Hydrogen Energy in the H2R Engine

Photo courtesy BMW AG, Munich, Germany

Pure hydrogen gas rarely occurs in nature. As there are no reserves of pure hydrogen on the planet, hydrogen must be extracted from other compounds if it is to be used a fuel source. For example, in the process of hydrolysis, electrical current is passed through water to break it down into hydrogen and oxygen according to the following reaction: 2H2O + electricity --> 2H2 + O2. The reverse reaction -- the combustion (oxidation) of hydrogen -- is the process by which energy is created in the H2R's engine: 2H2 + O2 --> 2H2O + energy.

As you can see, the only by-product of this reaction is water, which makes the combustion of liquid hydrogen a clean-burning alternative to the combustion of fossil fuels. Unfortunately, as hydrogen does not occur naturally in its pure state, an initial input of energy is required to separate pure hydrogen from other naturally occurring compounds. Essentially, we need to use "dirty" energy to produce "clean" energy. The BMW Group is researching ways to generate the initial energy input in environmentally friendly ways, such as through wind, solar or hydroelectric power.

The use of liquid hydrogen as a fuel source is not a new concept. The aerospace industry already uses liquid hydrogen in rockets and spacecraft, and liquid hydrogen is being considered for use in airplanes because of its low density. Hydrocarbon-based fuels are very heavy; an equal volume of liquid hydrogen weighs less and produces nearly three times more power than gasoline.

To learn more about the science of hydrogen as a fuel source, see How the Hydrogen Economy Works. For more information on the H2R and other concept cars, check out the links on the next page.

The BMW H7 In 2006, BMW introduced the world's first hydrogen-powered production vehicle -- the H7. BMW claims that the H7 will offer world-class luxury and performance along with the clean-air benefits of hydrogen technology. When it debuts, the H7 will be available only in select markets. Because of the present scarcity of hydrogen refueling stations, the H7 will feature a combustion engine that can run on either liquid hydrogen or gasoline. BMW's Double-VANOS and Valvetronic engine technologies will allow the engine to adjust to burning hydrogen/air or gasoline/air fuel mixtures. These sophisticated systems also help prevent nitrogen oxide (NOx) emissions in the combustion process. NOx emissions contribute to the formation of ozone and acid rain.