Hydrogen

Shell is a pioneer in developing hydrogen, the simplest element in the universe (it has only one proton) and the most plentiful gas on earth. But hydrogen doesn’t occur naturally in its pure form. It is mostly present in combination with oxygen (H2O - water), nitrogen (NH3 - ammonia) or carbon (CH4 - natural gas), and special processes are required to extract hydrogen out of these materials.

The most common way of producing hydrogen is from natural gas via a steam reforming process. This uses steam to convert methane (and other hydrocarbons in natural gas) into hydrogen and carbon. Around half of the world's hydrogen is produced in this way. Hydrogen can also be produced from water, where it’s extracted through electrolysis. This process uses electricity and a catalyst to separate the hydrogen from the oxygen in water. It can then be captured and stored as a fuel, for example compressed and stored as a gas, or cooled and stored as a liquid. There are also lots of other options being explored by industry for producing hydrogen.

Stored hydrogen can then be converted to energy via hydrogen fuel cells. It’s not yet practical to have fuel cells for home energy conversion, but it can be for cars. In hydrogen fuel cell vehicles, an electric motor powers the wheels. A chemical reaction inside the fuel cell – usually between hydrogen and oxygen – creates electricity for the motor, and the only resulting tailpipe emission from the vehicle is water vapour.
 

Making it green
Our technology focus at Shell is on learning as much as possible about hydrogen refuelling and how to meet future customer needs. This means hydrogen will initially be obtained mainly from natural gas, but ultimately we expect to produce hydrogen from renewables, such as wind and solar and one day biomass. The wide introduction of hydrogen technology based on natural gas will already substantially reduce greenhouse gas emissions. Where hydrogen is produced from renewable sources it will truly lead to zero emissions power, and that remains the ultimate goal. 

*Hydrogen is referred to as an energy carrier rather than an energy source. That is, a substance or system that moves energy in a usable form from one place to another. Electricity is the most well-known energy carrier, which is used to move the energy. Also like electricity, which might be produced from coal, hydrogen must be produced from another substance such as natural gas.

For more information please visit:  www.shell.com/hydrogen