Energy News  





. New Fuel Cell Design Adds Better Control While Reducing Complexity

The first applications of the new design would be for small machines such as lawn mowers and scooters
by Staff Writers
Princeton NJ (SPX) Jan 19, 2007
When Princeton University engineers want to increase the power output of their new fuel cell, they just give it a little more gas - hydrogen gas, to be exact. This simple control mechanism, which varies the flow of hydrogen fuel to control the power generated, was previously thought impossible and is a potentially major development in fuel cell technology.

The secret of their success is a system in which the fuel input itself changes the size of the reaction chamber, and therefore the amount of power produced. The breakthrough design also adds to the understanding of water management in fuel cells - one of the major obstacles to large-scale deployment of the technology in automobiles.

"It's almost so simple that it shouldn't work, but it does," said Jay Benziger, a Princeton professor of chemical engineering. Benziger developed the technique with Claire Woo, who graduated from Princeton in 2006 and is now pursuing a Ph.D. at the University of California, Berkeley. They will publish their findings in the February issue of the journal Chemical Engineering Science.

The first applications of their design are likely to be in small machines such as lawn mowers, the researchers said. The machines would be easy to use, incorporating a design similar to the familiar acceleration systems of cars that use a pedal to increase the flow of fuel and the power output. More important, Benziger said, the use of fuel cells in lawn care equipment would cut down on a major source of greenhouse gases, especially as emissions from these machines are not currently regulated.

At the most basic level, all fuel cells work by combining hydrogen with oxygen in a reaction that generates electricity, water and heat. In the Princeton system, some of the water produced as a by-product collects in a layer at the bottom of the reaction chamber, while the rest drains to an external tank. By varying the height of the water level in the chamber, Benziger and Woo are able to enlarge or shrink the reaction chamber.

For example, an increased flow of hydrogen into the chamber pushes more water out of the system, lowering the water level and increasing the space available for the reaction to take place. Similarly, a decreased flow of hydrogen causes the pressure inside the chamber to drop, drawing some of the water from the tank back into the system and shrinking the reaction chamber.

The water at the bottom of the chamber also serves to maintain the needed humidity for the fuel cell reaction to take place. This patented "auto-humidifying" design demonstrates an innovative use for the water produced during the reaction, which causes problems in most fuel cell designs.

Conventional fuel cells feature a complicated network of serpentine channels to combine the gases, maintain the appropriate humidity levels and eliminate water from the system. Often, droplets of water clog the narrow channels, leading to inefficient and irregular power production. The Princeton system mixes the gases via diffusion in a simple reaction chamber and relies on gravity to drain the water produced.

Benziger and Woo's reaction chamber is effectively sealed by the water at the bottom of the tank. By preventing fuel from leaving the system, this design ensures that the gases remain in the reaction chamber until they combine.

Most traditional fuel cells repeatedly run hydrogen and oxygen through an open reaction chamber, converting only about 30 to 40 percent of the fuel at each pass. Since the Princeton system is closed, 100 percent of the fuel can be used with no need for a large and expensive fuel recycling system.

Community
Email This Article
Comment On This Article

Related Links
Princeton University, Engineering School
Civil Nuclear Energy Science, Technology and News
Powering The World in the 21st Century at Energy-Daily.com
Our Polluted World and Cleaning It Up
China News From SinoDaily.com
Global Trade News
The Economy
All About Solar Energy at SolarDaily.com
Powering The World in the 21st Century at Energy-Daily.com




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Canada's New Government Launches EcoEnergy Technology Initiative
Ottawa, Canada (SPX) Jan 19, 2007
The Honourable Gary Lunn, Minister of Natural Resources, and the Honourable John Baird, Minister of the Environment, today announced the ecoEnergy Technology Initiative--a $230-million investment in the research, development and demonstration of clean-energy technologies.

.
Get Our Free Newsletters Via Email
  



  • Canada's New Government Launches EcoEnergy Technology Initiative
  • New Fuel Cell Design Adds Better Control While Reducing Complexity
  • Survey Shows Strong Support For Offshore Wind Power
  • Dynamotive Launches Higher Energy Content Renewable Biofuel For Industry

  • Zapatero Pins Faith In Renewable Energy Amid Nuclear Debate
  • Nuclear Waste Land
  • Most Germans Oppose Nuclear Power Phase-Out
  • Iran To 'Honor Principles' Of Nuclear Control Treaty

  • U.S. wood-fired boilers cause concern
  • Climate Change Affecting Outermost Atmosphere Of Earth
  • TIMED Celebrates 5-Year Anniversary
  • Steering Clear Of Icy Skies

  • Sweden's Tree Line Moving At Fastest Rate For 7,000 Years
  • Soil Nutrients Shape Tropical Forests, Large-Scale Study Indicates
  • Health Of Brazilian Rainforest Depends On Dust From One Valley In Africa
  • Forests Can Also Raise Temperature Of Earth

  • California Fruit Crops Devastated By Freeze Says Schwarzenegger
  • California's Big Freeze Threatening Citrus Crops
  • 150,000 Trout Killed At Fish Farm In Storm Off Norway
  • Clear Strong Guidelines Needed For Marine Aquaculture

  • When Will Russian Cars Go To Detroit
  • New Battery Era Fires Up GM
  • What Will Russians Drive In 2010
  • Chinese Carmakers Head West

  • Operational Testing And Evaluation Of Guardian Commercial Airline Anti-Missile System Begins
  • USGS Examines Environmental Impacts Of Aircraft De-Icers
  • China Gives Rare Glimpse Of Homegrown Jet Fighter
  • IATA Gives Cautious Welcome To EU Emissions Trading Plan

  • Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear
  • NASA plans to send new robot to Jupiter
  • Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission
  • Boeing Selects Leader for Nuclear Space Systems Program

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement