hydrogen storage- overview - department of energy
TRANSCRIPT
Hydrogen Storage - Overview
George Thomas, Hydrogen Consultant to SNL*
andJay Keller, Hydrogen Program Manager
Sandia National Laboratories
H2 Delivery and Infrastructure Workshop
May 7-8, 2003
* Most of this presentation has been extracted from George Thomas’ invited BES Hydrogen Workshop presentation (May 13-14, 2003)
Sandia National Laboratories
4/14/03 2 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
H2 storage is a critical enabling technology for H2 use as an energy carrier
The low volumetric density of gaseous fuels requires a storage method which compacts the fuel. Hence, hydrogen storage systems are inherently more complex than liquid fuels.Storage technologies are needed in all aspects of hydrogen utilization.
productiondistributionutilization
How do we achieve safe, efficient and cost-effective hydrogen storage?
4/14/03 3 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Hydrogen storage development offers many scientific and technical challenges
Fundamental studies are needed to explore new storage conceptsThere is intense interest in new storage concepts by industry
research is closely coupled to applied and developmental areas
Research areas include:materials sciencechemical sciencesadvanced analytical techniquesfundamental modeling and simulation
4/14/03 4 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Outline
Storage properties needed in different applications
Energy densities available from fuels
Current options for storing hydrogengasliquidsolidchemical hydride systems (non-reversible)
Where do we go from here?
reversible
4/14/03 5 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Different applications have different hydrogen storage requirements
Onboard storage (vehicles)FreedomCAR targets based on market needs
Forecourt storage (refueling stations)requirements being developed (IHIG)
Distribution storage (delivery trucks)high capacity, compact
Production storage (onsite)very large quantities
These are also interrelatede.g., onsite liquefaction LH2 delivery LH2 forecourt LH2 onboard
4/14/03 6 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Example forecourt requirements
Total hydrogen <50 teSystem volume <20 m3/teTemperature range -40/60° CDelivery flow rate >1 kg/minResponse time (0-90%) 30 secHydrogen purity 99.9Cycle life (fills) 10,000Calendar life 15 yearsCost tbd (US$/te H2)Permeation loss <1 scc/hr/l
Note that there is no weight requirement!
4/14/03 7 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Outline
Storage properties needed in different applicationsStorage properties needed in different applicationsStorage properties needed in different applications
Energy densities available from fuels
Current options for storing hydrogenCurrent options for storing hydrogenCurrent options for storing hydrogen••• gasgasgas••• liquidliquidliquid••• solidsolidsolid••• chemical hydride systems (nonchemical hydride systems (nonchemical hydride systems (non---reversible)reversible)reversible)
Where do we go from here?Where do we go from here?Where do we go from here?
reversiblereversiblereversible
4/14/03 8 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Specific energy of fuels (LHV)
120
3024 22 21 20 20 19 19 18 16 15 17
0
2024 25 25 26 25 26 25 26
11 5
0
25
50
75
100
125
hydrogen
methan
e
ethan
epropan
e
butane
pentan
ehex
ane
heptan
e
octane (
gasolin
e)ce
tane (
diesel)
ethan
olmeth
anol
ammonia
Ener
gy D
ensi
ty M
J/kg
carbonhydrogen
25 - 12 wt.%
4/14/03 9 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Energy densities (LHV) for fuels in liquid state
14 13 13 13 13 12 12 11 12 13 12 129
1113
2018 18 17 16 15
1212 9 8
4
0
10
20
30
40
cetan
e (dies
el)
octane (
gasolin
e)hep
tane
hexan
epen
tane
butane
ethan
epropan
eeth
anol
methan
emeth
anol
ammonia
liq. h
ydrogen
hydrid
ewate
r
Ener
gy D
ensi
ty (M
J/lit
er)
carbon
hydrogen
Hydrogen density range
4/14/03 10 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Energy densities (LHV) for fuels in liquid state
14 13 13 13 13 12 12 11 12 13 12 129
1113
2018 18 17 16 15
1212 9 8
4
0
10
20
30
40
cetan
e (dies
el)
octane (
gasolin
e)hep
tane
hexan
epen
tane
butane
ethan
epropan
eeth
anol
methan
emeth
anol
ammonia
liq. h
ydrogen
hydrid
ewate
r
Ener
gy D
ensi
ty (M
J/lit
er)
carbon
hydrogen
Hydrogen density range
4/14/03 11 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Outline
Storage properties needed in different applicationsStorage properties needed in different applicationsStorage properties needed in different applications
Energy densities available from fuelsEnergy densities available from fuelsEnergy densities available from fuels
Current options for storing hydrogen• gas• liquid• solid• chemical hydride systems (non-reversible)
Where do we go from here?
reversible
Where do we go from here?Where do we go from here?
4/14/03 12 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Reversible Hydrogen Storage Systems
4/14/03 13 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Compressed gas offers a straightforward H2 storage method
2.7 MJ/L
4.7 MJ/L
350 bar 700 bar
Compressed Gas Storage Density (300 K, LHV)
0
1
2
3
4
5
0 2000 4000 6000 8000 10000
Pressure (psi)
Ener
gy D
ensi
ty (M
J/lit
er)
4/14/03 14 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Composite tanks are robust and lightweight
Carbon fiber wrap/polymer liner tanks are lightweight and commercially available.
weight specific energy6 wt.% 7.2 MJ/kg7.5 wt.% 9.0 MJ/kg10 wt.% 12 MJ/kg
Energy density is the issue:
pressure gas density system density350 bar 2.7 MJ/L 1.95 MJ/L700 bar 4.7 MJ/L 3.4 MJ/L
4/14/03 15 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Liquid hydrogen storage requires cryogenic systems
Equilibrium temperature at 1 bar for liquid hydrogen is ~20 K.
Estimated storage densities1
Berry (1998) 4.4 MJ/literDillon (1997) 4.2 MJ/literKlos (1998) 5.6 MJ/liter
Issues with this approach are:dormancy.energy cost of liquefaction.
1 J. Pettersson and O Hjortsberg, KFB-Meddelande 1999:27
4/14/03 16 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Liquid Hydrogen EOS
0
100
200
300
400
500
600
20 30 40 50 60 70 80 90 100
Temperature K
Pres
sure
bar
High pressure cryogenic tank can reduce temperature requirements
S. Aceves, et al 2002
Estimated energy density: 4.9 MJ/L (Berry 1998)
4/14/03 17 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Another option is to chemically bond hydrogen in a solid material
This storage approach should have the highest hydrogen packing density
However, the storage media must meet certain requirements
Reversible hydrogen uptake/releaseLightweight with high capacity for hydrogenRapid kinetic propertiesEquilibrium properties (P,T) consistent with near ambient conditions
4/14/03 18 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Renewed interest in complex hydrides
Complex hydrides consist of a H=M complex with additional bonding element(s)Reversibility demonstrated in NaAlH4
By Bogdanovic and Schwickardi (1996)Hydrogen complexes include
(AlH4) – (alanates)(BH4) – H with Group VIII elements
Advantages:Can have lower formation energyCan have high H/M.
173 complex hydrides listed on hydpark.ca.sandia.gov
Al
H
4/14/03 19 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Total hydrogen content of somealanates
0 2 4 6 8 10 12
weight percent hydrogen
Sn(AlH4)4
Ce(AlH4)3
Zr(AlH4)4
In(AlH4)3
Ti(AlH4)4
CsAlH4
Ga(AlH4)3
Ti(AlH4)3
AgAlH4
Fe(AlH4)2
Mn(AlH4)2
Ca(AlH4)2
CuAlH4
Mg(AlH4)2
Na2LiAlH6
Be(AlH4)2
KAlH4
NaAlH4
LiAlH4
incr
easi
ng m
ol. w
eigh
t
4/14/03 20 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Issues with complex hydrides
ReversibilityRole of catalyst or dopant.
ThermodynamicsPressure, temperature.
KineticsLong-range transport of heavy species
Capacity
Only NaAlH4 has been studied in detail to date.- theoretical reversible capacity 5.5 wt.%- ~ 4-4.5 wt.% demonstrated
4/14/03 21 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Carbon materials offer an alternative approach to high density storage
Hydrogen adsorbs on carbon surfaces.liquid hydrogen density on surface. Van der Waals bonding (~6 kJ/mol).very high surface area needed to achieve sufficiently high packing density.
There are unique carbon structures with high surface area:
fullerenes.activated carbon.nanotubes.. . .
Smalley 1996
4/14/03 22 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Chemical hydrogen storage(regenerated off board)
hydrogen
process(rehydride)
extract hydrogen oxidize fuel
energy
energy
H2O
hydrogenhydride
Spent fuel
processH20, CH4
energy
CHEMICALHYDRIDESYSTEM
process oxidize fuel
H2O
H20, CH4
hydrogenenergy
energyREVERSIBLEHYDROGEN
SYSTEM
Need a low cost,low energy process
More infrastructure
4/14/03 23 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Where do we go from here?
Compressed gas greater than 700 bar (10,000 psi)Conformable tanksMicrospheres
Cryogenic storageImproved thermal management• Latency• Reduced weight, volume
High pressure cryogenicNew solid state or liquid systems
New materialsNonthermal systems
4/14/03 24 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Advanced concepts discussed at H2storage workshop in August 2002
Crystalline Nanoporous MaterialsSelf-Assembled NanocompositesInorganic – Organic CompoundsBN NanotubesHydrogenated Amorphous CarbonMesoporous materialsAdvanced HydridesBulk Amorphous Materials (BAMs)Nanosize powdersIron HydrolysisHydride AlcoholysisPolymer MicrospheresMetallic Hydrogen
adsorbed hydrogen(surface)
absorbed hydrogen(bulk)
chemical system(nonreversible)
compressed gas?
4/14/03 25 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
High H capacity compounds
ammonia-borane complex(A. T-Raissi, 2002 APR. Golden, CO)
H3BNH3(l) H2BNH2(s) + H2(g) 6.49 wt.%∆H=-21.7
kJ/molxH2BNH2(s) (H2BNH2)x(s) (polymerizes)
(H2BNH2)x(s) (HBNH)x(s) + xH2(g) 6.94 wt.%13.43 wt.%total
(HBMNH)x borazine + others BN + H2 (>500° C)
Can this system be modified for reversibility?
4/14/03 26 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Summary of energy densities
2005targets
2010targets
2015 targets
Fuels specific energy range
Fuels energy density range
0
5
10
15
0 5 10 15 20 25Specific Energy (MJ/kg)
Ener
gy D
ensi
ty (M
J/L)
liquidhydrogen
compressedgas
cryogenic
Na alanate nanotubes
hydrides
This improvement took 20 years!
gasolinehydrogencontent
4/14/03 27 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Outlook
Better understanding of reaction mechanismsFundamental studies aid development of advanced materials
Kinetics must be improvedAdvanced catalysts and doping procedures
Second reaction plateau pressure must be increasedElemental substitution
Effects of contamination must be investigated Further investigation into capacity loss
Reversibility in other complex hydrides must be demonstratedLi-alanates, Mg-alanates
Safety issues must be evaluated and addressedEngineering design and materials modification
4/14/03 28 Sandia National LaboratoriesFrom George Thomas, BES workshop 5/13/03
Special Acknowledgement
Steve GoodsKarl Gross
Weifang LuoEric MajzoubDon Meeker
Andreas OrozcoVidvuds OzolinsBrian SomerdayGary SandrockScott Spangler
Ken StewartSteve ThomasNancy Yang