Fuel cell vehicles are appearing on our roads. Hydrogen is being promoted as a clean and sustainable energy source. But as we move toward a hydrogen economy, we face a logistical problem. How do we deliver this fuel to the users?
Skeptics often point to the lack of infrastructure. They are right. It is a major barrier. We need a way to get hydrogen from the production plant to the refueling station or power generator.
The Case for Blending
One proposed solution is blending. This means mixing hydrogen into the existing natural gas pipeline network. It utilizes the assets we already have.
Building a purpose-built hydrogen pipeline network from scratch would cost billions of Euros. Using the current gas grid avoids this massive investment. It offers a unique opportunity to connect producers and end-users quickly.
This approach has environmental benefits too. Adding hydrogen to natural gas reduces greenhouse gas emissions. However, this only counts if the hydrogen comes from low-carbon sources. This could include renewables, bio-waste, or fossil resources paired with carbon capture technology.
Proven Viability
The industry has been working on this for years. The NATURALHY project, a pan-European effort, demonstrated the viability of mixing hydrogen with natural gas more than five years ago.
According to Energy Storage Europe, modern grids could handle a blend of up to 15 percent hydrogen in the midterm. A report by the US Department of Energy also supports this. It found that blending is a viable long-term solution. It allows renewable energy facilities to increase output now, while preparing for a future where we extract that hydrogen downstream for cars.
Engineering Challenges
It is not as simple as just swapping gas for hydrogen. The chemical properties are different.
The main limiting factor is the durability of existing pipelines. Some metal pipes degrade when exposed to hydrogen over long periods. This is known as embrittlement. It happens particularly at high concentrations and high pressures.
Operators must assess this on a case-by-case basis depending on the type of steel used. Strengthening pipelines costs money, but it is still far cheaper than building a new network.
Extraction and Direct Use
If we use the grid for transport, we might need to separate the hydrogen at the other end. The US Department of Energy highlights three primary technologies for this:
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Pressure swing adsorption (PSA)
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Membrane separation
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Electrochemical hydrogen separation (hydrogen pumping)
Extraction is most cost-effective at pressure reduction facilities. The drop in pressure helps the separation process. Without that drop, the energy required to recompress the gas makes it too expensive.
However, extraction is not always necessary. Power stations can burn the blended gas directly. Hydrogen burns at a higher temperature than natural gas. This makes gas turbines run hotter and more efficiently, while lowering the overall carbon emissions of the plant.
Global Progress
Countries are already moving ahead. Japan is constructing 100 hydrogen filling stations near major cities. Germany aims to have 400 stations by 2025.
The downstream infrastructure is expanding. As Henri Winand, chief executive of Intelligent Energy, notes, the industry must explore all avenues. The research proves it is feasible. Now the sector needs to turn that data into practical solutions.
