30% of the UK’s natural gas could be replaced by hydrogen, cutting carbon emissions

Almost a third of the natural gas fuelling UK homes and businesses could be replaced by hydrogen, a carbon free fuel, without requiring any changes to the nation’s boilers and ovens, a pioneering study by Swansea University researchers has shown.

Over time the move could cut UK carbon dioxide emissions by up to 18%.

Natural gas is used for cooking, heating and generating electricity.  Domestic gas usage accounts for 9% of UK emissions.  In an effort to reduce annual carbon emissions, there is presently a concerted effort from researchers worldwide to offset our usage of natural gas.

Enriching natural gas with hydrogen is one way forward.  Experiments have shown that modern-day gas appliances work safely and reliably with hydrogen-enriched natural gas as the fuel.  It is already used in parts of Germany and the Netherlands, with a £600m government-backed trial in the UK taking place this year. 

Natural gas naturally contains a small quantity of hydrogen, although current UK legislation restricts the allowed proportion to 0.1%. 

The question the Swansea team investigated was how far they could increase the percentage of hydrogen in natural gas, before it became unsuitable as a fuel, for example because the flames became unstable.  

The team, Dr Charles Dunnill and Dr Daniel Jones at the University’s Energy Safety Research Institute (ESRI), found: 

  • An enrichment of  around 30% is possible, when various instability phenomena are taken into account
  • Higher percentages make the fuel incompatible with domestic appliances, due to hydrogen’s relatively low energy content, its low density, and a high burning velocity.
  • 30% enrichment by hydrogen nevertheless equates to a potential reduction of up to 18% in domestic carbon dioxide emissions;

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Picture:  Hydrogen as a gas (H2), mixed with methane (CH4), results in Hydrogen-Enriched Natural Gas (HENG) which would help cut carbon emissions.

The research was published by the Royal Society of Chemistry.

Read the research paper

Dr Charles Dunnill of the Energy Safety Research Institute at Swansea University said:

“Up to 30% of the UK’s gas supply can be replaced with hydrogen, without needing to modify people’s appliances.

As a low carbon domestic fuel, hydrogen-enriched natural gas can cut our greenhouse gas emissions, helping the UK meet its obligations under the 2016 Paris Climate Change Agreement.

Hydrogen-enrichment can make a difference now.  But it could also prove a valuable stepping-stone towards a future, pure hydrogen, zero carbon gas network.”

The research was supported by the Welsh Government Sêr Cymru Program, FLEXIS, which is partially funded by the European Regional Development Fund, and the King Saud University as well as by the Welsh Government through the Sêr Cymru Chair for Low Carbon Energy and Environment.  Co-author is Waheed Al-Masry  an assistant professor in  the Department of Chemical Engineering at King Saud University, Riyadh, Saudi Arabia.

Find out more about the College of Engineering at Swansea University