exchemist

Reported

One thought that occurred to me later about this finding is that the world is badly in need of more efficient electrolysis methods, for green hydrogen production. Research into what is going on here might just yield new insights into options for catalysts. But it's still a mystery where the energy for this comes from. One would expect any potential difference between areas on the nodules to have become discharged long ago, given the whole thing is immersed in seawater. Something doesn't stack up here. I think we need to see the findings replicated. I wonder if they will discover there is some organism living in these nodules that is responsible, or something. I'm a bit sceptical about the battery idea.

Yes but the ions will start migrating through and neutralising the the acid on the other side - unless you try your idea of the central reservoir of NaSO4 of course. But this is quite a fun thread. 👍

It seems Dickens thought spontaneous combustion was a real thing, though many of his contemporaries thought it ridiculous of him to believe it. In Bleak House the victim, Krook, is an old drunkard - and many cases of supposed spontaneous combustion have involved an alcohol habit, no doubt because someone passed out through drunkenness won’t react to something setting their clothes on fire - a means of ignition is also invariably present. But the man allegedly strangled by his own thymus gland set new standards in bizarre hilarity. It came from a - shall I say breathless? - newspaper report in 1926:https://news.google.com/newspapers?nid=2202&dat=19260114&id=F9MlAAAAIBAJ&sjid=B_wFAAAAIBAJ&pg=5410,1795860 , which our poster presented as if it was yesterday’s news.

....and thereby creating a danger of............... spontaneous combustion! "and none other of all the deaths that can be died". * * cf. Bleak House

Then why do you say you are "wondering about the viability of such a study"?

Have the conclusions you cite already been reached? And has the work to support those conclusions already been done?

I'm a bit confused by this. Is this a proposal for a research project, or a summary of a paper that has already been written? If the latter, where is the actual paper, i.e. the content, with details of the studies considered and how they were analysed in order to draw conclusions? If the former, why does it prejudge the results before the research has been done?

Just found another synopsis of this, which touches on some of the issues we were discussing: https://www.nature.com/articles/d41586-024-02393-7 So the question of what about the hydrogen is indeed something to resolve, as is the energy source, given that the stored energy implied by the measured potential differences ought, by rights, to have run down long ago.

My favourite Napoleonic story concerns something I once read in a guide book on Sicily, to the effect that he at one point landed troops on the island but the campaign failed because the soldiers were bitten in the night by spiders that caused an outbreak of debilitatingly painful farts. However I have since been unable to substantiate this story, amusing though the image it conjures up undoubtably is. Maybe I am mixing it up with some story from the ancient world, though. Everyone, but everyone, has been to Sicily, even the Normans. It sounds the sort of bizarre and implausible thing Herodotus might write about.

That's an excellent point. So in the case of Mg there will be less tendency for the accumulating OH- ions to migrate through the pores and neutralise the accumulating acid.

Well that seems to be wrong, so as usual the journos have screwed up😄. This Wiki article is pretty unambiguous in stating the nodules are concretions composed of silicates, oxides and hydroxides of metals, in which Mn and Fe are major components: https://en.wikipedia.org/wiki/Manganese_nodule. "In both marine and terrestrial environments, ferromanganese nodules are composed primarily of iron and manganese oxide concretions supported by an aluminosilicate matrix and surrounding a nucleus.[2][3]" I expect the confusion arises due to the previous focus on the value of them as ores to be mined. Articles on that topic will talk in terms of the metal resource they represent, rather than the actual chemistry of the ore.

That was one of the things I noted with interest in the paper. I too had got the vague idea, from the newspaper reports of "manganese nodules" etc., that they were metallic. However it seems clear from the paper they are oxides and hydroxy-oxides, rather than native metal. When one thinks of it, given that even the lowest depths of the oceans are far from anoxic, the environment is an oxidising one, so it seems implausible that any mechanism could exist that would reduce metal ions to the metallic state.

OK sorry, I see what you mean and I'm sure that's right. But we don't have any metals here, so far as I'm aware, just chunks of porous aggregates of metal oxides and mixed oxide/hydroxides, in a saline aqueous environment. So it seems to me it's going to be more like an electrochemical cell than the potential difference between 2 metallic conductors.

Yes. To get to a molar acid concentration, i.e. pH ~0, might be a challenge, though - and of course there would still be metal cations present so it would be far from pure. But I suppose it depends on what you want to do with it.

Your doctors?

Well indeed, it’s the paper that is suggesting electrolysis, but the absence of free hydrogen is why I was speculating in my earlier post about some other process trapping hydrogen in some way.

I have to acknowledge the logic of swing state tactics though, as others have pointed out. But he's very useful guy to have around during the campaign, at least.

OK but work function is not really the right criterion. This is not removing an electron from a metal surface in a vacuum, it is taking water molecules, splitting them and forming new molecules of H2 and O2, in an aqueous environment, and in the process donating 2 electrons per molecule, from a metal oxide or hydroxide. What I took from the paper was that one needs 1.23V + 0.37V overpotential, so 1.6V whereas the potentials they have detected are only up to 0.95V. So I guess they must be assuming there are spots with a potential difference >0.95 that they just have not picked up. I can see that if Mn II goes up to MnIV, say, you have your 2 electrons, but the rest looks handwavy.

Just to come back to Buttigieg for a moment, this is what I mean about wiping the floor with these Republicans: Just watch the first 3 minutes. It's all done very gently, with humour, but he manages to make JD Vance look a prize a**hole without saying anything rude - and has the audience laughing. It is in truth hard not to laugh. The guy is a Rolls Royce. Harris will be nowhere near him in effectiveness.

Yes I saw this. I have tracked down the paper in Nature Geosciences and have been reading it: https://www.nature.com/articles/s41561-024-01480-8 It's not entirely clear there is sufficient potential difference to electrolyse water, but the researchers do seem to have evidence that oxygen is produced from the nodules rather than via something else. What the bobble hat persuasion has seized on, of course, is another argument for preventing the mining of these nodules to help the green energy transition. But the interesting thing to me is what the mechanism for electrolysis can be. I can't seem to find any mention of detecting hydrogen, which strikes me as suspicious if electrolysis is assumed to be the process. Or can it be some other process involving reduction and abstraction of hydrogen into the structure of these compounds? The paper doesn't really seem to get into the chemistry. Perhaps someone will pick this up and look into it further.

Yes I suppose that’s right: you could reduce the diffusion of H+ and OH- into each other’s presence by an intermediate reservoir of sodium sulphate. Also by making it a saturated solution, you could provide a reservoir of counterions to allow higher concentrations of H+ and OH- to be eventually reached.

Bikers? What’s your problem with them? More to the point, what does your rant have to do with the thread topic?

heh heh.👍

OK fair enough, that makes sense.