Unitized regenerative fuel cell
Encyclopedia
A unitized regenerative fuel cell (URFC) is a fuel cell
based on the proton exchange membrane
which can do the electrolysis of water
in regenerative mode and function in the other mode as a fuel cell recombining oxygen and hydrogen gas to produce electricity. Both modes are done with the same fuel cell stack
By definition, the process of any fuel cell could be reversed. However, a given device is usually optimized for operating in one mode and may not be built in such a way that it can be operated backwards. Fuel cells operated backwards generally do not make very efficient systems unless they are purpose-built to do so as in high pressure electrolyzers
, unitized regenerative fuel cells and regenerative fuel cells.
physicist Fred Mitlitsky studied the possibilities of reversible technology. In the mid-1990s Mitlitsky received some funding from NASA
for development of Helios and from the Department of Energy
for leveling peak and intermittent power usage with sources such as solar cells or wind turbines. By 1996 he produced a 50-watt prototype single proton-exchange membrane cell which operated for 1,700 ten-minute charge-discharge cycles, and degradation was less than a few percent at the highest current densities. A rated power of 18.5 kW URFC was installed in the Helios and was tested on-board during test flights in 2003. The aircraft unfortunately crashed on its second URFC test flight June 26, 2003
Fuel cell
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...
based on the proton exchange membrane
Proton exchange membrane
A proton exchange membrane or polymer electrolyte membrane is a semipermeable membrane generally made from ionomers and designed to conduct protons while being impermeable to gases such as oxygen or hydrogen...
which can do the electrolysis of water
Electrolysis of water
Electrolysis of water is the decomposition of water into oxygen and hydrogen gas due to an electric current being passed through the water.-Principle:...
in regenerative mode and function in the other mode as a fuel cell recombining oxygen and hydrogen gas to produce electricity. Both modes are done with the same fuel cell stack
By definition, the process of any fuel cell could be reversed. However, a given device is usually optimized for operating in one mode and may not be built in such a way that it can be operated backwards. Fuel cells operated backwards generally do not make very efficient systems unless they are purpose-built to do so as in high pressure electrolyzers
High pressure electrolysis
High-pressure electrolysis is the electrolysis of water by decomposition of water into oxygen and hydrogen gas due to the passing of an electric current through the water. The difference with a standard proton exchange membrane electrolyzer is the compressed hydrogen output around 120–200 Bar ...
, unitized regenerative fuel cells and regenerative fuel cells.
History
LivermoreLawrence Livermore National Laboratory
The Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...
physicist Fred Mitlitsky studied the possibilities of reversible technology. In the mid-1990s Mitlitsky received some funding from NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
for development of Helios and from the Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
for leveling peak and intermittent power usage with sources such as solar cells or wind turbines. By 1996 he produced a 50-watt prototype single proton-exchange membrane cell which operated for 1,700 ten-minute charge-discharge cycles, and degradation was less than a few percent at the highest current densities. A rated power of 18.5 kW URFC was installed in the Helios and was tested on-board during test flights in 2003. The aircraft unfortunately crashed on its second URFC test flight June 26, 2003
See also
- Glossary of fuel cell termsGlossary of fuel cell termsThe Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this fuel cell glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but a few. –...
- Hydrogen technologiesHydrogen technologiesHydrogen technologies are technologies that relate to the production and use of hydrogen. Hydrogen technologies are applicable for many uses....