Monday, April 12, 2010

Hydrogen fuel cell

Hydrogen is contained in almost everything around us, but is rarely found in its pure form. Most of the time, it is bonded with other elements in compounds such as natural gas and water. Hydrogen has to be extracted from these compounds through a manufacturing process that adds energy to break the bonds that hold the compounds together.

A fuel cell converts fuel to power through an electrochemical energy conversion. Using fuel and oxygen from the air, it produces electricity, water and heat. Water – pure H2O – is the only waste product emitted when hydrogen is used as a fuel in a fuel cell. A fuel cell can generate power almost indefinitely, for as long as fuel is supplied. Plus, a fuel cell is modular and can be scaled up by adding more cells to power everything from cell phones to automobiles to entire buildings.



The Hydrogen Fuel Cell

A hydrogen fuel cell electrochemically combines hydrogen and oxygen to generate electricity, water and heat. There are no other emissions. Different types of fuel cells use different electrolytes with different electrochemical reactions occurring, but the overall reaction is the same.

The basic structure of a fuel cell consists of an electrolyte layer in contact with an anode and a cathode.

Typically, fuel is fed continuously to the anode and an oxidant (e.g., oxygen from air) is fed continuously to the cathode. The electrolyte layer acts as a one-way door, allowing either positive or negative ions to travel across, but not electrons, forcing electrons to travel through the external circuit (electric current). This resulting electric current can be used to power electrical appliances.

Benefits of Hydrogen Fuel Cells

When it comes to converting fuel to power, the fuel cell is two to three times more efficient than the internal combustion engine, which is one reason why every major automobile manufacturer in the world is investing in the development of fuel cells. Fuel cells can offer significant benefits over traditional energy technologies including:

  • Superior fuel efficiency,
  • Hydrogen Fuel Cells have zero to near-zero emissions in comparison to combustion engines,
  • Versatility – hydrogen fuel cells can be applied in micro, portable, stationary, and transportation applications,
  • Low maintenance costs, due to few moving parts,
  • Modular design allowing for low cost high volume manufacturing,
  • Design freedoms and,
  • Quiet operation.

Hydrogen Fuel cells are on the road and being used in our communities – now. Vancouver commuters have been riding on hybrid fuel cell-natural gas buses since 1997. Ford Motors Company recently developed the Ford Focus Fuel Cell Vehicle (FCV) and presented a fleet to the Vancouver Fuel Cell Vehicle Program. Drivers from BC Hydro, BC Transit, Ballard Power Systems, the City of Vancouver, Fuel Cells Canada, the National Research Council (NRC), Natural Resources Canada and the Government of British Columbia will use state-of-the-art Ford Focus FCVs for their daily driving as part of a three-year hydrogen fuel technology demonstration program.

Fuel cells have been around since 1839, but it has taken many years for us to understand the range and value of their potential applications. Today, with the support of governments and the private sector, hundreds of companies worldwide are working towards making fuel cell technology a reality. Similar to the commercialization of the electric light bulb nearly one hundred years ago, today’s companies, government departments and end user organizations are driven by technical, economic and social forces to make the hydrogen fuel cell part of our everyday lives.

Hydrogen Fuel Cells - Science Terminology

  • Anode: the negatively charged terminal of an energy cell or storage battery
  • Cathode: the positively charged terminal of an energy cell or storage battery
  • Proton: a positively charged hydrogen ion
  • Electron: a negatively charged sub-atomic particle
  • Electrolyte: a chemical compound that allows conduction of ions, but not electrons
  • Electrochemical Conversion: an electrochemical process that converts chemical energy to electrical energy

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