Welcome to DiviGas' "hydrogen takes," where we explore, break down, debate, criticize, or endorse hydrogen technology for already hydrogen-savvy readers. DiviGas is a gas separation technology company that assists many other technologies, and we as a team realized a long time ago that this gave us a unique, in-depth, and technical capacity to discuss the H2 industry.

We all should stop using the ‘colors of hydrogen.’

We're all already accustomed to 'green' hydrogen, and many of us have heard of several other colors as well: blue, gold, pink, turquoise, white, etc. Often, they are described as a quick Google search reveals below.

Figure 1. A Selected Color-Code Typology of Hydrogen Production [1]

Figure 2. The Colors of Hydrogen [2]

In this opinion piece, we want to present the case that this "color" system has so many problems that it is basically worthless, and even arguably counterproductive aside from a very narrow setting.

It is an inconsistent system:

Let's start with the first and most obvious problem in the above two images. You can immediately see differences between both of these images. If you look at the blue hydrogen in the first, it considers gasification and natural gas reforming + CCUS, and in the second, it considers that it is steam methane reforming only. This is not a minor difference when you consider that gasification is a $100B market today. [3] The point here is not to skewer these two particular tables, or any of the dozen others you can find if you google 'colors of hydrogen’.

I wanted to highlight this because this vagueness of definition has real major consequences which brings me to our second point.

To fix a problem you need to agree on what the problem is:

Governments and regulatory bodies, investment funds, and all manners of institutions fall into color traps or overtly narrow definitions which leave out entire fields of solutions. We at DiviGas experience this firsthand. As a supplier of subcomponents, we still to this day do not fall into the vast majority of subsidies allocated for “green hydrogen” despite being a demonstrably critical subcomponent of many supposedly green systems because of the narrow definition of what green is. In effect, this means that this definition could mean all gas separation companies (not just DiviGas), which account for at least 20% of the final price $ tag per kg of most of the hydrogen made, are left with much less support because of a bad definition of green.

Another non-DiviGas example is the new (at the time of writing) US H2 tax credit unveiled in December '23. [4] It is notoriously narrow in its definition, both for good and bad reasons (and an amendment process for it is underway), but the credits are suspiciously narrow around what purists would call 'green' only. It focuses almost entirely on newly built electrolyzer-only hydrogen with power sourced only from renewable energy, which some would consider completely ‘green.’ However, dive deeper and within this definition do we even agree on what constitutes renewable energy? Let’s bring back biomass gasification from above, which is considered both a green and not green solution. Assuming here that we are gasifying a feedstock of wood chips or discarded corn husks. This biomass was originally created by sucking carbon out of the air to grow, then this material is gasified. [5] It would be impossible to argue that naturally grown wood isn't a renewable energy, but the biomass turned hydrogen will have carbon molecules emanated as well which will come out with the hydrogen. If these are released into the atmosphere, the process becomes net neutral since this CO2 will have been absorbed from the air in the first place. If they are captured and stored, the process stays net negative. But of course, the gasification process has emissions of its own, particularly because it’s a hot process. If it is heated via dirty grid power or fossil fuels then the process can easily become carbon positive.

So to recap, here we have a technology called green, by some, but not others, that's either carbon neutral, positive or negative, depending on key details that most people will never understand and will change operator to operator, and governments bank hundreds of billions of dollars around this. What could go wrong?

Capture breaks colors:

I even simplified a key topic above. Capture, or the act of preventing CO2 from going to or returning to the atmosphere is extremely fickle. Let's take the more-or-less definition of blue hydrogen, which I'm going to define here as 'hydrogen made from fossil fuels with emissions captured' (note this disagrees with the first image above as I wouldn't put gasification as blue). This definition omits that there are capture rates. Or in other words, it is nearly impossible (or at best extremely cost prohibitive) to capture 100% of the CO2 produced in this definition, but is 100% really realistic? Achievable? Worth it? If we take a steam methane reforming plant which produces 'grey' H2 and capture 60% of the CO2. Is this now blue hydrogen? Is it at 80%? At 95%? At 99%? The CO2 in this hydrogen-making process doesn't only come from the reaction of water with methane either, it comes from the burners that are used to heat water to steam. It also comes from emissions residue streams of the separation/purification process where about 20% of the hydrogen is still mixed with the CO2.

There are many projects attempting this already today, [6] and an enormous amount of press has written vitriol on the topic and arguing that blue H2 is a waste of time. [7] They lambast “blue hydrogen” as a whole and the fundamentally political process of regulators listens, but upon closer inspection and as we will write in a dedicated article, a lot of their science in these types of statements is at best superficial science. At worst they can be a biased and idealistic attempt to sabotage anything that isn’t a specific technology (such as electrolyzers) despite contradicting glaring human realities and incentives.

Still, borderline useless isn’t useless:

If these color schemes are so bad, then why do we use them? Why have I been referring to hydrogen made from fossil fuel with carbon capture as “blue hydrogen”?

Simplicity: We can't expect the average person to understand capture rates and the nuances of gasification or electrolyzers, we need a simpler framework, we need to bring everyone into the fight against climate change. There is no alternate novice-level framework (The IEA or some other agency should make a regularly updated suggested one!).

Brevity: It just takes too long to clarify every statement. In our day-to-day life discussing gas streams with sites and plants around the world, DiviGas staff semi-reluctantly still use the colors as I did above, but we make sure to always clarify what we mean by it at the beginning of a professional exchange to make sure we are categorizing a process from a same base of information

Unfortunately these colors until homogenized by a source of authority that isn’t overtly politicized (which seems impossible if history shows anything) will remain the very flawed yet broadly used tool that it is.

Yet there is hope for truth:

Thankfully, there are other ways to quantify the climate impact of various technologies. Life Cycle Assessments (LCAs) can yield specific quantifiable outcomes in the form of “kg of CO2 emitted per time” or even CO2 equivalent when talking about other greenhouse gases such as methane. In complex systems such as steam methane reforming, doing an LCA means doing many different analyses such as the emission of the feedstock, of the heating, the lost gases, the separation process and more. Still, this ultimately yields a relatively robust nuanced and reliable number on which to measure against others. Thankfully, a plethora of companies and startups are trying to build tools to simplify these calculations.

Unsatisfying:

The conclusion is that hydrogen is complicated, it takes a near-impossible amount of expertise to understand all of it, and over-simplifying it can harm key helpful technologies that we need to decarbonize. What we will keep promoting is for everyone to do their best to resist simplifications and highlight nuances, especially when talking to political entities. When you can perform credible LCAs.

References:

[1] R. Al-Ashmawy, S. Shatila, Mena Energy Investment Outlook 2022-2026, Apricorp.Org. (2022). https://www.apicorp.org/wp-content/uploads/APICORP-Annual-MENA-Energy-Investment-Outlook-2022-26_EN.pdf 

[2] The Colors of Hydrogen, Explained, FASTECH. (2024). https://www.fastechus.com/blog/the-colors-of-hydrogen-explained. 

[3] Biomass Gasification Market Growth Forecast Report, 2023-2030, P&S Intelligence. (n.d.). https://www.psmarketresearch.com/market-analysis/biomass-gasification-market#:~:text=Market%20Overview,USD%20187.3%20 billion%20by%202030.  

[4] J. Calma, The future of clean hydrogen in the US could hinge on a new tax credit, The Verge. (2023). https://www.theverge.com/2023/12/22/24012141/hydrogen-tax-credit-45v-biden-treasury-irs-clean-energy. 

[5] Hydrogen production: Biomass Gasification, Energy.Gov. (n.d.). https://www.energy.gov/eere/fuelcells/hydrogen-production-biomass-gasification#:~:text=Gasification%20is%20a%20process%20that,%2C%20hydrogen%2C%20and%20carbon%20dioxide.

[6] Blue Hydrogen Leaders – Q2 2022, GlobalData. (n.d.). https://www.globaldata.com/data-insights/macroeconomic/blue-hydrogen-leaders-q2-2022/#:~:text=Currently%20blue%20hydrogen%20projects%20accounts,transportations%20as%20main%20demand%20sectors%20.

[7] Blue hydrogen: Not clean, not low carbon, not a solution, IEEFA. (2023). https://ieefa.org/articles/blue-hydrogen-not-clean-not-low-carbon-not-solution.