Hydrogen Energy: An Overview

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Hydrogen Energy An Overview

• Kenneth M. Klemow, Ph.D.
• Wilkes University

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(No Transcript)
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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

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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

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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

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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

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Primary industrial uses of hydrogen

• Create ammonia
• 3 H2 N2 ? 2 NH3
• Cracking of high molecular weight hydrocarbons to
  form low m.w. hydrocarbons

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Hydrogen as an energy source
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Hydrogen internal combustion engines
Honda
Cadillac
London Olympics
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Hydrogen fuel cells
Animation
www.next-generation.ca
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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.

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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

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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

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The hydrogen economy
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Elements of the hydrogen economy

• Hydrogen generation
• Centralized
• Distributed
• Hydrogen storage
• Hydrogen distribution

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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

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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

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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

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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

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www.sciencedaily.com
Pellet of ammonia borane weighting 240mg. Can
store 0.5 L of hydrogen in small volume.
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So, is hydrogen power the answer to our energy
concerns?

• You tell me!