Nuclear plants could produce clean hydrogen
Nuclear power plants can produce hydrogen to fuel the 'hydrogen economy', say scientists from the International Atomic Energy Agency (IAEA) in Vienna.
Currently, most hydrogen production comes from natural gas or coal and pumps carbon dioxide into the atmosphere.
Electrolysis, which is much cleaner, uses an electric current flowing through water to split the water molecules into hydrogen and oxygen. The process is cheaper and more efficient if the water is first heated to form steam, with the electric current passed through the steam.
And, says Ibrahim Khamis, nuclear power plants are ideal for this, as they already produce both the heat and the electricity required. The current generation of nuclear power plants could use low-temperature electrolysis and 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 be coupled to 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," says Khamis. Some countries are considering building new nuclear plants together with high-temperature steam electrolysis (HTSE) stations that would allow them to generate hydrogen on a large scale.
"There is rapidly growing interest around the world in hydrogen production using nuclear power plants as heat sources. Hydrogen production using nuclear energy could reduce dependence on oil for fueling motor vehicles and the use of coal for generating electricity," says Khamis.
"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."
The team's now working to determine how existing nuclear power reactors — there are currently 435 operational worldwide — as well as future versions could be enlisted in hydrogen production.