Hydrogen 101

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What is hydrogen?

Hydrogen is the simplest, lightest element in the universe - it is also the most abundant. Hydrogen is made up of one proton and one electron. Hydrogen does not exist alone naturally on Earth, although it is abundant in stars such as our Sun. H2 is the bimolecular form of hydrogen. On Earth, it naturally combines with oxygen to form water. It also acts as nature's energy carrier when married to carbon in sugars and more complex carbohydrates made by plants through photosynthesis. Humans and other animals derive their "fuel" from these carbohydrates made up of carbon and hydrogen in high-energy bonds.

When hydrogen escapes into the atmosphere, it is so light that it floats and disperses immediately. That means that a hydrogen spill won't pool on the ground, pollute groundwater, or soak into clothing. In its normal gaseous state, hydrogen is colourless, odourless, tasteless and non-toxic, which makes it different from every common fuel we use.

What can hydrogen be used for?

Hydrogen is used extensively today in the production of ammonia, methanol, gasoline, heating oil, and rocket fuel. It is also used to make fertilizers, glass, refined metals, vitamins, cosmetics, semi-conductor circuits, soaps, lubricants, cleaners, and even margarine and peanut butter.

Hydrogen can fuel today's internal combustion engine vehicles with modest changes in design.

Hydrogen can fuel tomorrow's fuel-cell vehicles.

Existing wind and hydroelectric plants can produce hydrogen to store energy during off-peak hours.

Hydrogen production from hydrocarbons can also produce by-product carbon, which, when made into carbon fibre, has ten times the strength of steel. With more research, this carbon could be used for automobile bodies and structural members.

What are the advantages of hydrogen?

Hydrogen is a clean power source; when hydrogen is used in a fuel cell to create power, it is a completely clean technology. The only by-product is water. Electrolysis separates hydrogen from water, and the hydrogen recombines with oxygen to create water and power in a fuel cell.

It's safe; hydrogen can be used and stored more safely than gasoline, diesel, or natural gas.

In the long, run it is expected to become cost-effective as fossil fuels become increasingly scarce.

It's a reliable source of power; hydrogen can be produced anywhere there is electricity and water. People can even produce it in their own homes with relatively simple technology.

Is hydrogen safe?

Hydrogen disperses quickly. Being an extremely light molecule, hydrogen rises and spreads quickly in the atmosphere. If a leak were to occur, the hydrogen gas would quickly become so sparse that the risk of it burning would decrease just as rapidly.

Hydrogen is a non-toxic compound. By comparison, most petroleum products are poisonous to humans.

Hydrogen combustion produces only water. When pure hydrogen is burned in the air, only pure water is produced.

Hydrogen can be stored and distributed safely. Tanks currently being used for the storage and shipment of compressed hydrogen have been through rigorous testing, completed for their certification.

What are hydrogen fuel cells?

Hydrogen fuel cells are actually hydrogen batteries, stored sources of energy. They operate quite simply by joining hydrogen and oxygen atoms.

A hydrogen fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen over the other, generating electricity, water and heat. Hydrogen is fed into the anode (negative side) of the fuel cell. Oxygen enters the fuel cell through the cathode (positive side). Excited by a catalyst, the hydrogen atom splits into a proton and an electron, which take different paths to the cathode. The proton passes through the electrolyte. The electron creates a separate current by passing through an external circuit and powering any useful appliance before it returns to the cathode, to be reunited with the hydrogen and oxygen in a molecule of water.

What are the advantages of using hydrogen fuel cells?

Since hydrogen fuel cells rely on chemistry and not combustion, the emissions are virtually zero in comparison to the cleanest fuel combustion engines.

Hydrogen fuel cells can be built in a wide range of sizes. They can be used to produce small amounts of electric power for devices such as personal computers, or be used to produce high voltage power for electric power stations. Hydrogen fuel cell vehicles are an attractive alternative to regular battery-powered vehicles. They can be refuelled quicker and even run longer between refuelling, compared to the range of battery-powered vehicles.