Nukes Give a Hydrogen Boost
Monday, March 26, 2012 @ 02:03 PM gHale
The “hydrogen economy” is here and available and could begin commercial production in this decade, a scientist said.
Heat from existing nuclear plants could see use in the more economical production of hydrogen, with future plants custom-built for hydrogen production, said International Atomic Energy Agency’s (IAEA) Ibrahim Khamis, Ph.D., at the 243rd National Meeting & Exposition of the American Chemical Society (ACS).
“There is rapidly growing interest around the world in hydrogen production using nuclear power plants as heat sources,” Khamis said. “Hydrogen production using nuclear energy could reduce dependence on oil for fueling motor vehicles and the use of coal for generating electricity. In doing so, hydrogen could have a beneficial impact on global warming, since burning hydrogen releases only water vapor and no carbon dioxide, the main greenhouse gas. There is a dramatic reduction in pollution.”
Khamis said scientists and economists at IAEA and elsewhere are working intensively to determine how current nuclear power reactors — 435 are operational worldwide — and future nuclear power reactors could work in hydrogen production.
Most hydrogen production at present comes from natural gas or coal and results in releases of the greenhouse gas carbon dioxide. On a much smaller scale, some production comes from a cleaner process called electrolysis, in which an electric current flowing through water splits the H2O molecules into hydrogen and oxygen. This process, termed electrolysis, is more efficient and less expensive if water heats to form steam, with the electric current passed through the steam.
Khamis said nuclear power plants are ideal for hydrogen production because they already produce the heat for changing water into steam and the electricity for breaking the steam down into hydrogen and oxygen. Experts envision the current generation of nuclear power plants using a low-temperature electrolysis which can take advantage of low electricity prices during the plant’s off-peak hours to produce hydrogen. Future plants, designed specifically for hydrogen production, would use a more efficient high-temperature electrolysis process or couple with the thermochemical processes, which are currently under research and development.
“Nuclear hydrogen from electrolysis of water or steam is a reality now, yet the economics need to be improved,” Khamis said. He noted some countries are considering construction of new nuclear plants coupled with high-temperature steam electrolysis (HTSE) stations that would allow them to generate hydrogen gas on a large scale in anticipation of growing economic opportunities.
Khamis described how IAEA’s Hydrogen Economic Evaluation Programme (HEEP) is helping. IAEA has designed its HEEP software to help its member states take advantage of nuclear energy’s potential to generate hydrogen gas. The software assesses the technical and economic feasibility of hydrogen production under a wide variety of circumstances.