The Colors Of Hydrogen

There seem to be two types of stories circulating about the environmental crisis right now.  There’s the “We’ve lost, we’ve passed the tipping point” style, and then we have the “This is exciting! Look at all the technological possibilities” set.

Both genres at least acknowledge the science and recognize a need for action.   It is so tempting to ignore the “It’s all a hoax / The economy is what matters” end of the spectrum.  Unfortunately we need to keep it in the picture because so many voters and decision makers inhabit that space.

Doom or bright new technological future?

My inbuilt pessimism leans toward doom and that is supported by some new reports.  But I also feel that is all the more reason to do more and do it now.  Not soon, but now!

The technology stories – more solar, more wind, more batteries, smarter grid (central or local), hydrogen (and ammonia) of various colors – are interesting and exciting.  They open up new possibilities and are necessary – but not sufficient!  All seem to miss some major points:

  1. They address climate change, specifically greenhouse gas effects, and ignore all the other factors like species loss, soil degradation, deforestation, pollution etc. Climate change is a cause of many of these other problems, but population growth, consumption habits, economic drives and political motives also play a major part.
  2. They tacitly assume that it is necessary to generate and distribute energy at the same, or even higher level, than at present.  At the limit that argument ends with all the world population consuming energy at the level of the industrialized nations. (And wouldn’t the profits from that consumption be great!).  I believe that without major reductions in consumption none of the technology stories will prevent a ghastly future.
  3. They are tailored for the people lucky enough to live in the rich, industrialized, countries (and if you’re poor in those countries they don’t apply either).  Arguments of a hydrogen vs. battery transport infrastructure have no meaning to a huge portion of the world population.

Can we do more, can we do it now?  And just how can we do it? That is exactly the point raised in the ghastly future paper: “…what political or economic system, or leadership, is prepared to handle the predicted disasters, or even capable of such action”?

There have to be answers.  In democracies it means we need a significant change in voting patterns.  It is not impossible; in times of war people have voted for leaders who have asked for, and enforced, sacrifices.  Time to do it again.  We can’t keep having “economic growth”, which means more consumption. The mathematics of the biosphere does not allow it.   

The Colors Of Hydrogen

The potential “hydrogen economy” has relatively little exposure in the USA. It is a more common topic in Europe and Australia. There is much discussion about green or blue hydrogen.  What does that mean?  The diagram below gives a quick overview:

Diagram from Energy & Infrastructure What are the colors of hydrogen?

Blue and Gray are the same process, but gray releases the “waste” CO2 into the atmosphere, while blue captures and stores the CO2. The gas people say that makes blue practically green, but there are lots of loopholes and problems associated with CCS (Carbon Capture and Storage) – so not really green.

Brown (also called black) is worse than grey because of the additional pollutants.  And note how the diagram does not show the waste products for brown, or gray.

Green and pink are also the same process; electrolysis.  Which gets us into the “Is nuclear power green?” argument. (No, it’s not)

Ammonia (NH3) is produced in large quantities, primarily as a fertilizer.  Its role in the hydrogen economy is as a transport medium for hydrogen because it is much easier to store and transport than pure hydrogen.  Producing ammonia starts with the hydrogen processes above. The hydrogen is then combined with nitrogen to produce ammonia via the Haber-Bosch process.  When ammonia is referred to by color, it is based on the “color” of the hydrogen used to produce it.

If you are not familiar with the Fritz Haber story it is worth reading.  In a nutshell; Nobel prize for the Haber-Bosch process, which allowed vastly increased food production and arguably saved millions from starvation, development of poison gas weapons in WW1 and development at his institute of Zyklon A.)

At the point of use the ammonia is converted back to hydrogen, with the nitrogen released.  A promising process is described in this article.

The devil, as always, hides in the details. If you take truly green hydrogen and then power the Haber-Bosch process with more green electricity and transport the ammonia with gray fuels and then use pink electricity to release the hydrogen for end use, what color is that final hydrogen?

Further descriptions are: Potential Roles of Ammonia in a Hydrogen Economy (a technical paper by the US Department of  Energy, 2006) and Ammonia—a renewable fuel made from sun, air, and water—could power the globe without carbon (American Association For The Advancement Of Science, 2016)


OK – we have lots of fun technological solutions, including “a renewable fuel made from sun, air and water” – so why all the doom? Because of:

  • Fires, drought and heat in the western USA
  •  Smoke haze and smell all the way from the west of the continent to the east coast (Picture: Rt 84, CT, July 26, 2021)
  • Fires in Siberia, Brazil and seemingly everywhere else
  • The Amazonian rainforest turning from net CO2 sink to net emitter
  • Deadly floods in Germany, Belgium and Holland, etc.

All these items, and more, are referenced in World Scientists’ Warning of a Climate Emergency 2021.  Some key items from the report are in the graphs below.  It’s not all gloom; there are pledges, carbon pricing, fossil fuel disinvestments and so forth.  But these measures have yet to show a measurable impact.  Only Covid19 has had an effect – for all the wrong reasons.

A 2020 paper, by many of the same authors and cosigned by more than 11,000 other scientists, contains this statement: “The climate crisis is closely linked to excessive consumption of the wealthy lifestyle. The most affluent countries are mainly responsible for the historical GHG emissions and generally have the greatest per capita emissions” 

Further reporting and analysis is at:  Climate tipping points are now imminent, scientists warn and Critical measures of global heating reaching tipping point, study finds

Doom or Technological Nirvana?

We better do something now, before the future becomes inevitable.  Sure, the rich will be OK.  They will bemoan the loss of their favorite dive site or ski slope.  They will complain of the exorbitant price of almond milk and the poor quality of the salmon.  But they will make do with their air conditioned houses, shaded pools and electric cars.

It’s not going to be so nice for most of our children and grandchildren.

For some huge majority of the world population it will be very, very unpleasant – “ghastly” may well be the proper word.

And finally, what can we really do?  Sure we can take steps to reduce personal consumption. But in a democratic nation the most potent action is – to VOTE – if at all possible.

One thought on “The Colors Of Hydrogen

  1. TaDah – we now have another color:

    WHITE HYDROGEN – naturally occurring hydrogen. Found at depth similar to oil and gas deposits. Early days, but another possibility.
    “It Could Be a Vast Source of Clean Energy, Buried Deep Underground
    In eastern France, and in other places around the world, deposits of natural hydrogen promise bountiful power. But questions remain.”

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