Catalytic Membrane ReactorsCatalytic Membrane Reactorsinvolvinginvolving
InorganicInorganic MembranesMembranes--A short A short overviewoverview--
Anne JULBEAnne JULBECNRS Senior Research ScientistCNRS Senior Research Scientist
Institut Européen des Membranes (UMR CNRS 5635)- UM 2– CC047Place Eugène Bataillon – 34095 Montpellier cedex 5 – FRANCE
Vrnjačka Banja- Serbia- October 7-12, 2007
OUTLINEOUTLINE
Definition of inorganic CMRs
The possible membrane functions in CMRs* Extractor … examples* Distributor … examples* Contactor … examples
Other types of membrane reactors* Catalytic particle traps* Photocatalytic membrane reactors* Trifunctional membrane reactor* Zeolite encapsulated catalyst* SOFCs* SOECs
Barrier effectControlled transport
MEMBRANE
CATALYST
Chemicalreaction
A (+ B) C (+D)
The catalytic membrane reactor conceptImprovement of conversion and/or selectivity of several catalytic reactions
TheThe catalyticcatalytic membrane membrane reactorreactor conceptconceptImprovementImprovement ofof conversion conversion andand/or /or selectivityselectivity ofof severalseveral catalyticcatalytic reactionsreactions
TubularTubularmembranemembrane
Membrane Membrane ScienceScience CatalysisCatalysis
InnerInner catalystcatalyst
RM
Outlet
Outlet
Inlet
InletOperating Operating conditionsconditions
ChemicalChemical engineeringengineering
Introduction
Various types of membrane/catalystarrangements in membrane reactorsVariousVarious types of membrane/types of membrane/catalystcatalystarrangements in membrane arrangements in membrane reactorsreactors
CatalystCatalyst disperseddispersedin an in an inertinert membrane membrane
IntrinsicallyIntrinsicallyCatalyticCatalytic membranemembrane
CatalystCatalyst bedbedon on inertinert membranemembrane
IMRIMR CMRCMR
Introduction
Dense ionconducting
(O2-, H+)
Molecular sieve membranes
Types of inorganic membranesB
ackg
roun
d
Ionic (ZrO2, CeO2, Bi2O3…)Mixed ionic / ẽ (Perovskites,..)
Pd, Pd alloys (H2) +…Ag (O2)
Hydroxides
Stainless steel,Ti, Ni, Ag, Pd….
Al2O3, SiO2, glassZrO2, TiO2,….+ composites CerMet
ZeolitesCarbon
Introduction
Flat dense Flat dense or porous supportsor porous supports
HoneycombsHoneycombsTubular supportsTubular supportsPowdersPowders
Sintering
Shaping or casting of ceramic membranes Introduction
Thick top-layer(Loaded sols) Thin top-layer
Infiltratedcomposite layer
Thick top-layer(Loaded sols) Thin top-layer
Infiltratedcomposite layer
MEMBRANE MATERIALS for reactors
OrganicOrganic membranesmembranes (dense or (dense or porousporous)) : for low T° applications
Dense membranesPermeation by adsorption/ dissolution/ diffusion/ desorption
Porous membranesPermeation by convection, diffusion(s)
Selectivity Permeability
☺☺
☺☺
InorganicInorganic membranesmembranes : for applications at high T° and/or pressure
v
Viscous flow
Gas translation
Dec
reas
ing
pore
size
s
Knudsen diffusion
Bulk diffusion
Surface diffusion
Capillary condensation
POROUS MembranesPOROUS Membranes-- Transport Transport mechanismsmechanismsWhichWhich pore size for pore size for whichwhich functionfunction ??
⎟⎠⎞
⎜⎝⎛−=Π
RTEg.exp
MRT8.
kLg
πχ
Pm.RTL
r8
2
v ητε
=Π
RMT8
L3r2
kK πτθ
ε=Π
* Molecular sieving
H2 / SFSF66 or N2 / SFSF66 in MFIin MFIn-hexane / 2,2 2,2 dimethylbutanedimethylbutane orp-xylene / oo--mm--xylenexylene in MFIin MFI
* Difference in diffusivity
CO2 / CHCH44 in CHA and DDRin CHA and DDR
* Competitive adsorptionnn--CC44HH10 10 / HH22 in MFIin MFICOCO22 / CHCH44 in FAUin FAUCOCO22 / CHCH44 in CHA and DDRin CHA and DDR
MICROPOROUS MEMBRANESMICROPOROUS MEMBRANES--Separation mechanismsSeparation mechanisms
* Molecular sieving
* Difference in diffusivity
* Competitive adsorption
MFIMFI
DIFFUSION DIFFUSION •• materialmaterial intrinsicintrinsic propertyproperty, , •• micromicro--structurestructure•• drivingdriving force (force (ΔΔpp or or ΔΔE)E)
DENSE MEMBRANES- Transport mechanismsDENSE DENSE MEMBRANESMEMBRANES-- Transport Transport mechanismsmechanisms
ADSORPTION ADSORPTION Surface exchange
(+dissociation, charge transfer, surface diffusion, incorporation)
DESORPTIONDESORPTIONREACTION REACTION ……andand/or RECOMBINATION/or RECOMBINATION
MolecularMolecular OO2 2 or Hor H22/H/H22OO
Dense Dense CeramicCeramic(e.g. (e.g. oxygenoxygen deficientdeficient
fluorites, fluorites, perovskitesperovskites relatedrelatedstructures)structures)
P1
P2Active Active andand selectiveselective
subsurfacesubsurface speciesspecies O* or H* O* or H*
CATALYTIC REACTORS
MAIN MEMBRANE FUNCTIONS
Main membrane functions in reactorsMain membrane Main membrane functionsfunctions in in reactorsreactors
2-DISTRIBUTOR
BB BBA CC ( D )
A
BB BB
CC
BB
CCA A Controlled addition of a reactant. Limitation of side reactions
Increased selectivity
Dense or Dense or porousporousmembranesmembranes
3-ACTIVE CONTACTOR
A + B CCCatCat.
B
CC
A A + B
CC
or
Controlled diffusion of reactantsto the catalyst
Increased conversion (& selectivity)
CatalyticallyCatalyticallyactive membranesactive membranes
1-EXTRACTOR
Dense or ultraDense or ultra--microporousmicroporous membranesmembranes
A + B C C + DD
A, B
DD
CC
sweep
DDIncreased conversion
Equilibrium shift
Membrane Functions
1- MEMBRANE EXTRACTOR11-- MEMBRANE EXTRACTORMEMBRANE EXTRACTORMembrane Functions
Extractors
Important membrane characteristics : * permeability* selectivity* stability
Ex: Dehydrogenation reactions, Steam reforming of CH4, Water Gas Shift
Ex: Isomerization of xyleneD
X X
S S
New Energy and Industrial TechnologyDevelopment Organization (NEDO)& Japan Gas association
Membrane FunctionsExtractors1- MEMBRANE EXTRACTOR
Equilibrium displacement-MSR11-- MEMBRANE EXTRACTORMEMBRANE EXTRACTOREquilibriumEquilibrium displacementdisplacement--MSRMSR
Residual CO separatedfrom H2 is burnedand the generated heatis utilized for reformingreaction
CH4 + H2O CO + 3 H3 H22
Methane steam reforming (550°C; 0.1MPa)
The world's first compact and economical on-site H2 production unit based on membrane technology.
∆H = 49 Kcal/mol
NEDO & Japan Gas association
Membrane FunctionsExtractor1- MEMBRANE EXTRACTOR
MSR
(Polymer Electrolyte Fuel Cell)
PSA
11-- MEMBRANE EXTRACTOR MEMBRANE EXTRACTOR MSRMSR
NEDO PROJECT-
Ru-Al2O3
NEDO NEDO projectproject((FY2002 - FY2006)LeadedLeaded by Prof. by Prof. NakaoNakao
MSR (500°C)MSR (500°C)
ALMOST DENSE ALMOST DENSE SILICA MEMBRANESILICA MEMBRANE
Goal : CHGoal : CH44/H/H22 conversion conversion efficiencyefficiency >> 80%80%
Japan Fine CeramicCenter
1a1a-- MEMBRANE EXTRACTORMEMBRANE EXTRACTOREquilibriumEquilibrium displacementdisplacement
Need for a High-Efficiency, High-T°HH22 extraction membraneextraction membrane
Ni-doped silica
SolSol--gel gel –– P.PexP.Pex, 2005, 2005 CVDCVD-- D. Lee, 2004D. Lee, 2004
CVI, CVI, PhDPhD D. Lee, D. Lee, 20032003
ALMOST DENSE SILICA ALMOST DENSE SILICA ––Typical examplesTypical examples
FusedFused silicasilica
Pfaender
Na silicate glassNa silicate glass
(2.89Å)
(3.3Å)
(2.75Å)
MFI MFI zeolitezeolite membrane (5.5membrane (5.5ÅÅ ))
Ortho : 6.8 ÅÅ
Meta : 6.8 ÅÅPara : 5.8 ÅÅ
Catalyst(Isoxyl*)
MFI MFI zeolitezeolite membrane (5.5membrane (5.5ÅÅ ))
Ortho : 6.8 ÅÅ
Meta : 6.8 ÅÅPara : 5.8 ÅÅ
Catalyst(Isoxyl*)
Process and MFI membrane under development by NGK
Xylene isomerization reactorXylene isomerization reactor
Terephtalic acid
Membrane FunctionsExtractors1b- MEMBRANE EXTRACTOR
Selectivity improvement1b1b-- MEMBRANE EXTRACTORMEMBRANE EXTRACTOR
SelectivitySelectivity improvementimprovement
Y CMR > Y conventional reactor
* Isoxyl(Süd-Chemie)
ParaxyleneParaxylene Polyéthylène téréphtalate
L. van Dyk, L. Lorenzen, S. Miachon, and J.-A. Dalmon, Catal. Today, 104 (2005) 274.
MFIMFI
A B
C D
Membrane FunctionsExtractorsMFI zeolite membranes for
the separation of Xylene isomersMFI zeolite membranes forMFI zeolite membranes for
thethe separationseparation ofof XyleneXylene isomersisomersZ. Lai, G. Bonilla, I. Diaz, J.G. Nery, K. Sujaiti, M.A. Amat, E. Kokkoli, O. Terasaki, R.W. Thompson, M. Tsapatsis, D.G. Vlachos, Science, 300 (2003) 456-460.
22-- MEMBRANE DISTRIBUTORMEMBRANE DISTRIBUTOR
Rea
ctio
nzo
ne
A
* Increased S by homogeneous distribution of the reactant A(e.g. limiting undesirable side reactions)
* Increased Y by increasing the possible concentration ratios of reactants(e.g. overpassing the flammability limit)
* Limited catalyst desactivation …
* Distribution of selective (O* or H*) specieson the membrane surface
* Direct use of air instead of pure O2 (€)* No formation of toxic NOx ( )
For dense membranes (O2 or H2 selective)
22-- MEMBRANE DISTRIBUTORMEMBRANE DISTRIBUTORe.g. Partial e.g. Partial oxidationoxidation of of alkanesalkanes
O2 OO22
* Reduced [O2] along the catalyst bed Increased B selectivity* Possibility to use « dangerous » [O2]/[A] overall ratios
Increased B yield
AA
OO22
Progressive Progressive consumption consumption of Aof A
Membrane Membrane distributordistributor
AA
OO22
Progressive Progressive consumption consumption of Aof A
Membrane Membrane distributordistributorMembrane Membrane distributordistributor
BBAA
OO22
Progressive Progressive consumption consumption of Aof A
Membrane Membrane distributordistributor
AA
OO22
Progressive Progressive consumption consumption of Aof A
Membrane Membrane distributordistributorMembrane Membrane distributordistributor
BB
A BB ( C)
MethaneMethane to to syngassyngas :: CHCH44 + 1/2 O+ 1/2 O22 →→ COCO + 2 H+ 2 H22
Ex : Ex : LiLaNiO/LiLaNiO/γγ--AlAl22OO33 catalyst with Bacatalyst with Ba0.50.5SrSr0.50.5CoCo0.80.8FeFe0.20.2OO3 3 --δδ tube (Wang 2003)tube (Wang 2003)Y =80%Y =80%--875875°°CC
22-- MEMBRANE DISTRIBUTORMEMBRANE DISTRIBUTORfor the Partial for the Partial OxidationOxidation of of MethaneMethane (POM)(POM)
∆H = -9 Kcal/mol
Synthesis of mixed conducting oxide membrane (Sr-Fe-Co-O perovskite)(U. Balachadran et al., Cat. Today 36 (1997) 265)
Sr(NO3)2+ Fe(NO3)3･9H2O + Co(NO3)2･6H2O in deionized water
Drying up while stirring
Calcination at 850℃ for 16 h
Grinding in an auto mortar for 2 h
Sr-Fe-Co-O powder
Pressing at 3.7×103 kgf/cm2 for 5 min
Calcination at 1150℃ for 10 h
Self-supported membrane
22-- MEMBRANE DISTRIBUTORMEMBRANE DISTRIBUTORDense ion Dense ion conductingconducting ceramicceramic membranemembrane
22-- MEMBRANE DISTRIBUTORMEMBRANE DISTRIBUTORDense ion Dense ion conductingconducting ceramicceramic membranemembrane
3- MEMBRANE CONTACTOR33-- MEMBRANE CONTACTORMEMBRANE CONTACTORMembrane Functions
Contactor
Rea
ctio
nzo
ne
A+B
Rea
ctio
nzo
ne
A B
Interfacial
Flow-through
Enhancedcatalyst/reactant contact
* improved access X X
* controlled contact timeS S
A + B
C
- Precise control of the contact time- Forced diffusion
- Better access of B to the catalyst (solubility )- no intraparticular diffusion
B
AA
A + B
Pd nanoparticles in the pores (∅ 0.25-0.75 μm)
of a cross-linked PAA membrane
Membrane with defined pore structureand
convective mass flow of the reaction mixture
3- MEMBRANE CONTACTOR33-- MEMBRANE CONTACTORMEMBRANE CONTACTOR
Flow-through catalytic contactorfor fine chemistry hydrogenation
Controlled contact timeS S
A. Schmidt, R. Haidar, R. Schomäcker, Catalysis Today 104 (2005) 305–312
Compared to experiments with supported catalysts (Pd/C and Pd/Al2O3) in a slurry and a fixed bed reactor the selectivity for the desired products could be increasedby 3% (1-octyne) up to 40% (geraniol).
Membrane FunctionsContactor
WATERCATOX process. EU 5th FP contract N° EVK1-CT-2000-00073, 2001-2004Int. Patent Publ. N° 1368278, Norvegian Patent N° 313994 (2003)
20-80°C
5-15 bar
Membrane FunctionsContactor
3- MEMBRANE CONTACTOR33-- MEMBRANE CONTACTORMEMBRANE CONTACTOR
OTHER TYPES
OF CATALYTIC MEMBRANE REACTORS
* Catalytic particle traps* Photocatalytic membrane reactors* Trifunctional membrane reactor
* Zeolite encapsulated catalyst* SOFCs* SOECs
OO22, N, N22, H, H22OOCOCOxx, , CCxxHHyySootSoot
11--The The catalyticcatalytic particleparticle traptrap
OO22, N, N22, H, H22OONONOxx, , COCOxx, , CCxxHHyy
OO22, N, N22, H, H22OONONOxx, , COCOxx, , CCxxHHyy
OO22, N, N22, ,
COCO22, H, H22OO
CatalyticLayer (oxidative)covering the grains of the ceramic wall
Each channel isclosedon one size
(+(+NONOxx))
A A catalyticcatalytic contactorcontactor for a for a continuouscontinuous sootsoot oxidationoxidation
4 nm4 nm
NanophaseNanophaseCeOCeO22
A. JULBE, V. ROUESSAC, J. DURAND; A. AYRAL, Journal of Membrane Science (2007) in press
2- Photocatalytic reactor –Coupling separation & photocatalysis
UVvisible
UV
CO2 + H2O
H2O
MacromoleculesColloids
Aqueous Effluent
Small organicmolecules
PhotoactivePhotoactivesupportsupport
Non-photoactive membrane
Photodegradation in permeate
2Nonphotoactive
support
1
PhotoactivePhotoactive MembraneMembrane
Photocatalytic reactor, antifouling
500 nm500 nm
Homogeneous defect-free TiO2membranes with controlled thickness
5 nm 5 nm porepore--sizedsizedγγ--AlAl22OO33
150 nm150 nm
Non-photoactive
support1
Photoactive membranes
F. Bosc, A. Ayral, C. Guizard, J. of Membrane Science 265, 13 (2005).
2- Photocatalytic reactor –Coupling separation & photocatalysis
F. Bosc, PhD Thesis2004
33--Trifunctional membrane Trifunctional membrane reactorreactorfor for waterwater treatmenttreatment
Vr = 2.0 cm3
a = 5.7 cm2 cm-3
Residence time = 1-6 min O3distributor
THEHONG KONGUNIVERSITY OFSCIENCE &TECHNOLOGY
Out : Nanophaseozonation catalyst
In : pervapo-ration zeolite membrane
S. HENG, PhD Thesis,2006
Ozonation catalyst
Pervaporation(zeolite membrane)
4- Zeolite Membrane Encapsulated Catalyst
ZeoliteZeolite MembraneMembrane
N. Nishiyama & al, Micro. Mesoporous Mater. 83 (2005)244
* No need to prepare large perfect membrane areas* Traffic control over reactants and products
Pt/Pt/TiOTiO22
StraightStraightolefinolefin
Straightparaffin
Branchedolefin
CatalystCatalyst bedbed
ZMZMECC
An original micro-designed CMR
H2 , CO or CH4
OO2 2 + 4e+ 4e-- 2 O2 O==
HH2 + O= → H2O + 2e-
COCO + O= → CO2 + 2e- CHCH44 + 4O= → 2H2O + CO2 + 8e-
5- Fuel Cells – SOFCs are also CMRs
6- Membrane applications in the production of H2
from H2O
Water or steam electrolysis
Efficiency : 25-30% (classical low T°)30-40% (high T°)
"Oui, mes amis, je crois que l'eau sera un jour employ"Oui, mes amis, je crois que l'eau sera un jour employéée comme combustible, que e comme combustible, que l'hydrogl'hydrogèène et l' oxygne et l' oxygèène, qui la constituent, utilisne, qui la constituent, utiliséés isols isoléément ou simultanment ou simultanéément, ment, fourniront une source de chaleur et de lumifourniront une source de chaleur et de lumièère inre inéépuisables et d' une intensitpuisables et d' une intensitéé que que la houille ne saurait avoir. la houille ne saurait avoir. …… Ainsi donc, rien Ainsi donc, rien àà craindre.craindre.…… L' eau est le charbon de L' eau est le charbon de l'avenirl'avenir". (Cyrus Smith)". (Cyrus Smith)
Jules VERNE (1828-1905). L'île mystérieuse (1873)
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/electrol.html
H2O H2 + ½ O2H2O H2 + ½ O2
WATER or STEAM ELECTROLYSIS
ΔH = 285.83 kJ/mol Energy
H2 + ½ O2
Electrolysis :A chemical process in which bonded elements & compoundsare dissociated by the passage of an electric current.
Polymer Electrolyte Membrane (PEM) Electrolyzers:
1. Uses a solid plastic material as an electrolyte (3-30 mm; 100-200 €/m2)
2. Water reacts at the anode to form oxygen, electrons, and positively charged hydrogen ions (protons).
3. The electrons flow through an external circuit to the cathode.
4. The H+ ions move across the PEM to the cathode, where they combine with the electrons to form H2 gas
• Process which could increase conversion efficiency to the range of 45 to 50 %
• In France, both EDF and AREVA are currently examining the use of high T° electrolysis powered by nuclear technologies. The DOE is also active in this field
• High T° electrolysis utilizes a solid oxide electrolyte/electrodes
• The efficiency increase is achieved because highT° electrolysis utilizes a significant amount of heat, for example from a nuclear reactor.nuclear reactor.
• The added heat decreases the amount of electricity required to separate H2O into H2 and O2.
High Temperature Electrolysis
H2O H2
e-
e-
I
Circuit externe
O2
Anode 2O2- → O2+ 4 e-
Cathode 2H2O+ 4 e- → 2H2 +2O2-
e-
e- H2O
H2
I
O2
Circuit externe
Cathode 4 H++ 4 e- → 2H2
Anode 2H2
O→ O2+ 4 e- + 4H+
H2O H2
e-
e-
I
Circuit externe
O2
Anode 2O2- → O2+ 4 e-
Cathode 2H2O+ 4 e- → 2H2 +2O2-
e-
e- H2O
H2
I
O2
Circuit externe
Cathode 4 H++ 4 e- → 2H2
Anode 2H2
O→ O2+ 4 e- + 4H+
H2O H2
e-
e-
I
Circuit externe
O2
Anode 2O2- → O2+ 4 e-
Cathode 2H2O+ 4 e- → 2H2 +2O2-
e-
e- H2O
H2
I
O2
Circuit externe
Cathode 4 H++ 4 e- → 2H2
Anode 2H2
O→ O2+ 4 e- + 4H+
Solid oxide Solid oxide electrolyserselectrolysers : two strategies: two strategies
• Example of electrolyte : Y-ZrO2• Cathode : water combines with electrons
from the external circuit to produce H2gas and O=.
• The O= move through the membrane and release electrons to the external circuit.
• Functioning T° : 700– 1000°C
OO==
HH22OO
2O2O==
2O2O==AnodeAnode
CathodeCathodeHH++
HH22OO
AnodeAnode
CathodeCathode
4H4H++
4H4H++
• Example of electrolyte : Y-BaCeO3• Anode : water dissociates, releases
electrons and O2 gas and protons. • The H+ move through the membrane and
combines with electrons from the external circuit.
• Functioning T° : 450– 800°C
1 liter H2O 2kWh (theoretical)
1 liter H1 liter H22O O 2kWh (2kWh (theoreticaltheoretical))
CONCLUSION
H2H2
Imagine Imagine ……!!
