2009/12/29 Jones Beene <jone...@pacbell.net>: > OK, vorticians. This is could be an important paper and topic, so let me add > one more point of clarification to Michel Jullian's point about the "heat of > combustion" of hydrogen, compared to the anomalous "loading heat" of > Kitamura's claim. > > Michel correctly finds that if you only look at one-half of the reaction, > and ignore the mass of the end product, then what we have is: > > (294.6 / 2) / 6.02e23) * kJ = ~1.5 electron volts/amu based on hydrogen
I didn't ignore anything, I converted the energy released by the reaction of D2O formation (all two halves of the reaction ;) from a "per D2O mole" basis to a "per D atom" basis, the same basis Kitamura used for his 2 eV value, and the same basis you used for your 0.5 eV value presumably, since you compared it with Kitamura's. <Begin Fish drowning> > This is the energy released relative to initial hydrogen mass, but that > might assume that oxygen is unnecessary, if you leave it out. One should > take the mass of O2 into consideration for the comparison with reversible > hydride loading. > > ERGO. It would have been clearer back a few posts ago - if I had broken the > comparison down this way. The steam from hydrogen combustion will have a > molecular wt of 18 amu per hot molecule. The heat of combustion of the two > hydrogen atoms is ~3+ eV in total. The resultant energy per amu of the > steam, therefore, is 3/18 or .16 eV per amu of combustion end product. > > When we compare that energy per mass of combustion product - with the > Kitamura reaction of hydrogen which has been reversibly loaded into a metal > matrix, and then released, then we find that the amu of the end product is > still about one since there is/was no permanent bond. The thermal energy > released, according to Kitamura is ~2 eV, so the eV per amu is about a *ten > to one ratio,* when the energy of the hydride bond is deducted - compared to > hydrogen combustion (by mass of all non-renewable reactants). <End Fish drowning> (those who understand French, see http://www.linternaute.com/expression/langue-francaise/450/noyer-le-poisson/) Come on my dear Jones, a little more work and you will find that your 0.5 eV is correct for some thing or other I am sure ;-) > Next big issue. What is the "real" hydride bond energy for Pd? There is a > chart here (Fig 3): > > http://www.iop.org/EJ/article/1742-6596/79/1/012028/jpconf7_79_012028.pdf?request-id=e4195775-a6d5-4d5f-83b9-da98912aa8c1 Interesting paper, thanks for the pointer! > It appears that the bond energy for Pd varies between .9 eV and a negative > value, depending of a number of variables. The bond is field influenced, > which could be important. From the chart - an average value appears to be > less than .5 eV. However, the indication is that it could be much lower. > Therefore, if Kitamura were correct on the heat energy (which I am beginning > to doubt), then this kind of iterative recycling of hydrogen would be a > window of opportunity for gainfulness, since the spread is very large. The spread is not large for a given set of conditions. In particular there is one very important (IMHO) point which seems consistently overlooked, not just by you, which is that the binding energy is not the same on the surface (heat of adsorption) as it is in the bulk (heat of absorption). It's much higher on the surface. Interestingly, decreasing the Pd particle size increases the surface binding energy (I can dig up a ref if anyone is interested) , which is what the Kitamura work re-discovers IMHO. The surface binding energy is of course relevant for putative LENRs occurring there! Michel
