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published on

January 2023

A Tale of Two Gases: Hydrogen and Ammonia as Energy Carriers

As technology, industry, and their place in the world’s economy continue to grow, so does our dependence on energy sources necessary to get jobs done. Unfortunately, fossil fuels, the primary energy source we consume, are a finite resource and damaging to the environment. As our needs grow, so does the scarcity of this fuel source and its harmful impact on the environment. Increasing awareness of how our current fuel usage affects the world around us improves the development and proper implementation of clean, renewable energy alternatives a higher priority than ever. And as concern over continued fossil fuel usage grows, more research into effectively utilizing abundant natural sources of energy like solar, water, and wind is taking place to set our energy usage on a more sustainable, low carbon path.

A more recent consideration in the conversation is hydrogen, a promising alternative energy source for the future. The following is an examination of the pros and cons of utilizing hydrogen effectively and safely.

Blue hydrogen fuel cell public transportation bus

Why Hydrogen?

You may remember from school that hydrogen is the first element listed on the periodic table and the most abundant element in the universe. While rarely available on Earth in a pure form, hydrogen atoms are contained in nearly all organic compounds and many inorganic ones as well. Plants, animals, and humans contain hydrogen, but so do water, sugar, and various acids. As a result, it’s infinitely renewable, and while it may take time to acquire and use, hydrogen won’t run out in the same way a fossil fuel may (and probably will). Tack on the fact that it can be used in heating, powering, and energy storage without producing greenhouse gas emissions at the point of use — hydrogen has significant potential in a net zero economy.

So, what’s the problem?

Large-scale vented hydrogen explosion test performed by BakerRisk

Why Not Hydrogen?

Though hydrogen is a promising alternative to oil, natural gas, and other non-renewable fuel sources, the infrastructure necessary to utilize hydrogen safely and efficiently isn’t there yet. A core challenge in using hydrogen gas is that it takes more work to store. It has a low energy density and must be transported in high-pressure environments, making hydrogen transportation bulky, impractical, and expensive. Additionally, hydrogen gas is volatile, highly flammable, and difficult to detect without specialized sensors, meaning leak detection can be challenging and its usage potentially dangerous. Hydrogen also has a higher laminar burning velocity than most other fuel sources, making it far more energetic when ignited than more traditional fuel sources like methane. And while liquid hydrogen can be stored and transported, it requires cryogenic temperatures of around -250 degrees C to maintain its state, making it as difficult a solution than hauling it as a gas. Because of these difficulties, the demands often require hydrogen to be manufactured close to where it’s being used, making utilization on a global scale difficult.

What Does Ammonia Have to Do With It?

As a potential solution, “energy carriers” are utilized to transport energy sources more efficiently and effectively to their end destination. Ammonia, an inorganic compound made of nitrogen and hydrogen, is often proposed as one such carrier for hydrogen. Though comprised of hydrogen, ammonia is easier to store and transport than pure hydrogen. When liquified, transport is far more convenient, practical, and cost-effective in terms of the required temperature and pressure conditions necessary to maintain it. And though ammonia is corrosive and toxic, it’s more easily detectable by smell than hydrogen.

For these reasons, ammonia is often a favorite in the conversation of potential hydrogen carriers, allowing many of the same benefits hydrogen offers in producing clean energy, with the advantages of more efficient and less demanding forms of storage and transportation.

But ammonia isn’t perfect.

Trucks transporting anhydrous ammonia

Know the Risks.

Hydrogen and ammonia both, though potential avenues toward a net zero economy, come with risks that must be considered. Beyond the logistics of transportation, hydrogen itself can be dangerous. It’s an incredibly flammable gas, and if not handled correctly, it can cause fires and explosions. As a gas, hydrogen is also colorless, odorless, and tasteless, and it can be hard to tell when it is leaked. And because hydrogen is very light, no known odorants can be added that would diffuse at the same rate.

On top of that, hydrogen fires are virtually invisible. Where there’s a leak, there could be a flame or a potential explosion hazard. While ammonia is significantly less flammable, it nonetheless carries the risk of explosion or fire. It is also toxic even at very low concentrations.

Hydrogen and ammonia carry with them challenges and risks that keep them from being, as of now, the dream fuel source they initially seem. Transporting and using these fuel sources require specialized and effective means of doing so. The applications are there but knowing how to handle them is integral to the safety of workers and industries moving forward.

With a comprehensive understanding of hydrogen’s unique properties as well as the inherent safety-related risks, BakerRisk can provide the support necessary to understand the risks associated with hydrogen and its carriers. Our professionals don’t stop at assessing operational risks; we work with you to determine practical solutions for risk reduction and mitigation. Contact us today.