Plug-in hybrid using hydrogen injection
 

Hello,

Although this is my first post here, I have been casually viewing Ecomodder for some time and realize how controversial hydrogen systems are here. Therefore, I'll preface this post by saying that I absolutely agree with the existing evidence: HHO systems have negligible benefit, if any at all, when they're run off the vehicle's alternator (conservation of energy).

I have come here to bounce an idea off of you more experienced folks that has been kicking around in my head for a while now. I have read several papers (not sure if I'm allowed to link them yet, but I will post their titles below) which indicate without a shadow of a doubt that both HHO and pure H2 can significantly improve fuel efficiency in ICE vehicles. The problem with the existing commercial systems, as you know, is that they all claim to reap these benefits while running straight off the alternator with no adjustments. When used as directed right out of the box, these systems don't seem to confer any improvement whatsoever.

But what if the power for the electrolysis of the water came not from the vehicle's engine, but from a secondary battery charged via wall plug or EV charger? My thinking is that, if a conventional dry cell 12V HHO "water welder" system is instead connected to a pre-charged battery in the trunk and its output is passed into the intake manifold, fuel economy gains might be possible. This would, in effect, allow an ICE to be converted to a PHEV inexpensively and with zero invasive modifications.

So, wise hypermilers, what are your thoughts? I can't be the first person to come up with this idea. Have any of you tried it or something like it?

Eager to hear your opinions.

The papers I mentioned:

1. "Effect of hydroxy (HHO) gas addition on gasoline engine performance and emissions", Alexandria Engineering Journal, 2016, by Mohamed M. EL-Kassaby, Yehia A. Eldrainy, Mohamed E. Khidr, and Kareem I. Khidr.

2. (For diesel engines) "Effect of hydroxy (HHO) gas addition on performance and exhaust emissions in compression ignition engines", International Journal of Hydrogen Energy, 2010, by Ali Can Yilmaz, Erinç
Uludamar, and Kadir Aydin.

3. "A review on analysis of HHO gas in IC engines", Materials Today: Proceedings, 2019, by T.B. Arjun et al.

There are more. Type "HHO" into Google Scholar.

I see it as similar to solar cars. Do you put the cells on the car or on the garage?

The comparsion would be to a system that use 'shore power' to reform the gases and compress them. If the compressed fuel [amendment] weighs less than the seconday battery -- or no.

On the garage. I'm not an electrical engineer, but from the loose figures I've seen for DC electrolysis at 12 or 24 volts, panels on the car for long-term use wouldn't really be practical in terms of weight, required surface area, or output.

For simplicity's sake, let's maybe forget I said anything about solar panels (for now). Just assume I have near-infinite, free 120V power, but don't want to install a proper electric motor, modified alternator, or other existing PHEV system. This is just experimental, after all.

I confuse easily. I thought it was me that brought up solar panels.

I was comparing using whatever-sourced electricty to charge a battery and electolizer, who's weight one might compare to a tank (or two) of compressed gas.

I'm not sure if it's even a good idea to store compressed Brown's gas. Pure Hydrogen requires a tank lined with graphene to avoid loss. Generating it on the fly might be best.

That's also my main motivation for using an onboard battery + generator rather than a storage cylinder. H2 in a properly-sealed tank cannot autoignite... HHO can.

I imagine it would also be significantly less expensive to integrate a mobile generator, and probably more universally legal than carting around a huge cylinder of explosive compressed gas in a civilian vehicle.

Would you capture both gases or just the Hydrogen, and rely on ambient air for combustion?

One could feed the Hydrogen, store the Oxygen, and use it for a booster like NO2 ....or use it to rouse a sleepy driver.

We know hydrogen can improve fuel economy but with best case scenario cost hydrogen costs around 5 times as much as gasoline. The test engines in the studies used quite a bit of hydrogen.
Better off with aero mods.

My thoughts:

By using an external battery you're adding energy to the system from outside, so it will undoubtedly reduce gasoline consumption. Question is whether this is the simplest or most effective method. Consider the extra space and weight a hydrogen electrolyzer takes up, and the efficiency of such a system (~70% cracking the water, ~30% putting it back together in combustion) - you're getting use of around 20% of the energy you put into the battery. And, the amount of energy you can get out of it is limited to how much you can carry in your battery, times the efficiency of the system (20%). There really isn't all that much energy in your typical lead acid car battery.

By comparison, simply offsetting some of the energy generation needed from extremely inefficient alternators (~40% efficient alternator, and ~30% efficient from the gasoline burned, = ~10% efficient use of gasoline) means you're getting almost 50x the "bang for your buck" just using that extra battery you're carrying around to run the car's electronics instead of from the alternator, rather than using it to crack water. Plus you can carry even more battery if you don't have to carry water and an electrolyzer around.

Less efficient than offsetting alternator use, is using that battery to assist in propelling the car through an electric motor. You're still getting ~5x more bang for your buck that way than with electrolysis. However, by hybridizing a car in this way, you also have the other gains of a hybrid system, such as kinetic energy recovery, or the ability to start/stop the engine using electric motor.

Sure, grid-sourced hydrogen can be an improvement, but I think it misses the forest for the trees.

EDIT: Where it COULD make sense, is if you already have excess renewable (free) energy production at home, and you have the inability to sell it back to the grid at a remotely favorable rate or earn credit for it. Assuming you also have the ability to crack water and bottle pressurized hydrogen, using this otherwise excess/waste energy production to create hydrogen to burn in your car is win-win.

This last paragraph captures exactly the spirit of what I'm after. Is it going to be the best option? Absolutely not. Is it going to be a little silly and of questionable commercial value? Sure... but what I want is to know whether or not it will make a significant MPG increase, all other factors be damned.

Now the question is how well this will actually translate when I simply don't have access to the equipment or know-how needed to safely and efficiently bottle my generated hydrogen/HHO.

Regen is a big deal.

Speaking of Japanese Jeeps:

https://blogger.googleusercontent.co...101_092522.jpg
https://justacarguy.blogspot.com/202...-off-road.html