Hydrogen is a colorless gas, but there are different color names used to distinguish between the various ways of producing it. These color names are not official, but they are widely used in the industry. Here is a list of the different colors of hydrogen and what they mean:

 

Gray hydrogen: This is the most common type of hydrogen, and it is produced from natural gas using a process called steam methane reforming (SMR). SMR is a well-established technology, but it is also one of the most polluting ways to produce hydrogen.

 

Blue hydrogen: This is hydrogen that is produced from natural gas using SMR, but with carbon capture and storage (CCS) technology to capture and store the carbon dioxide emissions. CCS is an expensive technology, and it is not always effective, so blue hydrogen is not as clean as green hydrogen.

 

Green hydrogen: This is the cleanest type of hydrogen, and it is produced from water using electrolysis. Electrolysis is a process that uses electricity to split water molecules into hydrogen and oxygen. The electricity used to power electrolysis can come from any source, but if it comes from a renewable source like solar or wind power, then the hydrogen is considered to be green.

 

 

Turquoise hydrogen: This is a newer type of hydrogen that is produced from methane using a process called methane pyrolysis. Methane pyrolysis is a promising technology because it does not produce any carbon dioxide emissions. However, it is still in the development stage, and it is not yet commercially viable.

 

 

Pink hydrogen: This is a type of hydrogen that is produced from nuclear power using electrolysis. Nuclear power is a low-carbon source of energy, but it is also controversial due to the risks of nuclear accidents.

 

 

Purple hydrogen: This is a type of hydrogen that is produced from biomass gasification. Biomass gasification is a process that converts biomass, such as wood or agricultural waste, into hydrogen and other gases. Biomass gasification is a renewable energy source, but it can also be a source of air pollution.

 

 

Brown hydrogen: This is a type of hydrogen that is produced from coal using a process called gasification. Gasification is a process that converts coal into hydrogen and other gases. Coal is a major source of greenhouse gas emissions, so brown hydrogen is not considered to be a clean energy source.

 

 

So, can green hydrogen replace natural gas?

The answer is yes, but it will not be easy. Natural gas is a cheap and abundant source of energy, and it is deeply entrenched in the global energy system. Replacing natural gas with green hydrogen will require a significant investment in new infrastructure and technology. However, the benefits of green hydrogen, such as its low emissions and its potential to reduce reliance on fossil fuels, are significant. As the cost of green hydrogen technology continues to decline, it is likely to play an increasingly important role in the global energy mix.