In this series of articles, we started by exploring the challenges created by the White Gold Rush: lithium. Today in part 2, we dive deeper into UCSC’s green hydrogen breakthrough. In part 3, we will look at the current and upcoming technologies that bring both green and blue hydrogen energy to a scalable global solution. Hydrogen as a green energy alternative to fossil fuels and nuclear power, is a huge piece to the puzzle of decarbonizing our world.

Hydrogen is combustible and can be used in an internal combustion engine. Or it can mix with oxygen in a so-called fuel cell to produce electricity and steam as its exhaust gas. That electricity, in turn, can power a motor to run a car or a truck. But how do we get there?

Gray, Blue, Green

As the simplest and most abundant element in the universe, it consists of only one proton and one electron. It is an energy carrier, not an energy source: it can store and deliver usable energy. But it doesn't typically exist by itself in nature and must be produced from compounds that contain it. On Earth, hydrogen is found in the greatest quantities in water. It is also found in hydrocarbons such as natural gas, oil, and coal – often referred to as gray hydrogen. Two alternatives to gray hydrogen production are “blue” and “green”.

Blue hydrogen is produced from non-renewable energy resources such as natural gas using a process of steam methane reforming, where natural gas is mixed with very hot steam and a catalyst.

Green hydrogen is produced with renewable energy sources like wind, water, or solar.

Let’s focus on green hydrogen!

UCSC’s Breakthrough

In late August 2022, SCWorks’s article UCSC Makes Green Hydrogen Breakthrough, was one of our most viewed and shared articles in 2022. Hence these follow up articles. So why do scientists and researchers call this a “breakthrough”?

What makes this method a breakthrough?

Room temperature: The gallium/aluminum alloy can be formed at a little above room temperature to produce hydrogen (also at about room temperature). Whereas conventional gray and blue methods require higher heat.
Near lossless: there is very little loss of gallium - an otherwise very expensive elemental metal. Effectively all of the gallium separates out from the aluminum oxide and water and can be re-used to dissolve more aluminum.
Water and aluminum agnostic: any source of water can be used: city water, gray water, or rain water all work well. Salt water is much less efficient. Waste aluminum can be used: that includes used foil and the tops and bottoms of soda cans (the sides don't have that much aluminum in them).
Small scale: while conventional hydrogen production can realistically only be achieved on a highly commercial scale, this method can be produced in "boutique" environments.
Speed: this process is significantly faster than conventional production. So fast, it occurs right before your eyes.
No added electricity: this system makes hydrogen gas from water using chemical energy only.

Even before UCSC’s achievement, it was pretty well known that gallium and aluminum react with water to produce hydrogen. Many YouTube videos show the reaction. But no one before this has made this particular composition or, from what we can tell, worked out the ratio of gallium to aluminum to produce the alloy and to produce hydrogen most efficiently.

Commercial Viability

At first glance, it did not appear to be commercially viable given the energy and material costs required.

To produce 1 kg of hydrogen, you need 9 kg of aluminum and 9 kg of water. Considering that even waste aluminum is relatively expensive (e.g. $8-20), it is a losing proposition (compared to price targets for hydrogen).

Looking closer at the output, in addition to 1 kg of hydrogen, you get 17 kg of pure aluminum oxide (aka alumina). If the producer can sell that 17 kg of alumina for more than the cost of the waste aluminum + water, then the 1 kg of hydrogen is effectively “free”. You can balance out those input costs with just the alumina. For example, if 9 kg of aluminum is $20 ($2.22/kg), sell the alumina for at least $1.17/kg, you end up doing pretty well. If you can sell your alumina for more than that, it becomes a way to make clean alumina with hydrogen as a byproduct.

Alumina (depending on the purity) can be sold for *significantly* more than $1.17/kg. It's easy to find it retailing for $30, $100, or even $200/kg depending on purity.

So while this is the cleanest hydrogen you can produce, it's also the cleanest alumina production. Most of the world's alumina is produced from bauxite by an incredibly energy intensive process (Bayer Process) that produces an extremely caustic by-product called "red mud". Red mud just sits in pools contaminating water supplies.

Most alumina is used to make more aluminum. The rest is an additive into all kinds of products. UCSC is still working out the purity of the alumina resulting from the reaction as is. Any company licensing this process will need to figure out how to optimize it for their production.

$20-$30 input, yields $80-$170 of valuable output

Alumina is used as an additive in many materials (metals, ceramics, glass, etc.) So if this "cleanest hydrogen possible" can be sold at a premium, this "cleanest alumina possible" possibly can be as well. It is feasible that the alumina can be sold for at least $5 to $10/kg. If so, $20-$30 input, yields $80-$170 of valuable output. The UCSC research team is still determining the purity of the alumina produced as part of the reaction

As far as the gallium goes: 9 kg of aluminum is 333 moles of aluminum. If you were to process that all in one shot, that would take 1000 moles or about 70 kg of gallium, or about $30,000 worth of gallium. That's stupidly dangerous (at least right now). So the thing to keep in mind is that the above numbers illustrate the inputs and outputs for the production of 1 kg of hydrogen. It does not assume that an individual or company would produce 1 kg of hydrogen all in one shot (at least right now).

From the beginning, it was understood that the 9 kg of aluminum needed to make 1 kg of hydrogen would be dissolved into the gallium in batches. It'll be up to the company that licenses the technology to figure out what the optimal batch size/timing will be. So it’s unclear exactly how much gallium will need to be used, but it will depend on the application and the scale of production. While 95-99% of the gallium can be recovered from a small-scale reaction simply by letting the post-reaction components settle, that can be further optimized. That optimization, as well as determining if there's a long-term drop in efficiency of gallium after re-use. Again, we believe these are problems a licensee company can solve.

Small scale

Another commercial advantage to this technology is that small scale versions of this reaction can be used to make hydrogen (and therefore electricity) on-demand, literally anywhere - in remote locations including Antarctica and even Mars using this process). The aluminum/gallium nuggets can be stored indefinitely in a hydrocarbon (e.g. kerosene) without reacting.

Speed

Another commercial advantage to this is the speed of the reaction. It can produce liters of hydrogen in minutes. Electrolysis (which the world will still need for hydrogen production) doesn't work anywhere near that fast. In as little as 1 hour, an individual could produce all the energy needed for as many as 3 households. In the adjacent video, you can see an immediate production of hydrogen when when the aluminum gallium nugget is added to room temperature tap water.

No added electricity

“The amount of energy required to make hydrogen and turn it into liquid form is staggering. It is the most dumb thing that I could possibly imagine for energy storage.” Elon Musk

Aluminum metal is well known to be highly reactive with water and that reaction is known to produce hydrogen gas. The reason why the aluminum in everything we use doesn't react with water is because upon exposure to oxygen in the air, a "passivating" aluminum oxide layer (just a few atoms thick) forms on the surface of the aluminum. As we discussed before, aluminum oxide is effectively non-reactive.

What is happening in the UCSC process is that the act of dissolving the aluminum in the gallium (with a greater than 2-fold molar excess of gallium relative to aluminum) results in the formation of aluminum nanoparticles and (importantly) the removal of the passivating aluminum oxide layer. These aluminum nanoparticles in the gallium then react with the water to form the hydrogen and alumina.

This isn't free energy - UCSC is not violating thermodynamics. There's potential energy (chemical energy) stored in the aluminum. When the aluminum is able to react with water, that potential energy is released.

Contrary to conventional hydrogen production and Elon’s perspective, the green hydrogen production by UCSC is not inputting a lot of energy to separate the hydrogen from the oxygen in the water. It is however releasing a lot of stored chemical energy that is already present in the aluminum. The energy is already there in the aluminum. This is just the easiest known way to unlock it.

Summary

“Hydrogen is today enjoying unprecedented momentum. The world should not miss this unique chance to make hydrogen an important part of our clean and secure energy future.” Dr. Fatih Birol / ED of the International Energy Agency.

It is well-known that hydrogen has the potential to generate electrical power in both stationary and transportation energy sectors. As the world continues efforts to decarbonize, it is accelerating a hydrogen economy. According to a recent McKinsey report, there are more than 350 large-scale hydrogen projects underway, with a staggering $500 billion investment. Transportation, particularly shipping and aviation, provide the largest commercial opportunity – which is where institutional investment will have the largest ROI.

What about the rest of us?

“In a boutique environment such as a bike shop where you want to make a small amount of hydrogen to charge a small fuel cell, the UCSC solution makes even more sense because you don't really care about the cost,” explains James O’Connor, founder and CEO of Innovation Within. “It also provides an opportunity to de-centralize our energy distribution. ”

A good example of energy decentralization is Bloom Energy, headquartered in San Jose, California. It manufactures and markets solid oxide fuel cells that produce electricity on-site. The company was founded in 2001 and came out of stealth mode in 2010. It raised more than $1 billion in venture capital funding before going public in 2018.

The breakthrough at UCSC provides a solution for individual production and independence from “The Grid”. A home with solar panels could produce all the energy it needs via electrolysis. We will explore this further in Part 3 of this series. Green hydrogen brings our energy-starved planet significantly closer to a near-zero greenhouse gas emission future.

Big thanks to Jeff Jackson @ UCSC and James O/Connor @ Innovation Within for content contributions to this article. For more information about UCSC’s Green Hydrogen Breakthrough, contact innovation@ucsc.edu