A Hydrogen Economy Dr. Mazen Abualtayef Environmental Engineering Department Islamic University of Gaza, Palestine Adapted from a presentation by Professor S.R. Lawrence, Leeds School of Business, Environmental Studies, University of Colorado, Boulder, CO, USA
Agenda 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
The Hydrogen H 2 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 Waste product of burning H 2 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 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% Oil 30% Natural Gas 48%
How is Hydrogen Produced? Reforming fossil fuels Heat hydrocarbons with steam Produce H 2 and CO Electrolysis of water Use electricity to split water into O 2 and H 2 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 (H 2 O) reacts with methane (CH 4 ) CH 4 + H 2 O CO + 3 H 2-191.7 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 + H 2 O CO 2 + H 2 + 40.4 kj/mol Oxygen (O) atom stripped from steam Oxidizes the carbon (C) Liberates hydrogen bound to C and O 2
Hydrogen Steam Reforming Plants
Electrolysis of Water (H 2 O) 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 H 2 has low energy density per volume Requires large tanks to store H 2 can be compressed to reduce volume Requires heavy, strong tanks H 2 can be liquefied to reduce volume Both compression and liquefaction require a lot of energy
Ammonia Storage H 2 can be stored as ammonia (NH 3 ) 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
Transporting Hydrogen
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 Weight of steel tank Weight of carbon fiber tank Volume of tank contents Volume of tank Typical 18 wheel truck (diesel) Typical sedan (gasoline) 1175 lb (small) NA 22.5 feet 3 24.0 feet 3 108 lb (small) NA 2.25 feet 3 2.5 feet 3 Truck converted to ICE hydrogen 313 lb 31,300 lb 6,960 lb 67.5 feet 3 157 feet 3 Sedan converted to hydrogen fuel cell 17.4 lb 1740 lb 387 lb 4 feet 3 9 feet 3 http://planetforlife.com/h2/h2swiss.html
Problems with Hydrogen
Environmental Concerns 48% of hydrogen made from natural gas Creates CO 2 a greenhouse gas Hydrogen H 2 inevitably leaks from containers Creates free radicals (H) in stratosphere due to ultraviolet radiation Could act as catalysts for ozone depletion
Hydrogen vs. Methane Units Hydrogen Methane Density kg/m 3 0.0887 0.707 Gravimetric Energy MJ/kg 142.0 55.6 Volumetric Energy MJ/m 3 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
Hydrogen Energy Losses Windmills generate electricity. Electricity converted to H 2 70% efficiency. H 2 compressed for pumping 20% energy loss H 2 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
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 Waste product of burning H 2 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 Low energy densities Difficulty in handling, storage, transport Requires an entirely new infrastructure Creates CO 2 if made from fossil fuels Low net energy yields Much energy needed to create hydrogen