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To Infinity and Beyond - Hydrogen Fuel

© Danita LaSage

Okay, how's this for sustainable energy: instead of fossil fuels, which exist in only limited amounts, what if we could produce energy using a really common substance - in fact, the most common element in the universe. What if, instead of the 13% to 25% efficienty we get with gasoline engines, we had a fuel that was up to 58% efficient. And what if that element provided the highest energy content per unit weight known to man. While we're at it, let's have it be essentially pollution-free. Now we're talking serious energy. Now we're talking hydrogen. (No wonder NASA uses the liquid form for rocket fuel!).

The US Department of Energy hopes to see hydrogen and hydrogen fuel cells providing about 10% of our energy needs by the year 2030. Pretty interesting, considering that hydrogen doesn't even exist on Earth in its pure state (the diatomic molecule, H2). Oh, it's here, alright. After all, more than 90% of the universe is composed of hydrogen. But on Earth, it's found combined with other elements - like oxygen, commonly in the form H2O, or carbon, as CH4. So the dream of hydrogen fuel starts with other precious resources - water or methane. Hydrogen atoms must be stripped from water molecules before they can be harnessed for fuel, and that takes - well, it takes energy.

Steam re-forming, the most common and cheapest method of collecting pure hydrogen, is a technique whereby hydrogen is separated from methane, CH4. Hydrogen collected this way is used for fertilizers and chemical products, or to upgrade petroleum products, but isn't in a pure enough form to be used as a fuel itself. Of course, it's valuable even then. According to the US Department of Energy, adding a mere 5% H2 to gasoline lowers NOx emissions by 30 - 40%, a significant amount in a nation ever-conscious of its poor air quality.

But what we really need in order for hydrogen to be a viable fuel alternative is an efficient and affordable way to produce electrical power from it. Right now, fuel-quality hydrogen is produced by electrolysis, and the electricity for that ultimately involves combustion of fossil fuels (it takes about 0.14 kWh of electricity to produce one cubic foot of H2). Opponents of hydrogen fuel research argue that we're just spinning our wheels here, since using fossil fuels for the electrolysis that provides H2 is counter-productive. After all, we're talking about using hydrogen in order to avoid using fossil fuels, right? Fortunately, current research is focusing on using sustainable energy sources like solar or wind rather than fossil fuels for the electrolysis procedure. What we would require would be an energy source such as solar that provides for the base needs of a population, plus some extra for peak needs. Using the solar energy for electrolysis would convert the solar energy to chemical energy in the hydrogen, which could then be either transported more cheaply, or stored until needed.