Hydrogen might self-renew, reservoir found in France (Patreon)

[This is a transcript with links to references.]

I’ve been very critical of the so-called hydrogen economy.  But I’ve recently reconsidered my position because of an interesting development. A few months ago, Scientists drilled a hole in southern France to measure methane levels but instead they found hydrogen. Indeed, the French might be sitting on top of one of the biggest naturally occurring hydrogen reservoirs in the world. And it might not be the only one. There are now startups all over the world searching for the stuff. Let’s have a look.

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 Hydrogen burns cleanly with oxygen to water while creating energy.  That makes it sound like the ideal fuel. But there are a few problems. At atmospheric pressure and room temperature hydrogen is a gas,  and to handle it you need to either cool or, more commonly put it under pressure  . Hydrogen is also generally nasty to deal with. It’s such a small atom that it creeps into any other material and degrades it rapidly, a problem known as “hydrogen embrittlement”.

 But hydrogen is used in the chemical industry for all kinds of purposes, exactly because it reacts so readily. At the moment it’s predominantly produced from methane, also known as natural gas. The reason isn’t hard to see, if you have a look at the chemical formula for methane, that’s C H 4, which is a lot of h’s there.

You will also notice that methane has that C in there,  so what happens with that? Well to get hydrogen out of the methane, one uses a process known as steam reforming in which one combines the methane with water which produces hydrogen plus, wait for it, Carbon dioxide. Yes, so if you produce hydrogen from methane that leaves behind carbon dioxide

 Now the fans of hydrogen say that you can produce the hydrogen from water with renewable energy and also use it for energy storage. And yes that’s a nice idea in principle but in practice there are only a few tiny test facilities for that and using hydrogen to store energy is extremely inefficient.

You can make hydrogen from biogas, that’s methane produced basically by letting agricultural waste rot away. Bio-gas production exists, and it does work, but it has the rather obvious limitation that you need land to grow all the bio-stuff that you let rot away.  And if you crunch the numbers, bio-gas will realistically not supply enough hydrogen to power all transport vehicles.

And that’s why I think the so-called hydrogen economy is somewhat of a joke, because it will end up basically being natural gas. But.

Geologists have known for quite some time that there are hydrogen reservoirs in Earth’s crust. This in and of itself is somewhat surprising because, as I said, hydrogen is a very small molecule.  You expect it to escape. Even if it doesn’t escape, it likes to react with something that contains carbon, and then you get the carbon problem back. It turns out though that hydrogen doesn’t really care what geologists think it should be doing.

There’ve been a few reports going back to over a century of hydrogen bubbling out of the ground, sometimes leading to accidental explosions.  A particularly remarkable case is a borehole in Mali  that was shut down in 1987 because the gas coming out of it tended to explode. It wasn’t until 2012 that someone figured out it was almost pure hydrogen gas  and made a business out of this.  But more often hydrogen is a small fraction of gases that escape from the ground.

Estimate say that the new hydrogen deposit which they found in Southern France contains between 46 million and 260 million metric tons of hydrogen. This is roughly comparable to how much the world produces in one year, which is 96 million metric tons.

That would mean it’s basically one year without the greenhouse gas emissions coming from the usual hydrogen production.  Not bad, but not a game changer in and of itself. The game changer is that there could be more, much more. And it might be renewable.

Just how these hydrogen deposits come into being is somewhat unclear, so no one really knows how many there are. But the leading theory is that the hydrogen is produced when hot water underground reacts with hot iron rich minerals like forsterite  and other olivine stones. The oxygen in water bonds to iron, freeing up clean hydrogen atoms which rise and get stuck in porous rocks  much like methane. Depending on what the geological layers are above the production site, the hydrogen doesn’t necessarily escape to the earth’s surface. But if you drill into the rocks, the hydrogen escapes et voila.

If that theory was correct, this would be very exciting because it’d means that these hydrogen reservoirs can replenish  if more water runs over the hot rocks. They’re basically geothermal wells in which the hot rocks produce hydrogen.

George Ellis from the US geological survey has estimated that there could be tens of billions of tons naturally occurring hydrogen cached globally. If only 1% of this could be extracted that could cover 10 % of the world’s energy needs. This is why in the past years, hydrogen mining startups have sprung up everywhere, such as the Denver based companies Koloma  and Natural Hydrogen Energy,  the Spanish company Helios Aragón,  the British company H2Au.

And all that sounds very good, and I will admit it does make the entire hydrogen economy thing sound much more plausible.

Yet, I’m still kinda sceptical.  [[ https://www.youtube.com/watch?v=3d8hC71xGpc around 02:21 (black smoke), credits “Landsvirkjun”]]As we have seen in our earlier episode on geothermal energy, if you dig into the ground all kinds of gasses can come out, including methane, carbon dioxide, and nasty sulfuric stuff.

This makes me think it’ll be very rare they get almost pure hydrogen, more likely they’ll have to separate it from the carbon-containing stuff and figure out what you do with the rest. Whether this makes sense, economically, energetically, and environmentally, only time will tell.