Decoding the Hydrogen Rainbow

While the conversation about hydrogen in Canada continues to gain traction, it is important to understand the different types of hydrogen, their implications, and their availability. And the rainbow only has 8 colours – Hydrogen is now at 10 – and counting! The most common type of hydrogen is “Grey”, however, it is the least sustainable – except for Brown or Black – which are even worse! “Blue” and “Green” hydrogen represent two distinct approaches to hydrogen production, differing primarily in their environmental impacts and production methods. And if you were already having trouble keeping it all straight, there’s also now Pink, Turquoise, Orange, Gold and White hydrogen, which are less common, but offer different benefits and drawbacks.

And so here’s your decoder ring:

First – a few things to know:

• There are few substances that offer the same “energy density” offered by fossil fuels in the same amount of space, or with comparatively manageable risk. For example, nuclear fusion offers great energy density – but obviously not a great substitute for powering your vehicle – and refueling would likely prove to be difficult. Hydrogen – AKA “H2” – is the equal of fossil fuels or even better in terms of energy density: It can be compressed into smaller volume and yet can provide enough energy to power a Class 8 transport truck and haul the heaviest legal loads on the road over long haul distances. This is something batteries cannot yet do at a significant range – while weighing a fraction of what batteries weigh – and even less than diesel fuel. So, there’s less “overhead” in carrying the power supply allowing H2 powered / partially powered trucks to carry the same or even slightly more load than traditional or battery powered trucks. (The battery pack on a truck can reduce the allowable load by as much as 10 tons – a third of the capacity – and that weight never goes away, even after a truck drops its load off – so you not only have smaller loads, even the “deadhead” (empty trailer) runs mean hauling a decent sized load).

• It’s as safe or safer than gasoline to transport – no more flammable – and refueling with H2 can be accomplished in the same or even less time than refueling a comparable ICE / gas powered vehicle.

• When not connected to other elements, it’s a teeny tiny element on its own – meaning it can escape more easily through holes or imperfections in pipeline or container joints / seals than oil or natural gas. These escapes don’t endanger the environment or pose a risk – but they do reduce the overall efficiency. Consequently, H2 is sometimes combined with other molecules (i.e. ammonia) or merged with other fuels such as natural gas – making those fuels more sustainable while reducing H2 losses (see our Cleantech article 4 of 5, published today, to read about one very promising approach from Ayrton Energy).

• Hydrogen is the most common element on the planet – the “H” in H20. So it’s massively plentiful – but it’s mostly stored in water. Some H2 does occurs naturally (e.g. in geysers or volcanic gases).

• The “waste” from driving an H2 powered vehicle is a bond of H2 and O – so quite literally water.

As a chemical, H2 is problematic in that once the H2 molecule marries with another molecule – ie oxygen (or O) or methane – it often takes a LOT of energy to effect a divorce. However, once divorced, all types of hydrogen are chemically the same and provide the same energy values – and thus equally attractive as a powerful, energy rich fuel.

But how they get – or got – divorced matters and results in different names for the end product.

Getting it there:

Core to widespread adoption of H2 is finding solutions (literally solutions) that can bond with H2 for transport in light, ambient pressure and ambient temperature containers – and then have that bond be broken using minimal amounts of energy.

Ammonia is one such solution although less than ideal – enabling, for example, green H2 from Canada to be shipped in tanker ships to Germany and then extracted to replace Russian natural gas – but the combined energy to extract the original H2 – use it to create ammonia – ship it across the ocean – and subsequently re-extract the H2 from the ammonia is higher than ideal – and so the holy grail for R&D scientists is finding a chemical solution that can operate at ambient temperatures, under minimal pressure, and that will release H2 from the “transport solution” bond easily, and thus with minimal energy – while leaving no toxic waste. (Again – see the Ayrton info in today’s Cleantech Chronicles article). While H2 can be shipped on its own, that typically requires really high pressure and / or low temperatures – and thus very heavy containers. The thickness of the steel walls and their weight ultimately reduces the payload that can be moved on any form of transportation. Storing H2 in a solution for transport may add weight – but remove the need to use heavy steel containers – ultimately moving H2 in more or less comparable quantities – but with much less hassle for filling / unloading very cold or highly pressurized containers – and dramatically reducing the risk of a fiery outcome.

And so, below find a primer on the H2 rainbow – moving from worst to best of the most common forms – and then looking at some of the latest colours!

Black and brown hydrogen represent the traditional process for making hydrogen, which uses either black or brown coal (lignite). The method releases high amounts of CO₂ and carbon monoxide into the atmosphere. In 2020, world-wide, around a fifth of hydrogen was still made using coal, according to the International Energy Agency (IEA). This is obviously not a viable solution!

Grey hydrogen is the most common type of hydrogen produced and its production uses fossil fuels, typically natural gas, to generate hydrogen through a process called steam methane reforming (SMR). During this process, methane is reacted with steam to produce hydrogen and carbon dioxide. The key characteristic of grey hydrogen is that the CO₂ emissions from this process are not captured or stored; they are released into the atmosphere, actually contributing to greenhouse gas emissions.

Blue hydrogen, on the other hand, is made from natural gas through SMR similar to grey hydrogen. This involves reacting natural gas with steam to produce hydrogen and carbon monoxide, which is then further processed to generate more hydrogen and carbon dioxide (CO2). In contrast to grey hydrogen production, in blue hydrogen production, the CO2 is captured and stored underground, theoretically making it a low-emission process. Nevertheless, there are concerns about methane leaks during natural gas extraction and transportation, which can significantly contribute to greenhouse gas emissions despite the carbon capture efforts. And there’s also a question as to whether the resulting H2 has less energy than the natural gas mined and then consumed to create it – so if the CO2 is not captured and stored successfully, we may end up with less output from the original energy as well as GHGs. While touted as a “transition” strategy, Blue H2 essentially continues to advance the interests of the fossil fuel industry as they strive to make themselves relevant – and qualify as a “clean / green” investment option under new clean investment taxonomies being implemented around the world.

Green hydrogen is the “ideal” solution. It is produced through electrolysis, where electricity is used to split water into hydrogen and oxygen (H2 and O). The crucial factor here is that the electricity comes from 100% renewable sources such as wind, solar, or hydro power. This means that the entire process of generating green hydrogen does not emit carbon dioxide, making it a truly clean energy option. However, green hydrogen is presently more expensive because electricity is more expensive than natural gas for the same energy unit output – and then the the cost of electrolysis technology.

The Rainbow is getting more colours!

Pink hydrogen is a term used to describe hydrogen that is produced using nuclear power. Like green hydrogen, pink hydrogen requires electrolysis to be produced, however instead of relying on renewable electricity, pink hydrogen relies on nuclear reactors to generate electricity, which is then used to power the electrolysis. Since nuclear power produces low-carbon electricity, the hydrogen produced through this method has a lower carbon footprint compared to hydrogen produced from fossil fuels, making it a cleaner alternative, but not as ideal as green hydrogen, due to the leftover waste from nuclear plants.

Pink H2, however, has a key benefit, as production can utilize excess energy from nuclear plants which would otherwise be forced to turn generation up and down – a time consuming and inefficient process. Ideally nukes would run at the same baseload level all the time. But power demand fluctuates predictably with time-of-day / day-of-week – and unpredictably, based on weather (think passing storm / cloud cover leads to a dramatic downshift or surge in air conditioning demand in buildings across a city), and an array of other things that causes surges in demand that are presently met in many jurisdictions by either firing up / shutting down quick response gas-powered generators – or even requiring power operators to pay a premium for power from another grid – or dumping excess power to other grids – often having to pay to do so!

Firing up a nuke takes time – so tying H2 generation to a nuclear plant can enable the nuke to run at a consistently higher baseload that responds by making more or less hydrogen, and ultimately not only reducing the GHGs from running natural gas generators, but also offering cost savings from no longer having to pay other jurisdictions to take our excess, essentially using H2 as a long term storage battery. And critically – eliminating the need for fossil fuels to manage short term spikes in demand.

Turquoise hydrogen is a type of hydrogen fuel that is produced through a process called methane pyrolysis. Unlike the more common methods of hydrogen production, such as SMR or electrolysis, which typically generate carbon dioxide as a byproduct, turquoise hydrogen aims to be more environmentally friendly. Turquoise hydrogen is produced by breaking down methane into hydrogen and solid carbon at high temperatures – a process called ethane pyrolysis. The solid carbon can potentially be stored, used in various applications, or converted into other valuable products, making it easier to manage compared to CO₂ emissions. Therefore, turquoise hydrogen has the potential to be more energy-efficient than some other hydrogen production methods, but it is still under development and not as widely implemented as other hydrogen production technologies.

diagram credit: Hydrogen Today Info

Fall’s Latest Colours! Is Orange the new Green?

White hydrogen is the ideal solution – except there’s nowhere near enough of it! Like oil and gas, white hydrogen is naturally occurring – but so far only discovered in a few places – notably France and a few spots in South America with sizeable deposits. But exploration is limited thus far. Once discovered, it can be brought to the surface much the same way oil and gas are now.

Orange hydrogen represents a ground-breaking discovery in the field of sustainable energy. This unique form of H2 is naturally formed in certain geological formations through an interaction between elemental iron contained within minerals, and water. When these two elements encounter each other under specific conditions, such as at high temperatures and pressures commonly found deep within the Earth’s crust, a chemical reaction known as oxidation-reduction occurs. During this process, the iron reacts with water, leading to the production of hydrogen gas. What makes orange hydrogen distinct and its name fitting is the by-product of this reaction – iron oxides, which lend the orange color to the surrounding rock formations. As a side bonus, extraction using CO2 can lead to the carbon becoming a solid – thus sequestering – finally actual “use” in the CCUS (carbon capture use and storage) equation. Again – finding deposits is not something we have yet done in significant quantities.

Gold hydrogen refers to hydrogen produced by microbial activities in depleted oil wells. Injecting the right microbes can provide accelerated H2 production, and a Houston based company has recently successfully tested such a process where scientists increased microbe performance by six and a half times the rate needed to produce hydrogen at $1/kg, a key milestone necessary to advance the program toward commercialization. The subsequent field trial was completed in the Permian basin where the team successfully measured hydrogen concentrations three orders of magnitude above baseline. 

A Pathway for Fossil Fuel Companies?

This last trio are important not only for the H2 they potentially represent – but that they offer traditional oil and gas companies a chance to use their existing know-how and infrastructures to transform to a new green future. Discovery, drilling deep into the earth’s crust, and injecting chemicals into wells is something they already do – and Canada has no shortage of abandoned and polluting oil wells – the extraction of gold or orange H1 could well extend their economic usefulness – or fun clean ups and / or neutralize the mess remaining inside

So what’s the takeaway?

In summary, while Grey, Blue and Green hydrogen all aim to provide cleaner energy alternatives, “Grey” hydrogen production relies on fossil fuels and cannot be considered sustainable or helpful due to its environmental impact. The production process contributes to greenhouse gas emissions and climate change.

For hydrogen production to be more sustainable, Blue hydrogen or Green hydrogen are preferred – for now anyway. While Blue hydrogen relies on fossil fuels with an added carbon capture step, it is still subject to criticisms related to methane emissions that escape undetected and under-reported – and thus less than overall sustainability. Green hydrogen is produced using renewable energy and has no direct emissions, making it far more environmentally superior. Emerging Pink and Turquoise hydrogen production may prove to be equally clean overall, and even ultimately the best solutions, and while progress is happening, the industry has a way to go yet before we can look to a secure H2 future – which is where the Federal Government needs to do more than simply say what one of our clean tech leaders recently summed up as being “We need to have a H2 strategy”.

One thing is certain: the fossil fuel industry will continue to promote Blue hydrogen as “clean” – while ignoring the emissions from mining, and the associated methane loss. Don’t be fooled (or fueled!) To this writer, Pink represents a dramatically under-tapped resource that could have the biggest impact on GHGs in places with nuclear generators already in place.

Our hats off to long time hydrogen pioneer HTEC led by Clean50 honouree Colin Armstrong, who have been advancing the H2 economy for a while – celebrating their 20th anniversary earlier this week. Colin and other Clean50 members are proving that hydrogen can indeed be a reliable part of our future.