With I sinking feeling I am reviewing this “investment opportunity” from a friend and finding it rather wanting. However I don’t know enough about automotive tech to dismiss it outright. I thought I would ask here and ask what are the ramifications of such a system…
It purports to be a gas generation system that enhances the performance of the engine. It seems to work by electrolysis of a solution of baking soda to generate… not merely pure hydrogen, but “HHO”, a mixture of pure O2 and H2. The “HHO generator” looks suspiciously like a peanut butter jar with wires coming out of it, and the formula HHO is startlingly similar to that of water. Here’s how it works. Oh, my bad, on further review, it looks like “HHO” is actually “hydroxyl gas” according to the faq . I had 6 semesters of higher chemistry but I never heard of “hydroxyl gas”… perhaps it’s something new… :dubious:
It looks like an outright ripoff to me, but I don’t have quite the automotive expertise to understand whether it’s minor benefit, neutral, or detrimental to one’s car and performance. Since it’s a friend who is offering it, I hope at worse it’s nothing more than a low-tech gas mileage placebo…
By HHO I assume they mean a 2:1 hydrogen:oxygen mixture. It will burn extremely well. They tell you how the hydrolysis is done: electricity from the car’s battery. When you burn the HHO in the combustion chamber you will get back… appreciably less energy than it will take to recharge the battery to the level it was before you drew off power for electrolysis. Sorry!
This mixture is also known as Brown’s Gas. As noted, it is nothing more than a 2:1 mixture of hydrogen and oxygen. It burns to yield water. Aside from that, it has no special properties whatsoever.
They also claim that it makes the engine burn more of the fuel that is injected/aspirated as opposed to being exhaused unburned as waste. Also they claim the hydrogen/oxygen mix helps clean the inner workings of the engine. Any possibility of truth to that?
I’m not a degreed engineer, but I will say that this looks very much like a more crude form of a device that the company I work for used for several years to generate hydrogen for the operation of gas chromatographs. In our case, the hydroxygenerator, as it was called, used caustic soda, rather than baking soda, to facilitate the reaction, but otherwise was the same in principle: apply a high-amperage DC current to a soda/water mixture, producing H2 molecules and elemental oxygen.
So, in principle, the system might produce what it says it does. The question is whether it does anything useful in an automotive application, and I’d say no. The first thing that makes this device of doubtful utility is the fact that more energy has to go in (in the form of electrical current) than would be likely to come out in the form of combustible hydrogen. Secondly, im not sure how well baking soda facilitates the reaction, but I suspect at best one is producing a few cc’s/minute of H2, and without anything to reduce the amount of gasoline fed to the engine by a corresponding amount, I don’t see the net gain here. Yeah, I know it says the gasoline is burned more efficiently, but there is no particular reason why the presence of additonal hydrogen would facilitate this.
Thirdly, it is unavoidable that some water is carried along with the gas stream, and the mumbo-jumbo about it being beneficial to the combustion process seems to be just an excuse to avoid the complication of having some kind of drying medium (which would have to replaced frequently) downstream of the device.
Lastly, the system, if indeed configured as shown in the link, is downright dangerous. Our hydroxygenerator system needed a pressure switch to cut off the current if there was a blockage in the system; otherwise the pressure in the reaction chamber would keep on increasing until the chamber ruptured. This happened a couple of times in the field, with fairly spectacular results. Opening one’s hood to get peppered with a mixture of shards of plastic and caustic water solution is no way to start the day.
For our application, we have mostly abandoned the use of the hydroxygenerator in favor of pure H2 generators (using palladium-membrane devices). For an automotive application, it does indeed look like pure snake oil.
We’ve done this before. It boils (sorry) down to whether the presence of hydrogen and oxygen in the combustion chamber can help the engine recover more energy than the alternator steals from the engine to make the hydrogen. For large diesel engines, it’s [del]viable[/del] marketable enough that fleet managers have installed it in their trucks. This blog post includes some contrarian evidence, but then ends on a questionable note, saying that MIT is looking into it.
The argument that “It’s just turning water into water, so you don’t get as much energy out as you put in” is flawed unless you’re looking at the entire energy balance. You’re not burning the H2 and the O2 separately from the fuel-air mixture – the combination of the two reactions could make the fuel-air mixture burn hotter and/or more completely, raising the energy output closer to the theoretical maximum.
Whether that energy gain exceeds the alternator losses and the energy cost of electrolysis remains to be seen.
Doesn’t hydrogen burn about 100K hotter than fuel? And isn’t its heat of combustion much higher? I would think that either of those facts would be enough to bring the efficiency up… but I’m not a chemist, so I can’t tell how much those gains would get you, or whether they’d pay for the losses of electrolysis.
About hydrogen cars, what’s the technology on that? Isn’t it pretty much understood tech and a matter of making the hydrogen tank safe. That the problem was separating the hydrogen out of water efficiently in a car engine than bonding it back?
Right. The idea behind a hydrogen car is that you make the hydrogen someplace else than in the car. It still takes energy to do so, but you can get that energy from coal, or dams, or windmills, or whatever. So effectively, it’s a roundabout way of fueling cars with something we don’t have to import from the Middle East.
In context, I think it’s just lazy shorthand for a mixture of hydrogen and oxygen in the ideal ratio - not a molecular formula. If you wanted to ding the writers for abusing the notation, I’d not dissuade you.
As to Jurph’s point, the question is whether heating the combustion chamber higher is going to make the fuel/air burn more efficient. I’d argue for a “not proven” on that question for a start, as I have the possibly foolish notion that modern petrol engines already burn about as lean and hot as is good for them, and hotter is not necessarily better.
My understanding is that HHO is a physical mixture of hydrogen and oxygen atoms rather than a set of chemically combined H[sub]2[/sub]O molecules.
An analog would be invert sugar vs. sucrose. Sucrose is a chemical combination of the simple sugars glucose and fructose, while invert sugar is a physical mixture of half fructose and half glucose. The properties are very different.
There is some truth to that. One of the things that helps combustion is the presence of OH radicals, which react very quickly and do all sorts of chemical stuff to improve the overall messy combustion process. It is possible that you can end up with lower unburned hydrocarbons coming out - it has been shown to work in boilers and similar systems.
However, the combustion efficiency is usually determined by measuring the amount of carbon in the fuel and comparing that to the amount of carbon that is captured in CO2. Other forms (CO, hydrocarbons, soot) all represent carbon that could have yielded additional energy for use, but just didn’t quite make it all the way to complete combustion. From an efficiency standpoint, you are already burning out nearly all the carbon (if you have a well-tuned engine). Any increase would not be nearly enough to compensate for the energy that was used to generate the H2 in the first place.
Why? What component part of the efficiency is improving, exactly? Are the sensible heat losses improving? How, unless you change the boundary conditions? Are unburned combustible losses improving? Maybe slightly, but only if you replace already efficiently-burning fuel with more efficiently-burning fuel. And then, of course, hydrogen has those nasty latent heat losses which on a per-pound or per-Btu basis are, IIRC, higher than for any other fuel.
Before we go down the unburned combustibles route, search on this board. I’ve given numbers and such several times showing that modern engines do not produce large amounts of unburned combustibles.
It sounds as if this product is the usual scam, and has been thrashed to death on this Board over several years, IIRC.
Una Persson, we did this last time and hit a stalemate as far as I can tell. I’m still in the “not convinced that it couldn’t work” camp. You’re right that the hydrogen burning hotter (on its own) doesn’t bring up the efficiency – the mechanism they claim is an increase in flame velocity from the combined combustion causes the piston to push harder for a larger percentage of the rotation.
Like I said, I’m not convinced that it’s impossible, but you’ve convinced me that there are questions that need to be answered before I’ll believe that it works anywhere near the neighborhood of the 10% gains they claim.
