Hydrogen is often referred to as the fuel of the future, so it is important we understand the different forms the gas can come in. Typically, it can be categorised into two types: emissions generating and zero emissions.

Hydrogen itself is a colourless gas, but colour codes are used to identify how much carbon dioxide is emitted during the production process.

Emissions Generating Hydrogen

Brown Hydrogen

This is the most damaging form of hydrogen as it relies on burning coal. Brown hydrogen is the opposite of green and releases a substantial amount of carbon dioxide into the atmosphere.

Grey Hydrogen

This product involves a steam methane reforming process to split the natural gas into carbon and hydrogen, which emits CO2 back into the atmosphere. Grey hydrogen is the most common type of hydrogen and accounts for the majority of what we produce today.

Blue Hydrogen

Similar to grey hydrogen, this involves using a steam methane reform method to split natural gas into hydrogen and CO2. However, blue hydrogen implements technology to capture more than 90% of the carbon produced during the process. This captured carbon can also be recycled and used to create other things such as metal alternatives and sustainable concrete.

Zero Emissions Hydrogen

 Green Hydrogen

Green hydrogen is produced through an electrolyser powered by renewable energy sources, meaning it does not release any greenhouse gases into the atmosphere. The process involves splitting water into hydrogen and oxygen. This type of hydrogen is viewed as one of the most viable solutions to decarbonising the global economy.

Emerald hydrogen

This method is sometimes described as ‘turning waste into energy’ because it involves heating biowaste in an oxygenless environment to create hydrogen and biochar — another valuable output. This is also expected to become another critical energy source for our net-zero future.

White Hydrogen

While hydrogen is a naturally occurring gas found in geological deposits. Currently, companies are developing cutting-edge sustainable technology to extract this from underground pockets containing the gas.

Yellow Hydrogen

This term was recently developed to manufacture hydrogen through electrolysis fueled by solar power.

Turquoise Hydrogen

This is a relatively new type of hydrogen produced through a process called methane pyrolysis.

Pink, Purple and Red Hydrogen

 The colours pink, purple, or red refer to hydrogen produced through nuclear energy.