Idaho National Laboratory

Advancing the Nuclear

Hydrogen Initiative

Producing Hydrogen:

The Thermochemical Cycles

Efficient production of hydro

gen without increased green

house gas emissions is the key

to achieving the “hydrogen

economy” envisioned by the National Hydrogen Initiative. As the

lead laboratory for the Department of Energy’s Office of

Nuclear Energy, Science and

Technology, the Idaho National

Laboratory is assuming a major

role in developing technologies to

produce hydrogen using nuclear

energy. One of the most promising of these technologies uses

thermochemical cycles to produce

hydrogen.

What Are

Thermochemical Cycles?

Thermochemical cycles combine

heat with chemical processes to split

water into its hydrogen and oxygen

components. Several cycles have

been demonstrated at the laboratory

scale. For example, one cycle uses

sulfur, iodine and heat to split water into hydrogen and oxygen.

INL: Applying Nuclear

Science to the Thermochemical Cycles

INL has initiated an internally

funded project to move demonstration of the thermochemical cycles

from the laboratory to larger-scale

engineering demonstrations. INL’s

work focuses on overcoming technical barriers and applying nuclear

energy to create the heat necessary

to fuel the cycles.

Continued on back

Thermochemical cycles combine

heat with chemical processes to

split water into its hydrogen and

oxygen components.

Very High

Temperature

Reactor

Helium Heat Exchanger

Molten Salt

Heat Exchanger

Sulfuric Acid

Sulfuric Acid/Water

Mixture

Decomposed

Sulfuric AcidHeat Exchanger

Decomposed

Sulfuric Acid

Hydroiodic

Acid

Hydroiodic

Acid

Hydrogen/Iodine

Mixture

Oxygen

Iodine/Water

Mixture

Membrane

Water

Hydrogen
Idaho National Laboratory

Continued from front

INL’s themochemical cycles project

includes tasks to:

• Identify materials that can withstand the high temperatures and

corrosive conditions required in

many thermochemical cycles.

• Develop efficient separation

methods for complex chemical

mixtures.

• Improve kinetics.

• Improve the efficiency of electrochemical steps included in some

of the cycles.

Specific INL thermochemical cycles

projects include:

• Possibly integrating thermochemical water splitting as one of

the hydrogen production processes to be conducted by the Very

High Temperature Reactor that

could be operating at the INL site

by around 2015.

• Working as a subcontractor to

General Atomics on the conceptual design of an integrated

nuclear reactor/sulfur-iodine cycle

for hydrogen production.

• Participating with other national

laboratories in working with the

As the lead laboratory for the Department of Energy’s Office of Nuclear Energy, Science and Technology,

the Idaho National Laboratory is assuming a major role in developing technologies to produce hydrogen

using nuclear energy.

The INL is one of the U.S. Department of Energy’s

multiprogram national laboratories, and is

managed by Battelle Energy Alliance, LLC.

For More Information

Technical Contact:

Dan Ginosar

208-526-9049

Daniel.Ginosar@inl.gov

Management Contact:

John Kolts

208-533-7095

John.Kolts@inl.gov

Department of Energy’s Office of

Nuclear Energy, Science and

Technology on an R&D plan that

will lead to the eventual demonstration of hydrogen production

using nuclear energy.

05-GA50093-05