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Thermodynamics Aspects of
Hydrogen Storage in Metals
Guy Joël Rocher
Mech 6661
December 5th , 2011
Outline
• Introduction
• Thermodynamics of H2 Fuel Cells
• Thermodynamics of H2 storage
• Concluding Remarks
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3
1.
Introduction
Introduction
• Why Hydrogen Energy?1. Reduction in GHG emission
2. Reduction of oil dependency
3. Energy efficiency increase (conv. 20% elec. 45%)
• What is Hydrogen Energy? H2 is an Ultra High performance battery (Energy carrier)
Hydrogen = Electrification
• When? 2015 100 000 electric cars target in Europe
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Palcan Energy, Canada
A. Lulianelli, A. Basile, Catal. Sci. Technol., 2011
Canadian Interest in H2
• 18,608,297 cars in 2005 Canada (620/1000)
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Natural Resources Canada 2011
Environment Canada, 2011Environment Canada, 2011
• HEV: Hybrid Electric Vehicle
ICE + Battery
• PHEV: Plug In Hybrid Electric Vehicle
Large Battery
• FCEV: Fuel Cell Electric Vehicle
H2 Tank + Fuel Cell + Small Battery
Electric Vehicles Classification (EV)
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Electric Motor + 3-50KW
+ Electric Motor 100+KW
Electric Motor 75 KW Images: SAE Presentation, Dr. James Gover, Kettering University
H2 Powered Vehicles (FCEV)
• 2011 Honda FCX Clarity200 units, Southern California, 600$/month 3year term.
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http://automobiles.honda.com/fcx-clarity/
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2.
Thermodynamics of Fuel Cells
Electrochemical Cell “Engine”
• Open System with Mass Flow, Work and Heat
Classical Thermodynamics crucial for design & control of the system.
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1st Law of Thermodynamics
ΔU = Q – W
ΔU = Internal Energy
Q = Heat Added
W = Work Done
Chemical reactions: Operating Conditions, Material development, etc.
http://www.alternative-energy-news.info/technology/fuel-cells/
• At system level: Irreversible conversions
Chemical E. Electrical E. Mechanical E.
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Gerry Nolan, Silicon Chip, Issue 166, July 6 2002
Fuel Cells Operation
2nd Law of Thermodynamics
dS ≥ δq/T
S = Entropy
δq = Heat Added
T = Temperature
Operating Conditions, Material development, etc.
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3.
Thermodynamics of H2 Storage
• Compressed Gas
• Liquid H2
• Adsorption
• Metal/Complex Hydrides
• Chemical Reactions
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Thermodynamics of H2 Storage
Internal Energy Change
Phase Change
Weak Physical Bonding
Chemical Bonding
Product Generation
0
5
10
15
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0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040
Pr
es
su
re
(b
ar
)
Mass Fraction H/(Mg+Ni+H)
PCI Mg67Ni33 + H2350-5
325-4
300-3
Metal hydrides Theory
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AbsorptionDissociation
0
5
10
15
20
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0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040
Pr
es
su
re
(b
ar
)
Mass Fraction H/(Mg+Ni+H)
PCI Mg67Ni33 + H2350-5
325-4
300-3
Thermodynamic Modelling
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AbsorptionDissociation
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Material Matters, Volume 6, Article 2, 2011
A compilation of the Van’t Hoff plots of selected elemental, classical, and complex hydrides.
Thermodynamics Analysis Tools
The Van’t Hoff plot derived from the isotherms at various temperatures.
Nature 414, 353-358, 2001
ln(eq/eq0) = (-H/R)(1/T) + S/R
The Van’t Hoff equation
-H/R
• Why? Experimental investigation time consuming
• Models:• Liquid Quasi-Chemical
• Solid Solution Sublattice with random substitution
• Experiments provide:
• ΔHhydride, Solubility range, etc.
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Thermodynamic Modelling
gas + (Mg) + (Mg2Ni)
(Mg) + (Mg2Ni) + MgH2
(Mg2Ni) + MgH
2 + Mg
2NiH
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gas + MgH2 + Mg2NiH4356 C
327 C
302 C
22% Mg + 78% Ni -H
Mass fraction, H
log
P (
ba
r)
0 0.01 0.02 0.03 0.04 0.05 0.06
-0.5
0
0.5
1
1.5
2
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Modelling vs Experimental data
Buchner ,1978
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4.
Concluding Remarks
Concluding Remarks
• Classical & Statistical Thermodynamics essential for Hydrogen technologies .
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• Thermodynamic Modelling with key experiment allows to faster investigation.
• Renewable & Sustainable Energy?
• Multidisciplinary investigations linked through thermodynamics laws.
? ¿ Questions ¿?
THANK YOU
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