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Join Date: Feb 2009
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Seawater Electrolysis and Hydrogen Generation

02/09/2009 10:05 AM

I am currently engaged in the preliminary phase of examining the viability of a hydrogen generation system through the electrolysis of seawater.

I have some questions regarding the process,namely -

1)Can untreated seawater be electrolysed without any electrolyte?

2)What amount of electrical current and voltage would be the most conducive for the evolution of gaseous hydrogen?

3)Upon electrolysis what products would evolve? I am aware that theoretically these should be H2 and 02 gases in a 2:1 ratio but owing to the presence of dissolved salts I have also learnt that certain gases such as chlorine and salts such as sodium hypochlorite(NaOCl) would also precipitate but I am unclear as to the quantity and types of salts that would result from seawater electrolysis.

4)What methods and techniques such as special material electrodes could help in preventing or reducing the precipitation of salts or undesirable gases such as chlorine as these are a corrosive and unneccesary byeproduct.

5)What would be the volumes of hydrogen and oxygen evolved from a given volume of seawater and can these two be separately collected as the primary purpose is the generation of hydrogen?

Any advice or opinions regarding any or all of these aspects are welcome.

Thank you

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Pathfinder Tags: electrical electrolysis Energy hydrogen power Renewable seawater
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#1

Re: Seawater Electrolysis and Hydrogen Generation

02/09/2009 1:25 PM

I will give you the quick answers to the most important questions first.

1)Can untreated seawater be electrolysed without any electrolyte?

Yes.

5)What would be the volumes of hydrogen and oxygen evolved from a given volume of seawater and can these two be separately collected as the primary purpose is the generation of hydrogen?

Very, very little for the amount of energy required to separate it from the water.

A few of your other questions can be answered with a quick look in basic electricity and chemistry text books.

In conclusion, this subject has been covered extensively over the years, both here on CR4 and by scientists and backyard inventors. Have a look at the previous threads on CR4 for more information. If you are a student doing a project, there is plenty of information here on CR4. BE WARNED HOWEVER, if you are someone who is looking at trying to separate hydrogen from water as a source of renewable energy, forget it. Due to numerous fundamental laws in both electricity and chemistry you will always waste more energy trying to extract hydrogen from water than you can gain.

Another good place to look is at http://www.tinaja.com/h2gas01.asp

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#2

Re: Seawater Electrolysis and Hydrogen Generation

02/10/2009 12:04 AM

Jack is quite correct regarding his comments to this blog, therefore I gave him a GA for his response.

However there are some issues he did not include in his response. For instance where there is salt water there is generally not a lot of vegetation that would need to be cleared in order to erect a large wind turbine to take advantage of the sea breeze, thus providing energy that is free except for the maintenance and original cost to construct and place. The second issue is that, if you were to locate photovoltaic panels out on the edges of a salt marsh you could also take advantage of the sun to produce this electricity. It still requires a lot of energy just to split the water molecule but if the price is right it really does not matter.

Another issue is that some folks are getting promising results of reducing the overall energy needed and utilizing high voltage provided through mili amps of pressure and are seeing production increases. This technology is on going, and appears promising results are achievable.

As for the salt water, it is an electrolyte, needs no additives, is hard on metal, and does permit the water molecule to be split.

You could construct equipment from readily available "stuff" generally found locally, that will provide for the separation of the hydrogen gas from the oxygen gas. You could use a three stage water cooled compressor the compress the hydrogen into a suitable cylinder, provided you produced enough to supply the compressor with out introducing oxygen into the mix. If this were to occur you would have created Oxy-Hydrogen, a patented blend of the results of createing a highly volitile single duct fuel gas that is far more explosive and unstable than the hydrogen alone.

As Jack stated, all of this has been repeatedly discussed here on CR 4.. If you experiment with these gases be very careful, they can be deadly.

TooMuchFun

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#7
In reply to #2

Re: Seawater Electrolysis and Hydrogen Generation

02/11/2009 12:02 AM

Hi TMF,

You wrote,

If this were to occur you would have created Oxy-Hydrogen, a patented blend...

Oxyhydrogen is not patented. There are, however, many devices which have been patented that produce the mixture. A 1930's era carburetor replacement (which ultimately resulted in a fraud conviction) was one such device designed long before the various more recent devices by Brown, Rhodes, Klein, etc.

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#8
In reply to #7

Re: Seawater Electrolysis and Hydrogen Generation

02/11/2009 12:31 AM

Actually I have copies of Dr William A. Rhodes papers, the first and a later edition where by he did further investigation regarding the problem that had surfaced with some "experimenters" incurring explosions. Before you say more about the Oxy-hydrogen issue, get a little education about the issue.

I have not forgotten that you accused me of being a LIAR, so I take this opportunity to say to you "GO scratch your ass"!

TMF

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#9
In reply to #8

Re: Seawater Electrolysis and Hydrogen Generation

02/11/2009 2:49 AM

Did I accuse you of being a LIAR? I thought I called you a fraud. I use that term fairly frequently to describe HHO promoters who make the sort of unsupported and unsupportable claims you have made. Dennis Lee, for instance, is a convicted fraud and HHO promoter, and the two of you have made similar claims. If you can cite a reference in which I accused you of lying when what you wrote was true, then please produce that reference. If it turns out that what you wrote was true, then I'd be happy to apologize.

If I accused you of lying, I suspect it might have been in one of the several cases in which you said something entirely untrue, such as claiming that a large portion of the fuel injected into an engine goes out the exhaust port and into the catalytic converter unburned... which, as every combustion engineer knows, (and as any competent mechanic should know) is utterly and totally wrong. Further, this is the same claim other HHO promoters make, and they are clearly committing fraud: they know what they claim is incorrect, and they say it with the intent to defraud. They say that the HHO is not merely additional fuel, but something very special which burns in a way that is much different than the way HHO or H2 has been observed to burn in labs and in lab engines. They claim that adding HHO allows all the fuel to burn, instead of just some of it. As you know, that's hogwash. As you also know, the amount of HHO produced by HHO devices is far too small to have any measurable effect on combustion: once it is in the combustion chamber, it is just a few additional H2 and O2 molecules mixed in with all the rest of the hydrocarbons, oxygen, and nitrogen already there. We've been over this before, and you provided no evidence of any sort that the tiny amounts of HHO you claimed you were producing would have a measurable effect on combustion. I provided links to tests that demonstrate that HHO devices have no measurable effect at all, just as the science would predict.

You mention that I should get a little education. As it happens, I have a good deal of education about the oxyhydrogen issue. I'm not sure what your point is. But if you say that the mixture of H2 and O2 commonly known as oxyhydrogen (as used in an oxyhydrogen welding torch) is patented, you are either just plain wrong (because you don't know any better) or you are lying again. The Rhodes patent was for an "Apparatus For The Electrolytic Production Of Hydrogen And Oxygen And For The Safe Consumption Thereof." For anyone acquainted with the English language, it should be obvious that this patent is not a patent for a gas mixture. If you doubt that just read the claims in the patent application. Even the much earlier "carburetor" which produced oxyhydrogen was a patent on a device, not the gas.

Your rude remark does not help your case. What would help your case, if you want to be taken seriously, is ever so simple -- just produce legitimate dyno tests indicating that your scheme works. In engineering and science, evidence talks, BS walks.

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#11
In reply to #8

Re: Seawater Electrolysis and Hydrogen Generation

02/11/2009 8:39 AM

By the way, you will be glad to know that one of your major competitors in the HHO world, Dennis Lee (Dutchman Enterprises, United Community Service of America) has been shut down by the FTC.

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#12
In reply to #8

Re: Seawater Electrolysis and Hydrogen Generation

02/11/2009 10:07 AM

If you find the previous post too long to read, here it is in a nutshell:

If you can cite a reference in which I accused you of lying when what you wrote was true, then please produce that reference. If it turns out that what you wrote was true, then I'd be happy to apologize.

What could be simpler? In this crowd, evidence is far more effective than abusive language.

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#14
In reply to #12

Re: Seawater Electrolysis and Hydrogen Generation

02/14/2009 2:50 PM

Over the months that I have read a lot of your posts, and many of your responses are quite agressive. I always present my responses in a manner that permits the receiver to exonerate himself from the general group being address if said party feels that the response does not apply to him. You on the other hand do little experimentation as instructed by some of the posters to determine whether or not their is any possibility of their being successful.

"You' as does many others, "Always" refers to the energy performance of "tank gases" in this case hydrogen in your responsive comments. This makes your response void of any possible correctness. I have challenged you and others several times regarding this issue. It is clear that the blended result of oxygen and hydrogen commonly referred to as oxy-hydrogen produces a completely different performance result.

When I challenged you personally regarding this issue you blew your head gasket, and included me with a group of folks that I too question their integrity. I have repeatedly stated that I am not associated with any such people, and absolutely do not support their claims. In that response you stated that "I was a LIAR". If you wish to review the posts to find that what I am stating is correct then do so. If I could have reached through the internet and grabbed you by the throat, I am certain that you would still be kicking and struggling.

As for any further references to the matter I will simply totally ignore any of your posts and responses. I see nothing to be gained by continuing dialog with an absolute A-- H---!

TooMuchFun

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#15
In reply to #14

Re: Seawater Electrolysis and Hydrogen Generation

02/14/2009 7:50 PM

Hi TMF,

Nice to get your note, your further insults, and your crude language. Unless you are dealing with an audience of second graders, there is no difference between spelling a word out completely or leaving out a few letters -- we all know what you mean.

Your statement above regarding the common gas mixture oxyhydrogen (namely that it is patented) is untrue. If you think that my pointing out untruths is "aggressive" so be it. You can call that statement a lie, a misstatement, a fib, etc., but that does not change the fact that it is untrue.

If you believe your statement is true, then simply provide the patent number and the claims in that patent which support your contention... that is far more effective than name calling. Or if you want to be intentionally difficult, just supplying the patent number is fine -- but if you have the information, namely the claims, then why not just supply it. Rhodes's patents do not patent the gas oxyhydrogen, (or oxy-hydrogen, or any other such mixture), but rather patent a device which creates this gas mixture, and a means to use that mixture somewhat more safely.

Imagine how idiotic it would seem if I wrote to you: "Water is patented," and when you protested, you said "OK prove that it is not patented." Oxyhydrogen, oxypropane, oxyacetylene, oxybutane, H2O, NaCl, FeO3, etc etc etc are all mixtures and compounds that are not patented. They can't make it beyond the originality or obviousness challenges. Simply put, they are not inventions. If you have a patent, then produce a patent number. In science, sad to say, you have to offer some evidence, and if you say a patent exists on oxyhydrogen, then the evidence is very easy to offer. You have offered no such evidence.

The onus is always an the one making the extraordinary claim to offer some proof. You have offered none whatsoever, even though such proof would be so simple to offer, if it existed. I am not asking you to do a scientific experiment, only to produce a patent number of a patent you claim exists -- this should take you mere seconds, but you refuse.

"You' as does many others, "Always" refers to the energy performance of "tank gases" in this case hydrogen in your responsive comments. This makes your response void of any possible correctness.

This is entirely incorrect, untrue, a misstatement, a lie, a fib, or whatever your preferred wording might be. Tank hydrogen has countless valid uses, including augmenting combustion in diesel engines and in spark ignition engines, in reducing emissions in certain engines under certain conditions, in creating electricity via a fuel cell, etc, etc, etc. When I have written about oxyhydrogen (which, albeit dangerously, can also be a tank gas) I have meant just that, not the sort of H2 gas often stored in tanks. Again, if you believe I was writing "hydrogen" but meaning "oxyhydrogen", or writing "oxyhydrogen" but meaning "hydrogen" then the onus is on you to provide an example of such misuse. But in any case, the difference between the two is a little esoteric for the people usually promoting "HHO boosters" who are either unacquainted with basic chemistry, are lying, or are ill-informed. As should be obvious to a high school chemistry student, a gram of hydrogen burned in air has the same heat value as a gram of hydrogen burned with the stoichiometric quantity of oxygen (i.e that mixture which is sometimes called oxyhydrogen). The burn rates and temperature are obviously different, but the energy released (for instance, to heat air, to expand it, and to move a piston) is the same. This can be shown in a bomb calorimeter.

Some people have claimed that oxyhydrogen has magic properties. (Rhodes, in his device patent did no such thing.) The principal reason for ascribing magic properties to oxyhydrogen, but not oxyacetylene, or oxypropane, is to support frauds. No legitimate combustion engineer or scientist (for instance John Heywood, from MIT, is among the best in the business) has claimed anything magical about oxyhydrogen, and no legitimate scientist or engineer (with the requisite subject matter knowledge) has claimed that oxyhydrogen "improves" combustion in a way any different than an equal amount of the two gases (H2 and O2) do. (For the obvious reason that oxyhydrogen, like oxyacetylene and oxypropane, is a simple mixture of gases, not a compound. So when it is inducted into a cylinder, it becomes some number of H2 molecules and O2 molecules intermixed with the air and vapors in the cylinder, and has predictable effects -- shown by many of the research papers presented by scammers as support for their scams, ironically. The scammers fail to actually read the reports, or assume no one else will. Most notably, all the research papers cited use relatively huge volumes of H2 to get measurable effects -- typically 10 - 100 (or more) times higher than produced by HHO devices -- and the hydrogen, most critically, is produced off board, rather than onboard, using additional fuel to do so -- in, fact an amount of fuel with about 5 times the energy value of the oxyhydrogen produced.)

So why waould making oxyhydrogen appear to be magic support fraud. (Why not give oxypropane, etc, magic properties?) Because then you can "run your car on water," a scam that continues to go on 70 years after first started, and 70 years after the first fraud conviction. (Whereas with oxypropane, you'd need to buy the propane.) I think even you have admitted that running your car on water is not possible. But if one ascribes magical properties to HHO, (used as an additive) one can say: "Well, it enhances combustion through a catalytic effect which we do not understand", or "It so increases flame front speed that it puts peak pressure at a more advantageous point in the power stroke", etc, etc, etc. Unfortunately none of these claims is true -- again, they are fibs, or lies, or whatever you'd like to call them. If you repeat them and claim that they are true, then there will be people who will call them lies, and by extension will consider you a liar. Some may even call you a liar, which I have refrained from doing, as far as I know.

But what you have written here, in this thread, that oxyhydrogen (or oxy-hydrogen) is patented, is an untruth, presented as if we should believe it is a truth. Perhaps others can decide if you are lying. But calling me an asshole (or A-- H---) does not help your case. All you need to do to prove your point (if it can be proven) is to offer a patent number.

If you make the same claims as scammers (namely that onboard electrolyzers can improve your fuel mileage) and then further obfuscate the issues by claiming that pulsing, or resonance, or higher or lower frequency PWM, or optimizing voltages, etc, etc. will change the thermodynamics of the matter (as do the scammers), and then, if in addition you present no proof whatsoever (like the scammers), even when it is so simple to do so, such as providing a patent number... and further become rude and abrasive and foul-mouthed when people will not agree with your implausible and completely unsupported claims (as do the scammers), then you can probably see that people might start to think of you as a scammer.

But don't feel that you need to reform. If you admire foul-mouthed abrasive people who sometimes stretch the truth incredibly far and offer not a bit of support for their claims... then that is fine with me. I only get involved when I see complete untruths presented on CR4 as truths, simply because it degrades the utility and enjoyability of the site. Don't feel singled out.

Let me do a search here for LIAR and my name....

Hi, I'm back. The only thread in which I used the word LIAR (or even liar) is this one, in quoting you. Many others have used the term, though, particularly regarding scams such as "HHO boosting", "Magnet" motors, over-unity machines, etc.

I appreciate your offer to totally ignore my posts, and for that, I must say a heartfelt "Thanks."

You wrote:

If you wish to review the posts to find that what I am stating is correct then do so.

I did. It is not.

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#3

Re: Seawater Electrolysis and Hydrogen Generation

02/10/2009 12:23 AM

I would suggest you first distill the water by using vapor compression distillation, which is the lowest energy use for a distillation process known, and then use electrolyte directly to pressures of around 2,000-3,000 psi. If you go higher, the partial pressures will allow a large amount of O2 to contaminate the H2.

This will first yield pure water, and second compressed gas. Both processes can be continuous.

The vapor compression uses 1/200th that of normal distillation, and some say electrolyte to pressure is 50-70% efficient, for a likely total efficiency of near 50-60% at best.

The link to the Guru liar is not correct with respects to my suggestion, but is relative to what you are doing.

Hope that helps,

Seaplaneguy

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#4
In reply to #3

Re: Seawater Electrolysis and Hydrogen Generation

02/10/2009 6:33 AM

After I read this morning the questions about producing hydrogen through electrolysis by a source of renewable energy I was intersted in this topic because I plan with some experts a sistem of my own for this target,and I know that there are already some patented ideas in this field.

I was shocked because no one of the persons that I discussed this topic thought that the efficiency of the electrolysis will be so poor, it made me look for some material about it,and therefore I googled:"hydrogen electrolysis efficiency",and there I found that a scientist from Mit found a way to achive remarkably efficincy of the water electrolysis by using catalists.

Look at the following article:


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Posted - Aug 01 2008 : 3:33:08 PM


An article in the scientific journal Science of July 31st, 2008 reveals details regarding a form of high efficiency splitting of water mimicking the action of plants during photosynthesis. Daniel Nocera of MIT has identified new catalysts(electrodes of cobalt in the presence of phosphates for oxygen and platinum for hydrogen) that permit very high efficiency electrolysis of water. High efficiency electrolysis may dramatically reduce costs in generating hydrogen and may make possible a host of important hydrogen applications that have not been possible to this point because of the higher cost of generating and storing hydrogen. More information about this discovery can be found at the following web locations:

http://peswiki.com/index.php/Directory:MIT:Daniel_Nocera:Catalytic_Electrolysis

Quicktime Movie explaining technique
http://web.mit.edu/newsoffice

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#6
In reply to #4

Re: Seawater Electrolysis and Hydrogen Generation

02/10/2009 10:52 PM

I find the presentation by Nocera in this video very peculiar. He presents this as if he has discovered electrolysis. I thought perhaps he had in mind a direct sunlight to H2 reaction, eliminating the PV cells (where the efficiency is so low) but the video clearly shows the typical PV cell powering an electrolytic cell -- which is something we have been doing for many years. The Peswiki article (Pesiwki being the last place on earth for reliable scientific info) says the efficiency is near 100%. I think I remember Nocera saying, in an interview I heard a few months ago, a figure lower than that, and at the time thought that this did not represent a huge difference from current state of the art.

If the current state of the art in electrolysis is 75% efficiency, and this electrode increases that to 90%, that is a nice incremental improvement, but nothing to justify the tone of the MIT video, which seems to suggest that we can someday run our cars on water and sunlight, because of this process. We can do that today, (obviously not via the HHO/Stanley Meyer scam method) and the central problem with the PV electrolysis stations that are installed here and there does not lie in the inefficiency of electrolysis so much as it lies in the inefficiency and cost of solar cells (in addition to the complexities of compressing the gas, using the gas efficiently, inadequate range of the vehicle, etc.)

The other problems surrounding hydrogen as a fuel for cars are numerous, and a slight increase in efficiency will not alleviate those problems. I think Zubrin's article from a couple years back sums up some of the issues. Some related threads:

Hydrogen Bashing

Hydrogen Hoax

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#5

Re: Seawater Electrolysis and Hydrogen Generation

02/10/2009 10:28 AM

I too am in the process of developing a hydrogen generation system, I never thought to use seawater (within 1000' from my home) but it might be a good option. It might be too "dirty" and would give you clean H2 and O2 but the system might require cleaning more often, and I'm just not sure about the other gasses (probably inert) that might get introduced into your H2 and O2. The volumes should be calculateable and can be separated rather easily since the two gasses collect on the two annodes (H2 on one and O2 on the other)

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#10

Re: Seawater Electrolysis and Hydrogen Generation

02/11/2009 6:16 AM

A problem in diesel/electric submarines was that if water leaked into their electrics, Cl2 was liberated.

In your proposal, you will almost certainly generate chlorine, roughly in the proportion it is present in seawater.

For an electrolyte it is best to use NaOH, which doesn't release nasties, is readily available and is cheap.

As it is not consumed in the electrolysis one charge is all that is needed.

Ordinary tap water is not too bad for fouling electrodes, although you will eventually get some deposits, which can usually be remove with vinegar (acetic acid) or hydrochloric acid.

Use Stainless steel, carbon or titanium electrodes. Platinum is, of course, ideal but prohibitively expensive.

If your cell is built to handle high pressure, the resultant gases can be directly fed into a storage vessel without further compression. Voltage is also reduced at high pressure, so higher currents (hence greater output) can be used for the same power input.

Lower voltages mean that corroded electrodes cease working much earlier, so cleaning is more frequent.

It is a long time since I looked up the figures, but I seem to recall about 1 volt required at about 35MPa. (You will need to check that figure as my memory may be faulty here.) To this must be added additional voltage to allow for voltage drop through the electrodes and the rest of the electrical system when you pass through a reasonable current.

Output can be calculated by multiplying the electrochemical equivalent by the current to give the number of moles released.

All the above is from memory from many years ago, so the accuracy (especially the figures) will need to be checked.

It is important that you remove the gases from the electrodes quickly as they otherwise "polarize" ie form an insulating layer which prevents further electrolysis.

The apparatus is not difficult, expensive or particularly technical to build and could be interesting to play with.

Please note that the flammability limits for H2 range from about 3% to about 96%. This means it can be set on fire under almost any circumstances - one advantage of H2 in engines, but a definite safety hazard.

As you are also generating O2, extra Care is needed. The mixture is explosive, possibly spontaneously so. This means that great care must be exercised and under no circumstances should you compromise safety.

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#16
In reply to #10

Re: Seawater Electrolysis and Hydrogen Generation

02/17/2009 7:24 AM

Just found an ancient book - "Technical Chemists Handbook"; Lunge (1929). This gives the electrochemical equivalent of hydrogen as 0.0376 gm/amp hr.

You need a lot of amps to get much H2 out of it, although the bubbles on the electrode look pretty.

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#13

Re: Seawater Electrolysis and Hydrogen Generation

02/12/2009 11:38 AM

Electrolysis of sea water is extremely dangerous if the gases produced are introduced to sun light. They are highly volatile for starters and we exposed to UV light can explode.

If you only have salt water with which to work, be careful not to expose the gas generated to any Ultra Violet light, including fluorescent bulbs in shop lights.

The other problem is the current draw with high contents of elctrolytes. Stick to clean water and build your genrator using high surface area plates.

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#17

Re: Seawater Electrolysis and Hydrogen Generation

03/02/2009 10:13 AM

1) - yes

2) - please refer to the Wikipedia page on this topic

3) - sodium and calcium hypochlorites are the most popular. Electrolysis of saturated salt is a great way of making these for water sterilisation purposes.

4) - Electrolysis products depend upon the species present, not the type of electrode. The electrode material selected will be influenced by the corrosion resistance of the solids in presence of the ionic species.

5) - oxygen will remain bound-up in the hypochlorite groups.

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