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Hydrogen Energy: An Overview. Kenneth M. Klemow, Ph.D. Wilkes University. www.rise.org.au. www.inl.gov/. www.fuelcellstocks.com. Points to be covered. Some hydrogen chemistry Hydrogen as an energy source Producing hydrogen Benefits of hydrogen as an alternative fuel
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Hydrogen Energy: An Overview Kenneth M. Klemow, Ph.D. Wilkes University
www.rise.org.au www.inl.gov/ www.fuelcellstocks.com
Points to be covered • Some hydrogen chemistry • Hydrogen as an energy source • Producing hydrogen • Benefits of hydrogen as an alternative fuel • Hydrogen power initiatives • Disadvantages of hydrogen • The WebQuest
discovermagazine.com Some hydrogen chemistry • Lightest element (consists of only one proton and one) electron • Isotopes include one or more neutrons • Most abundant element in universe (75% by mass) • Component of most stars; as plasma
Hydrogen on earth • Easily reacts with most other elements, particularly oxygen, carbon, nitrogen, most metals. • Carbon-hydrogen compounds are basis of organic chemistry. • Basis of acid-base reactions. • Occurs in diatomic form in atmosphere • At typical temperatures and pressures, H2 is a gas. • Rare (ca. 1 ppm) due to ease of escape
Molecular hydrogen is combustible • 2 H2(g) + O2 (g) → 2 H2O(l) • H = -286 kJ/mol • Burns at concentrations as low as 4%. • Produces flame visible only in UV spectrum
Primary industrial uses of hydrogen • Create ammonia • 3 H2 + N2 → 2 NH3 • Cracking of high molecular weight hydrocarbons to form low m.w. hydrocarbons
Fuel for internal combustion engines Fuel cells www.evworld.com www.global-hydrogen-bus-platform.com Hydrogen as an energy source
www.london.gov.uk Hydrogen internal combustion engines Honda Cadillac London Olympics
Hydrogen fuel cells Animation www.next-generation.ca
Have many kinds of fuel cells • Proton Exchange Membrane (PEM) • Run at low temperatures, used in automotive applications • Solid Oxide Fuel Cells • Use ceramic electrolyte, central generating stations • Alkaline Fuel Cells • Long used by NASA in spacecraft • Regenerative fuel cells • Self contained, uses water and sunlight • Microbial fuel cells • Use bacteria and yeast under anaerobic cond.
How is hydrogen produced? • Reacting metals with acids • Zn + 2 H+ → Zn2+ + H2 • Processing hydrocarbons • CH4 + H2O → CO + 3 H2 • H = +191.7 kJ/mol • Hydrolysis of water • 2H2O(l) → 2H2(g) + O2(g) • G = +474.4 kJ/mol
Commercial hydrogen production • As a byproduct of coal gasification and natural gas processing • Through use of electricity generated by burning fossil fuels, nuclear, solar, hydropower, geothermal, wind
Elements of the hydrogen economy • Hydrogen generation • Centralized • Distributed • Hydrogen storage • Hydrogen distribution
Benefits of hydrogen as a fuel • Hydrogen exists in an unlimited supply • Hydrogen is renewable • Hydrogen is clean-burning • Water is main byproduct • No carbon dioxide released into air • Hydrogen weighs less and generates more power than hydrocarbon-based fuels. • Hydrogen burns faster and at a lower temperature than conventional gasoline
The vision • Convert vehicles to hydrogen power • Establish extensive distribution system for hydrogen • Produce massive amounts of hydrogen • No worries about carbon if using nuclear, wind, geothermal, hydropower • Use carbon sequestration techniques if using fossil fuels
Initiatives • Hydrogen.gov • Minnesota Renewable Hydrogen initiative • National Hydrogen Association • BP and GE Hydrogen initiative • Icelandic Hydrogen Energy • Germany Clean Energy partnership • Japan Hydrogen and Fuel Cell demo project
Disadvantages of hydrogen power • Hydrogen is difficult to contain; tanks are bulky • Hydrogen reacts with metal in tanks causing them to become brittle • Hydrogen is explosive, can be unsafe • Fuel cells are expensive, especially due to platinum catalysts • Hydrogen is an energy carrier; have inherent inefficiencies in generation. • Production via fossil fuel combustion still releases carbon dioxide - large scale sequestration may not be feasible. • Establishing distribution facility will cost trillions of dollars
www.sciencedaily.com Pellet of ammonia borane weighting 240mg. Can store 0.5 L of hydrogen in small volume.
So, is hydrogen power the answer to our energy concerns? You tell me!