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

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 discovermagazine.com

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

Hydrogen as an energy source Fuel for internal combustion engines www.global-hydrogen-bus-platform.com Fuel cells www.evworld.com

Hydrogen internal combustion engines www.london.gov.uk Honda Cadillac

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

The hydrogen economy

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 National Hydrogen Association Department of Energy Hydrogen & Fuel Cells Fuel Cells and Hydrogen Joint Undertaking Hawai’I Hydrogen Initiative Linde Group Hydrogen Initiative Duke Energy Hydrogen Initiative

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!