Hydrogen from hot iron and steam.

Have a look here:

http://history.nasa.gov/SP-4404/app-a1.htm

Perhaps that history article may prove helpful.

Thanks!

Actually I had already come across this reference, but although interesting it had no details of the actual gas separation and collection system used.

<>It is quite easy to visualise that H2O will dissociate in the presence of a lot of red hot porous cast iron, but how were the gases separated and collected for use in a balloon. Also perhaps how were they stored until the resulting hydrogen had cooled sufficiently to safely fill a ballon made of something like varnished silk or another organic product like "gold beaters skin" which was used right up until the 20th century to contain Hydrogen.

<>As usual in technology "The devil is in the details" and I would really like to get a grasp of just how this was done so early in the history of technology.

<>Still Looking!

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Crite 40

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I have heard about this. Would be interesting to find out. Back then it must have been a simple thought process to get to the conclusion. With CR4 on the case it looks like there will be an answer. I'll be doing some searching. Good luck. Ky.

Just a bit of a stab in the dark, but if you are passing steam over red hot iron, would not the oxygen react with the iron forming rust, leaving (mainly) hydrogen to be collected?

IPG

I am not certain, but that seems to be a potential mechanism. Note that the NASA article referenced indicated the use of Superheated steam and incandescent coke (Carbon) was used at one point. Unless I miss my bet, this is a way to produce a synthesis gas (CO2 + H2) assuming no air infioltrates the system. This not only be a dangerous gas from a toxicity standpoint, but would likely have a density around half that of air rather than 1/14th that of air.

The basic system used would be rather similar to the very rough diagram below - drawn in haste, scanned to .jpg, just now, especially for you, crite40.

The water tank at the left would have a one-way float valve,of course, to allow for replenishment of the water, as it boiled away to produce the steam.

Because the water at the collection vessel at the right, would become increasingly hotter, there would perhaps be a pump to remove some of that heated water, and replace with cold water).....

Thanx Sparkstation!

That was my own approximate idea of how it must be done too.

<>However I remain very concerned about the separation of the O2<>/CO2 and hydrogen in the output where the ballon is filled. 2 main reasons, years ago I filled small ballons for my kids with Hydrogen using a caustic soda/ Al reaction and found all was well until the sun came out. Result 2Cl+H2 2 HCl!!! and a burst balloon!

<>So I am sensitive to impurities perhaps.

<>Also the ballons used were quite small in volume and occasionally took up 2 observers. This probably implies that the Hydrogen was reasonably pure, at least if the old print of them I came across years ago is correct.

<>This reaction won't produce Chlorine of course but a lot of free O2 and H2 bubbling together in a tank of cold water might be a "dicey" proposition.

<>The main point is I guess just how much of the O2 would be absorbed in practice by the iron filings/chips and the old cannon barrels?

<>I reckon cleaning out the rust after a firing would be a good fatigue job for defaulters.

<>It aslo occurrs to me that the most probable source of Iron Chips/filings would be the cannon factories themselves, but this might still involve quite a lot of "heavy goods" transport to keep the French Airforce in the air.

<><>Strangely of course Napoleon, who was an artillery officer was the one who disbanded them later. This was despite them being instrumental in winning 2 or 3 battles against the Austrians in particular. I bet he regretted it at Waterloo when the Imperial guard attacked what he though was a gap in the Allied line which was actually full of fresh infantry out of sight of his position!
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Like your Handle! I have a genuine spark station here, a model Marconi rotary gap 50 watt rig I demonstrate at my vintage radio club sometimes.
Crite40<>

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How on earth did you generate Cl from caustic soda and aluminum?

No chloride existing in this system?

RHABE

If you're looking for generalization of producing syn gas or water gas, look at reformation or hydrogen generation. The action of water on hot iron or hot carbon is a widely used method of producing hydrogen (the cause of the explosion that blew apart the reactor at Chernobyl was firefighters pumping water onto the red hot graphite moderator blocks which generated hydrogen, which then mixed with the air (oxygen) and exploded). For example: Industrially, methane + water, using a Ni cat at 800 - 900 C, yields CO + 3 moles of hydrogen gas. If you are looking for the details of early French hydrogen generation, contact the French legation or embassy. They should be able to direct you to specific data sources.

Hi,

Guest in Post 3 is correct:

passing steam over iron (sintered parts) is producing a coating of Fe3O4 is temperature is above 550 °C.

The Fe3O4, known as magnetite, is hard and durable and abrasion resistant.

This is a cheap and effective process.

If temperature is below 550°C then Fe2O3 is resulting (the red oxide used in optical glass polishing).

Both processes produce more or less pure hydrogen.

Same situation in simple rusting.

If you encase the rusting surface gastight with a protective shield then the freed hydrogen can cause hydrogen embrittlementof the steel parts.

This was a near failure of some suspended bridges, only after half the steel wire were broken this was discovered and all the cabling had to be removed and replaced by a noncritical steel.

So there was no gas separation.

RHABE

Actually Rhabe you have a point there. The source of the chlorine was the Chlorinated tap water used in the solution I surmised.

<>It took very little Chlorine to react with the Hydrogen and Pop the toy balloons. I was taken quite by surprise, I remember, as we did it on an overcast day and the Ballons floated up to the ceiling very well, until the clouds cleared. There was a small amount of white powdery residue when they burst.

<>Certainly my kids, then about 10 and 12 were given a very good illustration of a chemical reaction triggered by light!

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<>Your point about Hydrogen embrittlement is also well taken. Its a scary thought when you cross some of the very long modern suspension bridges!

<><>The chemical explanation of the reaction in another post is also interesting in several ways. My own guesstimation is that the lower reaction temperature would be preferable, as it might be possible to clean and recycle some of the Iron.

<><>I was actually trying to solve what appeared to be a minor historical mystery, although I'm a retired Electronics engineer both my wife and I have degrees in history, she has a special interest in the French Revolution and I have a special interest in the history of Technology.

<><>Using 1794 technology the iron could only be used once at high temperatures and the Air force would require considerable supplies of old cast iron, filings, cannon turnings etc to maintain their balloons in service.

<>Most accounts talk of the iron barrels being "Red Hot" so it was probably a single use affair. At least that saves the "defaulters" a really horrble job of cleaning out all that "rouge" iron oxide!!!
Crite40

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Hi crite 40,

the ironoxide was certainly heated to convert the red "rouge" to black magnetite and then recycled to steel or iron. I don't know but I expect that at that time they made first cast iron and removed the excess carbon (as carbonmonoxide). Cast iron was invented as a failure of existing steelmaking around 1400.

I have some historical interest too, I am a mechanical engineer with some background in other fields of science and technology.

I am professionally mostly concentrated on precision engineering and measurement.

My interest is mostly evolution: astronomical, geological, biological, human, cultural.

Best reading in the last year was:

Jared diamond: The rise and the fall of the third chimpanzee and

Richard Conniff: The Ape in the Corner Office.

What I am interested in: is there any information about the Cornwall tin miners: was the ore smelted to tin before shipping?, is anything known how was the ore traded?, are the ports known?

For sure there was a lot of trade towards Cyprus and I suspect that there have been intermediate ports near Porto and/or Lisboa now submerged deeply under mud and clay and that the unknown culture of Malta and the first temple of Beirut is related to them.

Pure speculation but may be possible that some more fragments of knowledge is existing.

Early metal technology is a very interesting field.

We have nearby a blacksmith who can do damascene steel. And we tried a prehistoric type of steel furnace last July but with very limited success. (A lot of small iron spheres).

Back to your explosion of chlorine-hydrogen you were lucky not to have had more chlorine as this amount may result in severe injuries: 1 g of hydrogen with sufficient oxygen or chlorine is equivalent of 3 g of hydrocarbon fuel or 30g of high explosives.!!!

RHABE

A very interesting reply, a good thing our tap water wasn't too heavily chlorinated, or the plaster ceiling might have come down!!!

Actually I do have some family connections with Cornwall and Devon. Some of my fathers family come from the area along the river Tamar on the border near Plymouth, and there were a few tin and lead miners among them back in the mid 19th century, presumanbly before too.

There does indeed seem to be very little known about the Tin trade in Bronze age and even later Classical times however. I have come across a reference that some Bronze age cultures were so short of Tin that they made Bronze alloying Copper with Arsenic.
Presumably they had a good supply of replacements in the foundry as the Arsenic vapour took effect!!!

<>I would presume that by analogy with Copper, and because of the cost of shipping, it would have been smelted somewhere before making the long voyage back to the Easterm Med. The other side of my family are Irish and Scandinavian and I have watched with great interest a Danish blacksmith using some of the ancient techniques with "bog" iron. They have built a whole Viking age village in western Jutland using toools made from local iron for everything which I visited in 1997.

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<>As to the recycling of iron for balloons. I must confess I have some doubt as to whether it was done "on site". One thing all records seem to agree on is that the process used an inordinate amount of fuel, so unless a coal mine, forest or enemy town was available there might be fuel problems.

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Regards Crite 40

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Hi crite40,

I did not think about reworking the oxide on site but as you think about transporting somewhere else where enough coal was existing.

Regarding the arsenic in early bronze I did know only that this was used for a very early and very limited time as being readily available. May be the invention of how to roast the ore to remove sulfur and arsenic was the essential first step towards a usable alloy.

The problem with arsenic fumes and poisoning from inhaling these persited well into 1900.

The earlyest tin mining was just opposite Cyprus inside the coastal mountains of Turkey. This was detected by trace element analysis of the local small rivers and then followed up the river and searched for remains.

Soon after this was no longer productive the trade with Cornwall and Afghanistan started. I am not sure but I think this was more than 5000 years ago.

RHABE

G'dat Rhabe.

This is getting to be a very interesting discussion!

Your date of c3000BCE would be about right for the early part of the Minoan civilisation, who I am fairly convinced were about the most advanced people of the time in that area.

<>I had understood that Arsenic was actually used to harden Bronze
instead of Tin but perhaps that is not so?

One thing I have learned is that many historians are not really competent technically and can give those who refer to their work a lot of wrong impressions.

How interesting to hear that Copper was actually mined in modern Turkey before Cyprus. I wonder if the Trojans, or their predecessors were involved? It may have been one of the first sources of their wealth.

It does make it easier to see why the rich Copper deposits of Cyprus, which gave the island its name, were discovered when there was already some local expertise in mining and prospecting.

As to pre refining of the Tin ore, I was thinking more of a stopoff area like modern Brittany where more wood was available for fuel to process the ore. It could then be made into something like the "oxhide" ingots of Copper.
Here's a fertile research area for undersea archeology!

As far as I know Cornwall has never been heavily forested as the soils are not especially rich and the area is exposed to strong Atlantic gales.

Certainly the islands off South west Ireland are almost entirely treeless, as I know from personal experience, and have been so for at least 6 or 7 thousand years.
Crite40

Hi crite40,

not the copper came from Turkey but the first tin to make bronze. This was shipped to Cyprus and the deposit was exhausted soon.

I have not any knowledge about tin ore or metal being shipped until much later when only metal seems to be the merchandise.

Copper came from Cyprus but why should the Minoans and not the Cyprus people should have been able to reduce the ore or only to melt the native metallic copper pieces?

You are right that arsenic was used to harden early copper artefacts - but this alloy is not really good as it is hard but brittle. So as soon as bronze became available this replaced the use of arsenic totally.

As tin is easily extracted from the ore - very heavy black crystals - and as tin is soft a melting for mixing tin with copper is a natural experiment.

May be the Minoans overtook the local experts, may be the technology was much older (I heard about speculations that the first examples are 7000years).

In the egyptian Cheops pyramid there are some examples of bronze on the hidden ducts where only the small robots have access.

RHABE

Oh that explains it!

I had got it wrong and thought that you were talking of early Copper mines in Asia minor.

I was not familiar witht he common ores of Tin but the form you describe would be a sure thing for early metal workers to try as you say. Most of their ores were brightly, or at least definitely coloured and heavy, so trying out a heavy black stone would have been an obvious step.

As ti the Minoans, well it appears that they were travelling all over the Eastern Meditteranean by about 5,000 years ago and from the remains of their culture they were obviously highly advanced technically. Their role may have been as diffusers of new knowledge as well as traders.

The Bronze in the Great Pyramid is very interesting Rhabe. I had always understood that the Egyptians were rather backward in metallurgy and used plain Copper for a long time so the prescence of Bronze would be very interesting.
Crite40