Chris: I'm kind of disappointed that you don't want to continue the conversation. I thought it would be interesting to hear more, especially about the engineering of a home-based hydrogen generation. I liked the idea if it can make some sense economically because it short circuits the transportation/infrastructure problem, at least for some people.

Frankly, the BMW thing wasn't terribly interesting. They're defining efficiency based on the thermodynamic (Carnot) definition, which is technically fine, but irrelevant to those who are interested in what the technology can do for the millions of existing automobiles.

I think your response was a bit of "it's my football and I'm leaving!". I think the questions raised were asked mostly reasonably and gave you an opportunity to educate us. But you should realize that you're talking to experienced folks and a little questioning is healthy. I've got 40+ years in industrial R&D and academia, so I have a reasonably well tuned built-in doubter. But that doesn't mean I ignore carefully presented objective data.

Ultimately, this is primarily a forum for electronic stuff. Thus, if you got your needed information, great. But it would be a shame if you've got some legitimate ideas and technical challenges not to share them here and perhaps get back more than you put in.

 

You have to be kidding about -

Academic peer review of US patent #7,041,203 by John Timothy Sullivan of creating a magnetic shearing effect in electrolyzers would just be a big waste of time.

The patent is simply ludicrous. This is simply ammunition for a scam artist to gather donations for "research". One of the most identifiable characteristics of people who fall for these schemes is an ignorance of electronics and science.

If any of these devices worked, it would be in operation and displacing all the current power plants. Think about it.

 

OK, economics of solar/wind sourced electricity as opposed to fossil fuels (Remembering that Hydrogen is just a storage medium of the electrical energy we put into it


As for nuclear....that's the most expensive electricity we can make. And unless someone really does find cold fusion (we can all hope - and I'm not against trying) that price isn't coming down any time soon.

you are bouncing back and forth between "the economics of it all" and "a local H generator efficiency". i dont work in the Nuke field but went to school for Nuke Engineering. over the lifespan of a nuke power plant's uranium core the cost/kW is very very low compared to other generating technologies. if you have data that suggests otherwise please post it. nuke power is also very green (the spent fuel storage issue is a hype and can be dealt with properly). not so green if it melts down, etc, but todays engineering can handle that, and, is why we need more fusion research.

at the end of the day, the folks who put up the $$$ to support it will look at the global picture of economics behind the technology. there's a ton of variables that define it (green emissions, cost to build the electrolyzer, how much strain the electrolyzers place on the power grid which is currently 75% "dirty" power generation, safety, insurance premiums, facilities, cost to convert engines, cost of new H cars), etc etc etc.

i do not believe alternative fuels have any impact on the "per mile" cost to the end user. i believe the economics will show that we can spend zillions of $$$ on new technologies and net little positive overall gains. i believe its just a matter of which one has least impact on the environment. just look at ethanol. it's very "green" yet costs about the same per mile, and, little study has gone into showing its backend residual impacts. funny how the supporters of ethanol always show the exhaust pipe of a running car in their ads, but rarely (if ever) walk you through how much extra diesel it takes to run the crop machines to net the raw materials, or the extra strain there is on the power grid from the raw materials processing plants, etc etc. H is in the same boat as the rest, period.

solar PV is basically as free energy as we can get, very very green on the frontend but backend chemicals may make it not-so-green, yet very inefficient and high cost, why? First Solar will reduce their $/W costs by 50% in next 5-6years !!! yet still rather expensive and inefficient technology.

there's also the factor of "forced upon you". if H cars suddenly is mandated by the government and gasoline sales prohibited, then we will all be driving H cars and the development of H will go bonkers. gasoline cars were basically forced upon us, not by our government, but by shear discovery of vast oil fields around the world. the "lots-of-it lets-develop-it" mentality drove everyone to build refineries, build gasoline heat pumps for cars and trucks, etc etc. gasoline is not like electricity. we can use electricity for all sorts of things. other than to combust gasoline what else do we use gasoline for??

the wheel of a energy breakthrough looks like ∞

 

Well said DC Kid.

 

I'd sure like to see this thread focus on the topic of using electrolysis for manufacturing your own hydrogen. I'd like to see the economics of it laid out. Not something like the BMW car -- that's expensive future technology. Not fuel cells. But if do-it-yourselfers could generate hydrogen at home efficiently enough to compete with fuel at $5-$10 per gallon, then it's probably something to pay attention to for the future -- especially if it can be done with readily available stuff and the investment isn't too large.

Let's use the practical efficiency we all use with cars: miles per gallon. Since the specific gravity of gas is about 0.7, a gallon of gas has a mass of about 2.6 kg. So one mile per gallon is about the same as 1.6 km/2.6 kg, or 0.61 km/kg. Thus, a car getting 20 miles per gallon is getting about 12 km/kg. If gas costs $3/gallon, then the cost per kg is about $1.1. This results in it costing about 1/(0.61/1.1) = $1.8/km. Please check my arithmetic, as I prefer to work in SI units rather than the screwball hodgepodge of customary US units. Anyway, this gives us a rough cost number to shoot for with hydrogen.

Now, gasoline has around 43 MJ/kg for its heat of combustion. If a car gets 20 miles per gallon of gas (= 12 km/kg), then that means this car uses around (43 MJ/kg)/(12 km/kg) = 3.6 MJ/km; i.e., 3.6 MJ to go one km.

The average US cost of electrical energy is about 33 cents per MJ. Thus, if we could utilize this energy at 100% efficiency to transport the automobile, it would cost about $1.2 to go one km. This already includes the inefficiencies of the car's combustion. From my reference "Handbook of Elementary Physics", MIR Publishers, Moscow (a great little book I got in the 1970's), hydrogen has around 110 MJ/kg for its heat of combustion. Thus, it has roughly three times the energy as gas. So I'd guess the car could get about 30-35 km/kg if it was running on hydrogen.

Thus, to me at least, my interest in using hydrogen will all boil down to what it's going to cost me to make one kg of usable hydrogen using electrical energy. That will include the cost of electrolysis, collection, compression, and storage.

Another thought: since the oxygen is also being produced, any reason why it' shouldn't also be stored and used?

 

OK. I feel ganged up on....

Nevertheless, I won't take my football and leave yet. But everyone needs to have an open mind, especially those with high education. Anything that challenges what we learned in school can feel like a threat. After all, we paid a lot of money and a lot of sweat to earn titles. (I know, I'm back in school again at 47.)

DC_Kid, I support nuclear energy. I don't support ethanol (I never thought burning our food was a good idea and the numbers don't add up at all.) I also agree with you on almost everything you said (although the data about nuclear costs can swing either way depending on which camp you are in.( i.e. http://climateprogress.org/wp-content/uploads/2009/01/nuclear-costs-2009.pdf ) I still like the idea. We people need energy - lots of it and from lots of different sources. And we persons want it.

I say, if the Sullivan patent is "ludicrous," then lets put it in a lab and test it. Disproving an idea is a valid scientific process. And is it not really the only way to disprove something other than saying "I learned it won't work?"

Personally, I now fear the Sullivan patent will NOT work. I think there will be too much energy lost in the switching. I still want to prove it. Maybe I'll learn something in the process. And maybe that something won't have anything to do with physics or electronics.

I would like to know exactly how you are so sure it will not work. Please explain in depth. Why can't we increase electrolysis efficiencies? Anyone who has worked with electrolysis first hand knows that in real life there is a lot of wasted energy in the transformer as heat and EMF and in heat in the water. Why can't that be improved? My power supply uses a large capacitive "transformer." No heat, no EMF. What's wrong with putting it in the lab and testing it?

It's a fact that our electrical grid is over-burdened. As demand on the HV lines rises, there are large losses, they heat up. Efficiencies go down. "Peak demand" costs go up. Why shouldn't we try to use CF lights instead of incandescent?

And is it ALL about economics? There are gobs of people right here in Taos, NM that spend extraordinary amounts of money just to reduce their impact on the environment. Is that wrong?

Look, there is a LOT wrong with Hydrogen ICE conversions. (Including all mentioned above about the grid.) Right now, they don't even exist and there is a lot wrong with the practical implementation. So, should we just give up?

Regardless of the efficiency rates of Hydrogen vs Gasoline as a fuel, it is technically FEASIBLE to run an existing car on Hydrogen (electricity.) What in the world is wrong with that? It places lots more stress on the grid, which is why efficiency becomes important. We come full circle.

We can talk more about thermal efficiencies of Internal Combustion Engines. I have quite a bit of experience with them, both practical hand on as well as theoretical. But my original thread was just about designing a power supply for a very specific application.

People do hold their ideologies very close to their heart. I am working very hard on myself at looking at all directions and putting aside some long-held beliefs. School is good for that. A class last year in forestry pretty much completely changed my tune on some things about sustainability and the carbon cycle. Interesting stuff, good conversation, and everyone learned something including the professor.

But if you are a Phd on this forum telling me why this is not ridiculous, then please afford me the effort of saying exactly why it is, instead of backing me into a corner.

I wrote this just before someonesdad responded, so I will follow up with that too. I too would like to keep it in the realm of Hydrogen Electrolysis - that's what I started with.

Thank you.

 

Here's a link with the conversion problem.
http://www.aardvark.co.nz/hho_scam.shtml

 

Generally, it is valid to test something -

I say, if the Sullivan patent is "ludicrous," then lets put it in a lab and test it. Disproving an idea is a valid scientific process. And is it not really the only way to disprove something other than saying "I learned it won't work?"

The greatest problem with the "device" is that it is purely theoretical. The actual hardware to make the thing do its thing is not described. No schematics, no actual prototype. And only the vaguest of ideas about how to accomplish "molecular shearing".

Anyway, extraordinary claims require extraordinary proof. Show me something that works better than Mr. Faraday established back in 1820. Think about it - nobody here has to disprove it - the proof is required of the inventor. So far, no overunity device has ever been demonstrated to work. If nothing has come to light in over 30 years, think about why that might be.

You want an explanation in depth? Start reading the Ebook on this site. Learn some science. Ask a chemist about "molecular shearing" and see if he doesn't start to snicker.

Let me add something - if any such device can be demonstrated and the effect duplicated like any other experimental apparatus, I will have no problems with it. I will even build one for myself!

 

From the National Renewable energy Laboratory, http://www.nrel.gov/docs/fy06osti/39534.pdf , it takes 39 kWh of electricity to produce 1 kilogram of hydrogen at 25 degrees C, and 1 atmosphere. They based their efficiencies on that number.
Taking in the extra heat advantage, they use an equivalency of 1kg H2 = ~1 gal gas.

So, in a theoretical world (I know doesn't exist,) it would cost (@.08/kWhr) 39 x .08 = $3.12 .

My research shows the best electrolyzers use 60kWh to make 1 kg H2. 60 x .08 = $4.80 . Plus it will take energy to compress. (I haven't done those calculations yet.)

Yep, it's expensive, I admit. Right now it isn't even "green" coming from fossil fueled grid power. But if we can dream of the grid getting more and more renewable (or solar technologies becoming cheaper, which they will,) it could be fuel to make my gasoline SUV a clean machine.

And, like it or not, we have been talking of purely heat dynamics, not considering mechanical physics. We must consider this in the overall picture. The TIMING of pressure is important, not just the pressure itself. example:

Gasoline burns at about 2ft/sec and dynamite explodes at about 16,000ft/sec. A vehicle engine uses about 3 BTU of gasoline every time a cylinder fires. Three BTU of Dynamite would break the engine because the piston could not move fast enough to make use of the velocity of the explosion and the piston/head would shatter. (Point: Not a good fuel, but the same heat energy.)

Gasoline burns so slow that it requires iginition to happen before TDC. Heat is being transferred to the piston and head as this is happening (wasted heat.) Then, it is difficult to get all the long Hydrocarbon chains broken and combusted in time to help push on the piston. Mostly, it is used to prevent oxides of nitrogen. 14.7:1 air/fuel equals the best compromise between Nitrous oxide emmissions and hydrocarbon emissions.

Hydrogen is fast burning. With the right controls, it can get expansion done at the time it is needed most - TDC and pushing down. And be completely finished combusting with no leftovers before the valves open (approx 25 deg after TDC.)

Beenthere, no one here is trying to outdo Faraday. Bond energies are bond energies. Geez, no one is trying to sell you anything. Telling me to learn some science is a little presumptuous don't you think? You don't know anything about me. I get it. You are the "prove it to me" type. We need you guys. I'm the "lets try it" type. You guys need my type too.

I would rather prove it can't be done. Then you can tell everyone you said so. If you don't like electrolysis, fine. You would not be the first person to think it's a stupid idea.

 

We do get a certain number of posters who are convinced that Faraday's numbers can be exceeded. They are all scam artists, or victims of a scam. If you want to look at the "literature", you will find numerous devices that promise to be able to do electrolysis at significantly better than the laws of physics says it can. Essentially by using no power, but somehow jiggling the molecules apart.

As far as I can see, Sullivan is just another Stan Meyer. You can never prove it can't work because the device is so elaborately constructed that you have to fail in the attempt. Good cover for a scammer.

 

Thanks, Chris. Those numbers are useful and give a basis for further thinking. My own chicken scratches earlier today made me estimate that the energy cost for generating the hydrogen would be around three to four times the cost of gas today. Assuming petroleum is a non-renewable resource (this isn't established completely, as I've read that some folks suspect deeply buried microorganisms may be continuously producing it), the cost will continue to rise. For someone thinking ahead, starting now on something like producing your own hydrogen might not be such a bad idea. There are no overwhelming technical hurdles to overcome, but lots of important little things that have to be learned about (safety, hydrogen embrittlement, efficient compression and storage, etc.). Plus, the capital investments have to be looked at.

But I'm interested enough to keep looking at it.

 

Thus, to me at least, my interest in using hydrogen will all boil down to what it's going to cost me to make one kg of usable hydrogen using electrical energy. That will include the cost of electrolysis, collection, compression, and storage.

Another thought: since the oxygen is also being produced, any reason why it' shouldn't also be stored and used?

ah, i like your analysis.
i'm roughly thinking a car could carry 100pounds or 45.3kg of compressed gas (or whatever is mandated as max capacity by the DOT). so with 45.3kg a H engine could go (using your #'s) ~1359km, or ~844 miles !! that makes it attractive from a fill-up perspective. probably also "dangerous" to carry 100pounds of compressed H.

and beenthere is 100% right. converting from one source to another always involves loss. electric to heat is about the most efficient conversion their is. we all know we cannot achieve 100% efficiency, let alone try to surpass it (although a black hole might come in handy for this).....

so ChrisHelvey, what does it cost today in electric to generate 45kg of H using the most efficient electrolyzer out there? and, do you have any data of electrolyzing H from other chemical compounds other than water? one data source suggests $3.10/kg using high temp electrolysis via solar energy @50% conversion efficiency. so 45kg x $3.10/kg = $139.50, so thats $139.50/844miles = $0.165/mile. gasoline in the "best" engine (40mi/gal) on 1 gal of premium ($2.40/gal) = ~$0.06/mile. it still looks like gasoline per mile is cheaper. this makes H 2.75x more than gasoline. a factor of 2.75 is a big feat, and if done it only makes it the same as gasoline, hence a feasible alternative from the end user perspective (given cost of the cars are the same, etc). backend analysis still needs TBD.

another source stated "Some prototype Generation IV reactors operate at 850 to 1000 degrees Celsius, considerably hotter than existing commercial nuclear power plants. General Atomics predicts that hydrogen produced in a High Temperature Gas Cooled Reactor (HTGR) would cost $1.53/kg. In 2003, steam reforming of natural gas yielded hydrogen at $1.40/kg." so at $1.40/kg it costs $63/45kg or $0.07/mile....... this looks like they have already achieved a "same cost" alternative fuel.

but back to the original question. i think mosfet's would be a better choice for what you need. check out the International Rectifier website. you want high voltage fet's that can handle ~50A with as low as possible Rds(on). with a Rds(on) of ~30mOhm you'll need a heat sink to pull away ~30 watts (which is wasted energy in your efficiency equations).

 

HO generators are a subject I find interesting.

I think a lot of people take the wrong approach to the theory.

Adding HO to an engine is *nothing to do* with how much power the HO gives in isolation, which is obviously trivial.

As far as I can figure it out, the critical effects (and power gains) are due to replacing nitrogen in air by flammable components.

Air is only 20% oxygen and the remaining 80% nitrogen etc. drastically slows combustion - think of the classic 'Cigarette in oxygen' demo; from minutes for a cigarette to burn down in air to a single WHUF!

Basic calcs:
a 2 Litre 4 stroke engine uses 1L gas volume per revolution *at full throttle*.

Actual steady speed cruise is say, 2500 RPM and 20% throttle at a guess.
Gas volume throughput per minute = 20% of 2500L = 500L

20% of that is oxygen, or just 100L per minute of combustible gas.
(That's not counting the voume of the vaporised fuel, so actual oxygen is rather less than 100L / Min. so possibly 90L??).

Adding just 1L per minute of HO gives an obvious and significant difference and has a far greater effect on the combustion rate & heat produced (ie gas expansion and engine power) than the percentage change.

Some people are adding 3 - 5L HO per minute. That's going to give several percent change in the flammable / none-flammable mix ratio and possibly 10 - 20% power change?? (which in turn means lower throttle for the same cruise and proportionally less fuel).

Town driving, between tickover and say 1500 revs would give proportionally higher HO percentages and exponentially greater power gains / fuel efficiency improvements.

I've not tried it (yet) but I can see very definite theoretical benefits.
To dismiss it out of hand without thinking it through fully is dumb.

 

All the math is here. http://www.qsinano.com/white_papers/Water%20Electrolysis%20April%2007.pdf

For me, here in Taos, NM, I pay about .08/ kWh . Heat equivalency of a gallon of gasoline, considering an 85% efficiency on the electrolyzer - about $3.50 .

Thanks for your suggestion. I'll look more into MOSFets - they may be a better choice. The more I ponder it, the more I think it will not work just because there will be so much loss at the switches (Mosfets, etc.) Anyway, the capacitive power supply works very well. I guess I'm not just looking at making "the most efficient electrolyzer" as trying to make the best one possible - cheaply.

 

Oh, and there is no argument: Gasoline is cheaper. Way cheaper.

 

All the math is here. http://www.qsinano.com/white_papers/Water%20Electrolysis%20April%2007.pdf

For me, here in Taos, NM, I pay about .08/ kWh . Heat equivalency of a gallon of gasoline, considering an 85% efficiency on the electrolyzer - about $3.50 .

Thanks for your suggestion. I'll look more into MOSFets - they may be a better choice. The more I ponder it, the more I think it will not work just because there will be so much loss at the switches (Mosfets, etc.) Anyway, the capacitive power supply works very well. I guess I'm not just looking at making "the most efficient electrolyzer" as trying to make the best one possible - cheaply.

well, searching for the best FET is what you need to do. you can get power loss down to a minimum.