Large deposit of "white" hydrogen found underground in France | Hacker News Reader

Large deposit of "white" hydrogen found underground in France

cnn.com

"Hydrogen produces only water when burned"

This oft-repeated claim is incorrect. Burning hydrogen in air produces NOx and other pollutants, and this confusion is promoted by fossil fuel companies that persist in telling us that it's fine to keep burning things.

Hydrogen is great, but burning it is not sensible, be it by itself, or mixed into natural gas.

Can you pls elaborate why nox is produced? I thought too that burning hydro means just water

Burning would produce just water only when done in pure oxygen.

Normally burning is done in air, which has more nitrogen than oxygen.

At the high temperature of the flame, a small part of the nitrogen also burns, producing nitrogen oxides, besides the hydrogen oxide, a.k.a. water.

In air: hot nitrogen (~80% of air) + oxygen present -> some nitrogen will react even though it's not the fuel input.

Not much different from burning other stuffs in air, really (gasoline / diesel included). Of course the burn conditions have a big effect. And cleanup after the burn (catalysts) is possible.

But imho the more sensible thing would be to input the H2 into a fuel cell.

Could you not get it to produce nitrous oxide instead? Or can nox be used as an oxidiser like nitrous oxide?

If the byproducts are a liquid an a gas, seems like it would be easy to separate the two.

Or is there a cheap source of nitrogen less air/ oxygen?

The nitrogen oxides that are produced are gasses at room temperature.

And the water is liquid.

Sure, but if you’re burning H2 in pure O2 you aren’t producing nitrogen oxides, and if you’re burning H2 in air, you end up with a whole lot of N2, CO2, and Ar left over, residual H2 or O2 (because your combustion is not exactly stoichiometric), and a relatively small fraction of nasty nitrogen oxides as side products.

(And yes, you can and should condense out the water so you can recover the higher heating value instead of the lower heating value, and H2 will have the nice property that the condensate won’t be especially acidic, unlike boiler condensate from hydrocarbons, which is annoyingly acidic.)

Ah ok.

Well the fact remains you have an exhaust with elevated nox.

So the 3 options are to stop the nox being created to start with (no nitrogen), convert the nox into something else (nitrous oxide?) or release/store/use the nox for something.

I'm not a chemist so I don't know what's possible / economic, thus the question.

Yep, they spend a lot of money trying to convince people that hydrogen is juuuuuuust around the corner, but please keep using our products until it arrives.

> “hydrogen lobby, whose main players are fossil gas companies, declared a combined annual expenditure of €58.6m trying to influence Brussels policy making”

https://www.rechargenews.com/energy-transition/liebreich-oil...

It looks to me you just hate fossil fuel companies. Which is fine. But if they can help to get sooner at net zero, you'd rather say no?

Hydrogen can produce NOx when burned, if you burn it in air. You can burn it in flue gas (a combination of pure oxygen and CO2). Or you can simply use it in fuel cells to produce electricity.

To me the main issue with this discovery that that this "large deposit" is not nearly large enough. At the high end of the estimate it would be 250 million tons of H2, which would replace about 600 million tons of CH4, which would result in about 1.5 gigatons of CO2. That's a lot, but we emit about 50 gigatons of CO2 equivalent each year. We'd need many hundreds of these fields to make a significant dent in our emissions.

>You can burn it in flue gas (a combination of pure oxygen and CO2).

I don't think I quite understand your comment. What type of process equipment has flue gas with only O2 and CO2?

This one:

https://en.wikipedia.org/wiki/Oxy-fuel_combustion_process

Ah, interesting, never come across that before. All the process equipment I've worked with (boilers, furnaces, etc.) combust fuel with ambient air.

This comment is a solid of example of letting perfect be the enemy of good.

I had to look up what “white hydrogen” actually was: https://en.wikipedia.org/wiki/Natural_hydrogen

In a number of years, when someone say "Nobody could have predicted that pulling a very voluminous fuel from the ground would cause earthquakes," please remind them of this post I am making on 10/29/2023.

Pulling a fuel out of the ground can always cause earthquakes later on. Pulling a very voluminous and non-energy-dense fuel out of the ground will be more likely to cause earthquakes than pulling out an energy dense fuel.

Could be true, of course, but: what are you basing your opinion on? Do you research this topic? Is this just gut feeling?

They are probably referring to the know issue of tremors caused by natural gas extraction.

For example: https://www.nytimes.com/2019/10/24/business/energy-environme...

As another posted said, the precedent from pumping out oil and natural gas gives us clear evidence there is some chance of earthquakes. This comes from the evening news, at least in my area.

High school physics tells us that hydrogen is a much less energy dense fuel than is oil or natural gas, so more will need to be pumped out to yield the same net energy.

Common sense tell us if you pump more stuff out from underground there will be more sbsidance of the ground.

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