Transcript Hydrogen Economy

A Hydrogen Economy
Agenda
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A Hydrogen Vision of the Future
Hydrogen Systems
Producing Hydrogen
Storing and Transporting Hydrogen
Hydrogen Fueled Transport
Problems with Hydrogen
The Promise of Hydrogen
Hydrogen Summary
A Vision of a Hydrogen Future
"I believe that water will one day be employed as
fuel, that hydrogen and oxygen which constitute
it, used singly or together, will furnish an
inexhaustible source of heat and light, of an
intensity of which coal is not capable. I believe
then that when the deposits of coal are
exhausted, we shall heat and warm ourselves
with water. Water will be the coal of the future."
Jules Vernes (1870) L´île mystérieuse
The Hydrogen H2 Molecule
http://planetforlife.com/h2/index.html
Hydrogen Economy Schematic
Hydrogen Economy in Hong Kong
http://www.gii.com.hk/eng/clean_energy.htm
Hydrogen Fueling Station
Hydrogen Systems
Hydrogen Energy Cycle
http://en.wikipedia.org/wiki/Hydrogen_economy
Hydrogen Production Cycle
Crabtree et al., “The Hydrogen Economy,” Physics Today, Dec 2004
Operating the Hydrogen Economy
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Hydrogen Economy Supply Chain
Hydrogen Pathways
http://www.ch2bc.org/index2.htm
Advantages of a Hydrogen Economy
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Waste product of burning H2 is water
Elimination of fossil fuel pollution
Elimination of greenhouse gases
Elimination of economic dependence
Distributed production
http://www.howstuffworks.com/hydrogen-economy.htm
Issues with Hydrogen
• Not widely available on planet earth
• Usually chemically combined in water
or fossil fuels (must be separated)
• Fossil fuel sources contribute to
pollution and greenhouse gases
• Electrolysis requires prodigious
amounts of energy
Technological Questions
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Where does hydrogen come from?
How is it transported?
How is it distributed?
How is it stored?
http://www.howstuffworks.com/hydrogen-economy.htm
Producing Hydrogen
Current Hydrogen Production
•Current hydrogen
production
•48% natural gas
•30% oil
•18% coal
• 4% electrolysis
•Global Production
•50 million tonnes / yr
•Growing 10% / yr
•US Production
•11 million tonnes / yr
Electrolysis
4%
Coal
18%
Natural Gas
48%
Oil
30%
How is Hydrogen Produced?
• Reforming fossil fuels
• Heat hydrocarbons with steam
• Produce H2 and CO
• Electrolysis of water
• Use electricity to split water into O2 and H2
• High Temperature Electrolysis
• Experimental
• Biological processes
• Very common in nature
• Experimental in laboratories
http://www.howstuffworks.com/hydrogen-economy.htm
Steam Reforming
• From any hydrocarbon
• Natural gas typically used
• Water (steam) and hydrocarbon mixed
at high temperature (700–1100 °C)
• Steam (H2O) reacts with methane (CH4)
• CH4 + H2O → CO + 3 H2 - 191.7 kJ/mol
• The thermodynamic efficiency
comparable to (or worse than) an
internal combustion engine
• Difficult to motivate investment in
technology
Carbon Monoxide Reforming
• Additional hydrogen can be recovered
using carbon monoxide (CO)
• low-temp (130°C) water gas shift reaction
• CO + H2O → CO2 + H2 + 40.4 kJ/mol
• Oxygen (O) atom stripped from steam
• Oxidizes the carbon (C)
• Liberates hydrogen bound to C and O2
Hydrogen Steam Reforming
Hydrogen Steam Reforming Plants
Electrolysis of Water (H2O)
http://www.gm.com/company/gmability/edu_k-12/9-12/fc_energy/make_your_own_hydrogen_results.html
Electrolysis of Water
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/electrol.html
Renewable Energy for Electrolysis
http://www.howstuffworks.com/hydrogen-economy4.htm
Biomass Electrolysis Module
http://www.nrel.gov/hydrogen/photos.html
High Temperature Electrolysis
• Electrolysis at high temperatures
• Use less energy to split water
http://en.wikipedia.org/wiki/Hydrogen_economy
Biological H2 Creation
•Nature has very
simple methods to
split water
•Scientists are
working to mimic
these processes in the
lab; then commercially
Crabtree et al., “The Hydrogen Economy,” Physics Today, Dec 2004
Storing & Transporting Hydrogen
Hydrogen Storage
• Storage a major difficulty with hydrogen
• H2 has low energy density per volume
• Requires large tanks to store
• H2 can be compressed to reduce volume
• Requires heavy, strong tanks
• H2 can be liquefied to reduce volume
• Boils at -423 °F (cryogenic)
• Requires heavily insulated, expensive tanks
• Both compression and liquefaction
require a lot of energy
Ammonia Storage
• H2 can be stored as ammonia (NH3)
• Exceptionally high hydrogen densities
• Ammonia very common chemical
• Large infrastructure already exists
• Easily reformed to produce hydrogen
• No harmful waste
• BUT
• Ammonia production is energy intensive
• Ammonia is a toxic gas
Metal Hydride Storage
• Metal hydrides can carry hydrogen
• Boron, lithium, sodium
• Good energy density, but worse than gas
• Volumes much larger than gasoline
• Three times more volume
• Four times heavier
• Hydrides can react violently with water
• Leading contenders
• Sodium Borohydride
• Lithium Aluminum Hydride
• Ammonia Borane
Alkali Prod. Energy vs. Instrinsic Energy
Energy needed to produce alkali metal hydrides relative to the
energy content of the liberated hydrogen.
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Transporting Hydrogen
Storing & Transporting Hydrogen
• Store and Transport as a Gas
• Bulky gas
• Compressing H2 requires energy
• Compressed H2 has far less energy than
the same volume of gasoline
• Store and Transport as a Solid
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Sodium Borohydride
Calcium Hydride
Lithium Hydride
Sodium Hydride
http://www.howstuffworks.com/hydrogen-economy.htm
Hydrogen Fueled Transport
Hydrogen-Powered Autos
Hydrogen-Powered Autos
http://planetforlife.com/h2/h2vehicle.html
Hydrogen-Powered Trucks
http://planetforlife.com/h2/h2vehicle.html
Hydrogen-Powered Aircraft
Hydrogen powered passenger aircraft with cryogenic tanks
along spine of fuselage. Hydrogen fuel requires about 4 times
the volume of standard jet fuel (kerosene).
http://planetforlife.com/h2/h2vehicle.html
http://aix.meng.auth.gr/lhtee/projects/cryoplane/
Hydrogen-Powered Rockets
http://planetforlife.com/h2/h2vehicle.html
Implications of Hydrogen Transport
Weight
of fuel
Typical 18 wheel
truck (diesel)
Weight
of steel
tank
Weight of
carbon
fiber tank
Volume of
tank
contents
Volume
of tank
1175 lb
(small)
NA
22.5 feet3
24.0
feet3
Typical sedan
(gasoline)
108 lb
(small)
NA
2.25 feet3
2.5 feet3
Truck converted
to ICE hydrogen
313 lb
31,300 lb
6,960 lb
67.5 feet3
157 feet3
Sedan converted
to hydrogen fuel
cell
17.4 lb
1740 lb
387 lb
4 feet3
9 feet3
http://planetforlife.com/h2/h2swiss.html
Problems with Hydrogen
Environmental Concerns
• 48% of hydrogen made from natural gas
• Creates CO2 – a greenhouse gas
• Hydrogen H2 inevitably leaks from
containers
• Creates free radicals (H) in stratosphere
due to ultraviolet radiation
• Could act as catalysts for ozone depletion
H2 Energy Densities
Crabtree et al., “The Hydrogen Economy,” Physics Today, Dec 2004
Energy Densities for Various Fuels
Higher Heating Value (HHV) is a measure of energy
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
H2 and Energy Density for Various Fuels
Hydrogen density and HHV energy content of ammonia
and selected synthetic liquid hydrocarbon fuels
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Hydrogen vs. Methane
Units Hydrogen Methane
Density
kg/m3
0.0887
0.707
Gravimetric Energy
MJ/kg
142.0
55.6
Volumetric Energy
MJ/m3
12.7
40.0
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Liquifaction Energy vs. Intrinsic Energy
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Hydrogen Storage Densities
Crabtree et al., “The Hydrogen Economy,” Physics Today, Dec 2004
Hydrogen Energy Losses
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Windmills generate electricity.
Electricity converted to H2 – 70% efficiency.
H2 compressed for pumping – 20% energy loss
H2 pumped long distance – 30% loss
• 65% loss to Europe from the Sahara).
• Loss at filling stations – assume 5%
• Loss in fuel cell – 50% (possibly only 40%)
• Combining losses → only 15-18% useful
electricity, or vehicle motor power
• 9.3% in the case of the Sahara
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Criticism of Hydrogen Economy
• Hydrogen economy idea does not work for multiple
reasons.
• No practical source of cheap hydrogen
• No good way to store hydrogen
• No good way to distribute hydrogen
• Problems with physical & chemical properties of
hydrogen
• Technology cannot change these facts.
• Compact / convenient future energy carrier needed
• Methane, ethane, methanol, ethanol, butane, octane,
ammonia, etc. are better energy carriers.
• Difficult to understand the enthusiasm for hydrogen
• Hydrogen does not solve the energy problem and it is a bad
choice for carrying energy.
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Elemental Hydrogen Economy
Elemental Hydrogen Economy based on the natural cycle of water.
Elemental hydrogen is provided to the user
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
Synthetic Liquid Hydrocarbon Economy
A Synthetic Liquid Hydrocarbon Economy may be based on the two natural
cycles of water and carbon dioxide. Natural and synthetic liquid hydrocarbons
are provided to the user.
Bossel et al., The Future of the Hydrogen Economy: Bright or Bleak?, Oct 28, 2004
http://www.oilcrash.com/articles/h2_eco.htm
The Promise of Hydrogen
UNIDO-ICHET Projection
UNITED NATIONS INDUSTRIAL DEVELOPMENT ORGANIZATION
INTERNATIONAL CENTRE FOR HYDROGEN ENERGY TECHNOLOGIES
http://www.unido-ichet.org/ICHET-transition.php
The Iceland Example
• Iceland committed to be the first hydrogen economy
• 2050 goal
• Will use geothermal resources to create hydrogen
• Power autos, buses, and fishing fleet with hydrogen
http://en.wikipedia.org/wiki/Hydrogen_economy
Hydrogen Summary
Advantages of a Hydrogen Economy
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Waste product of burning H2 is water
Elimination of fossil fuel pollution
Elimination of greenhouse gases
Elimination of economic dependence
Distributed production
The stuff of stars
http://www.howstuffworks.com/hydrogen-economy.htm
Disadvantages of Hydrogen
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Low energy densities
Difficulty in handling, storage, transport
Requires an entirely new infrastructure
Creates CO2 if made from fossil fuels
Low net energy yields
• Much energy needed to create hydrogen
• Possible environmental problems
• Ozone depletion (not proven at this point)
Extra Slides
Energy Density of Hydrogen
Current Uses of Hydrogen
Thermochemical Production
Problems with Hydrogen
Prospects for the Future
http://www.howstuffworks.com/hydrogen-economy.htm
The Hydrogen Vision