Recently, US scientists presented research into using hydrogen blended with methane (natural gas) to bridge the energy gap and achieve carbon neutrality. Many industrial operators see the strategy as being a first step towards the US meeting its net-zero emissions target without having to compromise on energy security.
It is worth mentioning that most existing, installed process heat and space heat and power generation systems can safely convert to hydrogen blending of up to 20%. Similarly, there are already products available that enable on-site hydrogen blending.
This means that the technology is already here. However, what is needed is for the technology to go mainstream, and this means making it financially viable for the broader market.
Most people reading this are already familiar with climate change being an existential threat facing humanity and the world. Methane and carbon dioxide (CO2) are two of the most damaging greenhouse gasses responsible for increasing temperatures. This temperature rise has been tracked to the start of the Industrial Revolution and has brought about accelerating environmental damage.
That’s why we are now racing towards technologies that assist in phasing out fossil fuels in favor of low-carbon hydrogen and similar renewable energy. Together these clean energy sources can help ensure that we meet the zero-carbon emissions target.
In the past decade, hydrogen gas has received increased attention. Many scientists see it as a viable alternative fuel and energy carrier. Apart from the near-zero CO2 emissions, the most significant benefit of hydrogen is that it carries energy efficiently. Hydrogen is also one of the most abundant atoms in the universe, and it is renewable.
This means switching to hydrogen can help us reduce and even eliminate emissions. Wee can also accelerate our understanding of hydrogen integration and potential process change requirements with on-site hydrogen blendings.
It must be emphasized that the most valuable hydrogen sources are those produced with low levels of CO2 and minimal transportation requirements. Hydrogen can be sustainable and classified as having a low carbon intensity (CI) score if sourced this way.
The other advantage of switching from pure natural gas to blended hydrogen is that hydrogen blends can be made available with existing transportation and storage infrastructure. Using existing natural gas pipelines to transport methane to an end user’s location and distributed methane pyrolysis technology to split CH4 into hydrogen and solid carbon, local gas utilities can effectively deliver clean hydrogen for blending without any new infrastructure.
Hydrogen produces far less CO2 during combustion than natural gas or any other hydrocarbon. This also means that hydrogen is poised to take over from natural gas in many industrial applications, including electricity generation. However, there are still many potential challenges to using the existing gas infrastructure for the distribution of pure hydrogen.
In the US, as in many other parts of the world, there is existing natural gas infrastructure. This infrastructure can be easily repurposed to deliver methane as a feedstock for hydrogen production. This infrastructure is also a very effective and very large energy storage vessel.
This approach will help to fuel the carbon-neutral economy, but for this to happen, on-site methane pyrolysis and turquoise hydrogen plants need to be financially viable.
Today, the ability to efficiently repurpose existing natural gas infrastructure and use new methane decarbonization technology will help our country realize its full hydrogen potential. However, there are still several key challenges. One of these challenges is that hydrogen and methane have different properties, which isn’t a simple case of just replacing one gas with the other in most systems.
To realize and make large-scale conversions of our current infrastructure requires a detailed analysis of all associated factors including production, transportation, and storage. Additionally, there need to be end-users ready to accept hydrogen blends.
One solution presented is to gradually increase the amount of hydrogen in these hydrogen/methane blends over time. But this approach can be a challenge for engineers and operations teams as the blend percentage pushes past 20%. Overcoming the challenges will require a coordinated effort and a cross-functional approach.
From the end-user perspective, some concerns associated with switching from methane to hydrogen include changes in flame speed, burner design, and air-to-fuel ratios. From the local gas utility perspective, there are potential issues to monitor, including pipeline stress, pressure optimization, leakage, and long-term embrittlement that can be associated with high-pressure hydrogen in traditional metal pipes. Many of these issues are already being addressed by various projects.
Currently, many hydrogen and hydrogen blending projects are running around the world. Gas distribution companies with hydrogen demonstration projects underway include SoCalGas, PG&E, and NW Natural. These all support rapid market development and pave the way for cost-effective carbon reduction goals by 2050. The lessons learned from using hydrogen blends and across these demonstration projects will help industries and governments realize the development of more efficient, compatible, and safer hydrogen infrastructure.
Efficient on-site hydrogen blending can address most potential issues with energy density and customer process optimization. As the universe of hydrogen blending pilot projects increases, more comprehensive data will be available for analysis.
While many major players in the hydrogen production industry focus on extremely large-scale operations, some new technology products like Modern Hydrogen focus on smaller-scale hydrogen blending that can be done on-site in distributed locations.
These methane pyrolysis units do not use catalysts or electricity and can produce hydrogen at the same site where it is consumed. These operating efficiencies can deliver high-value cost savings and decarbonize at the same time.
In many of these instances, the same natural gas utilities currently invested in conventional fossil fuels are aggressively driving the decarbonization conversation. These LDCs are often the parties most interested in hydrogen blending options.
Both regulated and unregulated utilities want to remain relevant and leverage their existing infrastructure.
While the long-term future is undoubtedly built around green hydrogen, blending clean turquoise hydrogen today is a sensible first step, especially with on-site units. However, regardless of the path forward, time is of the essence, and rapid implementation is critically important.