Linnard?s hydrogen on demand system without electricity !

[motofox]

The efficiency of a fuel is dependent on the amount of power drawn from it. Drawing more power means drawing more current, which increases the losses in the fuel cell. As a general rule, the more power (current) drawn, the lower the efficiency. Most losses manifest themselves as a voltage drop in the cell, so the efficiency of a cell is almost proportional to its voltage. For this reason, it is common to show graphs of voltage versus current (so-called polarization curves) for fuel cells. A typical cell running at 0.7 V has an efficiency of about 50%, meaning that 50% of the energy content of the hydrogen is converted into electrical energy; the remaining 50% will be converted into heat. (Depending on the fuel cell system design, some fuel might leave the system unreacted, constituting an additional loss.)

For a hydrogen cell operating at standard conditions with no reactant leaks, the efficiency is equal to the cell voltage divided by 1.48 V, based on the enthalpy, or heating value, of the reaction. For the same cell, the second law efficiency is equal to cell voltage divided by 1.23 V. (This voltage varies with fuel used, and quality and temperature of the cell.) The difference between these number represents the difference between the reaction's enthalpy and Gibbs free energy. This difference always appears as heat, along with any losses in electrical conversion efficiency.

Fuel cells are not constrained by the maximum Carnot cycle efficiency as combustion engines are, because they do not operate with a thermal cycle. At times, this is misrepresented when fuel cells are said to be exempt from the laws of thermodynamics; meaning, as most people think of thermodynamics in terms of combustion processes (enthalpy of formation). The Laws of Thermodynamics hold for chemical processes (Gibb's free energy), like fuel cells, also but the maximum theoretical efficiency is much higher (83% efficient at 298K [9]) than the Carnot cycle (21% for a car with TL=293K and TH=373K), the most efficient combustion cycle). In reference to the exemption claim, the correct claim is that the "limitations imposed by the second law of thermodynamics on the operation of fuel cells are much less severe than the limitations imposed on conventional energy conversion systems" Consequently, they can have very high efficiencies in converting chemical energy to electrical energy, especially when they are operated at low power density, and using pure hydrogen and oxygen as reactants.
  Thanks to Wiki

[ResinRat2]

Thanks for the info motofox,

So the loss is in heat or escaped/unused hydrogen gas.

This means that if platinum coated wires sealed within the reactor could be used instead, then the efficiency should be-------  100%!!   The heat and the gas would go right back into the reactor. Both good for the reaction.

Right? Am I just bouncing an idea off a wall here or does it sound correct? It does to me.

This is the direction I should be going with this then.

Thanks again for the information.

[ResinRat2]

Hi Everyone,
After reassessing the last experiment I made a couple of changes. I lowered the concentration of electrolyte to 20%. Also I am using only KOH (With double the concentrations of colloids specified in the patent Experiment#13). This gives a solution that has a much, much lower viscosity and allows the bubbles to go straight up instead of downward, sideways, etc. Also I replaced my large fuel cell with a smaller one. I now have two identical (0.9V, 300mW) fuel cells. This is thanks to motofox who posted the information about the efficiency of fuel cells. I can already see that the smaller cell used for regeneration is holding a higher voltage after 12 hours. I will also be switching the regeneration electrode every 12 hours instead of 24 hours, just to see if this makes a difference in the formation of zincates. I also squeezed in a couple more tungsten/carbide cathodes to boost hydrogen production.

I will post videos after I get back from work and clean up my work area mess. They don't look much different from the previous experiment except the metal fuel cell is replaced by the Plexiglas smaller one. Theoretically this should be more efficient and regenerate the zinc at a higher voltage to retard the formation of zincates. We shall see if this is correct.

Future designs will incorporate platinum-coated wire mesh in place of the fuel cells.

Here's to longterm hydrogen generation. Cheers.

Thanks for your interest.

[Tinker]

R%R

What you have done is tenacious and admirable. The time and effort you have put in to this project is Awesome. Thank You!

You too Dingus.

I have a few thoughts that you can accept or reject as you please.

1. Your divider between the H2 and O2 zones in the reactor, Why the V ?
Is there an issue with H2 Migrating to the O2 Side? if not might I suggest a hole with a 30deg angle downward from the O2 side to the H2 side as O2 seldom falls and H2 in the O2 side I do not see as a problem. I could be wrong.

2. Leaks, Off the shelf containers might be something you might consider for future replications. "The Container Store" comes to mind here.

3. Mounting your anodes and electrodes to the lid of you container would give you flexibility especially in prototypes. And save time in leak detection and repair.

Please do not take this as criticism,  it is not.

You have done a good thing.

Thank You
Tinker

[ResinRat2]

Hi Tinker,
The V between the chambers is to keep gas from migrating. It works better now that the viscosity of my electrolyte solution is lower. The previous solution had a higher concentration of NaOH and KOH and was viscous. The bubbles migrated every direction and had a tendency to creep between the chambers. The oxygen getting into the hydrogen side is bad because it lowers the efficiency of the fuel cell and drops my output. The hydrogen getting into the oxygen side is bad only in the sense that I am losing potential energy from the lost hydrogen. I would like to keep either gas from migrating. The future designs will have a much steeper angle to further prevent gas migration.

As far as leaks go, I have them fixed now. I have tried getting off the self containers, but had little luck obtaining the design I wanted. I searched and searched at stores here where I live and on the net. No luck getting exactly what I want so far. If you look at the reactor design you can see what I mean. It is a bit specialized. Gaskets only caused me trouble, and it turned out that I simply had to glue the lid shut just like the rest of the reactor and only access the electrodes through holes in the sides sealed by the rubber stoppers. This worked out and I will do it this way through future designs.

I like the idea of the electrodes attached to the lid. This looks like what Linnard Griffin did in the video of his tiny reactor that ran the fans and toy stoplight. Again, it looks highly specialized and would need to be custom made. I appreciate the suggestions. I think suggestions are great as long as ridicule never enters into the picture. This has happened to me in the past and exposes my dark side, unfortunately. Sorry again everyone.

My reactor had an overflow issue overnight and blew electrolyte solution into the fuel cells. I see many areas where improvement and design alterations are needed. This was the first prototype afterall, but it is proving my concept of keeping the zinc electodes regenerated and the solution clean. I don't see any zincates so far; but my gas flow is disappointing. There is enough to power regeneration, but the fan only runs on and off intermittently. I need to double or triple the number of tungsten/carbide electrodes for better hydrogen output, but there is no room for that in the present design. So this is another step, another gathering of knowledge, and a very encouraging series of results.

In the next design I will greatly increase the number of tungsten/carbide electrodes. I will also try to incorporate the idea of platinum coated wires directly in the upper portion of the reactor so the gases flow over them in the electrolyte solution. This should generate a current directly so no outside fuel cells are needed. So I believe I have the maintenance issues ironed out pretty well. The switching of the electrode connections for regeneration seemed to work better every twelve hours instead of every twenty four hours. The hydrogen reactor solution maintained a clean appearance and the zinc electrodes had no evidence of zincates formed on the surface. Nice and uniform.

The reactor has been running 39 hours now and looks good as far as no zincates forming. The regeneration draw is 0.835 volts at 3.39mA. The fan draws over 50mA and hits 0.710 volts. This is my overunity, but it starts and stops intermittently. So I need higher hydrogen gas flow. Not possible in this present design. I am disappointed, but this is just another failed experiment that I get to learn from.

Also, the electrodes are very cold. Drawing energy from the environment. Maybe a thinner walled Plexiglas container would transfer heat more easily from the environment and speed the reaction. Though I do like the strength of the thicker-walled Plexiglas.

1) Higher gas output = more tungsten/carbide electrodes. This means a larger reactor size.
2) To incorporate the platinum wires I will need a second "tier" to hold them above the t/c electrodes.

The journey of a thousand miles begins with the first step.

Each step is closer to the goal.

Thanks everyone for your interest, ideas, and support.