THE SULFUR-IODINE AND OTHER TEHRMOCHEMICAL STUDIES …€¦ · NEA 3rd Meeting on Nuclear...
Transcript of THE SULFUR-IODINE AND OTHER TEHRMOCHEMICAL STUDIES …€¦ · NEA 3rd Meeting on Nuclear...
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 1
THE SULFUR-IODINE AND OTHER TEHRMOCHEMICAL STUDIES AT CEA
P. Anzieu, P. Carles, A. Le Duigou, F. Lemort, X. Vitart
CEA, France
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 2
A CEA R&D StrategyConcentrate efforts on a scientific approach
• data acquisition (development of specific analytical devices)• modeling (physical models, flow-sheet analysis, systemic approach)
Develop expertise on thermochemical cycles assessmentsBenefit from collaboration with international programs
Basic Research
ThermodynamicsData acquisition
ModelingFlow-sheet analysisCorrosion studies
TechnologicalAssessmentsLaboratory loopsDemonstratorsTechnological
improvementsIndustrial viability
Collaboration with USA : GA, Sandia, Argonne, IdahoCollaboration with Europe : HYTECH programCollaboration with Japan : JAERI
Data acquisitionAnalytical devices
ModelingFlow-sheet
Analyticalmethods
Collaboration with USAArgonne
Collaboration with EuropeHYTECH program
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 3
CEA’s program for nuclear hydrogen
Hydrogen massive production using nuclear heat
Thermochemical cycles HTE
Assessment Sulfur family Other cycles
Methodology
Flowsheet
Plant design
Reactor coupling
Sulfur-iodine Hybrid sulfur
Flowsheet
Process breakthroughs
Modeling
Materials
Materials for membranes
Flowsheet
Flowsheet
Technology
Modeling
Plant design
Economics
Reactor coupling
Economics
Bunsen: stoichiometry
H2SO4: high temperature part
HI: reactive distillation, membranes, catalysts
Hydrogen massive production using nuclear heat
Thermochemical cycles HTE
Assessment Sulfur family Other cycles
Methodology
Flowsheet
Plant design
Reactor coupling
Sulfur-iodine Hybrid sulfur
Flowsheet
Process breakthroughs
Modeling
Materials
Materials for membranes
Flowsheet
Flowsheet
Technology
Modeling
Plant design
Economics
Reactor coupling
Economics
Bunsen: stoichiometry
H2SO4: high temperature part
HI: reactive distillation, membranes, catalysts
Modeling Experiments Lower priority →
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 4
Where are we today ?
• A R&D program was defined to get better and better
• 3 years work give an estimated efficiency of 35±5%• A lot of key points are identified
Effi
cien
cyes
timat
e
Time in year
25%
50%
75%
0%
35% ± 5
20042001
• But will they come more and more ?
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 5
Main issues of Sulfur-Iodine cycleHI HI separationseparationHI HI decompositiondecomposition::•• catalystcatalyst ((reactivereactive distillation)distillation)•• incompleteincomplete reactionreactionHeatHeat demanddemand
SOSO33 decompositiondecomposition::•• catalystcatalyst•• couplingcoupling to to reactorreactor
450°C850°C H2SO4 Decomposition
H2
HIDecomposition
HIVaporization
O2
BunsenReaction
SO2
H2SO4Concentration
H20I2
SideSide reactionsreactionsStoichiometryStoichiometry
GeneralGeneral::Corrosion Corrosion IodineIodine losseslosses
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 6
Bunsen section: objectives
xI2 + SO2 + (n+2)H2O ⇄ [H2SO4 + (n-m)H2O] + [2HI + (x-1)I2 + mH2O]
Bunsen Reaction
H2SO4(aq) phase HIx phase
Objectives:• Reduce excess of H2O and I2
while keeping phase separation
• Minimize side reactions
• Minimize heat losses
H2SO4 + 6 HI ⇄ S + 3 I2 + 4 H2OH2SO4 + 8 HI ⇄ H2S + 4I2 + 4H2O
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 7
Bunsen section: experimental devices
Device Material Operating temperature Input chemicals
B0 Glass 30-60°C HI, H2SO4, I2, H2OB1 Glass 100-120°C (limit 1,5 bar) HI, H2SO4, I2, H2OB2 Ta 100-150°C I2, H2O, SO2
B3 Bunsen section of the I-NERI loop
B1
B0
B2
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 8
0
0.2
0.4
0.6
0.8
1
200 210 220 230 240 250
Longueur d'onde (en nm)
Abs
orba
nce
H2SO4 = 0.5 I-
H2SO4 = 5 I-
H2SO4 = 50 I-
Bunsen section: analytical methods• Objectives:
– Composition of the phases– Control of parasite reactions
• Available methods (ex situ):– I: UV-visible measurements
after reduction of all ioded species– S: ICP-AES– H+: potentiometric titration
• Under development:– Voltamperometry (ex situ)– γ-absorptiometry– ATR probe– Anti-Stokes Raman diffusion
insi
tu
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
fraction molaire HI
fract
ion
mola
ire I 2 Brut
HIxH2SO4
CEA results
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 9
Issues for the iodine section
Bubble Pressure of HI-H 2O Mixture
100°C
125°C
150°C
0
1
2
3
4
5
6
0 0.05 0.1 0.15 0.2 0.25
[HI]
P (b
ar)
Vapeur très pauvre en HI vapeur
Vapeur très riche en HI
[HI]azéotrope
• Exit of Bunsen section: HI/I2/H2O mixture (HIx)• HI/H2O(/I2) azeotrope: no simple separation• Slow and incomplete decomposition of HI
Azeotrope composition as a function of temperature for the binary mixture HI-H20 (models)
No experimental data available up to now in relevant conditions :flow-sheet calculations based on assumptions, extrapolations, best estimates
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 10
Main options for the iodine section
H3PO4 I2
HI/(H2O/H3PO4)
HI
HI/H2/I2
H2O/H2
HI/I2/H2O
HI/I2/H2O
H2O
I2
H2O
I2
HI
H2O/H3PO4Distillate
Add third body
Recycle
HIx mixture from Bunsen section
H2
Concentrate HIx
Distillate
Separate H2
Reactivedistillation
Extractive distillation Electrodialysis Reactive distillation
Separate H2
Decompose HI
H2O
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 11
HI section: experimental devicesObjective: HIx liquidObjective: HIx liquid--vapor equilibrium data in process vapor equilibrium data in process
Device Material Operating temperature Pressure Measurements
I1 Ta 100-300°C 1-100 bar Total pressure
I2 Glass up to 150°C 1,5 bar Partial pressures
I3 Ta 100-300°C 1-100 bar Partial pressures
conditionsconditions
Total Pressure of the ternary HI-H20-I2
0
200
400
600
800
1000
0 20 40 60 80 100 120
Temperature (°C)
Pres
sion
(mba
r)
LSRM
Littérature
I2
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 12
Corrosion of materials• Bibliographic study• Preliminary screening tests:
– Bunsen section– HI section
• Study of associated mechanisms
0,1
1
10
100
1000
10000
Tantale Zirconium Hastelloy B3
Cor
rosi
on/ µ
m/y
aer
H2SO4
HI
mixte
0,1
1
10
100
1000
10000
Tantale Zirconium Hastelloy B3
Cor
rosi
on/ µ
m/y
aer
H2SO4
HI
mixte
1,E-10
1,E-09
1,E-08
1,E-07
1,E-06
1,E-05
1,E-04
1,E-03
1,E-02
1,E-01
1,E+00-1,2 -1 -0,8 -0,6 -0,4 -0,2 0 0,2
Potentiel / V/ESS
Den
sité
de
cour
ant /
A/c
m²
tantale
zirconium
Hastelloy B3
H 2SO 4 9 m ol/LT=95°CVb = 600 m V/h
Electrochemical tests in H2SO4
Tantalum, Tantalum, ZirconiumZirconium : stable passive layer
HastelloyHastelloy B3B3: anodic dissolution
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 13
New devices for the study of corrosion• Bunsen section: from 2006
A new device for longer tests in more representative conditions
– Ta Reactor– Maximum temperature : 150°C150°C– Maximum pressure : 7 bars7 bars– Volume : 1.5 L1.5 L– Possible sampling of the
two liquid phases
• HI section: planned 2007
The CORBUN deviceThe CORBUN device
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 14
A long route to viability: efficiency and cost optimization
Time
100%
0%
Theoretical efficiency
First approach Energetic efficiency More precise Flow-sheet
Exergetic efficiency
System & ComponentsOptimizationTarget efficiency
EvaluationR&D
Demonstration
• The challenges:– R&D activities with no iterative process
• flow-sheet assessment, heat distribution, materials, innovative concepts…– Answer questions about strategy for the hydrogen economy
• position vs. competitors (especially electrolysis), raw materials availability, safety, public acceptance, massive or dispersed production units…
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 15
The UT_3 Cycle
Experimental Tests
Volatility Experimental evidence of high volatility of FeBr2 at 750°C
At 725°C/24h →→
At 750°C/24h Just above melting point of CaBr2→
→
CaBr2 ⇒ CaOCaBr2 ⇒ CaO Incomplete reactionParticle collapse
Hardened solidIncomplete reaction
Thermal cycling difficult
FeBr2 ⇒ Fe3O4 At 600°C/24h → Fe2O3 forms instead of Fe3O4→
At 700°C/24h
Incomplete reaction
Just above melting point of FeBr2� Fe2O3 forms instead of Fe3O4
The cycle is modified !
FeBr2 ⇒ Fe2O3
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 16
The Hybrid Sulfur CycleElectrolysis
SO2 + 2 H2O + →H2 + H2SO4
O2/SO2 Separation
ReductionSO3-> SO2 + ½ O2
H2
O2
H2O
SO2 (2-10 bar)
H2SO4 35-50% (20-110°C, 2-10 bar)
H2O + SO3(600°C)
H2O
H2SO4 90-98% (350°C)
DecompositionH2SO4-> SO3 + H2O H2SO4 Concentration
O2 + SO2 (20-30 bar)
O2 + SO2 (900°C)
900°C
Electrolysis sectionSulfur thermocycle section
ElectrolysisSO2 + 2 H2O + →H2 + H2SO4
O2/SO2 Separation
ReductionSO3-> SO2 + ½ O2
H2
O2
H2O
SO2 (2-10 bar)
H2SO4 35-50% (20-110°C, 2-10 bar)
H2O + SO3(600°C)
H2O
H2SO4 90-98% (350°C)
DecompositionH2SO4-> SO3 + H2O H2SO4 Concentration
O2 + SO2 (20-30 bar)
O2 + SO2 (900°C)
900°C
Electrolysis section
ElectrolysisSO2 + 2 H2O + →H2 + H2SO4
O2/SO2 Separation
ReductionSO3-> SO2 + ½ O2
H2
O2
H2O
SO2 (2-10 bar)
H2SO4 35-50% (20-110°C, 2-10 bar)
H2O + SO3(600°C)
H2O
H2SO4 90-98% (350°C)
DecompositionH2SO4-> SO3 + H2O H2SO4 Concentration
O2 + SO2 (20-30 bar)
O2 + SO2 (900°C)
900°C
Electrolysis sectionSulfur thermocycle section
ElectrolysisSO2 + 2 H2O + →H2 + H2SO4
O2/SO2 Separation
ReductionSO3-> SO
ElectrolysisSO2 + 2 H2O + →H2 + H2SO4
O2/SO2 Separation
ReductionSO3-> SO2 + ½ O2
H2
O2
H2O
SO2 (2-10 bar)
H2SO4 35-50% (20-110°C, 2-10 bar)
H2O + SO3(600°C)
H2O
H2SO4 90-98% (350°C)
DecompositionH2SO4-> SO3 + H2O H2SO4 Concentration
O2 + SO2 (20-30 bar)
O2 + SO2 (900°C)
900°C
Electrolysis sectionSulfur thermocycle section
ElectrolysisSO2 + 2 H2O + →H2 + H2SO4
O2/SO2 Separation
ReductionSO3-> SO2 + ½ O2
H2
O2
H2O
SO2 (2-10 bar)
H2SO4 35-50% (20-110°C, 2-10 bar)
H2O + SO3(600°C)
H2O
H2SO4 90-98% (350°C)
DecompositionH2SO4-> SO3 + H2O H2SO4 Concentration
O2 + SO2 (20-30 bar)
O2 + SO2 (900°C)
900°C
Electrolysis section
• Main issues: Electrolysis Section– Membrane (SO2 permeation)– Cell over-voltage
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 17
The Cerium Chloride Cycle
Ce-Cl
250°C
650°C
Cl2 + H2O
192 t/hCondenser
Cl295 t/h
H2O
24 t/h
H2O73 t/h
Cl2 + H2O
119 t/h
CeCl3660t/h
800°C
Evaporator
H2O
24 t/h
H2O24 t/h
+ X t/h
H2 + H2O +HCl
2.7 t/h + X t/h +287t/h
H2
2.7 t/h
CeO2461t/h
HCl
390 t/h
O2
21.4 t/hSeparating
device
liquidgazsolid
HCl295 t/h
SeparatingDeviceH2 + H2O
2.7 t/h + X t/h
UV
Evaporation
250°C
650°C
Cl2 + H2O
192 t/hCondenser
Cl295 t/h
H2O
24 t/h
H2O73 t/h
Cl2 + H2O
119 t/h
CeCl3660t/h
800°C
Evaporator
H2O
24 t/h
H2O24 t/h
+ X t/h
H2 + H2O +HCl
2.7 t/h + X t/h +287t/h
H2
2.7 t/h
CeO2461t/h
HCl
390 t/h
O2
21.4 t/hSeparating
device
liquidgazsolid
HCl295 t/h
SeparatingDeviceH2 + H2O
2.7 t/h + X t/h
UV
Evaporation
- Membranes were suppressed- High & rapid efficiency of reaction 2- Viability of reaction 3
Lab tests :
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NEA 3rd Meeting on Nuclear Production of Hydrogen, OARAI, Japan, 5-7 Oct. 2005 18
UT_3 cycle
Gas-solid reactions:
MO + H2O + SO2 → MSO4 + H2 exothermal - low T°
MSO4 → MO + SO2 + ½ O2 endothermal - high T°M could be Fe (T > 730°C), Ni, Co, Mn
Sulfate cycles --------------------
Hybrid Sulfur cycle -----------------
SO2 + 2H2O → H2SO4 + 2H+ + 2e- Low T° Electrolysis <120°CH2SO4 → 4H2O + SO2 + ½ H2 High T° Decomposition
• Main advantage : max T° lower than for S-I
• A lot of unresolved difficulties + bromine toxicity
=> negative conclusion. We have given up this cycle
• Advantage : 2 reactions cycles
• Difficulties : transfer of solid, parasites reactions (formation of MS, H2S)
=> Tests underway
Cerium Chloride cycle ---------------
CaO + Br2 -> CaBr + 1/2 02 (500-600°C)CaBr2 + H20 -> CaO + 2 HBr (700-750°C)Fe3O4 + 8 Hbr -> 3 FeBr2 + 4 H20 + Br2 (200-300°C)3 FeBr2 + 4 H2O -> Fe3O4 + 6 HBr + H2 (550-650°C)
Evaluation of Other Thermochemical Cycles
• High H2 purity, anode voltage lower than for water electro., H2 produced at low T°
• Comparable to S-I : same H2SO4 section, No iodine section.
=> positive First-analysis : seriously competing with S-I cycle
• Chloride and materials well none• Medium toxicity
=> study underway
H2O + Cl2 → 2HCl + ½ O2 ~ 650 °C8HCl + 2 CeO2 → 2CeCl3 + Cl2 + 4 H2O ~ 100 °C2CeCl3 + 4H2O → 2CeO2 + 6HCl + H2 ~ 750 °C