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Development of stainless-steel supported MFI and BEA type zeolite membranes [Elektronische Ressource] = Entwicklung von edelstahlgestützten MFI- und BEA-Zeolithmembranen / vorgelegt von Abhijeet Avhale

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Development of Stainless-Steel Supported MFI and BEA Type Zeolite Membranes Entwicklung von edelstahlgestützten MFI- und BEA- Zeolithmembranen Der Technischen Fakultät der Universität Erlangen-Nürnberg zur Erlangung des Grades DOKTOR-INGENIEUR vorgelegt von Abhijeet Avhale Erlangen-2010 Als Dissertation genehmigt von der Technischen Fakultät der Universität Erlangen-Nürnberg Tag der Einreichung: 01.02. 2010 Tag der Promotion: 05.05.2010 Dekan: Prof. Dr.-Ing. habil. R. German Berichterstatter: Prof. Dr. rer. nat. W. Schwieger, Prof. Dr.-Ing. R. Dittmeyer Acknowledgement This work was performed in the Institute of Chemical Reaction Engineering at the Friedrich-Alexander University of Erlangen-Nuremberg, Germany, between August 2004 and December 2008. First of all I would like to thank Prof. Wilhelm Schwieger, my Doktorvater as well as a fatherly figure, for giving me an opportunity to work in his group as a research during my masters studies and later accepting me as a PhD student, for being not only an excellent supervisor but also for looking after the welfare of every group member.
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Development of Stainless-Steel Supported MFI and BEA

Type Zeolite Membranes






Entwicklung von edelstahlgestützten MFI- und BEA-

Zeolithmembranen








Der Technischen Fakultät der

Universität Erlangen-Nürnberg
zur Erlangung des Grades




DOKTOR-INGENIEUR


vorgelegt von



Abhijeet Avhale




Erlangen-2010








































Als Dissertation genehmigt von

der Technischen Fakultät der
Universität Erlangen-Nürnberg



Tag der Einreichung: 01.02. 2010

Tag der Promotion: 05.05.2010


Dekan: Prof. Dr.-Ing. habil. R. German


Berichterstatter: Prof. Dr. rer. nat. W. Schwieger,

Prof. Dr.-Ing. R. Dittmeyer


Acknowledgement
This work was performed in the Institute of Chemical Reaction Engineering at the
Friedrich-Alexander University of Erlangen-Nuremberg, Germany, between August 2004 and
December 2008.
First of all I would like to thank Prof. Wilhelm Schwieger, my Doktorvater as well as a
fatherly figure, for giving me an opportunity to work in his group as a research during my
masters studies and later accepting me as a PhD student, for being not only an excellent
supervisor but also for looking after the welfare of every group member. Working in his
group has taught me not only the essence of research and development but also the essence of
humanity. I would like to thank Prof. Gerhard Emig, Prof. Nadejda Popovska and Prof. Peter
Wasserscheid for their acceptance, encouragement and the facilitation of this work.
My special thanks go to the master/bachelor and research assistant students: Deniz
Kaya, Jeanne D’arc, Amol Dhumal, Michael Wagner, Andrea Seibert and Shantanu
Shrivastava. Without their contribution this work would not have been possible.
My special gratitude to members of my research group who made my life as well as
work enjoyable. The scientific discussions that took place over a cup of coffee have given the
maximum inputs in this work. I was very lucky to work closely with Saiprasath Gopalkrishna
and Jürgen Bauer. Without their help, advice and criticism this work would not have been
successful. I am also greatful to Amer Inayat, Jimmy Ofili, Alexandra Inayat and Sofia Lopez
for maintaining a very coardial atmospehere within the group and helping me, specially at the
last phase of my thesis. I appreciate very much the understanding they showed in the last
phase of my thesis to give me a priority in most of the analytical measurements. I would also
like to thank Dr. Ayyappan Ramakrishnan, Hasan Basher, Marcelle Fankam, Hendryk Partsch
Elena Pleissner and Andreas Schwab for their support and help. I would also like to
acknowledge Dr. Thangaraj Selvam, Dr. Ralph Herrmann, Dr. Alessandro Zampieri, and Prof.
Franziska Scheffler for giving me a helping hand in the early phase of research career. My
special thanks goes for Mrs. Regine Müller and Mrs. Michele Menuet for not only for their
assitance but also for being a motherly figure for me at a place 8000 km away from home. I
reserve my atmost thanks for Dr. Godwin Mabande, a brotherly figure, who not only
supervised me during my masters’ studies but also taught me professionalism and finer
aspects of good human being.
I take this opportunity to thank other colleagues at the institute that I turned for advice
during different stages of my thesis. I would like to make a special mention of Dr. Peter
Schulz, Dr. Marco Haumann, Martinna Kormann and Katya Danova.
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No work can be successful without the crucial contribution of support staff. I am very
grateful to the staff of the institute. Thanks you Achim Mannke and Michael Schmacks of the
mechanical workshop. Thank you Gerhard Dommer and Walter Fischer and Karl-Heinz Ksoll
of the electrical workshop and IT department. Thank you Siegfrid Smolny for adsorption
measurements. Thank you Petra Singer and Petra Weber for secretarial assistance. Special
thanks goes to Helmut Gerhard for always being there at the moment of trouble and difficulty.
Without the help of these people I would never have been able to finish my work.
Contribution of people from partner groups and other departments is also greatly
appreciated. Thanks goes to partners from DECHEMA, Frankfurt: Prof. Roland Dittmeyer,
Dr. Stephane Haag and Dr. Thomas Stief for a very fruitful cooperation over a long period of
time. I take this opportunity to specially thank Prof. Dittmeyer for his guidance, advices and
also for agreeing to referee my dissertation. I would also like to thank Prof. Patrik Schmuki
and his group, especially Ms. Anja Friedrich for countless number of SEM measurements that
contributed significantly in the success of this work. Thanks to Prof. Schmuki and Prof. Axel
König for agreeing to be part of my dissertation examination board. I would also like to thank
Richard Kosmala and Roland Nolte of Material Science department for carrying out
membrane cross-section analysis and big chamber SEM analysis respectively.
I am also grateful to advices and encouragement received from researchers outside the
university. I would specially like to mention Prof. Jürgen Caro (University of Hanover), Dr.
Manfred Noack (ACA, Berlin) and Prof. Michael Tsapatsis (University of Minnesota) for
their guidance.
My deepest gratitude is reserved for my family, teachers and friends for their unflagging
support throughout my studies and during this work. I take this opportunity to thank my wife
Amarja and son Arjun for the patience and understanding they showed during the course of
this work. My special thanks are for my parents, brother (Kaustubh) and sister (Prachi) for
standing firmly behind me and showing belief in me throughout my life. Thanks to all of my
teachers, friends and countless number of good wishers who contributed directly of indirectly
in this work.
Finally I would like to thank German Research Foundation and BASF (especially Dr.
Thomas Heidemann) for financial assistance received during the course of this work as well
as other research projects.


Amsterdam, January 2010 Abhijeet Avhale
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dedicated to my parents









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1 Motivation and Aims .......................................................................................................... 1
2 Fundamentals and state of the art ....................................................................................... 3
2.1 Zeolites ....................................................................................................................... 3
2.2 MFI and BEA type zeolites ........................................................................................ 4
2.3 Membranes ................................................................................................................. 5
2.3.1 Classification and major applications ................................................................ 5
2.3.2 Terminologies used in membrane technology ................................................... 6
2.4 Zeolite membranes ..................................................................................................... 8
2.4.1 Overview ............................................................................................................ 9
2.4.2 Zeolite membrane preparation techniques ....................................................... 11
2.4.2.1 MFI and BEA type of membranes ............................................................... 14
2.4.2.2 b-Oriented MFI type of membranes ............................................................. 17
2.4.2.3 Template-free MFI type of membranes 20
2.4.2.4 Bi-layered membranes .................................................................................. 21
2.4.3 Adsorption-branch porosimetry ....................................................................... 22
2.4.4 Separation in zeolite membranes ...................................................................... 25
2.5 Inorganic membrane reactors ................................................................................... 29
2.6 Zeolite Membrane Reactors ..................................................................................... 31
2.7 Xylenes: properties, uses and production ................................................................. 33
2.7.1 Physical properties ........................................................................................... 33
2.7.2 Common sources and uses of xylenes .............................................................. 34
2.7.2.1 Toluene disproportionation (TDP) and transalkylation ............................... 35
2.7.2.2 Xylene isomerization .................................................................................... 37
2.7.2.3 Xylene separation ......................................................................................... 39
2.7.3 Xylene separation using zeolite membranes .................................................... 40
2.7.4 Xylene isomerization in the zeolite membrane reactor .................................... 45
3 Experimental .................................................................................................................... 47
3.1 Materials ................................................................................................................... 47
3.2 Preparation: membrane, catalyst .............................................................................. 49
3.2.1 MFI membrane preparation
3.2.1.1 MFI type of membranes using SSG ............................................................. 50
3.2.1.1.1 In-situ seeding ........................................................................................ 50
3.2.1.1.2 Membrane secondary growth ................................................................. 51
3.2.1.2 MFI type of membranes using MISC ........................................................... 52
st3.2.1.2.1 1 crystallization step ............................................................................. 53
nd3.2.1.2.2 2 and the subsequent crystallization steps ........................................... 53
3.2.1.3 b-Oriented MFI type of membranes 54
3.2.1.3.1 Preparation of Silicalite-1 seed crystals ................................................. 55
3.2.1.3.2 Synthesis of trimer-TPAI ....................................................................... 55
3.2.1.3.3 Deposition of mesoporous silica via sol-gel slip coating ....................... 57
3.2.1.3.4 Deposition of Silicalite-1 seed crystals using 3-CPTMS 58
3.2.1.3.5 Secondary growth using trimer-TPA as a template ............................... 59
3.2.2 BEA membrane preparation 59
st3.2.2.1 1 crystallization step ................................................................................... 60
nd3.2.2.2 2 and the subsequent crystallization steps ................................................. 60
3.2.3 BEA/MFI bi-layered membrane preparation ................................................... 60
3.2.4 Membrane, excess powder calcination and ion exchange ................................ 61
3.2.5 Xylene isomerization catalyst preparation ....................................................... 61
3.3 Characterization: Membrane, excess powder and powder catalyst .......................... 62
3.3.1 Physicochemical characterization .................................................................... 62
3.3.2 Membrane Leak (gas tightness) test ................................................................. 64
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3.3.3 Membrane quality evaluation by adsorption-branched porosimetry ................ 65
3.4 Permeation/ Separation measurements ..................................................................... 66
3.4.1 Xylene permeation/ separation ......................................................................... 66
3.4.2 Trimethylbenzene isomer separation ............................................................... 68
3.5 Catalytic testing ........................................................................................................ 68
3.5.1 Xylene isomerization ........................................................................................ 69
3.5.1.1 Membrane reactor residence time distribution .............................................
3.5.1.2 Xylene isomerization in the membrane reactor ............................................ 70
3.5.1.3 Xylene isomerization in the fixed bed reactor ............................................. 73
3.5.2 n-Hexane cracking in the fixed bed plug flow reactor ..................................... 73
4 Development of zeolite membranes for xylene separation .............................................. 75
4.1 Support characterization ........................................................................................... 76
4.1.1 Support surface and pore size analysis .............................................................
4.1.2 Support permeation characteristics .................................................................. 79
4.2 MFI membrane preparation via SSG technique ....................................................... 81
4.2.1 In-situ seeding .................................................................................................. 81
4.2.2 Secondary growth ............................................................................................. 82
4.2.3 Membrane quality evaluation ........................................................................... 85
4.2.4 Xylene separation 87
4.2.5 Concluding remarks ......................................................................................... 89
4.3 MFI membrane preparation via MISC technique .................................................... 92
st4.3.1 1 in-situ crystallization step ............................................................................ 93
4.3.2 The layer growth mechanism and the evaluation of the membranes ............... 97
4.3.2.1 Layer growth ................................................................................................ 97
4.3.2.2 Comparison between MISC- and SSG-assisted layer growth mechanisms 103
4.3.2.3 Membrane quality evaluation by adsorption-branched porosimetry .......... 105
4.3.3 Parameters affecting the membrane layer microstructure .............................. 107
4.3.3.1 Effect of template concentration on the crystal morphology ..................... 107
4.3.3.2 Effect of template concentration on the crystal intergrowth ...................... 108
4.3.3.3 Effect of aluminum composition (of the starting gel) on the layer quality 110
4.3.4 Xylene separation ........................................................................................... 113
4.3.4.1 Xylene separation as a function of permeation temperature ......................
4.3.4.2 unction of feed partial pressure ............................ 116
4.3.4.2.1 PX, OX (1 : 1) mixture permeation ...................................................... 117
4.3.4.2.2 Single component permeation .............................................................. 120
4.3.4.2.3 Comparison between single component and mixture permeation ....... 122
4.3.4.3 Reproducibility of the xylene separation results ........................................ 126
4.3.4.4 Comparison between MISC- and SSG-prepared membranes .................... 126
4.3.4.5 Comparison with literature ......................................................................... 127
4.3.5 Concluding remarks ....................................................................................... 131
4.4 Application of MISC technique for the preparation of BEA membranes .............. 133
st4.4.1 1 crystallization step ..................................................................................... 133
nd rd4.4.2 Growth during 2 and 3 crystallization steps .............................................. 136
4.4.3 Separation performance of BEA membranes ................................................. 141
4.4.3.1 As a function of permeation temperature ................................................... 141
4.4.3.2 As a function of feed partial pressure ......................................................... 143
4.4.4 Concluding remarks 146
4.5 Bi-layered and oriented zeolite membranes ........................................................... 147
4.5.1 BEA/MFI bi-layered membranes ................................................................... 147
4.5.2 b-Oriented MFI membranes ........................................................................... 149
4.5.2.1 Synthesis of trimer-TPAI 149
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4.5.2.2 Mesoporous silica layer deposition via slip coating ................................... 151
4.5.2.3 Seed deposition using (3-chloropropyl)-trimethoxysilane ......................... 153
4.5.2.4 b-oriented MFI film growth ....................................................................... 154
4.5.3 Concluding remarks ....................................................................................... 155
5 Acidic properties of the membranes ............................................................................... 157
5.1 NH -Temperature Programmed Desorption (TPD) ............................................... 157 3
5.2 n-Hexane cracking .................................................................................................. 159
5.3 Concluding remarks ............................................................................................... 160
6 Membrane reactor .......................................................................................................... 163
6.1 Development of tubular membranes ...................................................................... 163
6.2 Xylene isomerization using tubular membranes .................................................... 166
7 Short summary ............................................................................................................... 169
8 Conclusions and outlook ................................................................................................ 179
9 Appendix ........................................................................................................................ 183
9.1 Symbols and abbreviations ..................................................................................... 183
9.1.1 Greek symbols 183
9.1.2 Latin symbols .................................................................................................
9.1.3 Abbreviations 184
9.1.4 Dimensionless numbers .................................................................................. 186
9.2 XRD pattern of MISC prepared MFI membrane surfaces .....................................
9.3 Top view SEM pictures of MISC prepared BEA membrane surface .................... 188
9.4 EDX spectrum of the BEA membrane after 3 crystallization steps ....................... 189
9.5 Arrhenius plots for n-hexane cracking ................................................................... 189
9.6 Zeolite membrane reactor design and its residence time distribution .................... 190
10 References .................................................................................................................. 193
























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