A.G. Parkhomov—Study of processes using a pulsed plasma electrolysis unit

An interesting translated paper/detailed report an an experiment series by A.G. Parkhomov was uploaded yesterday by Bob Greenyer on the Internet during a livestream (also on ECW and FB).

It's partially related to electrolytic plasma experiments that I and others have been recently exploring, but since some fundamental and defining differences exist from the original subject and the paper itself deserves careful analysis and commentary, I thought it would be more useful to have a dedicated thread about it (and about experiments to replicate the observations)

Study of processes using a pulsed plasma electrolysis unit

A. G. Parkhomov

(also attached at the end of the post)

Quote

Abstract: A description of a system where plasma electrolysis was studied under different modes of reactor operation (immersion in the electrolyte, light touch, small gap, different polarity of the central electrode, different capacitance of the capacitor, single discharge or continuous operation) is given. The method of determining the ratio of heat released to the electricity absorbed by the reactor is described. A value greater than 100% is found only when the anode does not touch the electrolyte but is located at a small distance from it. In other cases, the heat is about the same as or slightly less than the electricity consumed. The results of the analysis of the elemental composition of the electrolyte before and after plasma electrolysis are presented.

As the central electrode (anode, i.e. positive electrode) is at a small distance above the surface and voltages of 1200V are used together with a 50 µF capacitor (typically), the discharges produced which generate anomalous results are quite energetic and have the nature of sparks (roughly 50–100 µs pulses peaking up to 1000A).

Current and voltage, as well as electrolyte temperature seem to be carefully recorded with an USB oscilloscope and data logger, which I identified as:

• Velleman PCSU200 USB oscilloscope
• Velleman PCS10 4-Channel USB Recorder/Logger

Links to short videos are also included in the paper, but last time I checked there were not any of the energetic sparks yet.

By the way, the USB oscilloscope used in Parkhomov's study only has a 12 MHz bandwidth and to be honest I'm not sure if it's sufficient to record all the peaks produced after the 1200V capacitor quickly discharges when the anode is at 0.5 mm above the surface of the electrolyte. In other words, current spikes shorter than the device's time resolution of 0.1 µs might not be observed.

I tried digitizing one such spikes (using Na₂CO₃) from figure 5 with the usual tool. If I am calculating everything correctly that spike should correspond to roughly 11.8 Joules of energy. The 50 µF capacitor(s?) used should be able to store 36 J of energy at 1200V (1/2 CV²), assuming it is only one capacitor and not a capacitor bank. It's possible it did not discharge completely; this could be easily checked.

So while that USB oscilloscope seems a nice relatively low-cost tool to have (I've seen it on a local store for about 120 euro), it might not necessarily be the best one.

Gennadiy Tarassenko

The USB oscilloscope (Velleman PCSU200) is available on the various European Amazon stores (amazon.fr, amazon.it, amazon.co.uk, amazon.de, etc.), but the data logger (Velleman PCS10) does not seem to be so easily available. They are likely also available elsewhere, but I don't know many stores where to get this sort of specialized equipment.

Of course, they are both available on Ebay as well (good luck with that).

I don't think it is necessary to get the exact same equipment, however. Better one from different manufacturers at similar prices might exist. An alternative is spending some more and getting an entry-level, full-featured 100 Mhz (or higher) oscilloscope with logging capabilities or a PC interface.

Alan Smith

I've just found that Parkhomov's logger (Velleman PCS10) used for slowly-changing data is sold for about 75 euro on Farnell.com (although not available right now for my region, it seems to be in this price range). The one you linked quickly adds up to steeper prices but I imagine it's more flexible.

The details of how the setup is arranged in Parkhomov's case have not been provided though—for instance, I'm assuming that thermocouple signal will have to be amplified since the logger only has a 10 mV accuracy and thermocouple voltage has variations in the order of µV.

From the datasheet, that one has several built-in sensors which which could be useful for various general-purpose small projects, but the analog input section is lacking and so overall for a data logger in replacement for the one used by Parkhomov it seems expensive.

Anyway I think this logger discussion is putting the cart before the horse, because the mode of operation which could possibly show anomalous results (according to the report at least) involves spark discharges up to tens of Joules from a 1200V capacitor/capacitor bank. This would have to be done safely for the measuring equipment, the setup itself (I don't imagine for example that the capacitors will have a very long life when used like this) and the operator in the immediate to short term. It will also be useful to not have neighbors who might complain about loud bangs.

It's not perfect due to the digitizing performed (since the raw data isn't available, so it will add more uncertainties in addition to the possible issues highlighted by Robert Horst above) but the pulse over the 10% sodium carbonate solution peaked at almost half a megawatt of power. This would be concentrated roughly on tip of the 1 mm-diameter anode.

Worth pointing out again that the sharp electrode is the anode (+ electrode), which is different from most other experiments of similar type.

Unfortunately there are no videos of such powerful discharges, generated when breakdown over the gap formed between the anode and the electrolyte surface occurs. At 1200V, this should be about 0.5 mm like it was done in the experiments (generally listed as 2–3 kV/mm in air at atmospheric pressure, but could be less just above the electrolyte solution).

Links to videos of other tests are in table 2 in the document; below they are in a format that can be copied/pasted elsewhere. The first column links to the videos.

Alan Smith

I was thinking of the effects of humidity but I do not have a clear idea of how it affects the gap distance. Once a visible mist forms, the breakdown voltage should indeed be significantly decreased, but for the first discharge it might take more effort and be more similar to standard conditions. This might imply that perhaps the vessel could be heated to initiate the process in case the initial gap distance is too high.

Given the installed capacitance in the case of the experiments described in the report of this thread, the maximum theoretical energy available for the discharge shouldn't be too far from that of a small caliber pellet, e.g. https://en.wikipedia.org/wiki/.22_CB

Paradigmnoia

I remember that quote (1:19:40 here, but it's not loading for real-time viewing: https://drive.google.com/file/…Mb0QDuQsDJJsugi_anbp/view).