the reader may select the interesting topics with the help of the introductory Chapter I and the summary in Chapter XI. Furthermore, if this preface is the only part a (future) membrane scientist reads, the message should be that the technical feasibility need no longer be a problem as long as the known challenges of bipolar membrane elec- trodialysis are treated appropriately. This technology, integrating separation and reaction in a unique manner, is on its way towards a mature unit operation.
Load more

Recommended publications
  • Exchange Membranes Used in Electrodialysis Process
    2011-2015 FINAL REPORT - COOPERATIVE AGREEMENT NO. R10AC80283 Page 541 Desalination & Water Purification Research And Development Program Report No. XXX Investigating and Understanding the Selectivity of the Conventional Ion- exchange Membranes used in Electrodialysis Process Prepared for Reclamation Under Agreement No. R10AC80283 by Leila Karimi, Abbas Ghassemi U.S. Department of the Interior Bureau of Reclamation Technical Service Center Water and Environmental Services Division Water Treatment Engineering Research Team Denver, Colorado December 2014 2011-2015 FINAL REPORT - COOPERATIVE AGREEMENT NO. R10AC80283 Page 542 MISSION STATEMENTS The mission of the Department of the Interior is to protect and provide access to our Nation's natural and cultural heritage and honor our trust responsibilities to Indian tribes and our commitments to island communities. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Disclaimer The views, analysis, recommendations, and conclusions in this report are those of the authors and do not represent official or unofficial policies or opinions of the United States Government, and the United States takes no position with regard to any findings, conclusions, or recommendations made. As such, mention of trade names or commercial products does not constitute their endorsement by the United States Government. 2011-2015 FINAL REPORT - COOPERATIVE AGREEMENT NO. R10AC80283 Page 543 Acknowledgements The authors would like to thank the U.S. Bureau of Reclamation and the Brackish Groundwater National Desalination Research Facility. Some parts of this report were retrieved from Leila Karimi’s Ph.D.
    [Show full text]
  • Hydraulic Permeability of Electrolyte in the Hybrid Seliarators Varies from 1.74 X 10-7 to 6.66 X Lo- 7 Ml.Cm/Sec
    Lawrence Berkeley National Laboratory Recent Work Title RESEARCH ON SEPARATORS FOR ALKALINE ZINC BATTERIES Final Report. Permalink https://escholarship.org/uc/item/1rm5f577 Author Yeo, R.S. Publication Date 1985-12-01 eScholarship.org Powered by the California Digital Library University of California LBL-20766 UC-94c t:. I l'1l1 Lawrence Berkeley Laboratory UNIVERSITY OF CALIFORNIA RECEIVED ~ LAWRENCE •' \. .. ,-_.' APPLIED SCIENCE Ft 1:3 1 R 1986 '·~· 1 DIVISION LIBRARY AND DOC":UMENTS SECTION RESEARCH ON SEPARATORS FOR ALKALINE ZINC BATTERIES: Final Report R.S. Yeo December 1985 For Reference Not to be iaken from this room APPLIED SCIENCE ·J DIVISION Prepared for the U.S. Department of Energy under Contract DE-AC03-76SF00098 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of California.
    [Show full text]
  • Perspectives on Thermoelectric Energy Conversion in Ion-Exchange Membranes
    entropy Review Perspectives on Thermoelectric Energy Conversion in Ion-Exchange Membranes V. María Barragán 1, Kim R. Kristiansen 2 and Signe Kjelstrup 2,* 1 Department of Structure of Matter, Thermal Physics and Electronics; Complutense University of Madrid, 28040 Madrid, Spain; [email protected] 2 PoreLab, Department of Chemistry, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; [email protected] * Correspondence: [email protected]; Tel.: +47-918-97079 Received: 29 October 2018; Accepted: 22 November 2018; Published: 26 November 2018 Abstract: By thermoelectric power generation we mean the creation of electrical power directly from a temperature gradient. Semiconductors have been mainly used for this purpose, but these imply the use of rare and expensive materials. We show in this review that ion-exchange membranes may be interesting alternatives for thermoelectric energy conversion, giving Seebeck coefficients around 1 mV/K. Laboratory cells with AgjAgCl electrodes can be used to find the transported entropies of the ions in the membrane without making assumptions. Non-equilibrium thermodynamics can be used to compute the Seebeck coefficient of this and other cells, in particular the popular cell with calomel electrodes. We review experimental results in the literature on cells with ion-exchange membranes, document the relatively large Seebeck coefficient, and explain with the help of theory its variation with electrode materials and electrolyte concentration and composition. The impact of the membrane heterogeneity and water content on the transported entropies is documented, and it is concluded that this and other properties should be further investigated, to better understand how all transport properties can serve the purpose of thermoelectric energy conversion.
    [Show full text]
  • Nernst–Planck Modeling of Multicomponent Ion Transport in a Nafion Membrane at High Current Density
    Nernst-Planck modeling of multicomponent ion transport in a Nafion membrane at high current density Citation for published version (APA): Moshtari Khah, S., Oppers, N. A. W., de Groot, M. T., Keurentjes, J. T. F., Schouten, J. C., & van der Schaaf, J. (2017). Nernst-Planck modeling of multicomponent ion transport in a Nafion membrane at high current density. Journal of Applied Electrochemistry, 47(1), 51-62. https://doi.org/10.1007/s10800-016-1017-2 DOI: 10.1007/s10800-016-1017-2 Document status and date: Published: 01/01/2017 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research.
    [Show full text]
  • Principles of Electrochemistry Second Edition
    Principles of Electrochemistry Second Edition Jin Koryta Institute of Physiology, Czechoslovak Academy of Sciences, Prague •Win Dvorak Department of Physical Chemistry, Faculty of Science, Charles University, Prague Ladislav Kavan /. Heyrovsky Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, Prague JOHN WILEY & SONS Chichester • New York • Brisbane • Toronto • Singapore Copyright © 1987, 1993 by John Wiley & Sons Ltd. Baffins Lane, Chichester, West Sussex PO19 1UD, England All rights reserved. No part of this book may be reproduced by any means, or transmitted, or translated into a machine language without the written permission of the publisher. Other Wiley Editorial Offices John Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, USA Jacaranda Wiley Ltd, G.P.O. Box 859, Brisbane, Queensland 4001, Australia John Wiley & Sons (Canada) Ltd, Worcester Road, Rexdale, Ontario M9W 1L1, Canada John Wiley & Sons (SEA) Pte Ltd, 37 Jalan Pemimpin #05-04, Block B, Union Industrial Building, Singapore 2057 Library of Congress Cataloging-in-Publication Data Koryta, Jifi. Principles of electrochemistry.—2nd ed. / Jin Koryta, Jin Dvorak, Ladislav Kavan. p. cm. Includes bibliographical references and index. ISBN 0 471 93713 4 : ISBN 0 471 93838 6 (pbk) 1. Electrochemistry. I. Dvorak, Jin, II. Kavan, Ladislav. III. Title. QD553.K69 1993 541.37—dc20 92-24345 CIP British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0 471 93713 4 (cloth)
    [Show full text]
  • Defect Chemistry and Transport Properties of Solid State Materials for Energy Storage Applications
    University of Kentucky UKnowledge Theses and Dissertations--Chemical and Materials Engineering Chemical and Materials Engineering 2018 DEFECT CHEMISTRY AND TRANSPORT PROPERTIES OF SOLID STATE MATERIALS FOR ENERGY STORAGE APPLICATIONS Xiaowen Zhan University of Kentucky, [email protected] Author ORCID Identifier: https://orcid.org/0000-0002-1422-6233 Digital Object Identifier: https://doi.org/10.13023/etd.2018.418 Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Zhan, Xiaowen, "DEFECT CHEMISTRY AND TRANSPORT PROPERTIES OF SOLID STATE MATERIALS FOR ENERGY STORAGE APPLICATIONS" (2018). Theses and Dissertations--Chemical and Materials Engineering. 88. https://uknowledge.uky.edu/cme_etds/88 This Doctoral Dissertation is brought to you for free and open access by the Chemical and Materials Engineering at UKnowledge. It has been accepted for inclusion in Theses and Dissertations--Chemical and Materials Engineering by an authorized administrator of UKnowledge. For more information, please contact [email protected]. STUDENT AGREEMENT: I represent that my thesis or dissertation and abstract are my original work. Proper attribution has been given to all outside sources. I understand that I am solely responsible for obtaining any needed copyright permissions. I have obtained needed written permission statement(s) from the owner(s) of each third-party copyrighted matter to be included in my work, allowing electronic distribution (if such use is not permitted by the fair use doctrine) which will be submitted to UKnowledge as Additional File. I hereby grant to The University of Kentucky and its agents the irrevocable, non-exclusive, and royalty-free license to archive and make accessible my work in whole or in part in all forms of media, now or hereafter known.
    [Show full text]
  • Transport Properties of Film and Bulk Sr0. 98Zr0. 95Y0. 05O3− Δ
    applied sciences Article Transport Properties of Film and Bulk Sr0.98Zr0.95Y0.05O3−δ Membranes Adelya Khaliullina, Liliya Dunyushkina * and Alexander Pankratov Institute of High Temperature Electrochemistry, 620137 Ekaterinburg, Russia; [email protected] (A.K.); [email protected] (A.P.) * Correspondence: [email protected] Received: 20 February 2020; Accepted: 23 March 2020; Published: 25 March 2020 Abstract: In electrode-supported solid oxide fuel cells (SOFCs) with a thin electrolyte, the electrolyte performance can be affected by its interaction with the electrode, therefore, it is particularly important to study the charge transport properties of thin electrode-supported electrolytes. The transport numbers of charged species in Ni-cermet supported Sr0.98Zr0.95Y0.05O3 δ (SZY) membranes were − studied and compared to those of the bulk membrane. SZY films of 2.5 µm thickness were fabricated by the chemical solution deposition technique. It was shown that the surface layer of the films contained 1.5–2 at.% Ni due to Ni diffusion from the substrate. The Ni-cermet supported 2.5 µm-thick membrane operating in the fuel cell mode was found to possess the effective transport number of oxygen ions of 0.97 at 550 ◦C, close to that for the bulk SZY membrane (0.99). The high ionic transport numbers indicate that diffusional interaction between SZY films and Ni-cermet supporting electrodes does not entail electrolyte degradation. The relationship between SZY conductivity and oxygen partial pressure was derived from the data on effective conductivity and ionic transport numbers for the membrane operating under two different oxygen partial pressure gradients—in air/argon and air/hydrogen concentration cells.
    [Show full text]
  • Short-Circuit Current in Polymeric Membrane-Based Thermocells: an Experimental Study
    membranes Article Short-Circuit Current in Polymeric Membrane-Based Thermocells: An Experimental Study V. María Barragán Department of Structure of Matter, Thermal Physics and Electronics, Faculty of Physics, Complutense University of Madrid, 28040 Madrid, Spain; [email protected] Abstract: Thermocells are non-isothermal electrochemical cells used to convert thermal energy into electricity. In a thermocell, together with the ion flux, heat is also transferred, which can reduce the temperature gradient and thus the delivered electric current. A charged membrane used as a separating barrier in the electrolyte liquid could reduce this problem. Therefore, the use of ion-exchange membranes has been suggested as an alternative in terms of thermoelectricity because of their high Seebeck coefficient. Ion transfer occurs not only at the liquid solution but also at the solid membrane when a temperature gradient is imposed. Thus, the electric current delivered by the thermocell will also be highly dependent on the membrane system properties. In this work, a polymeric membrane-based thermocell with 1:1 alkali chloride electrolytes and reversible Ag|AgCl electrodes at different temperatures is studied. This work focuses on the experimental relation between the short-circuit current density and the temperature difference. Short-circuit current is the maximum electric current supplied by a thermocell and is directly related to the maximum output electrical power. It can therefore provide valuable information on the thermocell efficiency. The effect of the membrane, electrolyte nature and hydrodynamic conditions is analysed from an experimental point of view. Citation: Barragán, V.M. Keywords: ion-exchange membrane; thermoelectricity; energy conversion; short-circuit current; Short-Circuit Current in Polymeric thermocell Membrane-Based Thermocells: An Experimental Study.
    [Show full text]
  • Perspectives on Thermoelectric Energy Conversion in Ion-Exchange Membranes
    entropy Review Perspectives on Thermoelectric Energy Conversion in Ion-Exchange Membranes V. María Barragán 1, Kim R. Kristiansen 2 and Signe Kjelstrup 2,* 1 Department of Structure of Matter, Thermal Physics and Electronics; Complutense University of Madrid, 28040 Madrid, Spain; [email protected] 2 PoreLab, Department of Chemistry, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; [email protected] * Correspondence: [email protected]; Tel.: +47-918-97079 Received: 29 October 2018; Accepted: 22 November 2018; Published: 26 November 2018 Abstract: By thermoelectric power generation we mean the creation of electrical power directly from a temperature gradient. Semiconductors have been mainly used for this purpose, but these imply the use of rare and expensive materials. We show in this review that ion-exchange membranes may be interesting alternatives for thermoelectric energy conversion, giving Seebeck coefficients around 1 mV/K. Laboratory cells with AgjAgCl electrodes can be used to find the transported entropies of the ions in the membrane without making assumptions. Non-equilibrium thermodynamics can be used to compute the Seebeck coefficient of this and other cells, in particular the popular cell with calomel electrodes. We review experimental results in the literature on cells with ion-exchange membranes, document the relatively large Seebeck coefficient, and explain with the help of theory its variation with electrode materials and electrolyte concentration and composition. The impact of the membrane heterogeneity and water content on the transported entropies is documented, and it is concluded that this and other properties should be further investigated, to better understand how all transport properties can serve the purpose of thermoelectric energy conversion.
    [Show full text]
  • Use of the Microheterogeneous Model to Assess the Applicability of Ion-Exchange Membranes in the Process of Generating Electricity from a Concentration Gradient
    membranes Article Use of the Microheterogeneous Model to Assess the Applicability of Ion-Exchange Membranes in the Process of Generating Electricity from a Concentration Gradient Denis Davydov, Elena Nosova, Sergey Loza, Aslan Achoh, Alexander Korzhov, Mikhail Sharafan and Stanislav Melnikov * Physical Chemistry Department, Faculty of Chemistry and High Technologies, Kuban State University, 350040 Krasnodar, Russia; [email protected] (D.D.); fi[email protected] (E.N.); [email protected] (S.L.); [email protected] (A.A.); [email protected] (A.K.); [email protected] (M.S.) * Correspondence: [email protected] Abstract: The paper shows the possibility of using a microheterogeneous model to estimate the transport numbers of counterions through ion-exchange membranes. It is possible to calculate the open-circuit potential and power density of the reverse electrodialyzer using the data obtained. Eight samples of heterogeneous ion-exchange membranes were studied, two samples for each of the following types of membranes: Ralex CM, Ralex AMH, MK-40, and MA-41. Samples in each pair differed in the year of production and storage conditions. In the work, these samples were named “batch 1” and “batch 2”. According to the microheterogeneous model, to calculate the Citation: Davydov, D.; Nosova, E.; transport numbers of counterions, it is necessary to use the concentration dependence of the electrical Loza, S.; Achoh, A.; Korzhov, A.; conductivity and diffusion permeability. The electrolyte used was a sodium chloride solution with a Sharafan, M.; Melnikov, S. Use of the concentration range corresponding to the conditional composition of river water and the salinity of Microheterogeneous Model to Assess the Black Sea.
    [Show full text]
  • Improved Energy Efficiency of Electrodialysis Desalination And
    Desalination and Water Purification Research and Development Program Report No. 212 Improved Energy Efficiency of Electrodialysis Desalination and Separation: Development of Percolating Network Nanocomposite Ion-Exchange Membranes for High Conductivity U.S. Department of the Interior Bureau of Reclamation Technical Service Center Denver, Colorado February 2019 REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) February 25, 2019 Final June 1, 2017 – December 31, 2018 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Improved Energy Efficiency of Electrodialysis Desalination and Separation: Agreement No. R16AC00124 Development of Percolating Network Nanocomposite Ion-Exchange Membranes for High Conductivity 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Ngai Yin Yip, Ph.D.
    [Show full text]
  • Electrodialysis
    4/9/2019 ELECTRODIALYSIS CEE 597T Electrochemical Water and Wastewater Treatment ■ ED is a method for the removal of electrolytes from water by transporting electrolyte ions through ion-exchange membranes to other solution under the influence of constant DC (direct current) directed perpendicular to the membrane plane. ■ The driving force of the process is the electrical potential gradient. ■ ED is based on the phenomena of electrolytic dissociation of salts, directed movement of ions in an electric field, and selective transfer of ions through ion- exchange membranes. 1 4/9/2019 ■ Electrolyte solution (for example, Na2SO4) is fed to all compartments of a simple electrodialyzer ■ When applying the potential difference to electrodes cations start to move toward the cathode (negative electrode) and anions move toward the anode (positively charged electrode). ■ Electrolyte concentration of the middle compartment (dilute or retentate compartment) will gradually become desalinated and filled with clean water. ■ At the same time electrode reactions will lead to the oxygen gas generation and formation of acid (H2SO4) at the anode and hydrogen gas evolution as well as alkali If electrolyte solution contains chloride ions, chlorine gas would (NaOH) formation at the cathode. Thus, be allocated in the anodic chamber along with the oxygen near-electrode compartments become enriched with alkaline or acid electrolyte (concentrate or permeate). Principles of Electrodialysis ■ Use of three-compartment electrodialyzers is a cost-consuming process due to the loss of energy to the electrode side reactions. ■ In this regard a significant improvement of cost efficiency can be achieved by using a large number of membranes. Usually electrodialyzers can contain up to 2000 of ion-Exchange membranes pairs.
    [Show full text]