HHO discussion (split off from the BSFC thread)

[MetroMPG]

If it's OK with everyone present, I'd prefer it if we didn't get into political theory on top of everything else.

Thanks!

[UFO]

^^^ 'nuff said. Points are made, data is forthcoming, hopefully.

[Ken Fry]

Originally Posted by MetroMPG

Thanks!

Thank YOU. I look forward to seeing the chemistry explanation and test results undiluted.

To expedite the scientific process, I offer that the Popular Mechanics electrolysis unit design is especially good. Because it separates each electrolysis cell from the next, there is less potential (pun intended) for applying a needlessly large voltage across plates. (The potential from positive input terminal to negative input terminal through the electrolyte is rarely perfectly matched with the mechanics of plate placement, when a bunch of series plates are stuffed into a mason jar.)

With a unit that puts out just a liter or two of oxyhydrogen (a large unit for car use), it is easy to do a calorimetry study right on a bench top. The torch orifice should be very small, (to keep gas velocity higher than flame front velocity) and it is important to have a flashback preventer, but these tests can be done pretty safely with commonsense precautions. An enclosure under the beaker of water, some fiberglass insulation, etc, and you can get within 10% of the values obtained in a real lab calorimeter.

Here is an electrolyser that uses common-duct oxyhydrogen gas for welding and heating. With a 350 watt input, it produces just over 1 Lpm. Studying such a unit will suggest the precautions one should take for safety, and also suggests overall energetic throughput for for the electrolysis and subsequent burning cycle. Doing the math shows that even professionally designed and assembled units are very inefficient. The energy returned by combustion is a fraction of the input to the electrolyser. I think everyone agrees that on an energy balance, HHO units operate at a net loss. Most also agree that the reason this loss has no measurable effect on fuel efficiency is that the 145 watts (14.5 v x 10 A) to 290 (14.5 v x 20 A) is far too small to measure in terms of increased fuel usage, even with a chassis dyno in which a constant load can be held. If 30 hp (22kW) is the test load setting, 150-290 watts one way or the other is just noise. Even as a designer and builder of dynos, I never advertised that measurement down to 1% was a reasonable expectation.

It would be illustrative to show that HHO is not (or is) an oxidizer while doing the calorimetry test. The classic, and simple way to do this is with a burning splint. Partially enclose the space under the beaker of water, leaving the bottom of the enclosure open. While the water is heating up, introduce the splint to that space. If there is excess oxygen, the splint will burn more brightly. If the H2 O2 mixture is stoichiometric (or nearly so) (this is as predicted by conventional science) then the splint will burn less vigorously, because some of the air under the beaker will have been replaced by the combustion product, steam.)

If the hypothesis to be tested is "HHO is a very fordimidable oxidizer" (meaning that it has excess O2 beyond that consumed by burning the H2 simultaneously introduced into the combustion chamber) then the calorimeter test alone should be able to demonstrate the effect: the splint should blaze convincingly: many of us remember doing these tests in chem lab, for example as a test of O2 presence in the standard (separate collection) electrolysis experiments.

If the calorimeter test shows that oxyhydrogen is a formidable oxidizer, then our experimenter can move onto the next experiment, if others find the experimental method satisfactory. If the methods has flaws, those can be addressed and the experiment can be redone.

If oxyhydrogen turns out not to be a formidable oxidizer, then there is no need for dyno testing -- there would be no reason to believe that such testing would show anything not already seen in the John Heywood tests or the Popular Mechanics test.

If oxyhydrogen turns out to be a formidable oxidizer, then perhaps discussion of a mechanism by which introduction of this gaseous mixture might improve combustion at partial throttle could ensue.

But the first step is to show that oxyhydrogen is a formidable oxidizer, and doing this alone would be pretty exciting. Such has been claimed by HHO promoters numerous times but never actually demonstrated experimentally.

[Ken Fry]

Originally Posted by Ken Fry

But the first step is to show that oxyhydrogen is a formidable oxidizer, .

Just to eliminate possible confusion, it would be good to define a couple terms that are often brought up in HHO discussions. Using these terms correctly in this discussion will help to reduce the amount of time wasted.

Oxidizer:
An oxidizing agent (also called an oxidant, oxidizer or oxidiser) can be defined as a substance that removes electrons from another reactant in a redox chemical reaction. The oxidizing agent is "reduced" by taking electrons onto itself and the reactant is "oxidized" by having its electrons taken away. Oxygen is the prime example of an oxidizing agent, but it is only one among many.
In simple terms:
The oxidizing agent is reduced.
The reducing agent is oxidized.

Catalyst:
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself.

Accelerant:
Accelerants play a major role in chemistry. Most chemical reactions can be hastened with an accelerant. Accelerants alter a chemical bond, speed up a chemical process, or bring organisms back to homeostasis. Accelerants are not necessarily catalysts as they may be consumed by the process. An accelerant can be any substance that can bond, mix, or disturb another substance and cause an increase in the speed of a natural, or artificial chemical process.

All these are from Wikipedia. The bolding re catalysts is mine.