Hydrogen Fuel: Using hydrogen for energy

Hydrogen Fuel: Using hydrogen for energy

Hydrogen basics

Hydrogen is the most abundant element on earth. With only one proton and one electron, it is also the simplest, lightest element. And hydrogen has the highest energy content by mass of any known fuel. Stars are made mostly of hydrogen and helium, including our sun.

Hydrogen gas (H2) is not found naturally on earth. It can, however, be extracted from other compounds. Hydrogen always combines with other elements to form new compounds like water, table sugar, ammonia, and hydrogen peroxide. Hydrogen is considered one of the building blocks of life.

Hydrogen is abundant and full of energy. But using hydrogen for energy presents some challenges.

Using hydrogen for energy

Hydrogen has to be extracted from other sources or compounds. This requires energy. For example, let's look at a water molecule, H2O. It is made up of two hydrogen atoms and one oxygen atom. The atoms share electrons to make a molecular bond. This bond is so strong that it requires electricity to break it, in a process called electrolysis. It is possible to extract hydrogen in a classroom. The activity uses electricity from a battery to separate the water molecule (H2O) into hydrogen (H2) and oxygen (O2).

Fuel cells use a process that is the opposite of electrolysis. Instead of breaking apart a bond, fuel cells create new bonds. This process generates electricity. Here's how: The catalyst in the fuel cell breaks apart O2 and H2 molecules. The fuel cell forces some of the electrons from the atoms to travel through an electrical circuit to generate electricity. The oxygen and hydrogen atoms re-form as water molecules (H2O).

How do we get hydrogen for fuel?

The United States imports more than half of the oil it uses. That means we buy most of our oil from other countries. And, the price of oil is going up. Economists think the price of oil will continue to rise. Also, fossil fuels are non-renewable, meaning that once they are used, they are gone forever.

Researchers are looking for new sources of energy so we can use less fossil fuel. Homes and businesses already use electricity harnessed from the sun, wind, water, and biomass. However, powering a vehicle needs a different solution. The power source needs to be portable, and it needs to allow the vehicle to go at least 300 miles before recharging or refueling.

Hydrogen could be one of the solutions. Since there are so many sources of hydrogen, more hydrogen fuel can be created as it is needed.

By-products: Pure hydrogen is already being produced in many manufacturing plants. Petroleum refining and chemical production create hydrogen as a by-product. Fossil fuels, such as natural gas, can be reformed to produce hydrogen gas.

Electrolysis: Renewable energy sources such as windmill farms, solar collectors or hydroelectric generators can supply electricity for electrolysis. Electrolysis is used to split water molecules into pure hydrogen and oxygen.

Nuclear power: Nuclear energy can produce large amounts of hydrogen. Nuclear power does not give off greenhouse gases or other harmful air emissions. The nuclear reaction used to make hydrogen does not use carbon-based materials, a common source of pollutants. Nuclear power does create radioactive waste from spent fuel rods.

New research: The U.S. Department of Energy has used photosynthesis to create pure hydrogen. In an experiment, plant enzymes were able to split water molecules, creating the hydrogen. In another experiment, glucose from plants was used. Glucose can also come from waste, like paper mill sludge, cheese whey and wood waste.