Hydrogen
Page Contents: Hydrogen
How Hydrogen is Formed
History of Hydrogen
Uses for Hydrogen
Hydrogen for Transportation
Demand for Hydrogen
Hydrogen is the simplest and lightest element known to exist, with only one proton and one electron per atom. It is an energy carrier, not an energy source—it must be produced from compounds that contain it. It is the most abundant element in the universe and is the source of the energy we receive from the sun, which is essentially a giant hydrogen gas ball. This radiant energy from the sun is important because it provides light and heat and makes plants grow.
On Earth, hydrogen is only found in compound form such as with oxygen to form water and with carbon to form compounds such as methane, coal and petroleum. At room temperature, it is a transparent, highly flammable gas.
How Hydrogen is Formed
Since hydrogen fuel is not found naturally on Earth, it must be manufactured. Hydrogen fuel is a byproduct of chemically mixing hydrogen/oxygen to produce electricity, water and heat. It is stored in a “cell” or battery.
Hydrogen is usually produced through steam reforming or electrolysis. Steam reforming, which is the least expensive way to create hydrogen, involves separating hydrogen atoms from carbon atoms in methane. This method accounts for about 95% of the hydrogen produced in the United States, but the process creates greenhouse gas emissions.
In electrolysis, an electric current is used to split water into hydrogen and oxygen; then the hydrogen can be extracted and used. Nuclear high-temperature electrolysis uses the heat from a nuclear reactor to warm up water before applying an electric current; by warming the water up first, less electricity is needed to separate the hydrogen and oxygen, reducing the energy consumption.
Today, hydrogen is primarily transported short distances via pipeline. In some instances, hydrogen can be transported via tanker trucks or barges. It can also be transported using elements like ammonia or ethanol that contain hydrogen atoms. When hydrogen is transported long distances, it is best to liquefy it and move it in a tanker truck. But liquefaction is expensive and energy-consuming, so it is usually used in close proximity to where it is created to avoid long transports.
