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New stainless steel can survive conditions for hydrogen production in seawater

sciencedaily.com

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Re: New stainless steel can survive conditions for hydrogen production in seawater

#121

Post by SoftTalker »

briandw wrote: post #67

I truly do not understand the fixation with hydrogen as a fuel. Compressing H2 to store it requires around half of the total energy that you can expect to get from its final application. Add in production losses and the difficulty in storage and handing, its always much worse than batteries. I can see the argument for use in industrial processes like steel manufacturing as a reducing agent, but not as a power source.

It's basically a battery. It's not a power source, it's energy storage. If the energy is cheap enough (e.g. solar) inefficiencies don't matter as much.

Re: New stainless steel can survive conditions for hydrogen production in seawater

#122

Post by pfdietz »

nyeah wrote: post #113
pfdietz wrote: post #63

Earlier quoted context omitted.

If you react large amounts of methane and chlorine, the methyl radicals will react with molecular chlorine to make methyl chloride. But if the methane and chlorine are dilute, as they would be here, the methyl radicals with react with something else (like oxygen) first. Destruction of methane by chlorine has been observed naturally, for example after the Hunga Tonga-Hunga Ha'apai eruption in 2022 (although the chlori…

The link points out that formaldehyde is one product of the methane-Cl reactions. Not sure we're better off with the formaldehyde (and its own further reaction products) than with the methane. They're not exactly talking about destroying methane. The methane is turning into chlorinated organic compounds.

Formaldehyde is also the product of the natural oxidation of methane by OH radicals.

No, the methane isn't being turned into chlorinated organic compounds. The reaction mechanism is CH4 + Cl --> CH3 + HCl. (Caveat: I don't think the side reaction CH4 + Cl --> CH3Cl + H occurs, but I need to confirm.) The chlorine ends up as hydrochloric acid, which washes out in rain. If you object to the acidity, note that the electrolysis of seawater was leaving behind the sodium ions as sodium hydroxide, so there would be no net increase in acidity. The methyl radical is also produced by the natural oxidation of methane by OH radicals, and would continue along that natural oxidation chain.

The link I referenced (and the paper it cites) do not, as far as I can tell, discuss any chlorinated organic products.

Re: New stainless steel can survive conditions for hydrogen production in seawater

#123

Post by SoftTalker »

dec0dedab0de wrote: post #89
briandw wrote: post #67

I truly do not understand the fixation with hydrogen as a fuel. Compressing H2 to store it requires around half of the total energy that you can expect to get from its final application. Add in production losses and the difficulty in storage and handing, its always much worse than batteries. I can see the argument for use in industrial processes like steel manufacturing as a reducing agent, but not as a power source.

I think the best argument for hydrogen is for automobiles. Existing cars can be converted to use it, doesn't spray pollution all over the city, and can be refilled quickly unlike a battery.

Can existing cars be converted? Yes for CNG/methane or LPG/propane but not sure I've heard of Hydrogen conversions. Wikipedia says conversion to Hydrogen requires:

... hardened valves and valve seats, stronger connecting rods, non-platinum tipped spark plugs, a higher voltage ignition coil, fuel injectors designed for a gas instead of a liquid, larger crankshaft damper, stronger head gasket material, modified (for supercharger) intake manifold, positive pressure supercharger, and high temperature engine oil.

For CNG or LPG conversion I think some fuel system components need to change but the rods, valves, head gasket, etc. are all unchanged.

My guess as to the reason is that hydrogen will basically detonate in the cylinder, whereas methane or propane will burn more like gasoline.

Re: New stainless steel can survive conditions for hydrogen production in seawater

#124

Post by 1970-01-01 »

boppo1 wrote: post #53
voxadam wrote: post #13

You just know that engineers and management in Toyota's delusional hydrogen division are salivating.

Can anyone give me a semi-technical reason on why the hydrogen division are delusional? I'm actually convinced of it "osmotically", but I just don't know enough about it. I've got chem 101 behind me but otherwise I'm a finance & tech guy. It would be nice to actually understand why it can't be done though.

Hydrogen leaks too much. You cannot transfer it without spilling a good chunk, around 8 percentage of it into the atmosphere. Now match that loss by your long term refuel needs and you'll simply run out of it. It can't scale up to anywhere near what would be considered a replacement technology for EVs.

Re: New stainless steel can survive conditions for hydrogen production in seawater

#125

Post by [deleted] »

pfdietz wrote: post #122
nyeah wrote: post #113

Earlier quoted context omitted.

The link points out that formaldehyde is one product of the methane-Cl reactions. Not sure we're better off with the formaldehyde (and its own further reaction products) than with the methane. They're not exactly talking about destroying methane. The methane is turning into chlorinated organic compounds.

Formaldehyde is also the product of the natural oxidation of methane by OH radicals. No, the methane isn't being turned into chlorinated organic compounds. The reaction mechanism is CH4 + Cl --> CH3 + HCl. (Caveat: I don't think the side reaction CH4 + Cl --> CH3Cl + H occurs, but I need to confirm.) The chlorine ends up as hydrochloric acid, which washes out in rain. If you object to the acidity, note that the elect…

[deleted]

Re: New stainless steel can survive conditions for hydrogen production in seawater

#126

Post by amluto »

asa400 wrote: post #54

Very interesting. Highly corrosion resistant "unconventional" steels have become somewhat popular in cutlery, with steels like LC200N, H1/H2, and MagnaCut. LC200N and H1/H2 in particular can be left in body of water uncoated/unpainted and come back in a year and they'll be fine. Obviously that's a different setting than electrified seawater for hydrogen production, though. So much cool materials science happening!

I'm not at all convinced that the highly corrosion resistant knife/tool steels you mention are actually especially high on the corrosion resistance scale -- I think they may just be excellent for a tool steel.

If you look at the knifesteelnerds article on H1 (https://knifesteelnerds.com/2019/06/24/h1-steel-how-it-works...), you'll find that it's an austentitic alloy (which is highly unusual for any sort of tool steel), and that it seems like it's likely a somewhat less corrosion resistant than usual variant on steels like 301 or 304. And the rather common stainless alloy used for non-tool applications where high levels of corrosion resistance is 316, which is more corrosion resistant than 304.

In any case, this new alloy is weird -- it seems like it specifically has excellent resistance to electrochemical corrosion when it is used as an anode, which is not what people usually use stainless steel for :)

Re: New stainless steel can survive conditions for hydrogen production in seawater

#127

Post by annoyingnoob »

inasio wrote: post #109

Stayed a few times in a place exposed to constant breeze from a tropical Pacific coast beach, and learned that stainless steel doesn't really last very long there. Everything stainless steel-based (fixtures, fridges, handles) rusts in a few years. I'd bet there's a market for upscale alloys

Depends on the alloy. Just a guess, you had 304 stainless which will rust fairly easily in saltwater. 316 would last longer. Also it can be tricky to retain the corrosion resistance when welding stainless, your part might corrode first at weld points.

https://www.nemaco.com/blogs/304-vs-316-stainless-steel-diff...

Re: New stainless steel can survive conditions for hydrogen production in seawater

#128

Post by pfdietz »

toast0 wrote: post #71
pfdietz wrote: post #48

Earlier quoted context omitted.

They'd use compressed gaseous hydrogen, but that has its own problems.

Yep... Anyone who looked at how CNG cars went in the US and was like yep, let's do that but with a gas that's harder to transport and store and has no existing network, had to know it wouldn't work out very well. CNG fleet vehicles work out for many fleets; especially those that have vehicle depots where fueling happens. I haven't looked into detail for the hydrogen cars, but I wonder if they made the same kinds of d…

In its defense, hydrogen cars would use fuel cells, not the IC engine of CNG cars. So there's at least a theoretical case that could be made for them. In practice it didn't work well at all.

The case for BEVs becomes even more clear when you look at complexity. BEVs are just simpler, even simpler than today's IC engine cars. IC engines have become baroque and expensive. The tooling needed to make these engines has become a boat anchor on the old car companies. And similarly for transmissions: the transmission of a BEV is a very simple thing, just a single stage of gear reduction without a clutch.

Fuel cell cars were a bet on the proposition that BEVs would be inhibited by range and charging time concerns, but rapid charging and widespread availability of such high power chargers has nixed that.

Re: New stainless steel can survive conditions for hydrogen production in seawater

#129

Post by Animats »

leonidasrup wrote: post #17
londons_explore wrote: post #11

Earlier quoted context omitted.

I don't think the efficiency or longevity of electrolysis equipment is the limiting factor... The limiting factor is that natural gas is very cheap and cracking it to make blue hydrogen is really easy at scale, and gives off CO2 which is useful for injection into wells to increase production. That sets a price ceiling of hydrogen. At the other end of the scale, there are batteries to store 'free' electricity and rese…

Sometimes the price of natural gas is even negative, there is too much of it. "Natural gas at Texas’s Waha hub is trading at negative $7.05 per million British Thermal Units, hitting a record low of negative $9.52 on April 15." https://www.barrons.com/articles/natural-gas-texas-negative-... There are different kinds of water electrolysis equipment, with different capital expenditure and operating expenses. "Alkaline…

That's what happens when the storage tanks fill up. Nobody can buy it because they have to accept delivery and put it somewhere.

Re: New stainless steel can survive conditions for hydrogen production in seawater

#130

Post by DoctorOetker »

briandw wrote: post #67

I truly do not understand the fixation with hydrogen as a fuel. Compressing H2 to store it requires around half of the total energy that you can expect to get from its final application. Add in production losses and the difficulty in storage and handing, its always much worse than batteries. I can see the argument for use in industrial processes like steel manufacturing as a reducing agent, but not as a power source.

with hydrogenotrophs you can create food (all amino acids) from solar hydrogen, supposedly about 10% more efficiently, this could return a lot of arable land for wilding, solar farms, housing, ...

Imagine dividing farmland by 10x by feeding hydrogenotrophs with solar H2.

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