Search for Excess Heat from a Pt Electrode Discharge in K2CO3-H2O and K2CO3-D2O Electrolytes
Scott R. Little, H. E. Puthoff Ph.D., and Marissa E. Little
September 1998
Introduction
At the 7th International Cold Fusion conference in Vancouver earlier this year, Mizuno, Ohmori, and Akimoto reported1,2 on an electrolysis experiment in which a Pt cathode becomes incandescent under certain electrolytic conditions. This experiment is similar to another experiment3 involving a W cathode, but they report observing substantially higher excess heat levels for the Pt experiment. Quoting from the abstract of reference 1, "High heat output of the order of several hundred watts was observed from input power of tens of watts." In other words they report a power gain of order 10 for the Pt experiment.
Unfortunately, there is no discussion of the excess heat measurements in the body of either report.
It was a simple process to modify the apparatus employed in our Incandescent W Experiments4 to perform this experiment. We have completed three runs including one run with a D2O solvent. With an excess heat detection limit of about 3% relative, we found no evidence of excess heat.
Apparatus
The apparatus employed is essentially identical to that described in reference 4 with the exception of the cathode. For these experiments we constructed an all-Pt cathode by crimping a 0.5 mm dia Pt lead wire to a square piece of heavy Pt mesh (tightly woven from 0.2 mm wire) about 0.5 cm on a side. The Pt lead wire was insulated with heavy-walled Teflon sleeving all the way from the cell cap down to the cathode mesh in order to prevent arcing near the surface of the electrolyte from igniting the explosive 2H2+O2 gas mixture in the head space.
For each run we filled the cell with 150 ml of 0.2M K2CO3 solution, a concentration typical of those used by Mizuno, et al. Electrical power delivered to the cell was measured with a Clarke-Hess 2330 power analyzer and heat released by the cell was measured with a water-flow calorimeter as described in reference 4. For all of these experiments we increased the observed Pout readings by an amount equal to 1.5 times the current in amperes to correct for the caloric value of the escaping H2 and O2 gases.
Results
This plot depicts the results of the first run. The horizontal axis is time and covers 3 hours. Various parameters are plotted vs. time and the traces are color-coded to the numeric displays above the plot. To the right of each numeric value the max/min scale values for the plot are given. For example, the electrical input power, Pin, is plotted in purple on a scale that runs from -50 watts to 450 watts (the horizontal grey line near the bottom of the graph represents zero for the power traces).
The run begins with a ~30 minute period during which the apparatus inside the calorimeter enclosure reaches thermal equilibrium with the calorimeter's cooling water, which is actively regulated at 40° C. You can see the Tcell trace come up to 40° C and you can see the Pout trace come up to zero at the end of this equilibration period. At that point the electrical input was applied to the cell and the energy accumulators (Eout and Ein) were simultaneously reset to zero.
The first 20 minutes of electrolysis served to warm up the electrolyte to about 88° C and to demonstrate a power balance under normal electrolysis conditions, which can be seen by the convergence of the Pout and Pin traces about 0.8 hours into the run.
At about 0.9 hours into the run, the voltage was raised to about 120 volts. This caused the gas sheath to form around the cathode with a corresponding drop in current from about 2.2 amps to 1.4 amps. Under these conditions the light emitted by the cathode was a mixture of orange incandescence and bluish light from the gaseous electrical discharges. We let these conditions persist for about 20 minutes during which time, from hour 1.0 to 1.2, a good power balance (Pout = Pin) was observed.
At about 1.2 hours into the run, we increased the cell voltage to 155, which caused the cell current to drop further to about 1.2 amps. We let these conditions persist until hour 1.5 and again observed a near-perfect power balance. At that point we turned off the input power and waited for the cell to again reach thermal equilibrium with the 40° C calorimeter cooling water. During this time, the Pout signal was continuously integrated to collect all of the heat energy stored in the cell during the electrolysis. At the end of the run, as you can see from the numerical values above the plot, the total input energy was 609.6 kilojoules and the total heat output energy was 604.9 kilojoules, 99.2% of the electrical input energy. There was no sign of excess heat.
Run 2 was a repeat of Run 1 except that more time was spent at high voltages (~195 volts).
The declining Pin and Pout traces during this period reflect the fact that the Pt cathode was being rapidly eroded by the intense electrical discharges. During this period we measured the gas flow from the cell and observed values ranging from 116% to 140% of that expected from electrolysis alone, possibly indicating that the Pt was being oxidized like the W was in reference 4.
At the end of Run 2 we observed a significant quantity of fine black precipitate on the bottom of the cell. We also observed that the cathode Pt mesh was about half its original size and coated with a similar black substance (platinic oxide monohydrate is black). It is surprising that Pt would be oxidized under cathodic conditions but perhaps the electrical discharges provide the means.
Run 2 also did not show any signs of excess heat.
For Run 3 we changed the electrolyte solvent from H2O to D2O (Aldrich #15,188-2, 99.9% isotopic purity). Again we made the electrolyte 0.2M K2CO3.
The run proceeded much the same as the previous except that we allowed an extra long equilibration period to demonstrate the stability of our calorimeter system. From hour 1.0 to 1.5, the average value of Pout was -0.34 watts, an acceptable residual offset for this 100+ watt experiment. As usual we allowed the system to equilibrate during warm-up electrolysis and then we raised the voltage to about 170 volts to initiate cathode incandescence. As you can see from the Pin trace, the input power was not very stable during incandescence with D2O.
This plot shows the voltage (top) and current (bottom) traces during incandescence. These traces look normal for this type of cell and do not explain the power instability.
Despite this instability, the Pout trace stayed very close to the average value of Pin indicating no significant excess heat generation during incandescence with D2O-based electrolyte.
After about 45 minutes of incandescent operation, we turned off the electrolysis power and let the calorimeter system continue to integrate the heat power from the cell until it had again reached thermal equilibrium. Over the entire run, 578.4 kilojoules of electrical energy were supplied to the cell and 573.2 kilojoules of heat energy were collected from the cell...a 99.2% heat recovery.
Surprisingly, the Pt cathode looked like clean, matte metal after Run 3. There was no sign of the black oxide formed in Run 2.
Conclusions
Mizuno claims in his report2 that "the reaction is 100% reproducible." A casual observer would certainly have to agree that we have replicated the basic phenomenon that Mizuno, et al were investigating. However, we see no sign of excess heat in our experiments. Our calorimetry has an overall accuracy of about 1% relative and this results in an excess heat detection limit of about 3% relative. Therefore we have not accidentally missed "high heat output of the order of several hundred watts...from input power of tens of watts".
We welcome suggestions towards making the reported excess heat phenomenon appear in our experiments.
References:
1 "Detection of Radiation Emission, Heat Generation and Elements from a Pt Electrode Induced by Electrolytic Discharge in Alkaline Solutions", T. Mizuno, T. Ohmori, T. Akimoto, p. 253, Proceedings of ICCF-7, Vancouver, B.C. April 19-24 1998
2 "Probability of Neutron and Heat Emission from Pt Electrode Induced by Discharge in the Alkaline Solution", T. Mizuno, T. Ohmori, T. Akimoto, p. 247, Proceedings of ICCF-7, Vancouver, B.C. April 19-24 1998
3 "Strong Excess Energy Evolution, New Element Production, and Electromagnetic Wave and/or Neutron Emission in Light Water Electrolysis with a Tungsten Cathode", T. Ohmori, T. Mizuno, p. 279, Proceedings of ICCF-7, Vancouver, B.C. April 19-24 1998
4 "The Incandescent W Experiment", S. Little, H.E. Puthoff, M. Little, August 1998, Internet: http://earthtech.org/Inc-W/Wreport.html