Sustainable Energy Science and Engineering Center
Hydrogen Storage
Sustainable Energy Science and Engineering Center
Main Energy Storage Market Segments
1. Utility/industrial applications including: grid
reinforcement,
renewables integration and uninterruptible power supply (UPS)
Applications
2. Transport / mobile applications including: on-board power
for vehicles, new drive trains (electric and hybrid electric
vehicles) and leisure applications (caravanning)
3. Portable applications including: computing, cell-phones
and cameras (the 3 ‘C’s’).
Source: Ian Edwards, ITI Energy, May 24th, 2005
Sustainable Energy Science and Engineering Center
Generic Storage Systems
Electrochemical systems
batteries and flow cells
Mechanical systems
fly-wheels and compressed air energy storage (CAES)
Electrical systems
super-capacitors and superconducting magnetic energy storage (SMES)
Chemical systems
hydrogen cycle (electrolysis -> storage -> power conversion)
Thermal systems
sensible heat (storage heaters) and phase change
Source: Ian Edwards, ITI Energy, May 24th, 2005
Sustainable Energy Science and Engineering Center
Potential Fuel
Energy Sources
Typical Chemical Energy Density
Hydrogen
Ethanol
Ammonia
Automotive Gasoline
Methane
Methanol
142.0 MJ/kg
29.7 MJ/kg
17.0 MJ/kg
45.8 MJ/kg
55.5 MJ/kg
22.7 MJ/kg
(Source: Chemical Energy, The Physics Hyper text Book)
Sustainable Energy Science and Engineering Center
Energy Density
Fuel
Typical Stored Chemical
Energy Density
Hydrogen
Ethanol
Ammonia
Automotive Gasoline
Methane
Methanol
7.1 MJ/kg
26.7 MJ/kg
13.6 MJ/kg
41.2 MJ/kg
44.5 MJ/kg
20.4 MJ/kg
@ 5wt%
@ 90wt%
@ 80wt%
@ 90wt%
@ 80wt%
@ 90wt%
Source: Ian Edwards, ITI Energy, May 24th, 2005
Sustainable Energy Science and Engineering Center
Energy Densities
Fuel
Hydrogen weight Ambient state Liquid volumetric
fraction
energy density(MJ/L)
Hydrogen
Methane 0.25
Ethane
Propane
Ammonia
Gasoline
Ethanol
Methanol
1
Gas
0.2
0.18
0.18
0.13
0.12
8.4-10.43 120
21(17.8)2 50 (43)2
Gas
23.7
Gas (liquid)1
22.8
Gas (liquid)1
13.1
0.16
Liquid
31.1
Liquid
21.2
Liquid
15.8
Mass energy
density (MJ/kg)
Gas
47.5
46.4
17.0
44.4
26.8
19.9
1
A gas at room temperature, but normally stored as a liquid at moderate pressure.
The larger values are for pure methane. The values in parentheses are for a “typical” Natural Gas.
3 The higher value refers to hydrogen density at the triple point
2
Source: Ian Edwards, ITI Energy, May 24th, 2005
Sustainable Energy Science and Engineering Center
Energy Density in wh/liter
Material
Volumetric
Gravimetric
Diesel
10942 Wh/l
13762Wh/kg
Gasoline
9,700 Wh/l
12,200 Wh/kg
LNG
7,216 Wh/l
12,100 Wh/kg
Propane
6,600 Wh/l
13,900 Wh/kg
Ethanol
6,100 Wh/l
7,850 Wh/kg
Methanol
4,600 Wh/l
6,400 Wh/kg
Liquid H2
2600 Wh/l
39,000 Wh/kg
150 Bar H2
405 Wh/l
39,000 Wh/kg
Lithium
250 Wh/l
350 Wh/kg
Nickel Metal Hydride
100 W·h/L
60Wh/kg
Lead Acid Battery
40 Wh/l
25 Wh/kg
Compressed Air
17 Wh/l
34 Wh/kg
Sustainable Energy Science and Engineering Center
Objective
To achieve adequate stored energy in an efficient, safe and
cost effective system.
Gravimetric storage density: the gravimetric storage density is the weight of the
hydrogen being stored divided by the weight of the storage and delivery system
proposed
Source: Oak Ridge National Laboratory Hydrogen Storage Work Shop, May 2003
Sustainable Energy Science and Engineering Center
Energy Storage
1970
1980
1990
2000
2010
Source: Ian Edwards, ITI Energy, May 24th, 2005
2020
Sustainable Energy Science and Engineering Center
Hydrogen Storage
Hydrogen pellets
Mg(NH3)6Cl2
1970
1980
1990
2000
2010
Source: Ian Edwards, ITI Energy, May 24th, 2005
2020
Sustainable Energy Science and Engineering Center
Technology Status
Sustainable Energy Science and Engineering Center
Storage Methods
Sustainable Energy Science and Engineering Center
Specific energy of fuels (LHV)
125
0
carbon
hydrogen
Energy Density MJ/kg
100
75
120
50
20
24
25
25
26
25
26
25
26
25
30
24
22
21
20
20
19
19
18
11
5
16
15
17
he
xa
ne
he
oc
pt
ta
an
ne
e
(g
as
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ce
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ta
ne
(d
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ha
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n
0
Sustainable Energy Science and Engineering Center
Energy Densities (LHV) in Liquid state
40
carbon
Energy Density (MJ/liter)
hydrogen
30
Hydrogen
density range
20
18
18
17
20
16
15
12
12
9
8
4
10
14
13
13
13
13
12
12
11
12
13
12
12
11
13
9
ne
oc
ta
ce
ta
ne
w
at
er
(d
ie
se
l)
(g
as
ol
in
e)
he
pt
an
e
he
xa
ne
pe
nt
an
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bu
ta
ne
et
ha
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pr
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m
et
ha
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m
et
ha
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on
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.h
ia
yd
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0
Sustainable Energy Science and Engineering Center
Compressed Gas
5
Energy Density (MJ/liter)
Compressed Gas Storage Density
(300 K, LHV)
Gasoline: 13 MJ/L
4
3
2
1
700 bar
350 bar
0
0
2000
4000
6000
Pressure (psi)
8000
10000
Sustainable Energy Science and Engineering Center
Compressed Gas
•
•
•
increased pressure (>700 bar)
– stronger, lighter composite tanks (cost)
– hydrogen permeation
– non-ideal gas behavior
conformable tanks
– maximum volume gain ~20% (cylind./rect. volumes)
– some increase in weight
microspheres
– multiple shell volumes
– close-packed packing density ~60% of volume
– hydrogen release/reload mechanism
Sustainable Energy Science and Engineering Center
Compressed Gas Cylinders
Carbon fiber wrap/polymer liner tanks
are lightweight and commercially
available.
weight
6 wt.%
7.5 wt.%
10 wt.%
specific energy
7.2 MJ/kg
9.0 MJ/kg
12 MJ/kg
Energy density is the issue:
Pressure
350 bar
700 bar
Gas density
2.7 MJ/L
4.7 MJ/L
System density
1.95 MJ/L
3.4 MJ/L
Sustainable Energy Science and Engineering Center
High Pressure Cryogenic Tank
600
Liquid Hydrogen EOS
Pressure bar
500
400
300
200
100
S. Aceves, et al 2002
0
20
30
40
50
60
70
80
90
100
Temperature K
• reduces temperature requirements
• eliminates liquifaction requirement
• essentially eliminates latency issue
Estimated energy density:
4.9 MJ/L (Berry 1998)
Sustainable Energy Science and Engineering Center
Liquid Storage
Requires cryogenic systems
•
•
•
Equilibrium temperature at 1 bar for liquid hydrogen is ~20 K.
Estimated storage densities1
Berry (1998)
4.4 MJ/liter
Dillon (1997)
4.2 MJ/liter
Klos (1998)
5.6 MJ/liter
Issues with this approach are:
– dormancy.
– energy cost of liquifaction.
1
J. Pettersson and O Hjortsberg, KFB-Meddelande 1999:27
Sustainable Energy Science and Engineering Center
Gaseous Hydrogen Storage
Hydride storage of
hydrogen may be
compared to the
compression of
hydrogen
Higher Heating value of
Hydrogen: 142 MJ/kg
1970
1980
Source: The Future of Hydrogen Economy: Bright or Bleak?
Baldur Eliasson and Ulf Bossel, ABB Switzerland Ltd.
1990
2000
2010
2020
Sustainable Energy Science and Engineering Center
Hydrogen Storage - Liquefaction
Total energy requirement for
liquefaction of 1 kg of H2
1970
1980
Source: The Future of Hydrogen Economy: Bright or Bleak?
Baldur Eliasson and Ulf Bossel, ABB Switzerland Ltd.
1990
2000
2010
2020
Sustainable Energy Science and Engineering Center
Hydrogen Delivery - Pipelines
1970
1980
Source: The Future of Hydrogen Economy: Bright or Bleak?
Baldur Eliasson and Ulf Bossel, ABB Switzerland Ltd.
1990
2000
2010
2020
Sustainable Energy Science and Engineering Center
Hydrides
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/release
– lightweight with high capacity for hydrogen
– rapid kinetic properties
– equilibrium properties (P,T) consistent with near ambient
conditions.
Two solid state approaches
– hydrogen absorption (bulk hydrogen)
– hydrogen adsorption (surface hydrogen)
including cage structures
Sustainable Energy Science and Engineering Center
Hydrides
Sustainable Energy Science and Engineering Center
Alanates
Sustainable Energy Science and Engineering Center
Complex Hydrides
Sustainable Energy Science and Engineering Center
Hydrogen Storage Volume
Sustainable Energy Science and Engineering Center
Hydrogen System Weight
Sustainable Energy Science and Engineering Center
Future
Sustainable Energy Science and Engineering Center
US DOE Strategy
Sustainable Energy Science and Engineering Center
US DOE Strategy
Sustainable Energy Science and Engineering Center
Complex Hydrides
Sustainable Energy Science and Engineering Center
Complex Hydrides
Source: Ali T. Raissi, FSEC
Sustainable Energy Science and Engineering Center
Fuel Tank Problem
Sustainable Energy Science and Engineering Center
Current Status
Sustainable Energy Science and Engineering Center
Compressed Gas System Requirements
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Storage System Requirements
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Improvements
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US DOE Targets
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US DOE Strategy
Sustainable Energy Science and Engineering Center
FCEV Storage System
Comparative Volumes and Weights
of a FCEV Hydrogen Storage System
(Capable of 560 km (350 mi) Range – Compact Sedan)
800
700
Liters
kg
600
500
L ite rs
kg
400
300
200
100
0
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Sustainable Energy Science and Engineering Center
LH2 Tank Configuration
inner vessel
super insulation
outer vessel
level probe
filling line
gas extraction
liquid extraction
filling port
suspension
liquefied hydrogen
253°C)
safety valve
gaseous hydrogen
(+20°C up to +80°C)
shut off valve
electrical heater
reversing valve
(gaseous / liquid)
cooling water
heat exchanger
Sustainable Energy Science and Engineering Center
Storage Systems
System
Weight
System
Volume
Extraction
Complexity
System
Cost
Fuel
Cost
Dormancy
Compressed
Gas (5,000 psi)
Cryogenic
Liquid H2
Cryo - Liquid
Compressed H2
Rechargeable
Metal Hydride
Carbon
Adsorbtion
Chemical Hydride
Good
Acceptable
Problem
Safety