Is this the "new" way forward for energy?

I'm having a bit of trouble squaring up the statements about low-grade heat with the high temperatures needed to get it running efficiently. Is it any more efficient than existing technology at lower temperature differentials? (Kinda rhetorical question).

Probably not at this stage. The question is if this new way of extracting power from waste heat will have more potential then the other known ways we try to work with now.

In any point of its development any new technology will struggle to prove itself as it is always compared to the existing methods, finely tuned by years of practise. The trick is to spot the winner before it has won.

Is this the next winner?

OK, I'm with you on that.

Next leetle question is "will this be put in the public domain?". I guess they've gone quite a long way along that path, in releasing the details to date. But they're going to have to make themselves a $ or 3 somehow - or am I just a cynical old sod?

John, you are just a cynical old sod, but that is why we like you.

Case, this is exactly the sort of thing that proves to me that my hope and optimism in the ability of engineers and scientists to solve CO2 issues is well founded.

Even if it is a non issue, and global warming is all just a hype, if it gives some of us the passion and incentive to create new solutions to the problems around producing clean energy then that is fantastic.

It is about time that someone dreamed up an new, more efficient, and pollution free heat engine: perhaps this is it. I hope so.

The guy has been using his private money as earned by producing toys. He will want some return for sure. Lets hope that if this works the oil industry or the automotive industry is not going to buy this idea and shelf it as they have too much at stake with current technologies. They have done that before.

Nothing like a good corrupt oil baron, car manufacturer, politician .......

Don't bet the farm on it. Nor hold your breath.

A heat engine operates between two temperature and produces work in the process. A working fluid is also expanded and contracted. Such machines have been mechanical in the past and a solid state "Machine" is not likely to produce usable output.

IF the work output is thermal then it must be between the two operating temperature and therefore a loosing game. Use the upper temperature and forget the SSHE!

Maybe the inventor wants attention or investors or ???

Scepticism is a healthy trait for engineers but also remember that the brain is like a parachute, it only works when it's open to suggestions.

If this principle works, it goes beyond the standard concept of thermodynamics. The heat moves the hydrogen atoms through a membrane. This will have an efficiency factor so you will end up with some loss as always. There is no expansion of gasses and therefor no contraction which limits the loss. The atom loses an electron by going through the membrane which is our electricity.

The big question is, as they state it re-uses the hydrogen, where does the missing electrons come from to enable the hydrogen to be used again?

Again the article is not too specific and totally not technical but if they have an answer it would be a massive step forward.

The big question is, as they state it re-uses the hydrogen, where does the missing electrons come from to enable the hydrogen to be used again?

The "missing electrons" return to the engine after they complete their path through the load -- just as is always the case for any source of electricity. After traversing the electrical circuit and returning to the engine, the electrons recombine with the protons on the other side of the membrane to form H atoms, which in turn immediately combine to form the original H₂ molecules. Cycle completed.

Ah, so you have initially a resorvoir of H2, a membrane and an empty reservoir.

While heat forces it through the membrane, the electrons strip of the provide electricity and the "empty" reservoir fills up with electron depleted H atoms. They wait there until the current provides the electrons back again to recombine.

All you have to do is to move the H2 back to the other side of the membrane to begine the cycle again.

Sounds too simple but I understand now. It does however bring up the question about losses. Where do the missing electrons come from that were lost due to various points in this circuit where they would either be wasted, or used up in some way. The electrons flow from one end of the "battery" to the other but due to the consumption of energy in the middle, you never get the same amount of electrons back.

Seems you end up with a reservoir full of electron depleted H atoms which would be highly unstable and not cheap to get rid of.

Am I so dim that I got this completly arsed up or am I right?

The electrons flow from one end of the "battery" to the other but due to the consumption of energy in the middle, you never get the same amount of electrons back.

I think that a battery always receives (at the cathode) exactly the same number of electrons that leave from it (at the anode). The returning electrons of course have a lower electric potential (voltage), having lost energy to the load. Otherwise, an imbalance between the number of departing and returning electrons would cause a charge buildup in the battery -- a very high energy situation akin to bottled lightning! As for electrons that leak out of the circuit, we can resolve this issue by noting that electrons can also leak (from ground) into the circuit to replace the wayward electrons. All electrons accounted for, no electron left behind.

Excuse me but electrons have exactly one electrons worth of charge, that cannot be tampered with. They cannot suddenly become an electron without , or less, charge. That is just wrong.

You must be able to explain this a bit better before I take your word for it. When electrons do their work, they get used and re-utilised in the system that converts energy from electrical charge into something else like light and heat. They are lost to the stream of current. This is what depletes the battery in the end, no more electrons left.

Excuse me but electrons have exactly one electrons worth of charge, that cannot be tampered with. They cannot suddenly become an electron without , or less, charge. That is just wrong.

You must be able to explain this a bit better before I take your word for it. When electrons do their work, they get used and re-utilised in the system that converts energy from electrical charge into something else like light and heat. They are lost to the stream of current. This is what depletes the battery in the end, no more electrons left.

At first I thought you were pulling my leg, but okay, not everyone understands the hairy details of the phenomenon called "electricity". I'll bite. When electrons exit a battery they have a certain voltage, for example 12 volts. Those electrons then pass through a load which offers resistance to flow. This causes a voltage drop which exactly equates to a loss of energy. Next, the electrons (now at a lower voltage, for example 5 volts) exit the load and return to the other terminal of the battery. The electrons don't get "used up", they simply lose some of their potential energy during their trip around the circuit. The charge of each electrons never changes. And, as I stated before, the number of electrons leaving and returning to the battery are exactly equal. Only the potential energy or kinetic energy of an electron can change.

As an analogy, think of water flowing over a cliff. The water has a large gravitational potential energy at the top of the cliff. As the water accelerates downward due to gravity, its gravitational potential energy converts into kinetic energy which could be used to drive a load such as a turbine. When the water reaches ground level, it has zero gravitational potential energy remaining, but the water molecules still exist (they don't get "used up"). To complete the cycle, the Sun's heat vaporizes the water, the water vapor rises to form clouds, and the clouds produce rain which falls into the reservoir at the top of the cliff. In this analogy, water molecules correspond to electrons, gravitational potential energy corresponds to electric potential energy, the height of the water corresponds to the voltage of the electrons, the turbine corresponds to an electrical load, and the Sun's energy corresponds to whatever energy raised the electrons to their high voltage. If my analogy doesn't enlighten, then I refer you back to the more rigorous physics explanations:

http://en.wikipedia.org/wiki/Electricity

http://en.wikipedia.org/wiki/Electric_current

http://en.wikipedia.org/wiki/Voltage

Ok, so the electrons are agitated somehow to have an elevated energy level (other than their charge which is always -1e) which is what is used up to convert into another energy useful to us. The used up energy changes the state of agitation from this electron back to normal and it is returned to the battery.

I understand this and can agree with that. The charge is not what does the work in this scenario, it is the agitates state of the electrons that has the potential, or difference, in energy levels which is what we use.

How will they in this new device, as originally posted, make the electrons useful to us? Just peeling the electrons from hydrogen is clearly not enough for us to do something with, they need potential. Seems that the heat forces the hydrogen through the membrane but that just leaves you with loose electrons, comparable with the ones that you return to the battery after they have done their work, useless to us in other words.

So my own answer to my own question would be that the heat keeps pushing the hydrogen through the membrane which would fill up the membrane with loose electrons (mobile electrons). When the membrane is full, or if it is always got some free electrons it will be immediately, the electrons will want to move away, which is the drift, and can do their work.

After this they are flowing naturally back to the other pole where they could be recombined with the hydrogen.

Neat.

Ok I read one of the links now and went on to battery as well. The agitated state is called "drift".

This is the source of the electricity and moves the electrons which makes them able to do work. Without the drift, no movement, no work. Indeed the electrons charge is important but it does not do the work, which is what was my misconception.

Thank you for pushing me to the right answer, I love learning, no matter how basic.

Yes, you grasped the subtleties very quickly. But I just want to add one conceptual detail: when the device strips electrons off of hydrogen atoms (by forcing H₂ gas into the membrane), note that this pulls negatively charged electrons away from positively charged nuclei (protons in this case). As you know, positive and negative charges experience a mutually attractive electromagnetic force. This is analogous to the attractive gravitational force between two masses. So pulling an electron from an atom requires an input of energy, just as lifting a boulder off of the ground does. In the case of the boulder, we have increased its gravitational potential energy. In the case of the electron, we have increased its electromagnetic potential energy, also known as its voltage. The device not only strips electrons from H atoms to give loose electrons as you said. In addition to attaining the freedom to move, those electrons also have been juiced up with extra energy (higher voltage). Whenever electricity flows through any circuit, the electrons behave analogously to water flowing downhill.

But the increase in their potential, voltage, does not make them move all by itself. This would be the drift, and has to be caused by yet another force.

In this case that should be the addition of more of such electrons by forcing more hydrogen through the membrane. Like marbles in a tube, you push one in and one falls out the other end.

The more you talk about this, the more it becomes clear that they:

1) still have a lot of work to do to overcome all the various problems and logistics

2) cannot produce an awful lot of power doing this.

I have to conclude that it may be another 5 to 15 years before this will be available if at all.

Secondly it may only be good for very small power consumptions such as LED's or maybe the charge of a mobile phone on standby. If you want more the quantity of hydrogen would inhibit the usefulness.

But the increase in their potential, voltage, does not make them move all by itself. This would be the drift, and has to be caused by yet another force.

The electrons move because their attraction to the positive voltage (relative excess of positive charge) at the cathode of the device. This is always the case in any closed circuit whether it's a powered by a induction generator, an electro-chemical cell, a photo-voltaic cell, thermo-electric converter, a piezo-electric transducer, or any current source. The "drift" (really just a slang term for current) results directly from the mutually attractive electromagnetic force between oppositely charged objects.

The more you talk about this, the more it becomes clear that they:

1) still have a lot of work to do to overcome all the various problems and logistics

2) cannot produce an awful lot of power doing this.

I have to conclude that it may be another 5 to 15 years before this will be available if at all.

I don't understand what you base your conclusions on. The working principle is completely sound, and fully explainable by well-tested theory. Only experiments will reveal how well the device operates in practice. But based on its ability to avoid the Carnot efficiency limitation (which applies to any engine that converts a heat differential into work via expansion of a gases), the device might achieve very high energy efficiencies. And I see no inherent reason preventing it from being scaled up as large as desired.

If you want more the quantity of hydrogen would inhibit the usefulness.

Now I see your real point: the technology might not be compact enough to use in power-hungry consumer products.** But the main application would be for large-scale power plants (powered by any heat source including fossil fuels, nuclear, or concentrated solar). Remember, this device is a heat engine, not a storage battery, so your objection does not apply to the technology's major application.

Footnote:

**If you think about it, there really aren't any existing practical devices for small-scale (portable) conversion of heat energy into electrical current (other than feeble outputs for wrist watches). So if your target application is conversion of heat to electricity, your objection sets a very high bar.

"The electrons move because their attraction to the positive voltage"

The electrons would indeed move but only if their was a circuit which would be a load. I understand it would be a question of delivering what is available rather than delivering what is needed. It is not a battery as such.

"I don't understand what you base your conclusions on. The working principle is completely sound, and fully explainable by well-tested theory"

They have not figured out how to "move" the depleted hydrogen to a place where it can be re-combined with the electrons. It should be , or become momentarily, part of the cathode but how to do that and to get them away once recombined?

The efficiency is possibly going to be high but that does not mean it will generate a high yield. Hydrogen only gives one electron per atom so the volume of hydrogen needed to generate electricity is going to be disproportionate. Also I would imagine that the membrane will pose some restriction, further limiting the speed with which the conversion can be done.

"But the main application would be for large-scale power plants (powered by any heat source including fossil fuels, nuclear, or concentrated solar). Remember, this device is a heat engine, not a storage battery, so your objection does not apply to the technology's major application."

This is not true as they state clearly that it could be used to syphon of low heat sources or waste heat. They refer to body heat as one possible source which indicates to the use of this device to power small personal gadgets rather than large scale stuff. Maybe it is something they are also looking at which would perhaps make this project more viable. I still think the amount of hydrogen needed woul dmake it difficult to say the least. We could calculate the amount needed for a certain amount of power /time unit but it is midweek, late and I am tired

Ok maybe I will have a go anyway, just to see if I can still think straight after all these years.

Ok. just for a laugh. It is probably wrong but let's see.

LED at 5V and 5W for 1 minute

I is 1A by ohm's law

Coulomb's law tells us that Q=Ixs so Q=60C

Avogadro's number tells us that one coulomb equates to 1.036 x 6.022 x 10^23 x 10^-5 electrons (charged particles)

Our figure is 60 x this so approx. equals 6.24 x 10^18 x 60 = 3.74 x 10^20 electrons

For this we need the same amount of hydrogen atoms which is 6.21 x 10-4 mole H

Mole weight of Hydrogen is approx 1 gram so this is 0.000621 grams of hydrogen needed to burn an led of 5V / 5W for 1 minute.

That means that 1 gram of hydrogen could burn this led for just over 26 hours!

This must be wrong as I thought that should be bags full of hydrogen. Somebody tell us right please. Mind you, how much volume of hydrogen would this be?

Big balloon or not?

Wrong or not I had fun

That means that 1 gram of hydrogen could burn this led for just over 26 hours!

Your calculation looks good in the sense that you show how much H₂ would be needed if the H₂ were not re-used. But note that in Johnson's device the same H₂ is used over and over, so the true limiting factor is the instead the rate of heat flow from the hot source to the cold sink -- this has more to do with the surface area of the device, and the rates of the electrochemical reactions. The more I think about this technology, the better it looks.

They have not figured out how to "move" the depleted hydrogen to a place where it can be re-combined with the electrons.

What makes you think that they have not figured out how to recombine the protons and electrons at the cathode? This process is very similar to what already occurs in existing fuel cells (except that in fuel cells, oxygen is also present, leading to the production of water instead of H₂). Note the following quote from the link you gave: "With the help of Heshmat Aglan, a professor of mechanical engineering at Alabama's Tuskegee University, Johnson hopes to have a low-temperature prototype (200-degree centigrade) completed within a year's time." It sounds like Johnson already worked out the recombination step, otherwise he wouldn't be scaling up (I assume he already demonstrated proof-of-principle, or his claim would not have appeared at PhysOrg.com).

The efficiency is possibly going to be high but that does not mean it will generate a high yield.

By "high efficiency" I meant high energy efficiency -- a high yield of energy. If your mention of "high yield" does not refer to energy, then to what do you refer?

This is not true as they state clearly that it could be used to syphon of low heat sources or waste heat. They refer to body heat as one possible source which indicates to the use of this device to power small personal gadgets rather than large scale stuff.

As you point out, Johnson mentions small-scale applications. But he also mentions large-scale ones, to wit: "Here's how it works: One MEA stack is coupled to a high- temperature heat source (such as solar heat concentrated by mirrors)". Think solar tower. And "This engine, Johnson says, can operate on tiny scales, or generate megawatts of power." Megawatts. When I specified large-scale applications as the most important, I meant that these would have the most beneficial impact. Replacing existing power plants (generally about 40% energy efficient) with Johnson's potentially 60% efficient heat engine would help humankind far more than small consumer applications like cell phone chargers. Of course if the small engines work well too, then we enjoy additional benefits.

With efficiency I meant the yield compared to maximum possible without loss. The total yield can be high but that depends on heat, size and efficiency of the membrane.

I must have got bored in the middle of that article as I did not read that last bit about solar towers. He certainly thinks big on that one, lets hope it works well enough.

With regards to the time frame he stated I think you must take into account that he will be looking for sponsors irrespective of what he says or has done so far with regards to funding.

If he thought it would take 15 years, he would never say that right now as funding would be more difficult to get. These things always end up taking longer than initially stated.

I suppose the hydrogen could just be transported (pumped) to a chamber with the cathode centrally in it and the recombination would most likely just occur. Still seems hit and miss that one, I am curious how he really thinks to do that. Isn't hydrogen with its electrons missing not highly unstable? You would want to keep it clean for fear of recombination with other elements.

With regards to the time frame he stated I think you must take into account that he will be looking for sponsors irrespective of what he says or has done so far with regards to funding.

If he thought it would take 15 years, he would never say that right now as funding would be more difficult to get. These things always end up taking longer than initially stated.

Fair enough -- as with all new technologies, the inventor tends to exaggerate the potential benefits, downplay the disadvantages, and underestimate the time required to bring the idea to market. So investors need to be careful, and really check out the science behind the idea. But as a chemist familiar with physical and electro-chemistry, I would make an educated guess that Johnson has come up with a winner. If were wealthy, I would like to invest in it.

Isn't hydrogen with its electrons missing not highly unstable? You would want to keep it clean for fear of recombination with other elements.

Hydrogen atoms with the electrons removed give hydrogen ions (H⁺). These are unstable only in the sense that they are very acidic (react exothermically with strong bases; corrosive to metal and flesh). But H⁺ is a very common species in industry, and even found in household products. Hydrochloric acid ("muriatic acid" used to lower pH in swimming pools) and sulfuric acid ("battery acid") contain copious amounts of H⁺. Proton exchange membrane fuel cells (PEMFC) routinely have H⁺ flowing through their membrane, exactly like occurs in Johnson's invention.