Hydrogen is Starting to Explode, in the Good Way 

One of the most promising ways to store energy, hydrogen was once seen by select automakers as the future of clean mobility. But in the past five years, that’s changed. In electric vehicles, the fuel has been rapidly usurped by lithium-ion batteries, which sport superior energy efficiency, make for easier integration with the grid, and are far, far safer than liquified hydrogen gas. 

 

Battery electric vehicles, such as the Nissan Leaf, have rapidly overtaken those powered by hydrogen fuel cells. Image [CC BY 2.0] used courtesy of Kārlis Dambrāns 

 

Yet, hydrogen remains full of potential. And testament to that is the recent influx of funding, from both the public and private sectors, fueling its development and deployment.

Since May 19, the Department of Energy (DOE) has announced more than $8 billion in investment to advance hydrogen technologies and establish a series of clean hydrogen hubs across the country; on May 24, multinational industrial gas manufacturer Air Liquide launched the largest liquid hydrogen production facility in its global portfolio in North Las Vegas, Nevada; and on June 2, Toyota announced it has developed a working prototype of a portable hydrogen cartridge for use at the consumer level.

Below, we’ll provide a light overview of the engineering involved in producing hydrogen, and then take a full look at these recent developments.

 

Hydrogen, its Production and “Colors” 

Hydrogen on earth is usually found in combination with other elements, most notably with oxygen in the form of water; in this form, both the hydrogen and oxygen atoms are in low-energy states. Through a process known as electrolysis, electrical power is used to sever the bonds tethering the oxygen and hydrogen atoms.

 

Electrolysis is carred out in units known as electrolyzers, pictured here at factory scale (right). Image used courtesy of McPhy

 

The effect of the process is to transfer electrical energy to newly synthesized hydrogen gas, which is now itself a source just brimming with energy that can, for instance, be applied to a fuel cell to recreate electricity. It can also be famously recombined with oxygen to muscle rockets up into space, though most hydrogen in the United States is used in settings far less sexy: industrial processes and in the production of agricultural fertilizers, as described by the U.S. Energy Information Administration. 

Its production and the colors used to describe it, though, are in fact far more varied. Electrolysis is but one method for procuring hydrogen. By far the most common technique is referred to as steam methane reforming, which utilizes high-temperature steam, methane and a catalyst to produce hydrogen, in addition to carbon monoxide and carbon dioxide.

 

Steam methane reforming via natural gas. Video used courtesy of Mahler AGS GmbH

 

Depending on the type of fuel used to power either process, that hydrogen will go by different color-coded names. 

When manufacturers utilize renewable sources of energy such as solar or wind to power electrolysis, the resultant hydrogen is known as “green hydrogen.” When nuclear power is used to fuel that process, the hydrogen is referred to as “pink.” Brown hydrogen is produced when coal is used in steam methane reforming. Gray hydrogen when natural gas is the source of methane. Blue hydrogen when carbon capture technology is deployed to prevent the escape of carbon dioxide. If a novel method involving methane pyrolysis is used, the final product is known as “turquoise hydrogen.”

And the list goes on.

 

A Whopping $8 Billion from the DOE 

On June 6, the DOE issued a Notice of Intent (NOI) to fund the $8 billion H2Hubs program, established last fall under the Bipartisan Infrastructure Law.

The program will work to develop regional clean hydrogen hubs, whose purposes will be to create networks of hydrogen producers, consumers, and local connective infrastructure to accelerate the use of hydrogen as a clean energy carrier, the DOE said in its press release announcing the investment.

Hydrogen gas is a major intermediary in many industrial processes, and one area of emphasis will be to explore how stakeholders can collaboratively manage these complex interrelationships for greater efficiency and lowered pollution. Another will be to reduce industry’s reliance on steam methane reforming—which as previously described is an environmentally damaging process—through the advance of clean electrolysis development. 

Indeed, last year the DOE launched its Hydrogen Shot program, which aims to cut the cost of green hydrogen to $1 per kilogram in just one decade. 

 

Six Additional Grants Totaling $24.8 Million

Several weeks prior, the DOE also announced that it had invested $24.9 million in six industry-sponsored research projects aiming to further advance clean hydrogen electricity generation.

The DOE expects the projects, whose recipients are based in the Carolinas, the Midwest, and the Northeast, to “fast-track” the development of hydrogen technologies, in line with the Biden administration’s target of a zero-carbon American power sector by 2035. 

Perhaps the most enticing project will be conducted at the Gas Technology Institute (GTI) in Des Plaines, IL, where engineers will study the use of ammonia-hydrogen fuel mixtures in gas turbines with a view to strengthening ammonia’s utility as a clean low-carbon fuel. 

 

GTI previously worked with the DOE to convert biomethane fuel into hydrogen for use in fuel cell-powered military buses. Image used courtesy of the U.S. Army

 

Ammonia (NH₃) is an energy-dense compound containing three high-energy hydrogen atoms, and the use of solar-powered modalities for its production is being explored worldwide.

The chemical itself may be nasty, but the chemical industry has over a century of experience in dealing with it, including its transport. As such, the day that a reasonably efficient method of converting renewable energy into ammonia is discovered is, in this engineer’s view, a day the world will change.

Another notable project will look to craft an engineering design study of a hydrogen gas plant able to capture between 90 to 99% of its CO₂ byproduct. Still others will explore the use of hydrogen and hydrogen/natural gas mixtures to power electric turbines. 

 

Air Liquide's Largest Liquid Hydrogen Production Facility

Marking a $250 million investment, Air Liquide on May 24 opened its North Las Vegas hydrogen production facility, which the company says is its largest in the world. Per Air Liquide’s release, the facility will produce 30 tons of liquid hydrogen a day. 
 

Air Liquide's facility in North Las Vegas. Image used courtesy of Air Liquide

 

Let’s look at the math. Considering that liquefied hydrogen has an energy content of 33 kilowatt-hours (kWh) per kilogram, that works out to:

 

$$(33 \ kWh/Kg) \ x \ (907 \ kg/ton) \ x \ 30 \ tons \ = \ 816,300 \ kWh$$

 

That’s 0.816 gigawatt-hours, which is a lot of energy, but maybe not quite as much as it seems—a fossil fuel plant produces that much in an hour. 

Although Air Liquide says the plant itself will be “fully powered” by renewable energy, it was not immediately clear from the announcement if that includes just the facility’s nuts and bolts—its lights, computers, air conditioning, and so on—or rather that clean energy will provide all, or even most of the energy required to actually synthesize the hydrogen. 

 

Toyota Develops a Portable Hydrogen Cartridge Prototype

Through its Woven Planet subsidiary, Toyota has developed a working prototype of its portable hydrogen cartridge, the company announced early this month. 

The cartridge is designed to allow consumers to convey gaseous hydrogen to applications where it can be directly exploited. Trials will be conducted in sites including Woven City, which Toyota calls a “human-centered smart city” under construction in Susono City, Shizuoka Prefecture, Japan. 

 

Toyota's portable hydrogen cartridge prototype. Image used courtesy of Toyota

 

The container measures 400 mm in length and 190 mm in diameter, translating to a volume of 10.2 liters. At one atmosphere, a liter of hydrogen holds just three watt-hours (Wh), so the new cartridge will contain slightly more than 30 Wh. 

Capacity expands rapidly with pressure, but Toyota did not specify what pressure the initial cartridge is capable of sustaining. The company did mention, though, that it envisions future high-pressure iterations that can hold the hydrogen equivalent of 3.3 kWh. 

 

An Engineer’s Take 

The reader will note that all uses proposed by the federal government herein, as I see it, are sensibly intra-industry. Nobody, other than highly-trained professionals, should get anywhere near hydrogen gas. But my concern, as reflected in Toyota’s cartridge venture, is that this line will soon be crossed.

In the U.S., I have no doubt that we will see two-year community college degree programs sprouting up stressing the care and feeding of both pressurized hydrogen gas and liquid hydrogen. There is also still significant interest in hydrogen-powered vehicles in East Asia, as well as in Europe. 

Development of the latter will involve converting gas stations into hydrogen stations, which will no doubt be serviced by the type of unseasoned youngsters flocking to those fledgling programs stateside. What’s worse, if Toyota’s cartridge gains traction, we will witness the phenomenon of complete novices gadding about with containers of highly-pressurized hydrogen gas. No engineering expertise, not even a hint of hydrogen background, and the power of the Hindenburg in their hands. 

 

Remember the Hindenburg.

 

Let’s just say that I am glad I live in America!  

 

Feature image used couretsy of Air Liquide