----- Original Message ----- From: Horace Heffner To: [email protected] Sent: Tuesday, September 04, 2007 4:37 PM Subject: Re: [Vo]:Re: Towards verification of BG claims
> > On Sep 4, 2007, at 5:47 AM, Michel Jullian wrote: > >> >> ----- Original Message ----- >> From: "Horace Heffner" <[EMAIL PROTECTED]> >> To: <[email protected]> >> Sent: Tuesday, September 04, 2007 12:55 AM >> Subject: Re: [Vo]:Re: Towards verification of BG claims >> >> >>> >>> On Sep 3, 2007, at 2:15 PM, Michel Jullian wrote: >>> >>>> Oh I see, I thought you meant the porous structure supported a >>>> continuous (waterproof) Pd foil, in fact the mesh is made of Pd or >>>> is Pd plated right? >>> >>> The immediate surface layers could be sintered Pd granules, but the >>> back more granular layers could be any metal I think. > > Here I should say any conductive material with very small holes in it > can be be co-deposited with an effective metal for hydrogen > generation, which is thus probably a hydride forming metal, provided > the metals won't separate when the hydride forming metal is hydrogen > saturated. The main purpose is to generate the hydrogen in locations > where it will be sucked into the cathode. Makes total sense: deloading will be at the sides and mostly back of the metal hydride grains. Their front will both load and bubble, but the amount loaded will be that much that doesn't bubble, so the active surface will be improved relative to non-hydridable metal grains forming the exact same porous structure. I wonder if this could help with my back-loading / front- deloading + electrolysis scheme, I suspect not. If I need smooth surfaces, equidistant from the anodes which is probably what will work best, what might work would be a vertical coaxial arrangement of the three electrodes, with vertical bubble entraining flow of electrolyte + scrubbing particles. >>>> Independently of the cathode material, the idea of flowing >>>> electrolyte through a porous electrode in order to maximize the >>>> ratio of active (bubble free) area to total area seems good, all >>>> the more so that it also increases the total area! In fact both >>>> electrodes could be made thus, and one could pump electrolyte into >>>> the interelectrode gap so the anode surface would be bubble free >>>> too, which would further maximize achievable electrolysis current. >>>> Has this ever been tried BTW? >>> >>> I think so, but I can't find the paper. I think it was done by these >>> folks: >>> >>> http://www.qsinano.com/white_papers/Water%20Electrolysis%20April% >>> 2007.pdf >> >> Interesting paper, but their Appendix 1 derivation of unity >> efficiency cell voltage 1.482 V takes them nine complicated steps. >> I posted a much simpler derivation here some time ago, it went like >> this: >> >> At 10^5 Pa and 25°C the endoenergetic overall electrolysis >> reaction H2O(l) -> 0.5 O2(g) + H2(g) consumes 285.83 kJ/mol_H2O >> (consumed energy = enthalpy change of the reaction = formation >> enthalpy of H2O since O2(g) and H2(g) being in their reference >> states have zero formation enthalpy). Per H2O molecule that's E = >> 285830/6.02e23 = 4.748e-19 J >> >> Efficiency is unity when E is exactly equal to the consumed >> electric energy per H2O, which is equal to the supply voltage V >> times the charge 2*e (two electrons circulated per molecule), so: >> >> V = 4.748e-19 / (2 * 1.602e-19) = 1.482 V >> >> Any electrolysis at a lower voltage would have to borrow energy >> from the environment, I don't know if that's possible ; > > > It is more than possible. Managing the thermal energy contribution > is essential to high efficiency industrial electrolyzer operating > design and a major component of the energy. I did say at 10^5 Pa and 25°C. At higher temperatures H2O has a lower formation enthalpy, so the thermoneutral voltage is lower. >>> Something you might want to think about regarding back loading at a >>> somewhat lesser negative potential V<v<0 than the front loading >>> negative potential V >> >> Why negative, relative to what? > > The anode of course. In electrochemistry the cathode is commonly > referred to as negative, the anode positive. But there are two anodes, isn't it better to use the cathode potential as the reference? Or better, let's talk about cell voltage, and about fusion side and loading side instead of front or back. The loading cell would have a higher voltage than the fusion cell. Or some other parameter could be used to create the loading dissymetry. As we have just discussed a higher temperature lowers the interface potentials (equivalent zener breakdown voltage), so we could play with temperature, even with identical voltages (one supply). Different hydrogen ion concentrations, different electrolyte conductivities, will create a dissymetry too. Any differing electrolysis parameter in fact, some will be more practical than others. >>> is the fact that most all CF experiments, due to >>> electrolyte currents and resistances, produce a range of potentials >>> across the cathode surfaces - especially the fluidized bed >>> experiments using beads. Nothing repeatable resulted from these >>> experiments AFAIK. I agree. A coaxial arrangement with smooth electrodes and tight tolerances shouldn't have such problems. A parallel planes arrangement should work too. >> I don't see how these are relevant to my back-loading + front- >> deloading & -electrolysis scheme, which doesn't mean they aren't, >> kindly explain. > > First let me be clear that whenever I talk about the front side that > is the side from which the loading occurs. The hydrogen moves on > average from the front side to the back side. Somewhere mid-stream > in the discussion you seem to have decided to reverse this meaning. > Maybe it was for your discussion in other groups. > > To obtain backside de-loading while simultaneously obtaining hydrogen > movement toward the back side from the electrolyte, the back side > must in fact be a cathode, and thus it is negative, but not equal in > negativity to the front side, otherwise it would in fact be the front > side, and the front side the back. Of course an electrode can be run > using AC or AC superimposed over DC, but that is not the scheme you > have been promoting. Indeed my preference goes to DC for now, it sems to me that's what will maintain the highest possible loading ratio for one thing, especially at the surface where we need it. > So, the back side operates at v, the front side > at V, where, V<v<0. This situation is common in ordinary > electrolysis cells. Due to electrolysis current in the resistive > electrolyte, potentials vary across electrode surfaces. In fluidized > beds the potential through the cathode material the surface potential > can vary all the way from V to 0. Hydrogen literally loads on one > side and de-loads on the other, or loads in one area while de-loading > in another, in all cases diffusing through the cathode. Yes, I see what you mean now. Michel
