Should Hydrogen Be Added to Natural Gas?

In a world in which fossil fuels are being increasingly marginalised as our primary energy source due to climate concerns, environmentalists, climate scientists and industry stakeholders are always on the hunt for innovative ways to curb our carbon footprint. Hydrogen has been touted as one means of doing so, due to the fact that it can be produced far more sustainably than alternative power sources such as oil, coal or natural gas.

Although there are various pathways to producing hydrogen sustainably, the most common involves using the electricity generated from solar, wind, wave or other renewable energy sources to split water into its constituent parts (hydrogen and oxygen). This is much more preferable in environmental terms than the drilling, extraction and processing methods used to harness natural gas, begging the question: should the former be added to the latter?

Benefits of adding hydrogen to natural gas

If hydrogen is created via sustainable energy generation methods such as solar, wind, wave, biomass or nuclear power stations, it is much less damaging to the environment than fossil fuels. As such, adding it to natural gas – which is primarily composed of methane, one of the gases with the highest global warming potentials (GWPs) – can significantly reduce the greenhouse gas emissions associated with energy use.

This benefit does not just apply to industrial, commercial and domestic applications of natural gas, but can also be employed in the transportation sector, too. That’s because the advent of fuel cell electric vehicles (FCEVs) has made the use of hydrogen a far less polluting means of getting around than traditional combustion engines powered by petroleum or diesel.

Meanwhile, one additional advantage of adding hydrogen to natural gas is as a delivery method for the gas. By blending the gases together, hydrogen can be safely and efficiently delivered to the end user without the need for dedicated infrastructure to deal with it. Of course, the savings incurred by avoiding that construction must be offset against the added expenses of blending and extracting the hydrogen from the stream, as well as any pipeline modifications which must be made.

Things to consider

Perhaps the primary consideration when adding hydrogen to natural gas is the concentration of each. The combination must retain a sufficient amount of the latter so as to avoid disruption to the functioning of the end user equipment and appliances. As a result, hydrogen must be added in modest amounts of normally between 5% and 15%, though the exact figure can vary or be higher depending on the situation. Nonetheless, even such a meagre blend will still impact greenhouse gas emissions greatly.

A no less significant consideration is the safety of the process. Since hydrogen is more likely to ignite under a wider range of conditions than either methane or natural gas, a thorough risk assessment must be performed on a case-by-case basis to ensure that it is fit for purpose and will not endanger the health and safety of the equipment, environments or individuals at any stage of the process.

Finally, it’s important to weigh up leakage and material durability when blending hydrogen with methane. Because hydrogen is more mobile than methane in a variety of plastics, polymers and other materials used in storage and distribution, precautions must be taken to prevent unwanted leaks. At the same time, it should be remembered that certain metals and other materials can become degraded when exposed to hydrogen over a prolonged period of time.

For a deeper dive into all things methane – including the possibility of adding hydrogen to the gas to boost its environmental profile – interested parties are invited to attend the Industrial Methane Measurement conference in the Netherlands this June.