alumina membranes presentation E

1. Supervisors: AYRAL Andre; andre.ayral@iemm.univ-montp2.fr
BACCHIN Patrice ; bacchin@chimie.ups-tlse.fr
January 26, 2012

2. 1. Introduction
 Ceramics:
 ‘’The art and science of making and using solid
articles which have as their essential component,
and are composed in large of inorganic nonmetallic
materials.’’ Kingerly
 ‘’All high-temperature chemistry and physics of
nonmetallic materials, and the techniques of forming
products at high temperatures.’’ Mitchell
2 January 26, 2012

3. 1. Introduction
 Aluminum is the most abundant metal in the earth's
crust and the third most element in the earth's crust,
after oxygen and silicon.
 Aluminum is too reactive to be found pure. Bauxite
(mainly aluminum oxide) is the most important ore.
3 January 26, 2012

4. 1. Introduction
 The following information has been gathered:
occurrence in nature
mineralogical characteristics
mechanical, thermal, chemical and colloidal properties
alumina membranes fabrication
modules and industrial applications
4 January 26, 2012

5. 2. Nomenclature
Figure 1: Dehydration Sequence Of Alumina Hydrates In Air
5 January 26, 2012

6. 3. Structure And Mineralogical
Properties
 Crystal structure is the main factor controls the
properties of alumina
 In general, the phases of alumina are produced by
pseudomorphic dehydration
 Pseudomorphosis is of considerable importance
because of its effect on surface area of the
intermediate phase structures, and on crystal size
and size distribution
6 January 26, 2012

7. 3. Structure And Mineralogical
Properties
 Alumina is widely used as a catalyst or catalyst support in
many heterogeneous catalytic processes owing to its high
surface area, superior chemical activity and low cost.
 Resistance to:
 softening
 swelling and disintegration when immersed in water or other
liquids
 thermal shock and corrosion
 The ability to return to the original highly adsorptive from
by a suitable thermal regenerative treatment
7 January 26, 2012

8. 4. Mechanical – Thermal
Properties
 Alumina has remarkable mechanical properties in
comparison with conventional porcelains and other
single oxide ceramics
 The interest in mechanical – thermal properties lead
to several applications such as possible substitution of
alumina ceramics for refractory metal parts in air-
bone equipment, or fabrication forms.
8 January 26, 2012

9. 4. Mechanical – Thermal
Properties
Mechanical properties
Tensile Strength (MPa) 173 117
Bending Strenght Mpa 413 307
Modulus of Elasticity (E) X 108 MPa 26.8 21.27
Compressive Strenght Mpa 3733 1600
Modulus of Ridity(G) X 108 MPa 11.3 8.67
Hardness on the mohs scale 9
Thermal properties
2051
Melting point OC
±9.7
3530
Boiling Point OC
± 200
9 January 26, 2012

10. 5. Chemical Properties
 Chemical reactions of alumina of general ceramic
interest include the resistance to attack of sintered
alumina by various reagents, particularly at high
temperatures.
 Finely divided alumina is rapidly dissolved by HF, hot
concentrated H2SO4, mixtures of these acids,
ammonium fluoride, molten alkali bisulfates or
pyrosulfates, and by concentrated HCl, especially when
under pressure.
10 January 26, 2012

11. 6. Alumina Membranes
 Alumina membranes
are constantly
growing area. In the
Figure 3, it can be
seen that, the
publication numbers
are highly increasing
parallel with the
membrane research
especially during
recent years.
11 January 26, 2012

12. 6. Alumina Membranes
 Excellent mechanical strength
 Tolerance to solvents, as well as pH, oxidation,
 Can be used at significantly higher temperatures
 Have better structural stability
 Can be backflushed
 Less cost
12 January 26, 2012

13. 6. Alumina Membranes
 Highly selective
 Permeable / Selective ( based on pore size and
dist.)
 Durable
 Hydrophilic to maximize flow and minimize fouling
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14. 6. Alumina Membranes
Table 2 : Selected commercial Alumina Membranes
14 January 26, 2012

15. 6.1. Macroporous Membranes
 Usage: Filtration , diffusion, dispersion rolls, inkpads
for fingerprinting
 Anodizing of pure aluminum most common path
 Anodizing well controlled process and provides
homogenous pore distribution
 The preparation of regular pore arrays typically
involves electrolytic polishing and multiple anodising
steps or even mechanical pre-texturing.
15 January 26, 2012

16. 6.1. Macroporous Membranes
 Macroporous alumina membranes also can be made from
particles or discontinuous fibers by the use of a binder or
by sintering .
 Silica, vitreous glass and also phosphate are widely
used binders in the refractory and ceramic industry
 This method is generally used to produce alumina
microfiltration filters, which contain larger pores and
supports for ultrafiltration membranes, which contain
smaller pores
16 January 26, 2012

17. 6.2. Mesoporous
Membranes
 Figure 4: Preparation procedure of boehmite sol
17 January 26, 2012

18. 6.2. Mesoporous
Membranes
 Figure 5: Schematic drawing of the rapid gelation processing, 1 -
nozzle, 2 - atomizing sol and 3 -substrate.
18 January 26, 2012

19. 6.2. Mesoporous
Membranes
 Mesoporous γ-alumina membranes are formed by dip-
coating a porous substrate in a Boehmite (γ-AlOOH)
precursor sol, will be treated by heat and sintering
steps.
 The quality and properties of the membrane depend
on the dispersion rheology and quality of the
Boehmite sol and the dip-coating process as well
19 January 26, 2012

20. 6.3. Microporous Membranes
 A conventional path to synthesis microporous membranes
is slipcasting.
 In the slipcasting method, a porous support is usually made
first by conventional ceramic processing techniques to
provide rigid structure with relatively large pore size for
slip deposition.
 The ability to consistently produce high quality alumina
membranes on a commercial scale has been the key to
wider acceptance of ceramic membranes as a separation
tool.
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21. 21 January 26, 2012

22. 7. Membrane Modules
Tubular mode / Multichannel / Monolithic
Cross-section of a
monolithic multi-channel
membrane element [Hsieh
et al., 1998]
Schematic side-view of membrane
module consisting of multi-channel
elements [Remigy, 2007] 22 12/5/2012

23. 7. Membrane Modules
Composite or anisotropic / Multilayer
Schematic representation of Polypeptide films formed inside
pore walls of a thin anodic alumina membrane [Duran H. et al.,
2004]
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24. 7. Membrane Modules
Honeycomb mode
(a) AnoporeTM alumina membrane with honeycomb pore size distribution
(b) Commercial version of honeycomb alumina membrane by Lianyungang
Highborn Technology Co., Ltd
12/5/2012

25. 7. Membrane Modules
•Alumina/Titanium
oxide layers
•7-84 channels
•Pore size>0.8μm
•Compact
•d<1178mm
•P>80bar
•Θ>80oC
•pH 0-14
Kerasep® alumina membrane module
Bulk fermentation / Milk and dairy products / Beverages (beer, wine,
water, fruit juice)
25 12/5/2012

26. 8. Applications
 Adsorption layer of alumina
 Microfiltration – Ultrafiltration
 Crossflow filtration – High Crossflow velocity
 Transmembrane pressure : driving force of operation
 Concentration of soluble molecules and suspended
solids &
 Clarification by removing suspended solids
 Pretreatment process

27. 8.1 Liquid phase separation
(LPS)
1. Environmental
 Ions removal from wastewater (Cr, F, Ar)
Eg. Microporous Alumina membrane for Heavy metals removal in petrochemical industry
 Oil Recovery
2. Food/Beverage
 Clarification of juices
Eg. Pretreatment prior ion exchange/chromatography of clarified juice
 Filtration of sugar cane juice
 Alcoholic beverages
ECN industry demonstration of
inorganic membrane module for
3. Pharmaceutical
liquid phase separation [ecn.nl]
 Fermentation broths clarification Eg. Recovery of antibiotics
 Fungal cells ultrafiltration
Eg. microfiltration of biological media, such as human red blood cells
 Lysozyme ultrafiltration, Penicillin recovery

28. 8.1 LPS / As (V) – Cr (III) Removal
In a wide range of wastewaters, alumina membranes assumed to be suitable
for Ar(V) and Cr (III) removal
 γ-Al2O3/α-Al2O3, mesoporous alumina / Calcium doped alumina / Composite membranes
 Concentration of arsenic ions decreased from 1ppm  in 5ppb
 Flocculation was used as a pretreatment / for the treatment of the stone cutting wastewater
Example:
 Pagana et al., 2008 : Composite γ-Al2O3 membranes made by sol–gel method
Pilot system for Cr(III) and Ar(V) removal
Ar(V) 2 stages adsorption – ultrafiltration process in series
Cr(III)  1 adsorption-ultrafiltration parallel process

29. 8.1 LPS / As(V) – Cr (III) Removal
Flow diagram of the Cr (III) removal process [Pagana et
al., 2008]
Conclusion: Adsorption-ultrafiltration ion process using ceramic membranes may offer a low cost
effective alternative arsenic and chromium purification technology basically in terms of membrane
stability, applied pressure and product flux with the additional advantage of being suitable for
small local units

30. 8.2 Gas Phase Separation (GPS)
1. Carbon Dioxide Capture
 CO2/N2 separation
 H2/CO2 separation
2. Hydrocarbons separation
 Acetone recovery
 Propane separation
 Alcoholic beverages INSIDE Céram membrane by TAMI
industry [tami-industries.com]
3. Catalytic reactors
 VOCs oxidation
 Methane to ethane reaction

31. 8.2 GPS /VOCs removal
Alumina membrane are used in combination with catalysts or used for
catalyst recovery in a wide range of applications
Example: Saraco et al., 1999 / University of Saragoza Chem. Eng.Lab.
 Pt/Al2O3 and perovskite-containing membranes
 Using hydrogenation reactions over Pt/Al2O3 catalysts in membrane module
 Purification (by catalytic combustion) of air streams containing volatile organic compounds
(VOCs) in low concentrations
 Membrane would be expected to give high contact efficiency in the reaction of diluted
streams
Conclusion: The membrane performed very efficiently in the combustion of VOCs at low
temperatures, although at the expense of a significant pressure drop.
31 12/5/2012
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32. 8.2 GPS /VOCs removal
Applications of membrane reactors [Coronas et al., 1999]
Schematic of a multi tube membrane module
for H2 and CO2 separation [Diriz et al., 2007]
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33. 9. Perspectives
 Nanotechnology / Composite structures
 Modifications
 Sensitive active layers
 Alumina Catalysts/ Surface Adsorption
 Nanofiltration
 Gas separation
 Lower Cost (10 times > Polymeric, Remigy, 2004)
 Lower Fragility / Fouling/ Cracking
Application of ceramic membranes in fields
“traditionally” dominated by polymeric membranes! 12/5/2012
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34. Acknowledgements
We would like to express our sincere thanks to
EM3E for its support
Prof.A.Ayral, Prof.P.Bacchin and A.Julbe
for their advices
EM3E GROUP FOR THIS FIRST…
HARD SEMESTER!
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35. Goodbye France!
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