Unconventional electrolysis

  • Earlier I made other tests by deliberately adding more impurities to the electrolyte, reusing the previous one which had already significant amounts of iron dissolved in it.

    • < 10 mg Al in the form of thin strips from a 20 micron foil
    • 130 mg Cu "powder" (cut from a stranded Cu wire)
    • Added a few more drops of HCl
    • Refilled with tap water (added just before the new test and during it)

    I haven't performed objective measurements, but it seemed more lively than before, in that discharges were seemingly more likely to occur. I also have the impression that water evaporated faster.


    Before I go through all the videos I made, I wanted to share this. Spraying water (tap water here) directly on the electrodes would cause often current to increase significantly, sometimes evolving in a full short-circuit (or "welding reaction" as I called it in the past).



    Interestingly but not unexpectedly the electromagnetic noise recorded with the AM radio stopped exactly when the continuous plasma started. The thick portion with high low-frequency content in the spectrogram below starts (0:40:65) when similarly an irregular low pitched noise starts in the video, and terminates (at about 0:40:15) when the "welding reaction" occurs. EDIT: the EMI recorded was also the highest throughout the testing session during this part.




    Regarding GM readings, the second set of red dashed lines below denote when the last testing session started-stopped. It doesn't seem like there was any increase, but right in the end there was a small CPS spike, which might or might have not been coincidental since that was about when I made the video above. The window was open during the test. EDIT: added the past 3.5 days of data. It seems as if today the tests made readings become slightly lower and irregular than in the past days. Hard to tell whether this is a genuine effect, though.



    Unfortunately electrode erosion and in particular anode erosion has been severe just during this test. For some reason the top portion of the anode became black - possibly due to chlorine from the electrolyte (but I don't think that much got evolved; no significant smell and no discomfort felt).




    EDIT:



    A longer, likely more boring video showing how it typically behaved after injecting tap water on the electrodes. At 1:55 and 2:05 larger "explosions" occur. The loud low-pitched noise was probably due to vibrations transferred from the coil.




    A brief earlier sequence where numerous small, presumably hotter (bluish) explosions/discharges occurred in quick succession, eventually evolving in a full welding-type short-circuit.

  • Today I made some more testing, but I couldn't quite get it to the same level of activity as yesterday. I think one reason could be that the electrolyte has acquired a relatively thick consistency from the dissolved metal/metal-oxide particles within it. I only made refills with tap water, which might also have contributed to this (e.g. alkaline impurities seem to make discharges less likely to occur and have to be counterbalanced with more HCl. This is obvious when adding KOH).


    Preparations:

    • Swapped electrodes to even out wear
    • Reused electrolyte from yesterday's testing
    • Added large HCl drop at the beginning of the test
    • AM Radio tuned to 1000 kHz
    • Placed Nd magnet on anode (thinking that hopefully it would help maintaining ferromagnetic particles on its surface)

    At the end of the test electrode erosion has been again severe. Below showing before-after the test.



    Geiger readings haven't moved significantly except perhaps downward. I don't know what to make of this (it could be due to environmental reasons). The last pair of dashed red lines denote test started-finished. In the previous days until yesterday afternoon (2019-02-08) readings were slightly more stable.



    This time I could make better videos using a lower resolution, but higher quality Panasonic SDR-H20 videocamera. Nothing particularly spectacular has been observed, but videos 002 and 004 show the "welding-type" short-circuit in a slightly higher clarity than before.


    I found that sometimes just turning the PSU off-on would solve that type of fault. Perhaps this could be monitored with an external circuit so that cell operation could be more autonomous.

    • 001
      • Low-level operation, with electrolysis ongoing at about 3A and small silent discharges occurring. The low-frequency noise comes from inductor-caused vibrations transmitted to the table.
    • 002
      • Slightly more active electrodes ending up into a full-blown short-circuit of the "welding" type. When this happens current rises to the maximum allowed by the circuit resistance, about 38A. The metallic noise that can be heard at the end of the video is due to a ferromagnetic tool getting attracted to the inductor by its magnetic field at high current.
    • 004
      • More irregular operation showing at times larger discharges than usual, both in magnitude and apparent voltage. Overall the discharges were silent. At the end of the video the current clamp warns about its auto-off function, while at the same time a welding type short circuit occurs and I manually turn off the power supply.
    • 005
      • A faint high frequency whine could be heard from the electrodes. With this new arrangement they typically don't produce loud resonating noises as in the previous one where the larger surfaces would oppose toward each other.
    • 006
      • Video showing the immediate effects of injecting tap water toward the end of the experiment. Typically this would result in a current surge and various noises from the electrodes. Here the reaction seemed less lively than usual, possibly due to the too high water level.
    • 007
      • Steady state operation toward the end of the experiment, where electrolysis would occur at about 3.0A and no particular change would occur. The cell felt as if it could continue at this rate indefinitely. Not many discharges visible through the top opening.


    Command to used convert the proprietary videos from my videocamera into a better format:

    Code
    1. ffmpeg -i MOV001.MOD -deinterlace -c:a copy -aspect 16:9 unconv-yyyymmdd-n-comment.mp4


    EDIT: I took note of water refills, by the way.

    • 12:39:32 2 ml
    • 12:43:37 1 ml
    • 12:51:53 1 ml
    • 12:57:13 2 ml
    • 13:10:29 2 ml
    • 13:12:13 2 ml
    • 13:13:44 1 ml
    • 13:16:10 1 ml
    • 13:17:39 2 ml
    • Total refilled: 14 ml

    I didn't take note precisely of input values, but the total running time was 45 minutes and current at 12V through the coil+electrodes should have been on average about 3A, for a total of roughly 100 kJ of input energy. If water only got evaporated, about 31.6 kJ left the cell this way.

  • I made a very quick test with the electrodes as shown previously, but outside the jar.


    First I tried to apply plain tap water to the narrow gap. This caused the formation of a relatively thick oxide layer from the anode extending to the cathode and filling the gap. Current was rather low at this point.


    Afterwards I tried to apply a diluted electrolyte solution composed of some K2CO3 and a couple KOH flakes. Current increased somewhat and the oxide layer got slightly thicker but nothing particularly noteworthy otherwise happened.


    Then I tried applying a few dabs of HCl using a plastic straw. Here is where things got more active. The AM radio started showing random noise and numerous small discharges occurred at the gap. I've made a video of the process (after it already started).


    (Link to the video)

    • At minute 0:20 I start adding HCl as described, with the AM radio already producing noise from testing made a couple minutes earlier.
    • At about minute 3:40 I apply the same alkaline electrolyte solution that previously didn't seem to have any flashy effect, but here it seemed to have the effect of transporting the HCl on the surface of the electrodes into the gap and produce more discharges.
    • At minute 4:03 a full welding-type short-circuit occurs and AM radio noise completely stops. It looks like the discharges do not need to be visible for AM noise to happen, and that a continuous arc doesn't produce any radio noise, or at least none that is captured by the AM radio I'm using.

    The radio noise by the way is in at least part induced by the cathode wire to the AM radio, so perhaps having it loop once or twice around it could improve its SNR relatively to the background radio signal.



    EDIT: relatively to noise detection with the AM radio, here are a couple more observations:

    • The noise appears to radiate mainly from the cathode wire, and almost not at all from the anode wire.
    • Placing the AM radio on the inductor/coil (which I'm using to boost up discharge voltage when short circuits occur inside the gap), in my case placed between the power supply and the cathode, also seems to be effective in detecting the same kind of noise observed closer to the cathode.
  • Wyttenbach

    1. Before I start using Pd, Rh or other precious or otherwise expensive metals, many other things would have to be improved in the setup and the equipment, and so far I have deliberately kept costs close to zero, using for the most part what I already have except for a few small things I needed.
    2. I'm making the anode erode on purpose to fill the electrode gap with a thick deposition layer, mainly to eventually induce short-circuits through it, both in visible and invisible form. Electrolysis with narrow-spaced electrodes in HCl (or likely any other acidic electrolyte) promotes these processes significantly.
      • The AM radio noise appears because of these brief electrodeposition-caused short-circuits.
      • Without erosion none of this would happen.

    For what it's worth, when John Dash made the Pd electrode as the anode, it eroded under electrolysis in 0.06M sulfuric acid (H2SO4). HCl would probably not have such a strong action on Pd under similar conditions, but with a narrow electrode gap as I've used so far, things could differ.

  • Not much to report for the past few days.


    Following the observation under semi-dry electrolytic conditions of facile synthesis of an unstable potassium-iron oxide compound that has been suggested to be the active compound in certain industrial catalysts (as I documented in this other thread) I tried making several small quick, mostly undocumented tests with the original idea that started this thread: narrow-gap electrolysis using neutral or alkaline solutions.


    Upon testing I realized how difficult is with an alkaline electrolyte (i.e. KOH, a strong base), even with a minimal gap, to make the electrodes short-circuit once a hydroxide film forms on the electrode gap surface, compared to using an acidic electrolyte (with HCl, a strong acid). This made it possible to use a very simple, yet effective and durable solution for keeping the electrodes together just using 1x0.09mm mica shims between both electrodes to obtain a narrow gap: steel wire (insulated from the electrodes).



    In retrospect this is a kind of obvious idea that I should have used in the past instead of toying with clips or zip ties. The main disadvantage though is that it cannot be quickly disassembled or adjusted and that it still won't last under prolonged testing in hot, strongly acidic/alkaline solutions.


    The primary reason for coming up with this is that in these tests where I deliberately allow the electrodes to dry out of the solution (with power applied) to form an oxide layer, the gap would get larger. Rust-driven expansion can indeed be a problem in certain applications:

    I haven't been successful yet at detecting any emission with the Geiger counter in the current semi-shielding location. Putting aside that I might not be making experiments that actually work, one issue is that my background is too high (90 CPM) and might be submerging in noise any low-level signal that could possibly be arising from these tests. The past week of Geiger data is overall stable. I couldn't tell on shorter term graphs whether any increase was due to non-natural emissions.



    Also, such (presumably) active K-Fe oxide compound appears to be hydrophobic, so it cannot be used during regular electrolysis with the electrodes completely immersed in water. It would probably work best under dry conditions (perhaps in a vacuum) or significantly higher temperatures than what I can use.


    In any case, even if short-circuits are not visually apparent, under narrow-gap electrolysis both with the electrode immersed and outside of the solution (after they have been wetted) the AM radio can detect significant continuous broad band noise from the cathode wire and the coil/inductor, although to a lesser extent and with a different quality than with HCl. Whether this is a desirable thing, I'm not sure. It would require better detection methods and/or calorimetry to know.

  • I found that in the mainstream literature a process exists, called Electrochemical Micromachining (ECM, or EMM), where very narrow electrode gaps (in the order of microns) are used for etching electronic components and other small pieces with a high degree of precision using electrolysis with DC or pulsed DC.


    A undesirable problem in this process is that under certain conditions "micro-sparking" can occur, which can cause damage to the work piece and the cathode electrode. This can in the worst case scenario evolve to continuous arcing ending up welding of the pieces together.


    In general it looks like it's favored by accumulation of byproducts in the gap including:

    • Gas generation
    • Electrolyte boiling (bubble generation)
    • Metal hydroxides
    • Debris
    • Poor electrolyte flow

    Or electrical parameters like:

    • Higher current
    • Higher voltage
    • Longer pulse-on time

    (source for these ones)


    This side effect causes RF emission, which can be monitored and studied for example with an antenna put close to the tool piece (cathode), and mitigating strategies be applied depending on the signal in order to reduce it.


    This sounds quite similar to what I was trying to accomplish on purpose in my tests.


    A rather interesting paper on this side effect, with some excerpts below: https://doi.org/10.1016/S0924-0136(97)00334-8




    From the "Cited by" page on Google Scholar for this paper many other references on process and related issues could be found.


    It would seem obvious that if this is actually useful for LENR, perhaps the opposite of what is commonly done to mitigate it in this other field could be done.